Document Detail

Early embryo development in the elephant assessed by serial ultrasound examinations.
MedLine Citation:
PMID:  18387665     Owner:  NLM     Status:  MEDLINE    
The elephant has an extraordinary long pregnancy, lasting 21 months. However, knowledge on embryo development is limited. To date, only single morphological observations of elephant embryo development associated with placentation are available, all lacking correlation to gestational age. The present study describes morphological characteristics of early embryo development in the elephant with exact biometric staging. Six pregnancies in five Asian and one African elephants with known conception dates were followed by 2D and 3D ultrasound, covering the embryonic period from ovulation to day 116 post-ovulation. The embryonic vesicle was earliest observed was on day 50 p.o. The proper embryo was not detected until day 62 p.o. Embryonic heartbeat was first observed on day 71 p.o. The allantois, which became visible as a single sacculation on day 71 p.o. was subdivided in four compartments on day 76 p.o. By day 95 p.o., head, rump, front and hind legs were clearly distinguished. Between days 95 and 103 p.o. the choriovitelline placenta was replaced by the chorioallantoic placenta. A physiological midgut herniation was transiently present between days 95 and 116 p.o. On the basis of the late appearance of the embryonic vesicle, delayed implantation in the elephant is discussed. The study provides a coherent description of elephant embryonic development, formation of the extraembryonic organs and their role in placenta formation, all of which are of interest for both comparative evolutionary studies and the improvement of assisted reproduction techniques.
B Drews; R Hermes; F Göritz; C Gray; J Kurz; I Lueders; T B Hildebrandt
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2008-04-02
Journal Detail:
Title:  Theriogenology     Volume:  69     ISSN:  0093-691X     ISO Abbreviation:  Theriogenology     Publication Date:  2008 Jun 
Date Detail:
Created Date:  2008-05-05     Completed Date:  2008-11-04     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0421510     Medline TA:  Theriogenology     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1120-8     Citation Subset:  IM    
Leibniz Institute for Zoo- and Wildlife Research, PF 601 103, 10252 Berlin, Germany.
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MeSH Terms
Elephants / embryology*
Embryo, Mammalian / ultrasonography*
Gestational Age
Placenta / growth & development,  ultrasonography
Pregnancy, Animal / physiology*
Retrospective Studies
Uterus / anatomy & histology,  physiology,  ultrasonography

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