Mutagen sensitivity of Neurospora meiotic mutants

Area of Science:

• Genetics
• Molecular Biology
• Mycology

Background:

• Meiotic mutants in *Neurospora* are crucial for understanding chromosome behavior during sexual reproduction.
• Previous studies identified several meiotic mutants, including mei-1, mei-2, mei-3, and mei-4.

Purpose of the Study:

• To investigate the cross-sensitivity of *Neurospora* meiotic mutants to various mutagens.
• To determine if mutagen sensitivity is a pleiotropic effect of meiotic genes.

Main Methods:

• Testing *Neurospora* meiotic mutants (mei-1, mei-2, mei-3, mei-4) for sensitivity to methyl methanesulfonate (MMS), gamma-irradiation, histidine, and ultraviolet (UV) radiation.
• Utilizing genetic crosses and recombinant analysis to map gene locations and assess allelism.
• Backcrossing experiments to evaluate the dominance of meiotic and histidine sensitivity traits.

Main Results:

• Mutants mei-2 and mei-3 displayed sensitivity to MMS, gamma-irradiation, and histidine.
• Mei-2 mutant showed no sensitivity to UV radiation at 20°C.
• Recombinant analysis confirmed that mutagen sensitivity and meiotic defects are pleiotropic properties of single genes (mei-2 and mei-3).
• The mei-2 gene was mapped to linkage group V, right of al-3, and found not to be allelic to mus-11.
• The meiotic effect of mei-2 shifted from dominant to partially dominant upon backcrossing, while histidine sensitivity remained recessive.

Conclusions:

• The mei-2 and mei-3 genes in *Neurospora* control both meiotic processes and sensitivity to specific mutagens and histidine.
• These findings highlight the pleiotropic nature of genes involved in DNA repair and meiotic recombination pathways.