Evolution and Development
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In our research, we use both the comparative method and experimental evolution for the study of evolution of a variety of processes, with special emphasis on development. Focusing mainly on Drosophila, we use an evolutionary framework to approach the origin and historical construction of complex adaptations, from evolutionary novelties to immunity. Other collaborative projects involve the study of adaptation to pesticide in C. elegans and the evaluation of its costs and, in collaboration with Marta Moita and Isabel Gordo both group leaders at the IGC, the study of the prisonner´s dilemma in rats.
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Browsing Evolution and Development by Subject "Animals"
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- Evolution of mir-92a Underlies Natural Morphological Variation in Drosophila melanogasterPublication . Arif, Saad; Murat, Sophie; Almudi, Isabel; Nunes, Maria D.S.; Bortolamiol-Becet, Diane; McGregor, Naomi S.; Currie, James M.S.; Hughes, Harri; Ronshaugen, Matthew; Sucena, Élio; Lai, Eric C.; Schlötterer, Christian; McGregor, Alistair P.Identifying the genetic mechanisms underlying phenotypic change is essential to understanding how gene regulatory networks and ultimately the genotype-to-phenotype map evolve. It is recognized that microRNAs (miRNAs) have the potential to facilitate evolutionary change [1-3]; however, there are no known examples of natural morphological variation caused by evolutionary changes in miRNA expression. Therefore, the contribution of miRNAs to evolutionary change remains unknown [1, 4]. Drosophila melanogaster subgroup species display a portion of trichome-free cuticle on the femur of the second leg called the "naked valley." It was previously shown that Ultrabithorax (Ubx) is involved in naked valley variation between D. melanogaster and D. simulans [5, 6]. However, naked valley size also varies among populations of D. melanogaster, ranging from 1,000 up to 30,000 μm(2). We investigated the genetic basis of intraspecific differences in the naked valley in D. melanogaster and found that neither Ubx nor shavenbaby (svb) [7, 8] contributes to this morphological difference. Instead, we show that changes in mir-92a expression underlie the evolution of naked valley size in D. melanogaster through repression of shavenoid (sha) [9]. Therefore, our results reveal a novel mechanism for morphological evolution and suggest that modulation of the expression of miRNAs potentially plays a prominent role in generating organismal diversity.
- Multispecies Analysis of Expression Pattern Diversification in the Recently Expanded Insect Ly6 Gene FamilyPublication . Tanaka, Kohtaro; Diekmann, Yoan; Hazbun, Alexis; Hijazi, Assia; Vreede, Barbara; Roch, Fernando; Sucena, ÉlioGene families often consist of members with diverse expression domains reflecting their functions in a wide variety of tissues. However, how the expression of individual members, and thus their tissue-specific functions, diversified during the course of gene family expansion is not well understood. In this study, we approached this question through the analysis of the duplication history and transcriptional evolution of a rapidly expanding subfamily of insect Ly6 genes. We analyzed different insect genomes and identified seven Ly6 genes that have originated from a single ancestor through sequential duplication within the higher Diptera. We then determined how the original embryonic expression pattern of the founding gene diversified by characterizing its tissue-specific expression in the beetle Tribolium castaneum, the butterfly Bicyclus anynana, and the mosquito Anopheles stephensi and those of its duplicates in three higher dipteran species, representing various stages of the duplication history (Megaselia abdita, Ceratitis capitata, and Drosophila melanogaster). Our results revealed that frequent neofunctionalization episodes contributed to the increased expression breadth of this subfamily and that these events occurred after duplication and speciation events at comparable frequencies. In addition, at each duplication node, we consistently found asymmetric expression divergence. One paralog inherited most of the tissue-specificities of the founder gene, whereas the other paralog evolved drastically reduced expression domains. Our approach attests to the power of combining a well-established duplication history with a comprehensive coverage of representative species in acquiring unequivocal information about the dynamics of gene expression evolution in gene families.
- Reversion of developmental mode in insects: evolution from long germband to short germband in the polyembrionic wasp Macrocentrus cingulum BrischkePublication . Sucena, Élio; Vanderberghe, Koen; Zhurov, Vladimir; Grbić, MiodragGermband size in insects has played a central role in our understanding of insect patterning mechanisms and their evolution. The polarity of evolutionary change in insect patterning has been viewed so far as the unidirectional shift from the ancestral short germband patterning of basal hemimetabolous insects to the long germband patterning observed in most modern Holometabola. However, some orders of holometabolic insects display both short and long germband development, though the absence of a clear phylogenetic context does not permit definite conclusions on the polarity of change. Derived hymenoptera, that is, bees and wasps, represent a classical textbook example of long germband development. Yet, in some wasps putative short germband development has been described correlating with lifestyle changes, namely with evolution of endoparasitism and polyembryony. To address the potential reversion from long to short germband, we focused on the family Braconidae, which displays ancestral long germband development, and examined the derived polyembryonic braconid Macrocentrus cingulum. Using SEM analysis of M. cingulum embryogenesis coupled with analyses of embryonic patterning markers, we show that this wasp evolved short germband embryogenesis secondarily, in a way that is reminiscent of embryogenesis in the beetle Tribolium castaneum. This work shows that the evolution of germband size in insects is a reversible process that may correlate with other life-history traits and suggests broader implications on the mechanisms and evolvability of insect development.