Expression of cyclin-dependent kinase inhibitors (CDKN1, CDKN5) in developmentally competent and incompetent porcine oocytes.

Although several reports have been published regarding the cyclin-dependent kinases (Cdks) in developmentally competent mammalian oocytes, still little is known about their expression pattern in develop - P < 0.001, P < 0.01, respectively). An increased CDKN5 mRNA level was observed in BCB + oocytes (Group III) compared to oocytes of Group I and Group II ( P < 0.01), respectively. The mRNA expression of both genes was always higher in BCB + compared to BCB - oocytes. Based on this study it can be supposed that CDKN1 and CDKN5 are differentially expressed in developmentally distinct porcine oocytes and in a maturation stage-dependent manner. Moreover, CDKN1 may play a role as a molecule which regulates cell cycle arrest and the specific "block of maturation" from MI to MII.