Tara L. McLaughlin1,2, & Benson E. Ginsburg1
Previous research in our laboratory has focused on strain differences in male sexual behavior and has explored their influence on the occurrence of pregnancy block in newly inseminated females (T.L.McLaughlin and Benson E. Ginsburg,1997,Behav.Genet.26,300). DBA1/J males have been observed to induce higher levels of pregnancy block, elicit greater levels of female defecation and vocalization and display higher levels of attempted mounts than have C57BL6/J males. The present study extends this line of research by examining the role that the Y chromosome may play in these strain differences. Males of the DBA1/c and DBA1/c x DBA1/c.C57BL10 Y congenic strains were tested for their ability to induce pregnancy block and were observed in dyadic encounters with newly inseminated females. Males of these strains, unlike DBA and C57 males, did not differ on any of the behavioral measures. Further, the results suggest that Y-chromosomal differences within Mus musculus may not be sufficient to induce pregnancy block, as measured in this study. These observations, when considered in light of the previously described strain differences between DBA and C57 males, suggest that male behaviors may interact with olfactory cues to influence the occurrence of pregnancy block. The contribution that the Mus musculus Y chromosome makes to this interaction may be too subtle to measure using the present paradigm.
Address: Department of Psychiatry, Washington University School of Medicine, 40 North Kingshighway #1, St. Louis, MO. 63108 Ph:314-286-2302, Fax:314-286-2213 Email:Tara@matlock.wustl.edu
1Biobehavioral Sciences Graduate Degree Program, University of Connecticut, Storrs,CT 06269. 2Currently with the Department of Psychiatry, Washington University School of Medicine, St.Louis, MO 63108. 3Supported in part by a Sigma Psi Grant-in-Aid-of-Research.