用CHEF凝胶电泳探测远缘担子菌间原生质体融合后的染色体变异

用电场诱导灰盖鬼伞(Coprinus cinereus Co5104,his~-)和佛罗里达侧耳(Pleurotusflorida Pf67, ade~-)两菌株的原生质体融合,获得了两类属间融合子:一类为不断发生分离的单核体,另一类为稳定的双核异核体。利用等高钳位均匀电场(CHEF)凝胶电泳技术比较融合子与两亲本的染色体长度多型性(CLP),显示出融合子的染色体变异以整条染色体的丢失为主。结合形态观察和DAPI核荧光染色的结果,推测单核融合子在胞质融合后很可能发生了核融合,但来自亲本Pf67的染色体不断丢失,最后融合子的遗传组成以来自Co5104的染色体为主;而双核融合子在质配之后可能并未发生核配,不过,来自各亲本的染色体最终均只有部分得以保留在融合子中。

CHEF GEL ELECTROPHORESIS AS A MEANS FOR PROBE OF CHROMOSOMAL ABERRATION INDUCED BY PROTOPLAST FUSION OF DISTANTLY RELATED BASIDIOMYCETES STRAINS

Two kinds of intergeneric fusants were obtained by protoplast electrofusion between Coprinus cinereus Co5104 (his-) and Pleurotus florida Pf67 (ade-): one is unstable monokaryon which continually segregated when sub-cultivated, the other is stable dinucleic heterokaryon. Comparison of Chromosomal Length Polymorphism (CLP) between fusants and their parental strains was conducted with Contour-clamped Homogeneous Electric Field (CHEF) gel electrophoresis. The result revealed that the deletion of entire chromosomes is the principal chromosomal aberration of fusants. Furthermore, combined with the results of morphological observation and DAPI nucleic fluorescence staining, this result of molecular karyotyping implied that: nucleic fusion, which follows the cytoplasmic fusion, probably takes place in the monokaryotic fusants, and the final genetic composition of this kind of fusants is mainly the chromosomes from parental strain Co5104 as a result of the continual deletion of chromosomes from the other parental strain Pf67. On the other hand, in dinucleic fusants, the nucleic fusion does not occur after cytoplasmic fusion; however, only a proper- tion of chromosomes from each parental stain were retained in this kind of fusants.