The phenotypic correlates and quantitative genetics of masculinization in the rodent, Octodon degus

D. A. Roff*, M. E. Wolak, L. A. Correa, M. Soto-Gamboa

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


In some mammals, female characteristics have been shown to depend, in part, on the intrauterine position during development of female fetuses relative to male fetuses. Females developing in close proximity to males show behavioral, physiological and life history characteristics that are masculinized. With the exception of one inconclusive study, nothing is known of the genetic basis of this phenomenon. In this paper, we reported an analysis of the quantitative genetic basis of masculinization, as indicated by the anogenital distance (AGD) at birth and weaning, in the rodent Octodon degus. Because AGD is related to weight, we included a genetic analysis of pup weight at birth and weaning. Pairwise correlations showed that AGD at birth varied negatively with litter size and parturition number but positively with weaning AGD, birth weight, dam AGD and percentage of males in the litter. AGD at weaning varied similarly except that it tended to vary positively with litter size. Genetic (co)variances of AGD at birth and weight at birth differed in females and males. In females, the best genetic model included substantial effects of direct additive, additive maternal and a negative additive genetic covariance between these two. In males, variances were small and there was difficulty in discriminating between additive maternal and common environmental variances. By weaning, genetic (co)variances had somewhat declined in weight and were not statistically significant in AGD in either sex. This paper showed the occurrence of both phenotypic and genetic components in masculinization with effects being greater in females.

Original languageEnglish
Pages (from-to)136-141
Number of pages6
Issue number3
Early online date12 Apr 2017
Publication statusPublished - 1 Sept 2017

Bibliographical note

Funding Information:
This study was funded in part by FONDECYT grant 10900302 (to MS-G) and a CONICYT Fellowship (to LAC).

Publisher Copyright:
© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.


Dive into the research topics of 'The phenotypic correlates and quantitative genetics of masculinization in the rodent, Octodon degus'. Together they form a unique fingerprint.

Cite this