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) All Versions of this Article: 75/1/122    most recent biolreprod.106.051581v1 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 Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Constant, F. Articles by Chavatte-Palmer, P. Search for Related Content PubMed PubMed Citation Articles by Constant, F. Articles by Chavatte-Palmer, P. Agricola Articles by Constant, F. Articles by Chavatte-Palmer, P.

Large Offspring or Large Placenta Syndrome? Morphometric Analysis of Late Gestation Bovine Placentomes from Somatic Nuclear Transfer Pregnancies Complicated by Hydrallantois

INRA,² UMR INRA-CNRS-ENVA, Biologie du Développement et Reproduction, 78352 Jouy-en-Josas, France UCEA,³ 91630 Bressonvilliers, France

ABSTRACT

Somatic nuclear transfer (NT) in cattle is often complicated by fetal oversize (i.e., large offspring syndrome), hydrallantois, and placentomegaly in late gestation. The aims of this work were to obtain data on the placentome structure in NT-recipient cows with hydrallantois (NTH) and to relate these with fetal and placental weights to better understand the abnormalities observed in NTH pregnancies during the third trimester. Pregnant cows were slaughtered between Gestation Days 180 and 280. The fetuses were weighed, and the placentomes were numbered and weighed. Placentomes were examined by histologic and stereological techniques. Macroscopic data showed that placental overgrowth preceded fetal overgrowth, and the ratio of the fetal to the total placentome weight in the NTH group was lower than that in controls after Gestation Day 220. This suggests that placental overgrowth is due to placental default rather than due to fetal overgrowth, as shown also by stereological analysis showing primary deregulation of the growth of cotyledonary tissues. Observed alterations, such as thinning of the maternal epithelium within placentomes and increased trophoblastic surface, could be secondary adaptations. Thus, placental growth deregulations would be due to modifications of the expression of placental factors. Various examples of placental deficiency were observed, suggesting that some fetal abnormalities observed in NTH calves, such as enlarged heart, enlarged umbilical cord, and abdominal ascites, are consequences of placental dysfunction. Therefore, the condition described by the term "large offspring syndrome" might better be described by "large placenta syndrome," because this syndrome affects an average of 50% of late-gestation NT pregnancies. No conclusion can be drawn from this work on apparently normal pregnancies.

assisted reproductive technology, conceptus, developmental biology, placenta, pregnancy

¹ Correspondence: M. Guillomot, INRA, UMR Biologie du Développement et Reproduction N°1198, Bât. 440, Domaine de Vilvert, 78 352 Jouy-en-Josas, France. FAX: 33 1 34652364; michel.guillomot{at}jouy.inra.fr

This article has been cited by other articles:

				R. E. Everts, P. Chavatte-Palmer, A. Razzak, I. Hue, C. A. Green, R. Oliveira, X. Vignon, S. L. Rodriguez-Zas, X. C. Tian, X. Yang, et al. Aberrant gene expression patterns in placentomes are associated with phenotypically normal and abnormal cattle cloned by somatic cell nuclear transfer Physiol Genomics, March 10, 2008; 33(1): 65 - 77. [Abstract] [Full Text] [PDF]

				S L Rodriguez-Zas, K Schellander, and H A Lewin Biological interpretations of transcriptomic profiles in mammalian oocytes and embryos Reproduction, February 1, 2008; 135(2): 129 - 139. [Abstract] [Full Text] [PDF]

				C J Fletcher, C T Roberts, K M Hartwich, S K Walker, and I C McMillen Somatic cell nuclear transfer in the sheep induces placental defects that likely precede fetal demise Reproduction, January 1, 2007; 133(1): 243 - 255. [Abstract] [Full Text] [PDF]