Research Abstract |
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.
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