Document Detail


Gestating for 22 months: luteal development and pregnancy maintenance in elephants.
MedLine Citation:
PMID:  22719030     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The corpus luteum, a temporally established endocrine gland, formed on the ovary from remaining cells of the ovulated follicle, plays a key role in maintaining the early mammalian pregnancy by secreting progesterone. Despite being a monovular species, 2-12 corpora lutea (CLs) were found on the elephant ovaries during their long pregnancy lasting on average 640 days. However, the function and the formation of the additional CLs and their meaning remain unexplained. Here, we show from the example of the elephant, the close relationship between the maternally determined luteal phase length, the formation of multiple luteal structures and their progestagen secretion, the timespan of early embryonic development until implantation and maternal recognition. Through three-dimensional and Colour Flow ultrasonography of the ovaries and the uterus, we conclude that pregnant elephants maintain active CL throughout gestation that appear as main source of progestagens. Two LH peaks during the follicular phase ensure the development of a set of 5.4 ± 2.7 CLs. Accessory CLs (acCLs) form prior to ovulation after the first luteinizing hormone (LH) peak, while the ovulatory CL (ovCL) forms after the second LH peak. After five to six weeks (the normal luteal phase lifespan), all existing CLs begin to regress. However, they resume growing as soon as an embryo becomes ultrasonographically apparent on day 49 ± 2. After this time, all pregnancy CLs grow significantly larger than in a non-conceptive luteal phase and are maintained until after parturition. The long luteal phase is congruent with a slow early embryonic development and luteal rescue only starts 'last minute', with presumed implantation of the embryo. Our findings demonstrate a highly successful reproductive solution, different from currently described mammalian models.
Authors:
Imke Lueders; Cheryl Niemuller; Peter Rich; Charlie Gray; Robert Hermes; Frank Goeritz; Thomas B Hildebrandt
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2012-06-20
Journal Detail:
Title:  Proceedings. Biological sciences / The Royal Society     Volume:  279     ISSN:  1471-2954     ISO Abbreviation:  Proc. Biol. Sci.     Publication Date:  2012 Sep 
Date Detail:
Created Date:  2012-08-13     Completed Date:  2013-01-09     Revised Date:  2013-10-11    
Medline Journal Info:
Nlm Unique ID:  101245157     Medline TA:  Proc Biol Sci     Country:  England    
Other Details:
Languages:  eng     Pagination:  3687-96     Citation Subset:  IM    
Affiliation:
Leibniz-Institute of Zoo- und Wildlife Research, Reproduction Management, 10315 Berlin, Germany. imke.lueders@gmail.com
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MeSH Terms
Descriptor/Qualifier:
Animals
Corpus Luteum / physiology*,  ultrasonography
Elephants / physiology*
Estrous Cycle / physiology*
Female
Follicular Phase
Immunoenzyme Techniques
Luteal Phase
Luteinizing Hormone / blood,  urine
Pregnancy
Pregnancy, Animal*
Progestins / blood,  urine
Species Specificity
Time Factors
Video Recording
Chemical
Reg. No./Substance:
0/Progestins; 9002-67-9/Luteinizing Hormone
Comments/Corrections

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


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