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Institute of Biology

Department of

Biology-Chemistry-Pharmacology

Freie Universität Berlin


Contents

Department of Biology-Chemistry-Pharmacology

6

Biology in Berlin 7

Structure of the institute 8

From our research 11

Neurobiology

Genetics

Protozoa

Chemical ecology

Neuroanatomy

Behavioural biology

Extremophile red algae

Molecular adaptation

Molecular photo-physiology

Cryoprotectin

Metabolic paths

Ecotoxicology

Botanic Garden and Botanical Museum 25

Studying at the institute 26

Biology in brief 27

Where to find us 30

Impressum

Published by

The Presidency of the Freie Universität Berlin

Press and Information Office

Felicitas von Aretin

pressestelle@fu-berlin.de

www.fu-berlin.de/presse

Edited by

Institute of Biology

Catarina Pietschmann

Translation: Richard Holmes

December 2000

Typesetting & layout

uni[:com] werbeagentur GmbH · www.unicommunication.de

Printers

VMK-Druckerei, Worms

Illustration credits

Institute of Biology


Ω Depatment

Department of

Biology-Chemistry-Pharmacology

Most scientific progress nowadays is the result of interdisciplinary

cooperation. In order to promote cooperation and innovation

in scientific research and teaching, the former Departments

of Biology, Chemistry and Pharmacology merged into a single

department in 1999. The leaner administrative structure in the

new large department makes it possible to operate faster and

more efficiently.

In future, the department’s research activities will be devoted to

life sciences. Biology and biochemistry have already worked

closely together in the past on collaborative research projects.

Contacts between crystallography and biochemistry will be

intensified under the heading of structural biochemistry. There

are also synergy effects to be achieved between organic chemistry

and microbiology which would provide new impulses, not

only for the work in this field, but also for pharmacology.

In the new combined department it will be possible to concentrate

on two core fields. One of these is research into transmitter

substances and their receptor molecules. Transmitter substances

are agents of communication within and between cells,

and they are of crucial importance, for example, for the operation

of the nervous system. In the new department, this field can

be investigated comprehensively at the levels of molecules, systems,

and the organism.

6 Freie Universität Berlin

A second core area in which the department is becoming

increasingly involved is bioinformatics. Here new bachelor and

master’s degrees are planned, and the department will contribute

to the teaching, but it will also participate in research in

this field. Handling large amounts of data is of major importance

in both genome research and in neurosciences, and combining

biology with computer science represents a major challenge

that can only be met by interdisciplinary cooperation.

Within the department itself there are plans to set up an interdisciplinary

"Bio-centre" that will bring together all the life sciences,

including the research groups in human and veterinary

medicine. Biologists at the FU have long dreamt of a new building

to house such a centre, but it has never been possible. Nevertheless,

it remains a goal for the future of the Institute of Biology.

www.chemie.fu-berlin.de/fbr.html

E-Mail: bcp@fu-berlin.de

Biology in Berlin

Die University biological research began in Berlin in 1810 with

the foundation of the Friedrich-Wilhelm University. The beginning

was made with chairs with zoological and botanical orientations.

A century later, parts of the university were relocated to

the Dahlem district - at that time still on the outskirts of the city.

Various Kaiser Wilhelm Research Institutes and the state biological

agencies were also set up here, along with a new botanic

garden. At the same time, the Botanical Museum was also

rehoused. A new building was erected specially for the Institute

of Plant Physiology, which was led from 1910 to 1923 by Gottfried

Haberlandt. Here he supervised the first cultivation tests

Biologie-Chemie-Pharmazie

7

Ω Biology in Berlin


Ω Biology in Berlin

on isolated plant cells and did work on phyto-hormones. Willy

Kükenthal was active at the Zoological Institute from 1918. He

is best known for his work on marine mammals, and also for a

standard textbook on practical zoology - still in print in its 23rd

edition.

When the Freie Universität was founded in 1948, all the biologists

moved together into the former Institute of Plant Physiology.

Today the building is occupied by research groups for apidology,

entomology, developmental biology, evolutionary biology,

insect immunology and protozoology. The former residence

of the director (fig: in 1914) is now the location of the applied

zoology / animal ecology group.

Many of the zoologists that came to the FU in its early years

were representatives of systematic and phylogenetic evolutionary

research, generally in the tradition of Franz Eilhard Schulze,

who had been in charge of the Zoological Institute of the

Friedrich-Wilhelm University from 1884 - 1917. The Freie Universität

in West Berlin saw itself as a legitimate successor to the old

Berlin university, especially after the Zoological Institute of the

Humboldt University in East Berlin formally ceased to exist in

1969.

FU biologists were the first at a German university

to establish a research group for ecology.

Behavioural biology was also established

as a sub-discipline at an early stage. Zoophysiology

was expanded considerably - concentrating

at first on metabolic physiology,

and later also including neurobiology.

A new branch of research was developed in plant physiology.

The technique of plant cell culture established by Jakob Reinert

in the 1960s made it possible for the first time to regenerate

entire plants from single cells, and on the basis of this, the institute,

which moved into a new building in 1971, established its

international reputation. Plant systematics - which had been the

responsibility of the Botanical Garden since 1959 - was also

given its own institute (Plant Geography and Systematic

Botany). In the course of expansion, numerous areas of

research were added, including biochemistry, human biology,

cell ultrastructure, developmental biology, then applied (plant)

genetics in 1972, and microbiology in 1984.

The structure of the institute

Today, the Institute of Biology is divided into a total of 28 groups

carrying out research on the major biological topics of the 21st

century. These include molecular biology and genetics with reference

to biotechnology and genetic engineering, and the new

field bringing together computer sciences and advances in the

8 Freie Universität Berlin

neurological sciences. In addition, the institute is also closely

linked with the concept of evolution, and in this context with

biodiversity. The investigation of ecosystems and in particular

the effects of human activities on ecosystems are further

aspects of the work.

In detail, the research concentrates on the following eight areas:

Ω Evolution, evolutionary biology, systematics in zoology;

Ω Molecular developmental genetics of animals;

Ω Molecular developmental biology/Developmental genetics

of plants;

Ω Neurobiology and behavioural biology

Ω Ecology, ecophysiology, and ecotoxicology;

Ω Systematic botany, geobotany and the Botanic Garden:

Ω Molecular plant physiology;

Ω Microbiology.

In recent years, neurobiology and molecular

plant physiology have gained increasingly

in profile. This is reflected in the fact

that the Collaborative Research Centre

(Sfb 515) "Mechanisms of developmentaland

experience-dependent plasticity in

the nervous system" and the postgraduate

research group "Signal cascades in living

organisms" are based at the Institute

(neurobiology section). Research groups

concentrating on molecular plant physiology

are partof the DFG Collaborative

Research Centre (Sfb 249) "Molecular

physiology, energetics and the regulation

of metabolic processes in plants".

The Botanic Garden, the largest in Germany, and the Botanical

Museum (together called BGBM) have been integrated in the

Free University since 1995 as a central facility. This has opened

up unique research opportunities in the fields of botany and

plant ecology, particularly relating to the geographic distribution

of species. The four separate libraries have been combined, and

since mid-2000 the central biological library is in the Botanical

Museum.

There is intensive cooperation with the adjacent Max-Planck

Institute for Molecular Genetics, and also with the Max-Delbrück

Centre, with which there are associated professorships in

the fields of molecular developmental neurobiology and

immunology. In addition, the Institute of Biology participates in

the interdisciplinary research group on "Structural biology".

www.biologie.fu-berlin.de

Biologie-Chemie-Pharmazie 9

Ω Biology in Berlin


From our research

Neurobiology:

Bees never forget either!

When animals learn, the connections between the

neurones change and thus establish knowledge.

This can then be used to improve the control of

behaviour in the future. Among the thousands of

tangled neurones, it is difficult to identify the specific

ones involved in the learning process, since

they cannot be observed directly during the formation

of memory. It is therefore advisable to begin

studying a relatively simple nervous system, but

one which is nevertheless in a position to learn

quickly and to form a stable long-term memory. In the Neurobiology

research group we are therefore investigating such problems

using the bee as our model. Bees can learn to recognise a

chemical signal even after they have been prepared for the optical

and electrical registration of their nerve functions. In this way,

we can locate the site of memory formation and measure

changes in the switching of neurones. This makes it possible, for

example, to show that when a chemical signal has been learnt it

leaves behind a precise neural representation in the brain. These

traces of memory can be followed back in the bee brain to single

identifiable neurones, which opens up the opportunity to track

down the switching elements which with their adaptable patterns

lay down the memory trace.

A special feature of the memory is the way it

develops over time. After the initial learning

process, an unstable short-term memory is first

formed, which is then transferred in stages over a

period of hours and days into long-term memory.

It has been found that these phases of memories

are linked with the reactions of certain signalling

molecules in the neurones involved. A key role is

played by the protein kinases. Their activation

leads initially to the functional alteration of existing

molecules then later to the synthesis of new

proteins - and finally to new structures. The memory content is

not stored by special molecules, but is manifested by the spatial

pattern of synaptic efficacies caused at the cellular level by these

general molecules, the switching of the neurones. This principle

of memory storage also applies for humans, so that the bee

brain provides a suitable model for studying general mechanisms

of memory formation.

www.neurobiologie.fu-berlin.de/menzel.html

E-Mail: menzel@neurobiologie.fu-berlin.de

Biologie-Chemie-Pharmazie 11

Ω Research

Crocus bee

Antennal

lobe of a

bee's brain


Ω Research

Domina'

protein

(red and

yellow)

Nerve

cells

(fruit fly)

Genetics:

What the fruit fly has in common with you

Many of the important genes of the fruit fly Drosophila

melanogaster are surprisingly similar in structure and function

to human genes. In order to learn more about the way in which

genes operate, it is possible to study Drosophila as a model

using techniques from genetics and molecular biology, and then

to draw conclusions about the importance of similar genes for

human beings. In Developmental Genetics I a research group is

studying the genes involved in the formation of chromatin - the

structural material of chromosomes. A further project is working

on genes that are active in the brain nerve cells of Drosophila,

regulating the hormone levels.

The DNA of eukaryotes is packed together with

proteins in the chromatin of the chromosomes.

Depending on the type and amount of the proteins,

the chromatin influences the activity of the

genes. Proteins involved in the formation of the

chromatin can have other additional functions. We

isolated a gene from the fruit fly, which we have

named 'Domina', that also plays an important part

in the development of the animal, in particular in

the formation of the nervous system, the eyes, and

the bristle structures. The 'Domina' gene codes for

a regulatory protein of the same name that is linked to specific

sites on the chromosome. (Fig. 1).

This gene corresponds to the 'winged-helix nude' gene (whn) in

humans, which plays a crucial role in the development of the

immune system. The molecular function of the 'Domina' / whn

factor is studied in transgenic Drosophilae.

As in humans, many of the fundamental processes

in the development and behaviour of insects

are controlled by hormones. Hormone production,

in turn, is influenced by signals from the

brain - often in accordance with circadian rhythms.

The molts of insect larvae and metamorphosis are

the most striking effects of the steroid hormone

ecdysone and juvenile hormone. Both are produced

in the drosophila larva by the ring gland.

Nerve cells have been identified in the brain of the

larva that have a direct link to the cells producing

the hormone (Fig. 2). Some of these cells have contacts to the

insect's 'biological clock'. Various genes are being investigated

that are active in these nerve cells.

The work of Developmental Genetics II involves the investigation

of genes in one of the target organs of the hormone

ecdysone - the salivary glands of the Drosophila larva. These

12 Freie Universität Berlin

organs fulfil various functions in the course

of development of the larva. At first, all the

cells of the gland (Fig. 3, green) produce a

digestive secretion. In the middle of the

final larval stage this function is restricted

to the anterior cells (Fig. 4, green) while the

posterior section (Fig. 4, red) produce

adhesive protein secretions. In the prepupal

stage a third synthesis programme is

initiated in all cells (Fig. 5, blue). The genes

involved in this are being analysed in order

to improve our understanding of the molecular

processes behind the hormonally

controlled reprogramming of differentiated

cells.

E-Mail: korge@genetik.biologie.fu-berlin.de

kress@zedat.fu-berlin.de

Protozoa: Small but essential

Fig. 3

Fig. 4

Fig. 5

They might be very small indeed, but

protozoa play a vital role in the ecosystem

of our planet. These single-cell animals

are found in the oceans, in freshwater

habitats, and in all soil formations.

Among other things, they regulate

bacterial numbers by feeding on

them. Another important role is that of

commensalists in the stomachs of ruminants or in the gastrointestinal

tract of certain insects. Here they make an important

contribution towards the degradation of the cellulose in the

food of their host. A more negative role is that of a highly dangerous

pathogen, giving rise to illnesses such as sleeping sickness,

malaria and coccidiosis. In humans suffering from AIDS,

various opportunistic protozoa pose a considerable threat to

the weakened immune system, and are often fatal.

The research work of the protozoology group focuses on the

nutrition of protozoa. How do these single-cell animals capture

their food, and then ingest

and digest it? An important

objective is to identify

underlying general principles.

Another topic of interest

is the ecological significance

of certain protozoa,

the minute nanoflagellates

living in the sediment of

aquatic habitats. In coopera-

Biologie-Chemie-Pharmazie 13

Vampyrella

feeding on

algal filaments

Ω Research

Amoebe

proteus


Ω Research

Amoebe proteus

Chilodonella with

ingested diatoms

14 Freie Universität Berlin

tion with groups in Great Britain, Israel and the

USA we are also currently carrying out the first systematic

international survey of the drifting of protozoa

in ship's ballast water. Ocean-going ships

take on vast quantities of water as ballast, which

they then discharge long distances away. Protozoa

'kidnapped' in this way are often able to multiply

in an uncontrolled fashion in their new environment.

The symbiosis between protozoa and insects is

being studied with the example of termites and flagellates.

These two groups of organisms are

directly dependent on each other: the termites

cannot decompose the cellulose they ingest without

the flagellates, which in turn can no longer live

outside the bodies of the termites.

In addition to research publications, the group

has also produced standard text books on protozoology,

as well as participating in numerous scientific

film productions on topics relating to protozoology

and cell biology.

E-Mail: hausmann@zedat.fu-berlin.de

Exchanging information in nature:

The chemistry of communication

Communication is not only important for exchanges between

humans in the information age, but is in fact vital to all organisms.

Chemical signals offer a very sophisticated and widespread

form of "silent" communication. The Applied Zoology

/Animal ecology group is investigating communication systems

in which natural substances are used to carry information. We

concentrate on insects that feed on plants, which account for

more than a quarter of all living species. They are often found as

pests in forests and on farm crops. Knowledge about the communication

signals of insects can be used, for example, to control

harmful pests by disturbing their transmission.

Comparative studies of the chemistry of signals

and their biogenesis also provide insights

into the evolution of communicating species. If

we know the ecological and physiological conditions

under which chemical signals are produced,

perceived, and replied to, then we can draw conclusions

about the phenotypic plasticity of genetically

fixed communications strategies.

The following example of sophisticated

exchange of information between plants,

feeding insects and their antagonists

gives an idea of just how complex the

communication systems can be. It has

been known for some time that plants can

respond to insect attacks by giving off

volatile chemicals. These attract insects

that prey on the pests or are their parasite.

The change acts as an alarm signal. We were able to show that

pests do not even have to begin feeding on the plant - laying

eggs on the leaves is sufficient to cause an alteration in the patterns

of chemicals the plant releases, attracting specialised egg

parasitoids. However, these will only be attracted if the plant is

carrying the "right" host eggs. Research is currently studying

numerous aspects of the chemistry of the signals, the mechanism

of signal induction, and the specificity of the system at the

level of the plants, the herbivore insects, and the egg parasitoids.

Chemical structures are analysed using

gas chromatography and mass spectroscopy.

In order to detect the chemicals registered by the insect

antenna, we combine gas chromatography with electro-antennography.

In field studies and laboratory tests we study the

behavioural response of insects to chemical signals. We cooperate

with other laboratories to extend the scope of available chemical,

electrophysiological and molecular biological methods.

E-Mail: hilker@zedat.fu-berlin.de

Neuroanatomy: The locust and its synapses

A characteristic feature of animals is their mobility. But they

would not be able to move very well at all if they did not get a

wide range of feedback responses from their sensory organs.

The Functional Neuroanatomy group studies such control

processes. Animals are still superior to robots when it comes to

crawling on branches or leaves, or climbing up rock faces. For

our studies, we have chosen the "simple" nervous system of

insects, which have a wide

motor repertoire: they walk,

run, climb, swim and fly. And

for the fine control of all these

movements they have a whole

arsenal of sensory cells and

neuromodulatory neurones.

The latter can alter the efficiency

of neuromuscular synaptic

transmission and the

Biologie-Chemie-Pharmazie 15

Ω Research

African

locusts


Ω Research

Ganglion with

neurones

Neurone in

culture

(3 days old)

metabolism of the muscles.

These mechanisms of plastic

alteration of the nervous

system are particularly

interesting because they

also play a crucial role in

neural development. Investigations

have concentrated

on the neurones that

release the so-called biogenic

amines, which control a wide range of body functions. We

have specialised on neurones that produce octopamine. This

substance is automatically released in every motoric process

and apparently increases the efficiency of synapses and helps

the muscles to conserve energy. Insects seem to have a particularly

effective "energy conservation program", because the more

frequently and the longer a muscle is used the more economical

it is with energy.

When it comes to elucidating the mechanisms of development,

insects are very good models. A pathway has been identified

which the adult locust uses for flight control. The nymph of the

locust already has all the muscles and motor neurones of the

adult insect, but does not yet have fully functional wings. These

are only available after the final moult. We have found out that

during the development, activity-dependent

plasticity is very

important for the formation of

the sensory system, whereas

the development of the motor

system is more dependent on

hormone control. In other

words, developmental mechanisms

are at work in the nervous

system of insects that

were previously assumed to be

restricted solely to vertebrates.

These processes must therefore

have been developed at a

very early stage in the evolution

of the nervous system, and

they are perfect for adapting

the neural circuits to the specific

demands of the organism in

question.

www.neurobiologie.fu-berlin.de/Pflueger.html

E-Mail: pflueger@neurobiologie.fu-berlin.de

16 Freie Universität Berlin

Behavioural biology:

From duet to dialogue -

rules and riddles of vocal communication

We are investigating how higher organisms such

as birds or mammals develop their signal systems

and how they use their rich repertoire of signals

during social interactions. The organisation and

accomplishment of auditory-vocal memories is

one priority topic. Many songbirds are experts in a

form of learning that was long thought to be the

prerogative of humans, so-called serial learning. A

real master singer is the nightingale (Luscinia

megarhynchos). Adult males have a repertoire of

about a thousand different song elements, and

then use these to compose more than 200 different

songs. We have started to elucidate the mechanisms

that enable the nightingale to memorise

such immense amounts of information. We are also interested

in the rules underlying the ontogenetic development of their

singing behaviour. Its developmental stages are studied by

comparing the tutored model song patterns and the final imitations

produced at the end of the ontogenesis.

A second project is concerned with message and meaning in

the field of acoustic signals. Acoustic signals allow a rapid

exchange of information, and are particularly useful when interacting

individuals do not have visual contact. We are investigating

how birds and mammals use such benefits, and also which

role they play during cases of laughter, crying, whispering or

other nonverbal signals in human beings. Included in this project

are issues like the influence of stress, anxiety, and other

states in mammals such as non-human primates, dolphins or

farm animals. One aim of this research is to provide tools for an

early detection of stressful situations and thus eventually

improve the living conditions of farm animals.

Social intelligence and its biological foundations is the topic of

a further project. An intelligent organism is able to cope with

new problems individually,

through cognitive mechanisms.

The development

of social competence in

semi-wild Barbary monkeys

(Macaca sylvanus)

and dolphins (Tursiops

truncatus) is of special interest.

Part of the project

examines the various factors

which influence the

Biologie-Chemie-Pharmazie 17

Ω Research

Male

nightingale

approaching

its song

post

Semi-wild

Barbary

macaques

examining a

mirror


Ω Research

Algal habitat

G. sulphuraria

viewed

through the

microscope

socialisation of young animals, and the experience that they

gather in playful encounters. It seems certain that animals can

derive socially important information from their observations.

How they do so is being studied with the assistance of new test

methods.

www.verhaltensbiologie.fu-berlin.de

E-Mail: todt@zedat.fu-berlin.de

Extremophile red algae: Some like it hot

18 Freie Universität Berlin

How does Galdieria sulphuraria survive in

hot, acidic sulphur springs with pH values

of 0.05 - 3, and temperatures of up to 60°C?

The unremarkable unicellular red alga has

an exotic ecology and physiology. It is only

found in very limited habitats, and mainly

grows terrestrially, and in some cases even

endolithically, that is enclosed in rock. In

the plant physiology research group we are

trying to unravel the mysteries of such

"extremists".

In order to be able to survive in an extreme environment, it has

been necessary to develop a series of special adaptations. For

example, in periods of very low light influx the alga uses metabolites

such as sugar and amino acids from the dead cells of the

population for its own growth. The significance of heterotrophy

(growth on a source of organic carbon in the absence of light) is

highlighted by the range of carbon sources that various strains

of Galdieria all over the world are able to use for their nutrition:

some 50 different sugars, amino acids, sugar alcohols, and

organic acids. Nothing like it is known for any other organism.

How then does the alga perceive such a wide range of substrates

and distinguish between them, and what uptake systems,

enzymes and regulation mechanisms have been developed

for this? It turns out that G. sulphuraria has sugar transporters

and enzymes of previously unknown selectivity. Genes

for various key enzymes have already been isolated, and the

longer-term goal is to develop a detailed metabolic scheme for

this model organism. The strains from various geographical

locations are genetically very different

despite considerable morphological and

physiological similarities. This suggests

that the populations have been separated

for a very long time, and also raises the

question as to how G. sulphuraria managed

to settle these biotopes. Because of its

extreme tolerance of acidity and heavy metals,

in combination with high productivity

under laboratory conditions, the alga has considerable potential

for biotechnological applications. Currently, a pilot plant is

being tested in cooperation with the Institute for Grain Crop

Processing (Potsdam-Rehbrücke) in which polluted industrial

waste products (acidic gas scrubbing condensate and carbon

dioxide) are being used for biomass production of this red alga.

E-Mail: galdi@zedat.fu-berlin.de

Molecular adaptation:

Bacteria under stress

The differing properties of the

various types of cells are the

result of the activation of different

genes. But how are

genes activated or inactivated?

In order to study such

problems, it is useful to have

model systems that are easy

to handle, for example bacteria.

In bacteria, genes are typically

activated in response to

environmental changes. Conditions are rarely ideal for bacterial

growth, indeed, the environment usually imposes considerable

stress. This is made worse by the fact that conditions also

change rapidly. The Microbiology I research group is investigating

how bacteria adapt to such adverse conditions by changing

the activity pattern of their genes. Stress factors can be shortages

of nutrients, high or low temperatures, or increased osmolarity.

But which genes are activated under such conditions?

How does a cell perceive stress? And finally, how does gene acti-

vation take place at the molecular

level?

In Escherichia coli, it has been

found that a highly complicated

genetic programme is activated

under stress, centred on an essential

regulator protein known as Sigma S.

Under a wide-range of stress conditions,

the level of this protein rises

dramatically, resulting in the activation

of 50-100 stress-protective

genes. In addition to Sigma-S, a

whole battery of other regulatory proteins

are also involved in modulating

this response. As a consequence, the

cells become highly-resistant against

many stress factors, and even change

their morphology. Underlying this

Biologie-Chemie-Pharmazie 19

Ω Research

Y. pseudotuberculosis(fluorescencemarked)

Regulation of degradation of

Sigma-S by stress signals


Ω Research

response are mechanisms of signal transduction and regulation

which are currently being studied at the molecular level.

This work is of more than purely theoretical interest. Many virulence

genes in pathogenic bacteria are stress-regulated, and the

central regulator Sigma-S plays a key role in the activation of

some of these. Bacteria deprived of Sigma-S as a result of mutations

are no longer pathogenic, and would in principle be suitable

as a living vaccine. Since inactivation of Sigma-S would

leave the cells less virulent and highly susceptible to stress,

Sigma-S may also be used as a target for novel antibiotics.

This prize-winning work has been carried on over the past

twelve years, and has been located at the Freie Universität Berlin

since 1998.

E-Mail: rhengga@ zedat.fu-berlin.de

Molecular photo-physiology:

The inner life of mosses

As an important light receptor system, the

phytochromes have a decisive influence

on the development of green plants. They

control key aspects of development such

as germination, chlorophyll synthesis,

growth and flowering. The nature of this

regulation is still not clear. Using modern

methods of molecular genetics, the Plant

A prokaryotic Physiology research group is investigating these regulation

phytochrome mechanisms in primitive green organisms, mosses and cyanobacteria.

Higher plants use the blue component of visible light to determine

the orientation for their growth - so-called phototropism.

Paradoxically, moss filaments orient themselves on the basis of

red light photons. The aim of the group is to find out the role of

the phytochrome in this process. Methods have been developed

to transfer phytochrome genes into moss filaments and to bring

them to expression. In this way, the light detection in the cells at

the end of the filament can be manipulated. It is only in primitive

plants that it is possible to modify the chromosomal genes

themselves. It was possible to identify the existence of a prokaryotic

phytochrome - in the cyanobacteria Synechocystis. This phytochrome

is very convenient for biophysical studies, since it can

be produced in large amounts. Various approaches are being

used to find out how the phytochrome works at the molecular

level. The molecules are modified by means of molecular genetics

in order to study the effects of changes on the structure and

function. Crystallisation of the phytochrome molecules would

also make it possible to establish their three-dimensional struc-

20 Freie Universität Berlin

ture using x-ray analysis. The phytochrome

studies are supported by a

sub-projekt of the DFG Collaborative

Research Centre 498 "Protein-Cofactor-Interactions

in biological processes”

and a DFG-Project La 799/6-1

"Isolation of genes for the Synthesis

of the phytochrome chromophore”

A sub-project of the DFG Collaborative Research Centre 429

"Molecular physiology, energetics, and regulation of primary

metabolism in plants" is working on the metabolism of lipids.

Oil seed plants such as sunflowers are important sources of

unsaturated fatty acids for human nutrition. Knowledge of the

regulation of the relevant metabolic pathways is therefore of

great importance. As a model organism, the researchers are

using the moss Physcomitrella patens. This is particularly wellsuited

for physiological studies because it can be easily cultivated

and genetically transformed. Furthermore, in contrast to

higher plants, it can be used to generate knock-out mutants by

homologous recombination. The goal of the work is to shed

light on the biosynthesis and function of phospholipids in

plants.

E-Mail: hartmann@zedat.fu-berlin.de

Cryoprotectin:

Frost protection in winter hardy plants

Frost damage gives rise to considerable

problems for farmers in our climate

zone. If we could improve the frost resistance

of wheat by only 2°C, it would be

possible to increase the area on which

the crop was grown by 25%. In order to

develop strategies for better frost protection,

it is first necessary to understand the mechanisms of frost

damage. The Developmental Biology research group is looking

at the molecular mechanisms of frost hardening and frost resistance

of photosynthetic membranes (thylakoid membranes). A

particularly interesting aspect is the protective role of the surrounding

cytoplasm.

When outside temperatures fall below freezing point, tiny ice

crystals form in the spaces between cells. The more the temperature

falls, the more water is extracted from the cells and

freezes, further increasing the concentrations of solutes in the

cells themselves. The water losses can be dramatic. At -20°C the

level of liquid water in the cell can be reduced to 5%. Cryoprotective

proteins (cryoprotectins) from winter-hardy cabbage

Biologie-Chemie-Pharmazie

Moss cells

filled with

oil drops

Spinach

leaves

(r.: intact,

l.: frost

damaged)

21

Ω Research


Ω Research

Frozen

spinach cells

leaves, which provide effective specific frost protection

for the membranes, have been identified and

purified. A new test system can now be used to test

any substances for their cryoprotective properties.

Thylakoid membranes are isolated from spinach

leaves and frozen in a test tube under precisely

defined conditions. Before freezing, the "anti-freeze"

candidate is added to the membrane isolate. After thawing

again, the state of the membranes is determined, and the level

of protection provided by the substance can be assessed.

It could be shown that cryoprotectins are some 50 000 times

more effective relative to their molecular weight than sucrose.

Only a few millionths of a gram is enough to provide complete

in vitro protection of the thylakoid membrane. The cryoprotectin

prevents the membrane from bursting. In this property it differs

from all other proteins that have been considered as likely frost

protection candidates. The mechanism of these "anti-freeze"

proteins is either unclear or they only have an indirect influence

on frost damage by reducing or promoting ice formation. Examples

of such proteins can be found in fish in the polar circles.

Other proteins in insects influence compartment-specific nucleation.

The aim of the work is to identify genes that code for the

cryoprotectins, to transfer these to frost-sensitive crops, express

them there and test their effects in the organism.

http://userpage.fu-berlin.de/~schmitt

E-Mail: schmitt@zedat.fu-berlin.de

Metabolic pathways

Metabolic pathways are functional units whose enzymes catalyse

a certain sequence of reactions. In the past it was assumed

that such metabolic pathways arose in the course of bacterial

evolution and were then passed on as a unit to the eukaryotic

organisms (animals, fungi, plants). Today many gene sequences

are known with which the origin of each gene and thus of the

entire metabolic path can be determined.

The research group on the Metabolic Physiology of Plants is

studying the genetic expression of sugar phosphate metabolism

as a sub-project of the DFG Collaborative Research Centre Sfb

429 "Molecular physiology of plants." An important part of

sugar phosphate metabolism is the glycolysis/gluconeogenesis

- a form of glucose degradation/formation, and the Calvin cycle,

the key photosynthetic carbon reduction cycle in plants and bacteria.

We were able to clone and sequence many of the genes of

the Calvin cycle of higher plants for the first time. Phylogenetic

analysis showed two eubacterial groups of organisms from

which the eukaryotic enzymes originate: cyanobacteria and

alpha-proteobacteria. These two groups, respectively, are

22 Freie Universität Berlin

regarded today as precursors of chloroplasts

and mitochondria (semiautonomous

intracellular organelles of the

eukaryotes). That means that the enzymes

of glycolysis / gluconeogenesis and the

Calvin cycle have come together from two

very different bacterial groups in eukaryotes

to form a new functional unit.

Although these metabolic pathways in bacteria

and eukaryotes form a functional unit,

it is not important in evolutionary terms

that the relevant genes in animals and

plants have very different origins. A special

feature of plants is that different enzymes

(isoenzymes) are responsible for the gluconeogenesis in cytosol

and in the chloroplasts. The occurrence of these isoenzymes is

attributable to gene duplication in various phases of evolution,

namely the bacterial, the early eukaryotic, or the early plant

phase. This contradicts the hypothesis that isoenzymes all originated

at the same time and as a block. There are even examples

for the independent evolution of such isoenzyme pairs many

times over.

In other metabolic pathways, most of the genes of the mitochondrial

tricarboxylic acid cycle (an energy-generating metabolic

pathway) came to the eukaryotic organisms with the evolution

of mitochondria from alpha-proteobacteria. In contrast,

the genes for the glyoxylate cycle, which is responsible for the

transition of acetate to glucose, were either formed in the microbodies

from gamma-proteobacteria or by duplication of mitochondrial

genes of the tricarboxylic acid cycle. In the course of

evolution, the function of the metabolic pathways was thus preserved.

The individual eukaryotic genes were recruited, however,

from very different organism groups. Such examples show that

the evolution of genes is a much more complicated process

than has previously been assumed.

E-Mail: schnarre@mail.zedat.fu-berlin.de

Ecotoxicology:

Biotests for a clean environment

A million years ago, our ancestors already began to adapt their

environment to their needs as they became human beings. For

a long time, low population densities meant that the environmental

impact of human activities remained a local problem.

However, with the growth of the world's population from 500

million in 1650 to some 6 billion today, the problems have

become global ones. Pollutants generated in the cities now

spread over the entire world and damage communities of living

organisms (biocoenoses) even in the most distant regions of

the world.

Biologie-Chemie-Pharmazie 23

Ω Research

Gene transfers

in evolution

(_) and

expression of

the gene

today (---)


Ω Research

Folesomia

candida

Enchytraeus

crypticus

(REM-image)

Some substances accumulating

in the soil have been introduced

there intentionally, such

as insecticides, herbicides,

fungicides, and also landfill

waste. Other substances also

accumulate, such as metals,

explosives, salts, heating oil

and fuel, carcinogenic organic

chemicals, and pharmaceutical

products for humans and

for animals. The negative

effects of these substances are often only noticed when the surface

vegetation shows signs of damage, or when humans and

animals fall ill. But by then it is already too late - the biocoenosis

is irreversibly harmed. The Ecotoxicology and Biochemistry

research group is investigating the influences of chemicals in

the environment on the behaviour and population development

of soil invertebrates such as springtails, enchytraeid worms,

threadworms, and single-cell organisms. Biotest systems are

developed using selected species which can indicate the habitat

quality of soils by means of well-defined reactions. Together

with plant tests, microbiological and genotoxic investigations,

these biotests form part of an internationally applied test battery

with which the damage to the soil and its retention function can

be determined. They can also be used to establish limit values

and thresholds for planning authorities in contaminated areas,

or to assess the need for decontamination measures.

Some substances are effective at the cellular

level, and lead to profound developmental

changes in animals. Chemicals

and pharmaceutical products resembling

hormones, for example, can lead to hermaphrodism

or sex changes in animals

even though they are only present at environmental

concentrations near or even

below current limits of detection. A

biotest is therefore being developed at the

molecular level - the Ökotox-Genchip.

This quick test system can show if a substance

activates relevant genes of a test organism (threadworm).

Since humans possess comparable genes, this can provide

indirect evidence of the potential threat to people and the

ecosystem posed by the substance in question.

www.biologie.fu-berlin.de/agachazi/

E-Mail: achbiofu@zedat.fu-berlin.de

24 Freie Universität Berlin

Botanic Garden and Botanical Museum

Berlin-Dahlem

The Botanic Garden is special among

the institutions of the Freie Universität

Berlin, and indeed among the botanical

gardens of the world. With more than

20 000 wild plant species on an area of

43 hectares, it is one of the most richly

stocked and largest gardens of its kind.

On one third of the area, typical representatives

of the flora of the temperate

zones of the northern hemisphere are

cultivated. Only a few steps will take

visitors from the European countryside past the steppe of Asia

and the Himalayas to the peaceful Japanese landscape and on

to North America and its colourful Indian Summers.

Plants of the tropics and subtropics

grow in the shelter of 15 public

glasshouses, including the Tropical

House, the largest single-roof

glasshouse in the world. Tropical crops

strive side by side with orchids, cacti

and – a major attraction – the giant

water lily. In Europe's only botanical

exhibition museum, models demonstrate some of the features

nature usually conceals from view: microorganisms and stinging

hairs, roots and the interior architecture of plants, as well as

the products of the world's most important crops. Evolutionary

and ecological processes are presented and explained in a way

that is easy to understand.

The library with some 400 000 books

and journals, and the herbarium with 3

million specimens are also unique.

Jointly they provide the basis for the

research work at the Botanical Museum.

Numerous students and postgraduates

use the facilities for their

work in systematic botany and plant

geography. Plant taxonomy is also

taught.

www.bgbm.fu-berlin.de/bgbm/

E-Mail: zi@zedat.fu-berlin.de

Biologie-Chemie-Pharmazie

25

Ω BGBM


Ω Studying

Studying at the institute

The Institute offers two programmes for students working for

their first biology qualification - a Diplom programme and a

programme leading to a state certificate as a teacher. The diploma

programme can be completed in ten semesters, and the

state exam can take from six to ten semesters.

The beginning of each summer

semester is marked by the Gottlieb

Haberlandt lecture - in honour of

the great botanist. The winter

semester is opened with the

Johannes Müller lecture, preserving

the memory of this great

zoophysiologist. Both lectures are

introductions for new students and

reunions for all members of the

institute. A modular course system offers advanced students a

wide choice. It is also possible to select a non-biological science

as an additional option. Whether law, pharmacology, philosophy

or computer science, anything is possible - provided of course

that the lecture schedules can be coordinated.

Biology at the FU is characterised by the emphasis on research.

Numerous excursions offer the opportunity to study in their natural

surroundings organisms that the students have already

encountered in their lectures and laboratory work, either on a

day-trip to the countryside near the city, or for several weeks in

the South of France, the Canary Isles, Israel, or South America.

The trips for one or two weeks to Sylt, Helgoland, the Baltic

Coast, Eschwege, or Carinthia in Austria are firm favourites and

have featured regularly in the programme for many years.

26 Freie Universität Berlin

Students are encouraged to

spend some time abroad, making

use of the SOKRATES /

ERASMUS programmes of the

European Union. Agreements

have been reached with partner

universities in Ghent (Belgium),

Valencia (Spain), Bordeaux, Lille

(France), Crete (Greece), Birmingham,

Cambridge, Swansea

(Britain), Parma, Milan, Sienna

(Italy) and Stockholm (Sweden).

Biology in brief

Central address

Freie Universität Berlin

Institute of Biology

Königin-Luise-Strasse 1-3

14195 Berlin

Germany

Tel.: +49-30-838-54682

Fax: +49-30-838-53925

www.biologie.fu-berlin.de

E-Mail: biologie@zedat.fu-berlin.de

Research groups / Professors

Animal physiology

Irene Zerbst, agsystem@zedat.fu-berlin.de

Applied zoology / Ecology of animals

Monika Hilker, hilker@zedat.fu-berlin.de

Bee research

Berkhard Schricker, agbienen@zedat.fu-berlin.de

Behavioural biology

Dietmar Todt, todt@zedat.fu-berlin.de

Didactics of biology

N.N.

Development biology

Jürgen Schmitt, schmitt@zedat.fu-berlin.de

Development genetics I

Günter Korge, korge@genetik.biologie.fu-berlin.de

Development genetics II

Horst Kress, kress@zedat.fu-berlin.de

Development physiology

Hans-Dieter Pfannenstiel, devbiol@zedat.fu-berlin.de

Ecotoxicology and biochemistry

Rudolf Achazi, achbiofu@zedat.fu-berlin.de

Entomology

Ekkehard Wachmann, wachmann@biologie.fu-berlin.de

Evolution and morphology of tracheophytes

Werner Greuter, w.greuther@mail.bgbm.fu-berlin.de

Evolutionary biology

Walter Sudhaus, sudhaus@zedat.fu-berlin.de

Functional neuroanatomy

Hans-Joachim Pflüger, pflueger@neurobiologie.fu-berlin.de

Human biology

Carsten Niemitz, cniemitz@zedat.fu-berlin.de

Immunology

Thomas Blankenstein, tblanke@mdc-berlin.de

Metabolic physiology of plants

Claus Schnarrenberger, schnarre@zedat.fu-berlin.de

Microbiology I

Regine Henge-Aronis, rhengga@zedat.fu-berlin.de

Biologie-Chemie-Pharmazie 27

Ω Biology in brief


Ω Biology in brief

Microbiology II

Robert Mutzel, rmutzel@zedat.fu-berlin.de

Mol. developmental biology of plants

N.N.

Mol. developmental neurobiology

Fritz Rathjen, rathjen@mdc-berlin.de

Molecular genetics and cytogenetics

N.N.

Morphology of phanerogams

Hartmut Hilger, hahilger@zedat.fu-berlin.de

Neurobiology

Randolf Menzel, menzel@neurobiologie.fu-berlin.de

Plant physiology

Elmar Hartmann, hartmann@zedat.fu-berlin.de

Protozoology

Klaus Hausmann, hausmann@zedat.fu-berlin.de

Population genetics

Horst Nöthel

Soil zoology and ecology

Gerd Weigmann, weigmann@zedat.fu-berlin.de

Systematic botany and plant geography

Wolfgang Frey, wfrey@zedat.fu-berlin.de

Zoology and evolutionary biology

N.N.

Collaborative research centre:

Sfb 515: "Mechanisms of developmental- and experiencedependent

plasticity in the nervous system"

Postgraduate research group "Signal cascades in living organisms"

Central facility Botanic Garden and Botanical Museum (BGBM)

(www.bgbm.fu-berlin.de/bgbm)

Students and personnel (March 2000)

1335 students

29 professors

65 scientific personnel

80 other personnel

86 student tutors

Research and academic achievements (1999)

Funding / third-party funding: DM 1.3m /DM 5.7m

Degrees awarded 80

Ph.D.s 42

Habilitations 6

Scientific cooperation in Germany (examples)

Universities: Aachen; HU Berlin; Bonn; Braunschweig; Frankfurt;

Göttingen; Cologne; Mainz; Munich; Ulm;

Witten/Herdecke; Würzburg

28 Freie Universität Berlin

Non-university institutions:

Berlin: IInstitute for Water Ecology and Fishing; Max-Delbrück

Centre; Max-Planck Institute (MPI) for Molecular Genetics;

Robert-Koch Institute; Schering; Federal Environmental

Agency; Berlin Zoological Garden.

Freiburg: MPI für Immunology.

Gatersleben: Institute of Plant Genetics and Crop Research.

Golm: MPI for Molecular Plant Physiology.

Schmallenberg: Fraunhofer Institute of Environmental Chemistry

and Ecotoxicology.

Tübingen: MPI für Developmental Biology.

International cooperation (selection)

Argentina: Univesidad de Buenos Aires.

Australia: University of Sydney.

Cuba: Jardin Botanico National, Universidad La Habana.

Czech Republic: Zoological Institute, University of Prague.

Egypt: Ministry of Agriculture.

France: Insitut Pasteur, Paris; Human Frontier Science Programme,

Strasbourg.

Great Britain: University of Leeds.

Holland: Leiden University; Tropenbos.

Israel: National Institute of Oceanography,

Haifa; University of Tel Aviv.

Italy: Instituto Ortobotanico, Palermo University.

Japan: Metropolitan University of Tokyo.

New Zealand: Department of Conservation, Tongariro.

Russia: State University of Irkutsk; Lossomov State University,

Moscow; Voronezh State University.

Sweden: Lund University.

USA: United States Department of Agriculture; NIH Bethesda,

Maryland; Biocommunication Lab, UC/Davis; North Dakota

State University, Fargo; University of Hawaii; University of

Texas/Houston; New York University; University of Arizona,

Tucson; Sonoma University, California; University of Utah, Salt

Lake City; College of Environmental Science, State University

Syracuse, N.Y.

Academic qualifications awarded:

Diploma in Biology

State teaching qualification for biology

Services

Student counselling: Tel: 838-53840

Student office: Tel: 838-55550;

e-mail: bioini@zedat.fu-berlin.de

Library Central biology library in

Botanical Museum,

Tel: 83006-191

Biologie-Chemie-Pharmazie 29

Ω Biology in brief


Ulf Kaiser

Ω Dies ist ein Thema

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