Outbred embryos rescue inbred half-siblings in mixed-paternity broods of live-bearing females

Females commonly mate with more than one male, and polyandry has been shown to increase reproductive success in many species. Insemination by multiple males shifts the arena for sexual selection from the external environment to the female reproductive tract, where sperm competition or female choice...

Full description

Saved in:

Bibliographic Details
Published in:	Nature 2006-01, Vol.439 (7073), p.201-203
Main Authors:	Zeh, Jeanne A, Zeh, David W
Format:	Article
Language:	eng
Subjects:	Animal and plant ecology Animal behavior Animal reproduction Animal, plant and microbial ecology Animals Arachnida - genetics Arachnida - physiology Autoecology Biological and medical sciences Breeding Embryo, Nonmammalian - physiology Embryos Fathers Female Fertilization - physiology Fundamental and applied biological sciences. Psychology Inbreeding Male Minisatellite Repeats - genetics Panama Protozoa. Invertebrata Pseudoscorpiones Siblings Spermatozoa - cytology Spermatozoa - physiology Viviparity, Nonmammalian - physiology
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Females commonly mate with more than one male, and polyandry has been shown to increase reproductive success in many species. Insemination by multiple males shifts the arena for sexual selection from the external environment to the female reproductive tract, where sperm competition or female choice of sperm could bias fertilization against sperm from genetically inferior or genetically incompatible males. Evidence that polyandry can be a strategy for avoiding incompatibility comes from studies showing that inbreeding cost is reduced in some egg-laying species by postcopulatory mechanisms that favour fertilization by sperm from unrelated males. In viviparous (live-bearing) species, inbreeding not only reduces offspring genetic quality but might also disrupt feto-maternal interactions that are crucial for normal embryonic development. Here we show that polyandry in viviparous pseudoscorpions reduces inbreeding cost not through paternity-biasing mechanisms favouring outbred offspring, but rather because outbred embryos exert a rescuing effect on inbred half-siblings in mixed-paternity broods. The benefits of polyandry may thus be more complex for live-bearing females than for females that lay eggs.
ISSN:	0028-0836 1476-4687 1476-4679