Using RNA-seq to determine patterns of sex-bias in gene expression in the brain of the sex-role reversed Gulf Pipefish (Syngnathus scovelli)

Mar Genomics. 2018 Feb:37:120-127. doi: 10.1016/j.margen.2017.09.005. Epub 2017 Sep 22.

Abstract

Sex-bias in gene expression is a widespread mechanism for controlling the development of phenotypes that differ between males and females. Most studies on sex-bias in gene expression have focused on species that exhibit traditional sex-roles (male-male competition and female parental care). By contrast the Syngnathid fishes (sea horses, pipefish, and sea dragons) are a group of organisms where many species exhibit male brooding and sex-role reversal (female-female competition for mates and paternal parental care), and little is known about how patterns of sex-bias in gene expression vary in species with sex-role reversal. Here we utilize RNA-seq technology to investigate patterns of sex-bias in gene expression in the brain tissue of the Gulf Pipefish (Syngnathus scovelli) a species that exhibits sex-role reversal. Gene expression analysis identified 73 sex-biased genes, 26 genes upregulated in females and 47 genes upregulated in males. Gene ontology analysis found 52 terms enriched for the sex-biased genes in a wide range of pathways suggesting that multiple functions and processes differ between the sexes. We focused on two areas of interest: sex steroids/hormones and circadian rhythms, both of which exhibited sex-bias in gene expression, and are known to influence sexual development in other species. Lastly, the work presented herein contributes to a growing body of genome data available for the Syngnathids, increasing our knowledge on patterns of gene expression in these unusual fishes.

Keywords: Gene expression; Male pregnancy; Syngnathidae; Transcriptome assembly.

MeSH terms

  • Animals
  • Brain / metabolism
  • Female
  • Gene Expression Profiling
  • Gene Expression*
  • Male
  • Sequence Analysis, RNA
  • Sex Factors
  • Smegmamorpha / genetics*
  • Smegmamorpha / metabolism