Molecular mechanism of proliteration and differentistion of male germ cells analyzed by using the cell line that undergoes "meiosis"in vitro.

1.我们使用GC-2 M细胞系（一种源自小鼠精细胞系GC-2spd（ts）的克隆系，被认为在体外进行减数分裂）获得了以下结果：通过RT-PCR，在GC-2 M中未检测到已知对减数分裂特异的基因表达。核型分析表明，大多数细胞含有74 - 75条染色体，接近四倍体，有些细胞含有约37条染色体，不存在单倍体细胞。流式细胞术显示GC-2M细胞和NIH/3T3细胞的DNA含量均为4n。GC-2M细胞的DNA含量为4n或8n时，其克隆性培养表明细胞能增殖并将DNA含量降至2n。这些结果表明，GC-2M细胞中存在染色体数目减少的现象，但其过程不同于正常的减数分裂。细胞裂解液，获得10个克隆。他们对小鼠睾丸切片进行化学染色。鉴定抗体识别的蛋白质的试验并不成功。我们建立了第一个人卵巢无性细胞瘤细胞系HDGO。核型为46，XX，并在细胞中检测到生殖细胞特异性蛋白Vasa的表达。HDGO细胞在SCID小鼠中形成肿瘤，并且鉴定了c-Kit原癌基因的组成性激活。

1. Using the GC-2M cell line, a clonal line derived from the mouse spermatocytic cell line GC-2spd(ts) and thought to undergo meiosis in vitro, we obtained the following results.By RT-PCR, no expression of genes known to be specific to meiosis was detected in GC-2M. Karyotype analysis demonstrated that most cells have 74-75 chromosomes, near tetraploid, with some cells containing around 37 chromosomes, and that no haploid cells were ~present. Flowcytomery showed that the major peak in GC-2M as well as NIH/3T3 cells corresponded to 4n DNA contend Clonal culture of GC-2M cells with 4n or 8n DNA content suggested that they could proliferate and reduce the DNA content to 2n. These results indicate that the reduction of the number of chromosomes occurs in GC-2M cells, but the process is different from regular meiosis.We raised mouse monoclonal antibodies against GC-2M. cell lysates, and obtained 10 clones. They immunohistochemically stained the sections of mouse testis. Trials to identify the proteins recognized by the antibodies were not successful.2. We have established the first human ovarian dysgerminoma cell line HDGO. The karyotype was 46, XX, and expression of Vasa, a germ cell specific, protein, was detected in the cells. HDGO cells formed tumors in SCID mice, and constitutive activation of c-Kit proto-oncogene was identified.