Variação: Desenvolvimento e Selecção

Interesse da Investigação

My research in the area of evolutionary developmental biology is focused on the genetic and developmental dissection of phenotypic variation. Heritable phenotypic variation is the raw material of evolution by natural selection, and a universal property of biological systems - including traits of medical and economic importance. Understanding the mechanisms that generate phenotypic variation is, thus, a key challenge in contemporary biological research. What are the gene types (e.g. transcription factors versus enzymes), specific genes, and gene regions (e.g. regulatory versus coding sequence) that contribute to evolutionarily relevant variation? How do these genes lead to change developmental programmes and translate into variant adult phenotypes?

My work so far has concentrated on a diverse and ecologically-relevant phenotype that represents a laboratory-tractable system for the dissection of variation in complex traits: wing color patterns on butterfly wings.

Membros do Grupo

Projecto de Investigação

The contribution of novel genes to the formation of evolutionary novelties

The origin and modification of evolutionary novelties (i.e. lineage-specific, adaptive traits such as feathers in birds, carapaces in turtles and wing patterns in butterflies) is a key topic in evolutionary developmental biology. Recent studies have shown that lineage-restricted traits often arise by redeployment of shared regulatory circuitry. While there is no doubt that conserved developmental pathways can acquire new functions and be recruited for the formation of new traits, the contribution of genes restricted to specific lineages remains under-tested. In fact, the popular expression that assigns the evolution of novelties to "teaching old genes new tricks" might be biased by the standard approach which studies "shared genes" known in lab models, rather than identify and pursue "new ones" in non-models. This project will contribute to overcome this bias and specifically test the involvement of candidate novel (or highly diverged) new genes in the formation of butterfly wing color patterns (evolutionary novelties characteristic of lepidopterans and used in visual communication).

Funding

PTDC/BIA-BDE/099808/2008

Projecto de Investigação

Coping with changing environments: genetic and physiological mechanisms of adaptive plasticity

Phenotypic plasticity, the ability of some genotypes to develop into distinct phenotypes depending on environmental conditions, is of special interest in the study of how organisms cope with changing environments. Adaptive phenotypic plasticity leads to a better match between phenotype and selective environment and may represent a potential solution to the problems posed by fluctuating environments. Many insects living in fluctuating environments have evolved phenotypic plasticity for different types of traits, including seasonal polyphenisms is pigmentation in butterflies. Butterfly wing color patterns are interesting models to study adaptive phenotypic evolution and its underlying mechanisms because they are highly diversified (most species, and even geographical variants within species, can be told apart by their characteristic wing patterns), ecologically relevant (in relation to both biotic and abiotic factors), and amenable to developmental analysis. This project focuses on exploring how temperature during pre-adult life-stages regulates the production of alternative seasonal forms mediated by physiological and epigenetic factors.

Funding

PTDC/BIA-BDE/100243/2008

Projecto de Investigação

Evolution of caste polyphenism in social insects: patterns of morphological diversification in ants

Caste determination in ants is a dramatic 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, we will obtain a detailed phylogenetic-wide characterization of caste-specific morphologies and behaviors. This will allow us to link the two aspects of the phenotype and to understand their evolutionary diversification. We will also use selected experimental systems to investigate the exact mechanisms whereby changes in individual phenotype result from the regulation of development. Specifically, we will investigate which and how changes in gene expression are mediated by different physiological and epigenetic factors. This project will investigate both the proximal mechanisms that link within-colony changes in individual phenotype to changes in developmental environment, and the ultimate evolutionary mechanisms responsible for the across-species diversification of castes within specific ecological environments.

Funding

Post-doc fellowship for Dr. Roberto Keller: SFRH/BPD/65529/200

Publicações

(ten selected publications) Updated June (2011).

Saenko SV, MSP Marialva, P Beldade. (2011). Involvement of the conserved Hox gene Antennapedia in the development and evolution of a novel trait EvoDevo 2 :9

Beldade P, ARA Mateus, RA Keller. (2011). Evolution and molecular mechanisms of adaptive developmental plasticity Molecular Ecology 20 :1347-1363

Saenko SV, PM Brakefield & P Beldade (2010). Single locus affects embryonic segment polarity and multiple aspects of an adult evolutionary novelty BMC Biology 8 :111

Beldade, P., SV Saenko, N Pul & AD Long (2009). A gene-based linkage map for Bicyclus anynana butterflies allows for a comphenesive analysis of synteny with the lepidopteran reference genome PLoS Genetics 5 :e1000366 Link

Wittkopp PJ & P Beldade (2009). Development and evolution of insect pigmentation: genetic mechanisms and the potential consequences of pleiotropy Seminars in Cell & Developmental Biology 20 :65-71

Beldade, P., Rudd, S., Gruber, J.D. & Long, A.D. (2006). An Expression Sequence Tag resource for Bicyclus anynana butterflies, an evo-devo model BMC Genomics 7 :130 Link

Beldade P, Brakefield, P.M. & Long, A.D. (2002). Contribution of Distal-less to quantitative variation in butterfly eyespots Nature 415 :315-318 Link

Beldade, P., Koops, K. & Brakefield, P.M. (2002). Developmental constraints versus flexibility in morphological evolution Nature 416 :844-847 Link

Beldade, P. & Brakefield, P.M. (2002). Genetics and evo-devo of butterfly wing patterns Nature Reviews Genetics 3 :442-452 Link

Beldade P, K Koop & PM Brakefield (2002). Modularity, individuality, and evo-devo in butterfly wings Proceedings of the National Academy of Sciences U.S.A 99 :14262-14267