chapter 1 - Bentham Science

FOREWORD
This eBook on “Hemolymph Proteins and Functional Peptides: Recent Advances in Insects and Other
Arthropods” represents an up-to-date compilation of the major functionalities of hemolymph proteins as
there are lipid transport and energy mobilization realized by lipophorins, larval amino acid storage and yolk
precursor functions in the adult as well as immune and stress responsive proteins. Evidently the
hemolymph, a primary colonization substrate for invaders, supported by the inflow of antimicrobial
peptides from both the fat body and the hemocytes, harbors complex but effective immune pathways. As a
circulatory system, the impact of heartbeat changes on hemolymph functioning cannot be overestimated,
however its assumed regulation by neuropeptides seems non-physiological. According to this primary
transport role, the hemolymph assures a direct reciprocal interface between the midgut digestive system and
all other organs, including the brain, which is mainly mediated by regulatory peptides, proteins and related
compounds. The insulin-like censoring and signaling pathway, among others, communicates food and
energy supplies to the insect assuring either initiation/continuation or arrest of major functionalities like
reproduction. To complete this eminent list of functions dedicated to proteinaceous and peptidic
hemolymph factors, final focus is directed towards the presence of the multifunctional ENF family type
peptides helping the insects defence system/development in many aspects.
Being a generalist in insect physiology since 1977, I really enjoyed reading all these manuscripts in
preview: they are really uploaded with most recent data in their fields of expertise. Indeed in each chapter
the authors succeeded to expand the comprehensive knowledge of previous or even recent reviews of their
research fields by critically surveying over 1100 papers. Whenever relevant, the authors shed some light to
new ongoing or planned research and by doing so the readers’ curiosity to learn about results in the pipeline
is awakened.
Evidently, as suggested by their title, some chapters are seemingly biased by the overwhelming data
obtained in insect model organisms or related arthropod lab rats, however comparative interspecies
approach, sometimes highlighting species-specific peculiarities, helps the in-depth understanding and ecophysiological
significance of the fluctuations linked to hemolymph components and whenever necessary
restricts the over-extrapolation of data that are only obtained in a single model organism.
The combined up-to-date knowledge about hemolymph factors, their origin and targets not only have
fundamental value or feed healthy curiosity. Indeed the parallels between processes here described for
insects and related arthropods and those known in vertebrates in general and mammals in particular
underline the importance of continued reciprocal complimentary research. Evidently, the here discussed
data and extensive interpretations here will be of direct benefit for those involved in integrated pest
management.
The research of the last decennium was boosted by “omics” research and the genome-wide screenings shed
light on the overall complexity of regulatory pathways. The revitalized functional protein/peptide research,
originally restricted to trans-gene over-expression or knockout models, since the introduction of RNAi can
be extended to most species. This single technological realization already accounts for more than thousands
of recent “RNAi-insect” reference hits. This simple example underlines the value of regular up-to-date
integrating reviews. We can only be respectful to the editors Dr. M. Tufail and Dr. M. Takeda for bringing
together all these exciting data with the help of the respective authors.
Roger Huybrechts
Insect Physiology and Molecular Ethology
Dept. of Biology of the Catholic University of Leuven
Belgium
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