THE GENETIC ANALYSIS OF A CHROMOSOME-SPECIFIC MEIOTIC MUTANT THAT PERMITS A PREMATURE SEPARATION OF SISTER CHROMATIDS IN DROSOPHILA MELANOGASTER
1984; Oxford University Press; Volume: 107; Issue: 1 Linguagem: Inglês
10.1093/genetics/107.1.65
ISSN1943-2631
Autores Tópico(s)Plant Genetic and Mutation Studies
ResumoABSTRACT mei-G87 is a recessive meiotic mutant that increases second chromosome nondisjunction in both males and females. A significant proportion of the diplo-2 exceptions are equational. In females, diplo-2 reductional exceptions are usually noncrossovers, but, in equational exceptions, crossover frequency and distribution are the same as that found in the haplo-2 controls. The frequencies of nondisjunction are relatively low: 0.6% in females and 1.3% in males. Nondisjunction frequency is affected by environmental conditions (possibly humidity). The defect in mei-G87, as in other "second division" mutants, appears to be a failure to maintain sister-chromatid cohesion. mei-G87 increases nondisjunction of only the second chromosome. This may indicate either a weak mutant with only the second chromosome being sensitive enough to misbehave or it may indicate that chromosome-specific regions responsible for sister-chromatid cohesion exist.
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