title: Induction of Ski Protein Expression upon Luteinization in Rat Granulosa Cells.
abstract: Ski protein is implicated in proliferation/differentiation in a variety of cells. We had previously reported that Ski protein is present in granulosa cells of atretic follicles, but not in preovulatory follicles, suggesting that Ski has a role in apoptosis of granulosa cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells; however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of the present study was to locate Ski protein in the rat ovary during luteinizationto predict the possible role of Ski. In order to examine the expression pattern of Ski protein along with the progress of luteinization, follicular growth was induced by administration of equine chorionic gonadtropin to immature female rats, and luteinization was induced by human chorionic gonadtropin treatment to mimic luteinizing hormone (LH) surge. While no Ski-positive granulosa cells were present in preovulatory follicle, Ski protein expression was induced in response to LH surge, and was maintained after the formation of the corpus luteum (CL). Though Ski protein is absent in granulosa cells of preovulatory follicle, its mRNA (c-Ski) was expressed and the level was unchanged even after LH surge. Taken together, these results demonstrated that Ski protein expression is induced in granulosa cells upon luteinization, and suggests that its expression is regulated post-transcriptionally.
authors: Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan ; Animal Genetic Resources Station, National Institute of Animal Science, RDA, Namwon 590-832, Korea.
authors: Hyun
authors: H
authors: Kim
authors: Animal Genetic Resources Station, National Institute of Animal Science, RDA, Namwon 590-832, Korea.
authors: Dong Hun
authors: DH
authors: Kim
authors: Animal Genetic Resources Station, National Institute of Animal Science, RDA, Namwon 590-832, Korea.
authors: Soo Bong
authors: SB
authors: Park
authors: Animal Genetic Resources Station, National Institute of Animal Science, RDA, Namwon 590-832, Korea.
authors: Yeoung-Gyu
authors: YG
authors: Ko
authors: Animal Genetic Resources Station, National Institute of Animal Science, RDA, Namwon 590-832, Korea.
authors: Sung-Woo
authors: SW
authors: Kim
authors: Animal Genetic Resources Station, National Institute of Animal Science, RDA, Namwon 590-832, Korea.
authors: Yoon Jun
authors: YJ
authors: Do
authors: Animal Genetic Resources Station, National Institute of Animal Science, RDA, Namwon 590-832, Korea.
authors: Jae-Hong
authors: JH
authors: Park
authors: Korean Native Cattle Experiment Station, National Institute of Animal Science, RDA, Pyeongchang 232-952, Korea.
authors: Boh-Suk
authors: BS
authors: Yang
keywords: Arkadia; Granulosa Cells; Luteinization; Ski