Xiang Wanyi, MacLaren Leslie A
Department of Plant and Animal Sciences, Nova Scotia Agricultural College, Truro, Nova Scotia, Canada B2N 5E3.
Biol Reprod. 2002 Jun;66(6):1790-6. doi: 10.1095/biolreprod66.6.1790.
The superficial placentation of cattle involves the development of fetal binucleate cells that arise from the chorion and migrate between adjacent cell tight junctions to fuse with maternal epithelium. Thus, the temporal and spatial patterns of expression of the cell migration, adhesion, and fusion molecules fertilin and CD9 were investigated in bovine trophoblast and endometrium. Bovine fertilin alpha and fertilin beta messenger RNA sequences were amplified by reverse transcriptase-polymerase chain reaction in testis (positive control), peri-implantation (Days 18, 19, and 21), and postimplantation (Days 35-40) trophoblast RNA, but not in caruncular endometrium (Day 40). Northern blot analysis indicated that the transcript hybridizing to fertilin alpha in trophoblast RNA was approximately 4.0 kilobases (kb), whereas in testis, 2 transcripts of approximately 3.3 and 3.8 kb were indicated. The transcript hybridizing to the fertilin beta probe was also larger in trophoblast than in testis ( approximately 3.8 vs. 2.4 kb, respectively). In situ hybridization revealed that fertilin beta mRNA was expressed by trophoblast cells, including binucleate cells. Immunohistochemical study of CD9, a member of the transmembrane-4-superfamily which is thought to be involved in sperm-egg fusion, showed that CD9 was present on the apical surface of uterine epithelium and in a subpopulation of binucleate cells of the trophoblast. Immunoprecipitation followed by Western blot analysis showed association between CD9 and integrin alpha3 in endometrium. The results support the hypothesis that fertilin and CD9 are involved in bovine binucleate cell migration and fusion.
牛的浅表胎盘形成涉及源自绒毛膜的胎儿双核细胞的发育，这些细胞在相邻细胞紧密连接处之间迁移并与母体上皮融合。因此，研究了细胞迁移、黏附及融合分子受精素和CD9在牛滋养层细胞和子宫内膜中的表达时空模式。通过逆转录-聚合酶链反应在睾丸（阳性对照）、着床前期（第18、19和21天）以及着床后期（第35 - 40天）的滋养层细胞RNA中扩增出牛受精素α和受精素β信使RNA序列，但在肉阜子宫内膜（第40天）中未扩增出。Northern印迹分析表明，滋养层细胞RNA中与受精素α杂交的转录本约为4.0千碱基（kb），而在睾丸中，显示出约3.3和3.8 kb的两种转录本。与受精素β探针杂交的转录本在滋养层细胞中也比在睾丸中更大（分别约为3.8 kb和2.4 kb）。原位杂交显示，受精素β mRNA由包括双核细胞在内的滋养层细胞表达。对CD9（一种被认为参与精卵融合的跨膜4超家族成员）的免疫组织化学研究表明，CD9存在于子宫上皮的顶端表面以及滋养层双核细胞亚群中。免疫沉淀后进行的Western印迹分析显示，子宫内膜中CD9与整合素α3之间存在关联。这些结果支持了受精素和CD9参与牛双核细胞迁移和融合的假说。
