Genetic patterns of paternity and testes size in mammals

Soulsbury, Carl D. (2010) Genetic patterns of paternity and testes size in mammals. PLoS One, 5 (3). e9581. ISSN 1932-6203

Documents
Soulsbury_2010_(Testes_mass).pdf
pdf of manuscript
[img]
[Download]
[img]
Preview
PDF
Soulsbury_2010_(Testes_mass).pdf - Whole Document

208Kb

Official URL: http://dx.doi.org/10.1371/journal.pone.0009581

Abstract

Background: Testes size is used as a proxy of male intrasexual competition, with larger testes indicative of greater competition. It has been shown that in some taxa, social mating systems reflect variance in testes size, but results are not consistent, and instead it has been suggested that genetic patterns of mating may reflect testes size. However, there are different measures of genetic patterns of mating. Multiple paternity rates are the most widely used measure but are limited to species that produce multi-offspring litters, so, at least for group living species, other measures such as loss of paternity to males outside the social group (extra group paternity) or the proportion of offspring sired by the dominant male (alpha paternity) might be appropriate. This study examines the relationship between testes size and three genetic patterns of mating: multiple paternity, extragroup paternity and alpha paternity.

Methodology/Principal Findings: Using data from mammals, phylogenetically corrected general linear models
demonstrate that both multiple paternity and alpha paternity, but not extra group paternity, relate to testes size. Testes size is greater in species with high multiple paternity rates, whereas the converse is found for alpha paternity. Additionally, length of mating season, ovulation mode and litter size significantly influenced testes size in one model.

Conclusions/Significance: These results demonstrate that patterns of mating (multiple paternity and alpha paternity rates) determined by genetic analysis can provide reliable indicators of male postcopulatory intrasexual competition (testes size), and that other variables (length of mating season, ovulation mode, litter size) may also be important.

Item Type:Article
Additional Information:Background: Testes size is used as a proxy of male intrasexual competition, with larger testes indicative of greater competition. It has been shown that in some taxa, social mating systems reflect variance in testes size, but results are not consistent, and instead it has been suggested that genetic patterns of mating may reflect testes size. However, there are different measures of genetic patterns of mating. Multiple paternity rates are the most widely used measure but are limited to species that produce multi-offspring litters, so, at least for group living species, other measures such as loss of paternity to males outside the social group (extra group paternity) or the proportion of offspring sired by the dominant male (alpha paternity) might be appropriate. This study examines the relationship between testes size and three genetic patterns of mating: multiple paternity, extragroup paternity and alpha paternity. Methodology/Principal Findings: Using data from mammals, phylogenetically corrected general linear models demonstrate that both multiple paternity and alpha paternity, but not extra group paternity, relate to testes size. Testes size is greater in species with high multiple paternity rates, whereas the converse is found for alpha paternity. Additionally, length of mating season, ovulation mode and litter size significantly influenced testes size in one model. Conclusions/Significance: These results demonstrate that patterns of mating (multiple paternity and alpha paternity rates) determined by genetic analysis can provide reliable indicators of male postcopulatory intrasexual competition (testes size), and that other variables (length of mating season, ovulation mode, litter size) may also be important.
Keywords:testes size, paternity, mating systems, sperm competition
Subjects:C Biological Sciences > C120 Behavioural Biology
Divisions:College of Science > School of Life Sciences
ID Code:6477
Deposited By: Carl Soulsbury
Deposited On:08 Oct 2012 22:06
Last Modified:04 Dec 2013 15:04

Repository Staff Only: item control page