title: Detection of the hyaluronan receptor CD44 in the bovine oviductal epithelium.
abstract: Hyaluronan is involved in fundamental reproductive events such as sperm storage in the female reproductive tract, fertilization, and early embryo development, these functions are presumably mediated by its major cell surface receptor, CD44. The present study was conducted to investigate the presence and localization of CD44 in the bovine oviductal epithelium, using immunohistochemical and Western blot methods on tissue sections and epithelial cell extracts collected from the uterotubal junction (UTJ), isthmus, and ampulla of animals in the oestrus or luteal phase of the oestrous cycle. While positive immunolabelling for CD44 was found on the ad-luminal surface and supra-nuclear region of epithelial cells in all tubal segments investigated, in the UTJ, there were epithelial cells in which the entire cytoplasm positively stained. We found no differences in terms of CD44-positive staining between the different stages of the oestrous cycle. Presence of CD44 was detected by Western blotting in the tubal epithelium as a single band at 200 kDa. Although it appeared in all tubal segments, the expression of CD44 protein was more accentuated in the sperm reservoir (UTJ) than in the other segments. This is the first time CD44 has been detected in the epithelium of the tubal sperm reservoir in cattle, suggesting a pathway for the action of hyaluronan in this segment.
authors.affiliation: Division of Comparative Reproduction, Obstetrics and Udder Health, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Sciences, SLU, Uppsala, Sweden. ann-sofi.bergqvist@kv.slu.se
authors.forename: Ann-Sofi
authors.initials: AS
authors.lastname: Bergqvist
authors.forename: Masaki
authors.initials: M
authors.lastname: Yokoo
authors.forename: Renée
authors.initials: R
authors.lastname: Båge
authors.forename: Eimei
authors.initials: E
authors.lastname: Sato
authors.forename: Heriberto
authors.initials: H
authors.lastname: Rodríguez-Martínez
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002417:Cattle; D004847:Epithelial Cells / Q000166:cytology*; D004848:Epithelium / Q000378:metabolism; D030762:Estrous Cycle; D005260:Female; D018960:Hyaluronan Receptors / Q000096:biosynthesis*; D006820:Hyaluronic Acid / Q000737:chemistry; D007150:Immunohistochemistry; D010057:Oviducts / Q000378:metabolism*; D014599:Uterus / Q000378:metabolism
chemical_list: D018960:Hyaluronan Receptors; D006820:Hyaluronic Acid