Exp Clin Endocrinol Diabetes 2008; 116(3): 158-161
DOI: 10.1055/s-2007-992121
Article

© J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York

Molecular Cloning and Expression of StAR Protein in the Canine Corpus Luteum During Dioestrus

M. P. Kowalewski 1 , B. Hoffmann 1
  • 1Clinic for Obstetrics, Gynecology and Andrology of Large and Small Animals, Justus-Liebig-University Giessen, Giessen, Germany
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Publikationsverlauf

received 20.04.2007 first decision 04.07.2007

accepted 02.10.2007

Publikationsdatum:
20. Dezember 2007 (online)

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Abstract

Expression of the steroidogenic acute regulatory protein (StAR) in the canine corpus luteum (CL) was examined throughout the luteal phase covering the periods of CL formation, early and late regression. Following a homology cloning and characterization of a cDNA fragment of the canine StAR spanning the sequence coding for the open reading frame (ORF), which encodes a 286 amino acid protein being highly conserved (86-91%) between species, quantitative RT-PCR was performed with the respective primers. Expression of StAR was demonstrated on all days examined; mRNA-levels increased gradually in developing CL from day 5 until 25; a steep, 4-fold downregulation was observed on day 35 with a further gradual decrease thereafter. Similar data were obtained by immunohistochemistry and the effect of time was highly significant (p<0.0001). These data suggest that the progesterone production during the canine CL-phase is controlled by the provision of substrate at the level of cholesterol transfer to the inner mitochondrial membrane, a step which involves the StAR-protein activity.

References

Correspondence

Prof. Dr. Dr.h.c. B. Hoffmann

Clinic for Obstetrics

Gynecology and Andrology of Large and Small Animals

Justus-Liebig-University Giessen

Frankfurter Strasse 106

35392 Giessen

Germany

Telefon: +49/641/993 87 04

Fax: +49/641/293 28

eMail: Bernd.Hoffmann@vetmed.uni-giessen.de