Séminaire de Hélène DEFENDINI (IGEPP, INRAE, Rennes), dans le cadre du cycle de Séminaires d'ECOBIO
Next Friday, September 8th, at 1pm in room OSUR, we will welcome Hélène DEFENDINI, from IGEPP, INRAE, Rennes. She will give us an overview of her soon-to-be defended PhD with a seminar about "Changes in gene expression associated with the relaxation of sexual conflicts in the pea aphid" Please see the abstract below and on the poster. We hope you can join us. It is also possible to follow the seminar via zoom with the \*NEW\* following link: [[https://univ-rennes1-fr.zoom.us/j/97365448620](https://univ-rennes1-fr.zoom.us/j/97365448620)](https://univ-rennes1-fr.zoom.us/j/97365448620) (password: ecobio). Abstract: Changes in gene expression associated with the relaxation of sexual conflicts in the pea aphid Males and females share most of their genome, but often exhibit different phenotypes underlying genomic conflicts. Resolution of these conflicts may involve differential gene expression according to sex. However, unresolved conflicts may remain, leading to suboptimal gene expression patterns in each sex. Sexual conflict is no longer present in asexual lineages, making them relevant systems for understanding the extent to which sexual conflict drives gene expression. The pea aphid has populations with contrasting reproductive modes that are geographically isolated. In cyclically parthenogenetic (CP) populations, which alternate between asexual and sexual generations, conflicts can arise between the three morphs produced (males, sexual females, parthenogenetic females). In contrast, obligately parthenogenetic (OP) populations do not generate sexual females, severely limiting the mating opportunities for the few OP males that are produced. In OP lineages, gene expression in parthenogenetic females is thus no longer constrained by that of other morphs. We analyzed gene expression in parthenogenetic females and males from OP and CP pea aphid lineages to test whether the disappearance of sexual conflict would result in expression shifts toward the parthenogenetic female optimum. We predicted that parthenogenetic female-biased genes would be more highly expressed in OP than in CP morphs. As expected, OP males overexpress parthenogenetic female-biased genes relative to CP males, but surprisingly also overexpress testis-specific genes. Contrary to predictions, OP parthenogenetic females do not overexpress parthenogenetic female-biased genes, but ovary specific sexual female-biased genes. These changes in morph-biased genes in OP lineages may result from relaxation of selection or dysregulation of gene networks otherwise used in sexual morphs in CP lineages.