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Beijing, China

Song J.-Z.,China Agricultural University | Xue K.,China Agricultural University | Li S.,Ji Pulin Biotech Ltd. | Li N.,China Agricultural University
Progress in Biochemistry and Biophysics | Year: 2010

Mammary stem cells (MaSCs) is an ideal model for studies of organogenesis, cell proliferation, differentiation, survival and apoptosis. Recent researches showed that many adult stem cell surface markers belonged to cell adhesion molecule (CAM) family. Therefore, analysis of relationship between mammary stem/progenitor cells and the expression pattern of CAM have directive meanings for identifying embryonic mammary stem/progenitor cells and understanding their properties. Here, cells in E14 mouse mammary anlagen were purified using the adult mouse mammary epithelial stem cell (MaESC) markers of CD24 and CD49f. It was found that CD24 and CD49f double-positive cells contain two distinct cell populations: CD24hiCD49f+ and CD24medCD49f +, and their percentages in total mammary anlagen cells were 16% and 47%, respectively. In the following monolayer culture and in vivo transplantation tests, it was found that the CD24medCD49f+ cells could attach plate and regenerate mammary ductal units; correspondingly, CD24hiCD49f+ cells did not possess of these capabilities. These results indicate that the two mammary anlagen cell populations represent different cell types, and CD24medCD49f+ population may contain the self-renewal mammary anlagen stem/progenitor cells. Afterwards, the differences in the expressions of 19 mammary-related CAM transcripts in the two cell populations were validated by quantitative real-time PCR analysis. The data show that the CAM gene expressions of mammary repopulating-CD24 medCD49f+ cells are dramatically different from that of CD24hiCD49f+ cell population. The expressions of several adult stem cell markers in CD24medCD49f+ cell population are remarkable higher than those in CD24hiCD49f+ cell population. Source


Xue K.,China Agricultural University | Song J.,China Agricultural University | Wei H.,China Agricultural University | Chen L.,China Agricultural University | And 6 more authors.
Molecular Reproduction and Development | Year: 2010

As a transcriptional coactivator and acetyltransferase, CREB-binding protein (CBP) is widely characterized due to its functions in cell proliferation and development. However, the activities of CBP in oocyte meiosis are not completely clear. Here we showed that the localization and expression of CBP changed regularly with the progression of porcine oocyte meiosis. The emergence of CBP in chromosomal domains is temporally coincident with the establishments of acetylated lysine 18 (AcH3/K18), lysine 23 (AcH3/K23) and dimethylated arginine 17 (dime-H3/R17) of histone H3 at meiotic stages from germinal vesicle breakdown (GVBD) to metaphase I (MI). Both CBP expression and these three histone modifications persisted to telophase I (TI). When trichostatin A (TSA) was used to enhance histone acetylations in porcine oocytes, we found that hyperacetylations of H3K18 and H3K23 occurred at meiotic stage from GVBD to TI, together with advanced and enhanced expression of CBP in the nucleus. In addition, disturbance of CBP activity by treatment with 2-Naphthol-AS-Ephosphate (KG-501, a drug targeting the KIX domain of CBP that disrupts the formation of CBP functional complex) led to synchronous decreases of CBP expression, AcH3/K18 and AcH3/K23 in chromosomal domains during oocyte meiosis. Therefore, these results indicate that the synchronous changes of CBP expression, AcH3/K18 and AcH3/K23 occur during porcine oocyte meiosis. © 2010 Wiley-Liss, Inc. Source


Chen L.,China Agricultural University | Hu X.,China Agricultural University | Dai Y.,Ji Pulin Biotech Ltd. | Li Q.,China Agricultural University | And 8 more authors.
Frontiers in Bioscience - Elite | Year: 2012

MicroRNAs (miRNAs) are a class of small noncoding RNAs involved in multiple cellular processes. Recent findings indicate that miRNA activity is globally suppressed in mouse oocytes. However, whether miRNAs are expressed and function in porcine oocytes remains unknown. In this study, our aims were to ascertain if miRNA biogenesis occurs and whether miRNA activity is globally suppressed during porcine oocyte maturation. First, to identify if miRNA biogenesis occurred, a TaqMan low-density array containing 365 mature human miRNAs was used to examine miRNA expression. This analysis revealed dynamic changes in miRNA expression, suggesting miRNA biogenesis during porcine oocyte maturation. Then, to identify if miRNA activity was globally suppressed in porcine oocytes, we focused on miR-27a, which functions in the cell cycle. miR-27a was found to facilitate the first cleavage and repress the translation of its messenger RNA target (MAP2K4), suggesting that miR-27a activity was not suppressed in porcine oocytes. Taken together, our results suggest that miRNA activity was not globally suppressed in porcine oocytes, at least for miR-27a. However, because we only investigated the activity of miR-27a, further experiments are definitely required to ascertain this point. Source

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