Variation: Development and Selection
Permanent URI for this community
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.
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.
Browse
Browsing Variation: Development and Selection by Author "Beldade, Patrícia"
Now showing 1 - 4 of 4
Results Per Page
Sort Options
- Adaptive developmental plasticity: Compartmentalized responses to environmental cues and to corresponding internal signals provide phenotypic flexibilityPublication . Mateus, Ana; Marques-Pita, Manuel; Oostra, Vicencio; Lafuente, Elvira; Brakefield, Paul M; Zwaan, Bas J; Beldade, PatríciaThe environmental regulation of development can result in the production of distinct phenotypes from the same genotype and provide the means for organisms to cope with environmental heterogeneity. The effect of the environment on developmental outcomes is typically mediated by hormonal signals which convey information about external cues to the developing tissues. While such plasticity is a wide-spread property of development, not all developing tissues are equally plastic. To understand how organisms integrate environmental input into coherent adult phenotypes, we must know how different body parts respond, independently or in concert, to external cues and to the corresponding internal signals.
- Ecdysteroid Hormones Link the Juvenile Environment to Alternative Adult Life Histories in a Seasonal InsectPublication . Oostra, Vicencio; Mateus, Ana Rita A.; van der Burg, Karin R. L.; Piessens, Thomas; van Eijk, Marleen; Brakefield, Paul M.; Beldade, Patrícia; Zwaan, Bas J.The conditional expression of alternative life strategies is a widespread feature of animal life and a pivotal adaptation to life in seasonal environments. To optimally match suites of traits to seasonally changing ecological opportunities, animals living in seasonal environments need mechanisms linking information on environmental quality to resource allocation decisions. The butterfly Bicyclus anynana expresses alternative adult life histories in the alternating wet and dry seasons of its habitat as endpoints of divergent developmental pathways triggered by seasonal variation in preadult temperature. Pupal ecdysteroid hormone titers are correlated with the seasonal environment, but whether they play a functional role in coordinating the coupling of adult traits in the alternative life histories is unknown. Here, we show that manipulating pupal ecdysteroid levels is sufficient to mimic in direction and magnitude the shifts in adult reproductive resource allocation normally induced by seasonal temperature. Crucially, this allocation shift is accompanied by changes in ecologically relevant traits, including timing of reproduction, life span, and starvation resistance. Together, our results support a functional role for ecdysteroids during development in mediating strategic reproductive investment decisions in response to predictive indicators of environmental quality. This study provides a physiological mechanism for adaptive developmental plasticity, allowing organisms to cope with variable environments.
- Evolution of thorax architecture in ant castes highlights trade-off between flight and ground behaviorsPublication . Keller, Roberto A; Peeters, Christian; Beldade, PatríciaThe concerted evolution of morphological and behavioral specializations has compelling examples in ant castes. Unique to ants is a marked divergence between winged queens and wingless workers, but morphological specializations for behaviors on the ground have been overlooked. We analyzed thorax morphology of queens and workers in species from 21 of the 25 ant subfamilies. We uncovered unique skeletomuscular modifications in workers that presumably increase power and flexibility of head-thorax articulation, emphasizing that workers are not simply wingless versions of queens. We also identified two distinct types of queens and showed repeated evolutionary associations with strategies of colony foundation. Solitary founding queens that hunt have a more worker-like thorax. Our results reveal that ants invest in the relative size of thorax segments according to their tasks. Versatility of head movements allows for better manipulation of food and objects, which arguably contributed to the ants' ecological and evolutionary success. DOI: http://dx.doi.org/10.7554/eLife.01539.001.
- Genetic basis of thermal plasticity variation in Drosophila melanogaster body sizePublication . Lafuente, Elvira; Duneau, David; Beldade, PatríciaBody size is a quantitative trait that is closely associated to fitness and under the control of both genetic and environmental factors. While developmental plasticity for this and other traits is heritable and under selection, little is known about the genetic basis for variation in plasticity that can provide the raw material for its evolution. We quantified genetic variation for body size plasticity in Drosophila melanogaster by measuring thorax and abdomen length of females reared at two temperatures from a panel representing naturally segregating alleles, the Drosophila Genetic Reference Panel (DGRP). We found variation between genotypes for the levels and direction of thermal plasticity in size of both body parts. We then used a Genome-Wide Association Study (GWAS) approach to unravel the genetic basis of inter-genotype variation in body size plasticity, and used different approaches to validate selected QTLs and to explore potential pleiotropic effects. We found mostly "private QTLs", with little overlap between the candidate loci underlying variation in plasticity for thorax versus abdomen size, for different properties of the plastic response, and for size versus size plasticity. We also found that the putative functions of plasticity QTLs were diverse and that alleles for higher plasticity were found at lower frequencies in the target population. Importantly, a number of our plasticity QTLs have been targets of selection in other populations. Our data sheds light onto the genetic basis of inter-genotype variation in size plasticity that is necessary for its evolution.