Document Detail

Evidence for spontaneous postlactational estrus in gray short-tailed opossums (Monodelphis domestica).
MedLine Citation:
PMID:  10819788     Owner:  NLM     Status:  MEDLINE    
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.
L M Jackson; J D Harder
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Biology of reproduction     Volume:  62     ISSN:  0006-3363     ISO Abbreviation:  Biol. Reprod.     Publication Date:  2000 Jun 
Date Detail:
Created Date:  2000-08-17     Completed Date:  2000-08-17     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0207224     Medline TA:  Biol Reprod     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1823-7     Citation Subset:  IM    
Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, Ohio 43210, USA.
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MeSH Terms
Body Weight
Estradiol / blood
Estrus / physiology*
Genitalia, Female
Opossums / physiology*
Pheromones / physiology
Time Factors
Reg. No./Substance:
0/Pheromones; 50-28-2/Estradiol

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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