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

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal My Folders Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Jackson, L. M. Articles by Harder, J. D. Search for Related Content PubMed PubMed Citation Articles by Jackson, L. M. Articles by Harder, J. D. Agricola Articles by Jackson, L. M. Articles by Harder, J. D.

Evidence for Spontaneous Postlactational Estrus in Gray Short-Tailed Opossums (Monodelphis domestica)¹

^a Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, Ohio 43210

Previous studies of the gray short-tailed opossum have shown that ovarian activity and estrus are induced by male pheromones, but we recently documented urogenital sinus (UGS) estrus in postlactational females despite their isolation from the male stimuli known to be associated with induced estrus. Body weights and UGS smears were collected after removal of pups in midlactation (19–37 days postpartum), after weaning (55–61 days postpartum), or after pheromone exposure. Estradiol was measured by RIA in plasma samples collected from dams during lactation, after separation from pups, and at estrus. Average days to UGS estrus from pup removal or initial pheromone exposure differed (P < 0.05) only between the midlactation and pheromone exposure groups. Postlactational females showed a decrease in body weight from the time of pup removal or weaning to estrus, which contrasts with the increase seen in pheromonally stimulated females. Plasma estradiol was elevated at estrus in all groups, and females that were paired with males at postlactational estrus mated and produced litters. This study demonstrates that gray short-tailed opossums consistently experience estrus within 2 wk of weaning their young and that postlactational estrus appears to be hormonally and behaviorally equivalent to estrus induced by direct exposure to male pheromones.

First decision: 19 January 2000.

¹ This work was supported by NSF grant IBN9616588 and The Ohio State University.

² Correspondence: John D. Harder, Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, 1735 Neil Ave., Columbus, OH 43210. FAX: 614 292 2030; harder.2{at}osu.edu

This article has been cited by other articles:

				P. B. Samollow The opossum genome: Insights and opportunities from an alternative mammal Genome Res., August 1, 2008; 18(8): 1199 - 1215. [Abstract] [Full Text] [PDF]