交配型因子和细胞质对香菇双核体中两组成型核比例的影响(英文)

Implication of mating type and cytoplasm factors in asymmetric distribution of two types of monokaryons recovered from dikaryons in Lentinula edodes

对造成香菇原生质体单核化后两种交配型单核体比例偏离1∶1分离的遗传背景进行探讨.结果表明,B因子或是与B因子连锁的因子对这种偏离有明显的影响,而A因子对此影响不明显.B因子特异性不同,与之相对应的交配型单核体出现的比例亦不同,特异性越高,其对应交配型单核体在经原生质体单核化后将以较大的比例出现.参试的2个香菇菌株中4个B因子特异性顺序为B1>B3>B4>B2.双-单杂交所形成的由受体细胞质和受体、供体细胞核组成的同质异核体经原生质体单核化裂解后均与受体交配型相同的核居多,表明受体细胞质环境对双-单杂交所得异核体裂解后的核的存活和数量起着重要作用.作为供体的2个核中只有亲和力强的那个核优先迁移到受体中,形成新的异核体,即存在先导核.先导核与B因子的亲和特异性有关,特异性越高,先导核迁移速度越快.

The genetics background for the phenomenon of significantly distortion to the expected 1 ： 1 ratio of the two constitute nucleus in Lentinula edodes was investigated after protoplast monokaryotization. The results reveal that specificity of the B factor, or of a gene linked to the B factor, appeared to influence survival of dedikaryotized nuclei, whereas specificity of the A factor had no apparent effect on this phenomenon; Specificity of B factor correlated with percentage survival of the component nuclear types recovered from both kinds of heterokaryons, it can be put in an hierarchical order with respect to this function, the hierarchical order of these B factors was B1〉B3〉B4 〉B2 between two tested strains. Data from di-mon mating show that the monokaryons with acceptor nuclear type outnumbered exclusively those entered donors＇ nuclear types in all secondary derived homocytoplasm heterokaryon, which consists of acceptor cytoplasm, acceptor and donor karyons. It was indicated that some factors in cytoplasm are probably responsible for influencing survival of nuclei recovery from dedikaryotization. Moreover, the nucleus migrated from a dikaryon to a monokaryon is one with stronger compatibility between different B factors, then they form derived dikaryon. This showed that a preentrance nucleus existed in donor and pre-entrance nucleus was mainly dependent on the compatible specificity of B mating-type factor between acceptor and donor nucleus; the higher the specificity, the faster the migration of pre-entrance nucleus.