Project description:Sex determination evolves rapidly, often because of turnover of the genes at the top of the pathway. The house fly, Musca domestica, has a multifactorial sex determination system, allowing us to identify the selective forces responsible for the evolutionary turnover of sex determination in action. There is a male determining factor, M, on the Y chromosome (Y^M), which is probably the ancestral state. An M factor on the third chromosome (III^M) has reached high frequencies in multiple populations across the world, but the evolutionary forces responsible for the invasion of III^M are not resolved. To test if the III^M chromosome invaded because of sex-specific selection pressures, we used mRNA sequencing to determine if isogenic males that differ only in the presence of the Y^M or III^M chromosome have different gene expression profiles. We find that more genes are differentially expressed between Y^M and III^M males in testis than head, and that genes with male-biased expression are most likely to be differentially expressed between Y^M and III^M males. This suggests that male phenotypes, especially those related to male fertility, are more likely to be affected by the male-determining chromosome, supporting the hypothesis that sex-specific selection acts on alleles linked to the male-determining locus driving evolutionary turnover in the sex determination pathway. We additionally find that III^M males have a "masculinization" gene expression profile, suggesting that the III^M chromosome has accumulated an excess of male-beneficial alleles because of its male-limited transmission.
Project description:Using mRNA next generation sequencing, we analyze the transcriptome of Musca domestica embryos through five stages of early development: from syncytial blastoderm to dorsal closure stage.
Project description:Using mRNA next generation sequencing, we analyze the transcriptome of Musca domestica embryos through five stages of early development: from syncytial blastoderm to dorsal closure stage. We select 100 embryos for five developmental stages: syncytial blastoderm, cellular blastoderm, gastrula, germ band extension and dorsal closure. A total of 10 samples of mRNA were obtained, represent two biological replicates for each stage.
Project description:To investigate how MdCht9 contribute to the development and digestion of Musca domestica, we silenced the chitinase gene 9 (MdCht9) by its dsRNA, while silenced the GFP as the control. Then we compared the differental expression genes between the test group and the control group.
