Location of a mutation resistant to cobalt and nickel in LG IIIR of Neurospora crassa

C.H. Wilson(1), L.S. Sajani and P. Maruthi Mohan - (1)Fungal Genetics Stock Center, Dept. of Microbiology, University of Kansas Medical Center, Kansas City, KS 66160-7240 and Dept. of Biochemistry, Osmania University, Hyderabad-500 007, India

cor is resistant to 10 mM Co2+ or 10 mM Ni2+. It was induced in ORS-6a (FGSC 4200) by serial transfers on cobalt-containing (32 mM) agar medium as described by Venkateswerlu and Sivarama Sastry (Biochem J. 132:673-680). A cross of cor to alcoy indicated a location in linkage group III. It was then crossed to acr-2 trp-1 dow. 98 spores germinated and gave the following results:

Parental                      Double crossovers
     acr  trp  dow   +   28        acr   +   dow   +    4
      +    +    +   cor  22         +   trp   +   cor   2         
                                    +   trp  dow  cor   1
Single crossovers
     acr  trp   +   cor  15      Simple recombination percentages:
      +    +   dow   +   12        cor-acr        41.8
                                   cor-trp        34.7
     acr   +    +   cor   5        cor-dow         1.0
      +   trp  dow   +    9

- - - P.M.M. thanks the Dept. of Science and Technology and the CSIR, New Delhi, for financial assistance.