Two years ago, Dr. Käfer and Dr. Schroeder independently summarized genetic information on mutagen-sensitive mutants in Neurospora crassa (Fungal Genetics Newsletter 35:11-13, 1988; DNA Repair 3:77-98, 1988). So far, 30 genetic loci related to mutagen-sensitivity have been indentified. The mutants are more sensitive to UV, X-rays and/or chemical mutagens than the wild-type strain. We have studied DNA-repair mechanisms of Neurospora for several years. During the study, several mutagen-sensitive mutants were isolated and the mutations were mapped. To confirm that they are mutations in new genes, we tested allelism between these mutations and previously reported mutagen-sensitive mutations. Here, new mutations are listed and new mus numbers are given to them as follows.
allele gene# linkage group sensitivity
(isolation #) (near marker) UV MMS
SA11 mus-31 IR (ad-3B) 0 S
SA32 mus-32 IR (ad-3B) S S
SA33 mus-33 VII (met-7) S S
SA18 mus-34 VR (am) S S
SA50 mus-35 VII (nic-3) 0 S
SA51 mus-36 IV (pan-1) 0 S
SA52 mus-37 V (cyh-2) 0 S
SA56 mus-38 IL (leu-3) S 0
0 - similar to wild type In Fungal Genetics Newsletter 35:11-13, 1988, mus(FK131), mus(FK132) and mus(FK133) were not yet mapped. We have mapped the mutations and tested allelism with other mutagen-sensitive mutations. The results showed that both mus(FK131) and mus(FK132) are allelic to mus-21. The mus(FK133) mutant has a mutation in a new gene, located in linkage group VI (8% to ylo-1). Thus mus(FK133) has been designated mus-39. These new mutants will be characterized for mutagen-sensitivity, mutagenesis, meiosis and fertility.