Meiosis in Neurospora crassa.

I. Isolation and partial characterization of dominant meiotic mutants constituting meiotic gene cluster, V-1 on LG V

抄録

Among 85 dominant meiotic mutants isolated after UV mutagenesis by the application of allelic complementation between inl (37401) and inl (38201(t)) on LG V, those mutants localized proximal to al-3 expanding putatively from ilv-2 to am on LG V were described. Twelve mutants Asc(KH2B88), Asc(KH2B95), Asc(KH2B124), Asc(KH2B129), Asc(KH2B132), Asc(KH2B241) , Asc(KH2B249), Asc(KH2B341), Asc(KH2B394), Asc(KH2B424), Asc(KH2B540) and Asc(KH2B755) were mapped to the relatively small area. Of these five mutants were found to produce abortive ascospores only when they were protoperithecial parent (class I) and two mutants expressed their traits independent of protoperithecial or conidial parent (class II). Five mutants were marginally sensitive to UV compared with that of a Mei-2 mutant used as a reference. At least three mutants showed relatively high aneuploid formation in LG V (15-19%) in the heterozygous zygotes. Two mutants showed low recombination recovery rates (23-36%) and four mutants locating distal side of this gene cluster showed elevated recombination frequencies between al-3 and inl, which were 2.5-3.5 times higher than that observed in wild type. From these observations at least 9 mutations were assumed to be derived from different genes and revealed the existence of meiotic gene cluster, designated V-1 at the area.