Variation and Selection in the Putative Sperm-Binding Region of ZP3 in Muroid Rodents: A Comparison between Cricetids and Murines

Genes (Basel). 2021 Sep 20;12(9):1450. doi: 10.3390/genes12091450.

Abstract

In mammals, the zona pellucida glycoprotein 3 (ZP3) is considered a primary sperm receptor of the oocyte and is hypothesized to be involved in reproductive isolation. We investigated patterns of diversity and selection in the putative sperm-binding region (pSBR) of mouse ZP3 across Cricetidae and Murinae, two hyperdiverse taxonomic groups within muroid rodents. In murines, the pSBR is fairly conserved, in particular the serine-rich stretch containing the glycosylation sites proposed as essential for sperm binding. In contrast, cricetid amino acid sequences of the pSBR were much more variable and the serine-rich motif, typical of murines, was generally substantially modified. Overall, our results suggest a general lack of species specificity of the pSBR across the two muroid families. We document statistical evidence of positive selection acting on exons 6 and 7 of ZP3 and identified several amino acid sites that are likely targets of selection, with most positively selected sites falling within or adjacent to the pSBR.

Keywords: Cricetidae; Murinae; female fertilization protein; positive selection; sperm receptor; zona pellucida glycoprotein 3.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arvicolinae / genetics*
  • Binding Sites
  • Exons
  • Genetic Variation
  • Male
  • Murinae / genetics*
  • Phylogeny
  • Rodentia / genetics
  • Selection, Genetic
  • Spermatozoa / metabolism
  • Zona Pellucida Glycoproteins / genetics*
  • Zona Pellucida Glycoproteins / metabolism

Substances

  • Zona Pellucida Glycoproteins