A genetic analysis of CRM negative mutants at the td locus ofNeurospora crassa

Abstract

The possibility that primary CRM−isolates at the td locus ofNeurospora crassaare multisite lesions has been examined. By comparing the behavior of primary CRM−mutants to known multisite CRM−mutants in the genetic tests of recombination and reversion, it can be concluded that primary CRM−mutants are not multisite. The genetic implications of a CRM−and CRM+mutant have been discussed.

Molecular analysis of intragenic recombination at the tryptophan synthetase locus in Neurospora crassa

“…The trp-3 locus in N. crassa is one of the most well studied loci from genetic (Kaplan et al 1964), immunological (Matchett et al 1987) and biochemical (Pratt and DeMoss 1988) perspectives. One outcome of this depth of research is that there are abundant unique well-characterized mutant strains carrying mutations at trp-3 (McCluskey and Plamann 2004), as well as strains with trp-3 mutations in the presence of second site suppressors (Yourno and Suskind 1964).…”

“…Sequences analysed using Sequencher (Gene Codes Corporation, Ann Arbor, USA). Comparative (Kaplan et al 1964;Suyama et al 1964). NR, status of strains not reported.…”

“…Because of the relative facility of generating and identifying mutants at this locus, intragenic recombination was used to characterize the relationship among different alleles of trp-3 and these studies showed that a gene was 'composed of a larger number of elementary units, arranged in a linear sequence' (Kaplan et al 1964). At the same time, studies of the bifunctional tryptophan synthetase protein complex were being carried out in Saccharomyces cerevisae (Kakar 1963) and in Escherichia coli (Crawford and Yanofsky 1958).…”

“…Most of the strains originate in the same mutagenesis project (Kaplan et al 1964;Suyama et al 1964). Strain 861 carries a trp-3 locus that originated in an Emerson background.…”

Complementation and recombination between indole utilising tryptophan-3 mutants of Neurospora crassa

“…Recombinational studies on indole utilising mutants have been conducted in the past by Kaplan, Suyama and Bonner (1964), Suyama, Lacy and Bonner (1964), Lacy (1965) and Ahmad et al (1966), who have given the map length occupied by the indole utilisers as 0020, 0038, 0003, and 0022 respectively. The genetic map constructed using 10 indole utilising mutants has given a map length of about 009 centimorgan ( fig.…”