Open AccessArtificial selection and heritability of sperm length in Gryllus bimaculatus
Author(s) -
Morrow Edward H.,
Gage Matthew J. G.
Publication year - 2001
Publication title -
heredity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.441
H-Index - 118
eISSN - 1365-2540
pISSN - 0018-067X
DOI - 10.1046/j.1365-2540.2001.00921.x
Subject(s) - biology , heritability , gryllus bimaculatus , sperm , genetics , trait , offspring , field cricket , evolutionary biology , selection (genetic algorithm) , cricket , genetic variation , quantitative trait locus , zoology , gene , pregnancy , artificial intelligence , computer science , programming language
The adaptive significance of variation in sperm size remains poorly understood but there has been even less attention focused on the genetic mechanisms controlling spermatozoal traits (only three species have been studied). Here we explore heritability and artificial selection of sperm length in the cricket Gryllus bimaculatus . Using a within‐family selection design we selected sperm with increasing and decreasing sperm size and bred divergence across five generations. Although we recorded no significant parent–offspring heritability, realized heritability from a within‐family analysis was significant at 0.52 ± 0.06 SE ( P = 0.01) and we successfully achieved significant divergence. However, we only achieved a response when the maternal line was incorporated into selection (from the F 1 onwards) and our findings therefore suggest that sperm length in G. bimaculatus is a sex‐linked trait that is influenced by genes which are active on the female chromosome. Accordingly, sperm length heritability in G. bimaculatus can only be measured using a within‐family design because the spermatozoal phenotype is sex‐limited (to males) while the genotype is sex‐linked (to females). The evolutionary significance of the heritability of sperm length is discussed with reference to sex‐linkage of this important sex‐limited trait.