Project description:The evolution of female choice mechanisms favouring males of their own kind is considered as crucial step during the early stages of speciation. However, although the genomics of mate choice may influence both the likelihood and speed of speciation, the identity and location of genes underlying assortative mating remain largely unknown. We used mate choice experiments and gene expression analysis of female D. melanogaster to examine three key components influencing speciation. We show that the 1,498 genes in Zimbabwean female Drosophila melanogaster whose expression levels differ when mating with more (Zimbabwean) versus less (Cosmopolitan strain) preferred males include many with high expression in the central nervous system and ovaries, are disproportionately X-linked and form a number of clusters with low recombination distance. Significant involvement of the brain and ovaries is consistent with the action of a combination of pre- and post-copulatory female choice mechanisms, while sex linkage and clustering of genes lead to high potential evolutionary rate and sheltering against the homogenizing effects of gene exchange between populations. Taken together our results imply favourable genomic conditions for the evolution of reproductive isolation through mate choice in Zimbabwean D. melanogaster and suggest that mate choice may, in general, act as an even more important engine of speciation than previously realized. We measured gene expression of adult female Drosophila melanogaster from a composite Zimbabwe (Z) strain population named SZ, produced by mixing the genomes of six Z strain isofemale lines, shortly after mating them with either SZ strain or cosmopolitan (M strain) males. Data from four replicates of each of the two treatments (SZ mated with SZ; SZ mated with M) are presented, giving a total of eight arrays.
Project description:Insulators are considered as chromosome organizers. BEAF, one of the insulator proteins, is highly conserved in Drosophila speies but also limited to Drosophila spcies. BEAF associates with TSS of active genes. Comparative study of BEAF binding landscapes in four Drosophila species reveals BEAF association with gene pairs, and the results suggest the role of gain or loss of BEAF binding during the speciation of Drosophila species.
Project description:Background The evolution of female choice mechanisms favouring males of their own kind is considered as crucial step during the early stages of speciation. However, although the genomics of mate choice may influence both the likelihood and speed of speciation, the identity and location of genes underlying assortative mating remain largely unknown. Methods and Findings We used mate choice experiments and gene expression analysis of female D. melanogaster to examine three key components influencing speciation. We show that the 1,498 genes in Zimbabwean female Drosophila melanogaster whose expression levels differ when mating with more (Zimbabwean) versus less (Cosmopolitan strain) preferred males include many with high expression in the central nervous system and ovaries, are disproportionately X-linked and form a number of clusters with low recombination distance. Significant involvement of the brain and ovaries is consistent with the action of a combination of pre- and postcopulatory female choice mechanisms, while sex linkage and clustering of genes lead to high potential evolutionary rate and sheltering against the homogenizing effects of gene exchange between populations. Conclusion Taken together our results imply favourable genomic conditions for the evolution of reproductive isolation through mate choice in Zimbabwean D. melanogaster and suggest that mate choice may, in general, act as an even more important engine of speciation than previously realized.
Project description:Insulators are considered as chromosome organizers. BEAF, one of the insulator proteins, is highly conserved in Drosophila speies but also limited to Drosophila spcies. BEAF associates with TSS of active genes. Comparative study of BEAF binding landscapes in four Drosophila species reveals BEAF association with gene pairs, and the results suggest the role of gain or loss of BEAF binding during the speciation of Drosophila species. DNA sample from ChIP for BEAF and input are collected for each of four Drosophila species
Project description:D. grimshawi microarray used to text for gene expression differences between two populations subjected to control or low-intensity heat for one week during maturation Anthropogenic influences on global processes and climatic conditions are increasingly affecting ecosystems throughout the world. Hawaii Island’s native ecosystems are well-studied and local long-term climatic trends well-documented, making these ecosystems ideal for evaluating how native taxa may respond to a warming environment. This study documents adaptive divergence of populations of a Hawaiian picture wing Drosophila, D. sproati, that are separated by only 7km and 365m in elevation. Representative laboratory populations show divergent behavioral and physiological responses to an experimental low-intensity increase in ambient temperature during maturation. The significant interaction of source population by temperature treatment for behavioral and physiological measurements indicates differential adaptation to temperature for the two populations. Significant differences in gene expression among males were mostly explained by the source population, with eleven genes in males also showing a significant interaction of source population by temperature treatment. The combined behavior, physiology, and gene expression differences between populations illustrates the potential for local adaptation to occur over a fine spatial scale and exemplifies nuanced response to climate change.