HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Eisen, E. J. Search for Related Content PubMed PubMed Citation Articles by Eisen, E. J.

Genetic and Phenotypic Factors Influencing Sexual Maturation of Female Mice^{1, 2,}

North Caroline State University, Raleigh 27607

Abstract

Genetic and phenotypic influences on age at sexual maturation were examined in weanling (3 weeks) female mice paired continuously with either an adult virgin or non-virgin male. Age at sexual maturation, as measured by the first vaginal plug was not influenced by the previous sexual experience of the male. When compared with females already sexually mature (70.22 ± 4.56 days of age) at pairing with an adult male, no significant differences were found in percent females littering, number born, number born alive and progeny birth weight. Young females had a significantly (P < .01) lower percent born alive than the controls (96.0 vs. 99.0). The distribution of age at vaginal plug was decidedly non-normal in the young females with a mean of 29.59±4.53 days. Age at vaginal plug decreased linearly with increased weaning weight and increased quadratically with increased weight at vaginal plug. There was a negative quadratic relationship between age at vaginal plug and gain per day from weaning to vaginal plug. The regressions of number born alive (and of progeny birth weight) on female body weights at weaning and at parturition were positive and of about the same magnitude. Age at vaginal plug had no significant influence on number born alive or weaning weight. Paternal half-sib heritability estimates for age at vaginal plug, weight at vaginal plug, weight gain from weaning to vaginal plug, gain per day and number born alive were 0.13, 0.35, 0.16, -.10 and 0.16, respectively. Maternal effects had a small influence on age and weight at vaginal plug. The genetic correlations between weight at vaginal plug and weaning weight, gain and number born, respectively, were positive.

¹ Paper No. 4000 of the Journal Series of the North Carolina State University Agricultural Experiment Station, Raleigh.

² The technical assistance of Billie Jean Edwards is greatly appreciated.