Abstract

The role of maternal care in mediating variation in offspring phenotype has been examined in the rat and demonstrates that mother–infant interactions are critical for inducing long-term changes in behavior. Though phenotypic differences between mice strains are often attributed to genetic factors, the influence of early maternal environment has not been extensively explored. To understand maternal influence on phenotype in mice, we must first explore the nature of differences in behavior. In the present study, we examine aspects of maternal care differentiating mice strains and explore the relationship between postpartum behavior and measures obtained by a standard test of maternal responsivity (Retrieval Test). We compared inbred 129Sv ( n = 25), C57BL/6J ( n = 23), and outbred Swiss ( n = 23) lactating female mice. Swiss females had shorter latencies to retrieve and crouch over pups ( P < .01), whereas 129Sv females had shorter latencies to nestbuild ( P < .05). Conversely, observations of homecage behavior indicate that 129Sv females nestbuild less frequently. 129Sv females also engaged in very low levels of pup licking/grooming ( P < .001) and long periods of nursing/contact ( P < .05) with pups compared to C57BL/6J and Swiss females. Temporal analysis suggests that the magnitude of these differences varies both within and between days. No significant correlations were found between any aspect of maternal responsivity and postpartum behavior. These results illustrate that through detailed analysis of maternal behavior in mice, variations between strains can be observed. These variations represent strain specific strategies for promoting growth and survival of offspring during infancy that may also mediate “epigenetic” differences in phenotype in adulthood.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.