A Test of Haldane’s Rule in Neodiprion Sawflies and Implications for the Evolution of Postzygotic Isolation in Haplodiploids

Emily E. Bendall, Kayla M. Mattingly, Amanda J. Moehring, Catherine R. Linnen

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Haldane’s rule—a pattern in which hybrid sterility or inviability is observed in the heterogametic sex of an interspecific cross— is one of the most widely obeyed rules in nature. Because inheritance patterns are similar for sex chromosomes and haplodiploid genomes, Haldane’s rule may apply to haplodiploid taxa, predicting that haploid male hybrids will evolve sterility or inviability before diploid female hybrids. However, there are several genetic and evolutionary mechanisms that may reduce the tendency of haplodiploids to obey Haldane’s rule. Currently, there are insufficient data from haplodiploids to determine how frequently they adhere to Haldane’s rule. To help fill this gap, we crossed a pair of haplodiploid hymenopteran species (Neodiprion lecontei and Neodiprion pinetum) and evaluated the viability and fertility of female and male hybrids. Despite considerable divergence, we found no evidence of reduced fertility in hybrids of either sex, consistent with the hypothesis that hybrid sterility evolves slowly in haplodiploids. For viability, we found a pattern opposite to that of Haldane’s rule: hybrid females, but not males, had reduced viability. This reduction was most pronounced in one direction of the cross, possibly due to a cytoplasmic-nuclear incompatibility. We also found evidence of extrinsic postzygotic isolation in hybrids of both sexes, raising the possibility that this form or reproductive isolation tends to emerge early in speciation in host-specialized insects. Our work emphasizes the need for more studies on reproductive isolation in haplodiploids, which are abundant in nature but underrepresented in the speciation literature.

Original languageEnglish
Pages (from-to)40-54
Number of pages15
JournalAmerican Naturalist
Volume202
Issue number1
DOIs
StatePublished - Jul 1 2023

Bibliographical note

Publisher Copyright:
© 2023 The University of Chicago. All rights reserved.

Keywords

  • arrhenotoky
  • dominance theory
  • faster-X theory
  • haplodiploidy
  • intrinsic postzygotic isolation
  • speciation

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

Fingerprint

Dive into the research topics of 'A Test of Haldane’s Rule in Neodiprion Sawflies and Implications for the Evolution of Postzygotic Isolation in Haplodiploids'. Together they form a unique fingerprint.

Cite this