Submission Number: CHR-4-35-14

Abstract Number: 395

HAPTOGLOBIN IS EXPRESSED IN BOVINE REPRODUCTIVE TISSUES.

Christoph Gabler*, Karen Lavery and Gary J Killian*

The J. O. Almquist Research Center, The Pennsylvania State University, University Park, PA ¹

Abstract:
Haptoglobin (Hp) is an acute phase protein existing in three major phenotypic forms composed of alpha and beta chains. The aims of this study were to isolate and sequence bovine Hp cDNA and to examine the expression of Hp mRNA in the organs of the bovine female reproductive tract: ovary, oviduct and uterus. The organs were collected at the slaughterhouse, the ovary and the endometrium were snap-frozen and the oviducts were flushed to harvest mainly oviductal epithelial cells. Degenerated primers were designed and used in RT-PCR to amplify a 302 bp segment of bovine Hp beta subunit cDNA. This PCR product showed 81.8 % homology to the human Hp and 75.8 % homology to the mouse Hp gene. However, only a low homology of the deduced amino acid sequence of 78 % to the human and 76 % to the mouse protein were noted. Total RNA was extracted from the ovary, endometrium and oviductal epithelial cells and subjected to semi-quantitative RT-PCR. We examined the expression pattern of Hp mRNA during different estrous cycle phases. Highest expression was detected in the oviduct after ovulation (d 1-5 and d 6-12) compared with the late luteal phase (d 13-18) or before ovulation (d 19-21). Expression of Hp was detected in the ovary and the endometrium during both the luteal and pre-ovulatory phases. We conclude that the ovary, oviduct and endometrium synthesize Hp and that a cycle-dependant regulation of HP occurs in the oviduct. These results suggest that the multifunction-protein haptoglobin is regulated by hormonal changes within the oviduct and may play an import role in creating the optimal conditions for fertilization and early embryo development in the bovine reproductive tract. (Supported by USDA grant 96-35203-3428 and NIH Training Grant # GM 08619).

Keywords: Haptoglobin, oviduct, endometrium, ovary

This abstract is being presented at: 8:00 AM in session:
Uterus/Oviduct I