Urushihara Hideko, Saigo Tomoko, Yanagisawa Kaichiro
Institute of Biological Sciences, University of Tsukuba, Tsukuba, Ibaraki 305, Japan.
Dev Growth Differ. 1990 Apr;32(2):111-116. doi: 10.1111/j.1440-169X.1990.00111.x.
Cellular slime mould Dictyostelium discoideum propagates as single haploid cells and under certain environmental conditions enters into a sexual cycle called macrocyst formation. There are homothallic and heterothallic strains reported, the former being able to form macrocysts in clonal cell populations while the latter to do so only in the presence of opposite mating-type strains. Molecular basis for differential mating systems is an intersting subject totally unknown yet. In the present study, sexual cell interactions in AC4, a homothallic strain of D. discoideum, was studied in comparison with the heterothallic mating system. The conditoned medium of AC4 cells was found to promote the sexual cell fusion among themselves. In addition, it also enhanced the cell fusion between heterothallic strains. Furthermore, the conditioned medium obtained from the mated culture of heterothallic strains reported to induce the sexual cell fusion in the heterothallic strains (Saga and Yanagisawa, 1983) was found also to promote the cell fusion in AC4. These results suggest that common regulatory mechanisms operate for sexual cell fusion among different mating systems in D. discoideum.
细胞黏菌盘基网柄菌以单倍体细胞形式繁殖，在特定环境条件下进入一个称为大囊泡形成的有性周期。有同宗配合和异宗配合菌株的报道，前者能够在克隆细胞群体中形成大囊泡，而后者只有在存在相反交配型菌株时才能形成大囊泡。不同交配系统的分子基础是一个尚未完全了解的有趣课题。在本研究中，将盘基网柄菌同宗配合菌株AC4中的性细胞相互作用与异宗配合交配系统进行了比较研究。发现AC4细胞的条件培养基能促进其自身之间的性细胞融合。此外，它还增强了异宗配合菌株之间的细胞融合。此外，据报道，从异宗配合菌株的交配培养物中获得的条件培养基能诱导异宗配合菌株中的性细胞融合（佐贺和柳泽，1983年），也被发现能促进AC4中的细胞融合。这些结果表明，盘基网柄菌不同交配系统中的性细胞融合存在共同的调控机制。
