organisation - the Instituto Gulbenkian de Ciência

of ca. 30 candidate genes for expression analysis. For the latter, we have designed
primers and probes and started optimizing semi-quantitative PCR and in
situ hybridisation protocols for analysis of levels and spatial patterns of gene
expression, respectively.
COPING WITH CHANGING ENVIRONMENTS:
GENETIC AND PHYSIOLOGICAL MECHANISMS OF ADAPTIVE PLASTICITY
Phenotypic plasticity is the ability of some genotypes to develop into distinct
phenotypes depending on environmental conditions. Adaptive phenotypic plasticity
leads to a better match between phenotype and selective environment
and can be a solution for dealing with fluctuating environments. Many insects
living in such environments have evolved phenotypic plasticity, including seasonal
polyphenisms in butterfly wing patterns. This study investigates the proximate
mechanisms (genetic and physiological) behind developmental plasticity in
butterfly wing patterns, and explores their potential role in contributing to how
species cope with changing environments.
We analysed the data on the effects on adult phenotypes (including wing patterns
and body-part allocations) of ecdysteroid manipulations in pupae, and
we started preparing two manuscripts where these results will be reported on
(Mateus et al. in prep; Oostra et al. in prep). We also finished gathering images
to characterize wing pattern reaction norms for different genetic backgrounds
(to assess genetic-by-environment effects, and the role of candidate loci in
plasticity).
EVOLUTION OF CASTE POLYPHENISM IN SOCIAL INSECTS:
PATTERNS OF MORPHOLOGICAL DIVERSIFICATION IN ANTS
Caste determination in ants is a classic example of developmental plasticity.
Larvae of the same genotype can develop into adults with very distinct morphologies,
each adapted for different roles within a colony. Typically, one or a
few larger and winged queens ensure the reproductive function, whereas many
wingless workers are responsible for colony maintenance. The developmental
switch into alternative phenotypes is regulated by larval nutrition, which itself
is under the control of the social environment. In collaboration with the group
of Christian Peeters in Paris, this project studies how plastic developmental systems
are regulated, and how they evolve and diversify. Specifically, we want to:
1. Establish a link between caste-specific morphologies and behaviours, in
relation to colony ecology;
2. Characterize the environmental regulation of caste development.
We analysed the data and started to prepare a manuscript (Keller et al. in prep)
on the characterisation of caste-specific morphologies and their correlations
with behaviour (at the level of caste-specific roles within a colony, and of reproductive
strategies of whole colonies) for multiple ant species. Roberto Keller
also established new lab populations of the ant Aphaenogaster senilis and
established “colony partition” protocols to manipulate frequency of different
sexes and castes produced.
MORPHOLOGICAL DIVERSIFICATION THROUGH THE EVOLUTION
OF DEVELOPMENTAL NETWORKS
The genes that regulate development are organized into intricate networks
whose origin and evolution remains a largely unresolved topic. Of great interest
is to what extent the different components of such networks contribute to
phenotypic variation and diversification. The evolutionary outcome of changes
on a developmental network depends on both the nature of the change and
the point in the network hierarchy where the change occurs. The diversified
eyespot patterns that decorate the wings of satyrine butterflies offer the opportunity
to address these issues. Analysis of cross-species diversity and within-species
variation in wing colour patterns can be integrated with an analysis
of the underlying sequence of developmental steps and genetic underpinnings.
Leila Shirai (PhD student) will investigate which type of changes in the underlying
gene networks and respective developmental mechanisms are responsible
for morphological diversification of this model novel trait.
We carried out the phylogenetic analysis of the recruitment of four conserved
genes for expression in association with the early establishment of eyespots and
eyespot-like elements in 13 species. The results of this analysis were prepared
IGC ANNUAL REPORT ‘11
RESEARCH GROUPS
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