Investigating X chromosome non-disjunction in \u3cem\u3eDrosophila melanogaster su(var)3-9\u3c/em\u3e mutants

Meiotic recombination is a highly regulated process necessary for promoting proper chromosome disjunction during the first meiotic division. Notably, reduced levels of meiotic recombination are observed in heterochromatic regions of the chromosome. This study seeks to investigate the molecular mechanisms underlying this observation by examining the effects of reduced heterochromatin on non-disjunction rates in Drosophila melanogaster. To accomplish this, we measured non-disjunction in wild-type and reduced heterochromatin mutant su(var)3-9 flies. To begin, we confirmed the presence of a mutation within su(var)3-9 via Sanger sequencing. Next, we created allele-specific primers and designed a PCR protocol to more accurately identify mutant flies at the molecular level. Finally, we assayed non-disjunction in wild-type and su(var)3-9 mutant flies and discovered that su(var)3-9 mutants have significantly higher levels of non-disjunction than wild-type flies. We also uncovered a striking sex bias in the non-disjunction progeny of su(var)3-9 mutants