Oral Presentation Society for Molecular Biology and Evolution Conference 2016

Do retroCNVs resolve intralocus sexually antagonistic conflicts in Drosophila? (#107)

Esther Betran 1 , Anna Williford 1
  1. University of Texas at Arlington, Arlington, TEXAS, United States

Retroposed copies of new genes (also known as retrogenes) are copies of genes that are produced from an mRNA intermediate. It has been observed that retrogenes often acquire testis-specific expression in a variety of lineages including mammals and dipterans, possibly as a consequence of new genes being inserted close to testis-expressed genes. In addition, in Drosophila, it has been shown that testis-expressed retrogenes often evolve under positive selection, show pattern of recurrent duplication in different lineages and exhibit an overrepresentation of particular gene ontologies, including nuclear-encoded mitochondria genes, nuclear transport and proteasome functions. We have proposed a model that postulates the existence of intralocus sexually antagonistic variation (i.e., allelic variation conferring opposite fitness effects for males and females due to the effects in male germline) in the parental gene, followed by gene duplication that resolves this antagonism. While DNA-mediated duplications could also resolve this antagonism and have the same effect (e.g., we do see a high number of testis-specific nuclear-encoded mitochondria duplications that are DNA mediated), the high frequency of retrogenes expressed in testis should facilitate this outcome. Because of this, we are undertaking an extensive search for retroCNVs using available genomic data, including genomic localization of retroCNVs, analysis of parent-daughter expression patterns and examination of the allelic variation in the parental genes. Candidate retroCNVs that show features consistent with the model will be used to study sex-specific fitness effects to explore their role in resolution of sexual antagonism. We will provide an update on those efforts.