CELL BIOLOGICAL AND BIOCHEMICAL STUDIES ON FUNCTION OF THE ter GENE IN PRIMORDIAL GERM CELL DEFICIENCY IN ter MUTANT MICE.

具有ter（畸胎瘤，Chr.18）突变的突变株可作为研究小鼠原始生殖细胞（PGC）的增殖、存活和畸胎瘤发生的有用工具。所获得的ter基因的特征总结如下：1.将129只/Sv-+/ter小鼠的ter基因分别导入到B6、LTXBJ和C3 H品系的遗传背景上，建立了B6-+/ter、LTXBJ-+/ter和C3 H-+/ter等3个ter/ter品系小鼠，从妊娠第8天开始，ter基因诱导小鼠出现PGC缺陷; 2.利用ter基因座附近微卫星标记的SSLP方法，对3个ter/ter品系小鼠胚胎的每个ter基因型进行鉴定; 3. ter突变睾丸的PGC缺陷归因于其小管内缺陷，用ter睾丸体细胞重建的睾丸中，+/+生殖细胞发生凋亡，而有自身体细胞的则分化为生精细胞。5.与自身体细胞共培养的PGC在胎儿性腺+/+和+/ter体细胞的条件培养液（CM）中增殖，而在terCM中不增殖。CM含有支持PGC存活的蛋白样物质，但terCM不含。6.提示性腺体细胞可能产生一种新的支持PGC存活的可溶性和膜结合型PGC生长因子（TER Factor，TERF），它可能由ter基因座上的正常基因编码，而ter PGC是正常的。

Mutant strains having the ter (teratoma, Chr.18) mutation can serve as useful tools for studies of proliferation, survival and teratocarcinogenesis of primordial germ cells (PGC) in mice. Characteristics of the ter gene obtained are summarized below :1.The ter gene induces PGC deficiency from 8 days of gestation in ter/ter mice of the ter-congenic strains such as B6-+/ter, LTXBJ-+/ter and C3H-+/ter which we have established by introducing the ter gene from 129/Sv-+/ter mice onto the genetic backgrounds of B6, LTXBJ and C3H strains, respectively.2.Each ter genotype of each embryo of ter-congenic strains was identified by SSLP of the microsatellite markers near the ter locus.3.PGC deficiency in ter mutant testes is ascribed to their intratubular defect and +/+ gonocytes occurred apoptosis in reconstituted testes with ter testicular somatic cells, whereas they differentiated to spermatogenic cells in those with own somatic cells. These indicate that the ter gene may function in ter somatic cells.4.This type PGC-deficiency was not rescued by addition of several PGC growth factors in vitro and was induced by apoptosis in the G1 phase of PGC.5.PGC co-cultured with own somatic cells proliferated in conditioned medium (CM) of +/+ and +/ter somatic cells of fetal gonads, but they did not in terCM.+/+CM contained protein like substance supporting PGC survival, but terCM did not. Both +/+ and ter PGC isolated proliferated on the +/+ somatic cells, but they occurred apoptosis on the ter ones.6.It is concluded that a novel PGC growth factor (designated as TER Factor, TERF), both soluble type and membrane bounded type, supporting PGC survival may be produced by gonadal somatic cells and that it may be coded by the normal gene on the ter locus, and also that ter PGC are normal.