Investigating X-chromosome Non-disjunction in Su(var)3-9 Drosophila melanogaster Mutants
College
College of Arts and Sciences
Department
Biology
Faculty Mentor
Dr. Kathryn Kohl
Abstract
Meiosis is the process by which homologous chromosomes segregate to form four, genetically diverse haploid gametes. In most organisms, crossing over between all homologous chromosomes must occur accurately and efficiently to ensure the proper segregation of chromosomes. However, in the model organism Drosophila melanogaster, meiotic crossover events do not occur on the 4th chromosome for reasons still unclear. Since Drosophila chromosome 4 is primarily heterochromatic at ~70%, with respect to the other Drosophila chromosomes at ~30%, we hypothesize that the abundance of heterochromatin may be responsible for preventing meiotic crossing over on chromosome 4. To test this hypothesis, a mutant of one the genes responsible for production of heterochromatin, su(var)3-9, was used to understand the effects of decreased heterochromatin levels on the number of cross over events.To begin, we confirmed the presence of a mutation within su(var)3-9 via Sanger sequencing. Next, we created allele-specific primers using the WASP tool and designed a PCR protocol to more accurately identify mutant flies at the molecular level. Forthcoming, we will measure levels of non-disjunction on the X chromosome in wild-type and su(var)3-9 mutants to gain insight into the effect of heterochromatin on meiotic chromosome dynamics.
Course Assignment
Undergraduate Research in Biology, BIOL 471, Dr. Kathryn Kohl
Previously Presented/Performed?
South Carolina Academy of Science Annual Meeting, Winthrop University, April 2016
Grant Support?
Supported by a grant from the National Institutes of Health IDeA Networks for Biomedical Research Excellence (NIH INBRE)
Start Date
22-4-2016 2:15 PM
End Date
22-4-2016 2:30 PM
Investigating X-chromosome Non-disjunction in Su(var)3-9 Drosophila melanogaster Mutants
West Center, Room 219
Meiosis is the process by which homologous chromosomes segregate to form four, genetically diverse haploid gametes. In most organisms, crossing over between all homologous chromosomes must occur accurately and efficiently to ensure the proper segregation of chromosomes. However, in the model organism Drosophila melanogaster, meiotic crossover events do not occur on the 4th chromosome for reasons still unclear. Since Drosophila chromosome 4 is primarily heterochromatic at ~70%, with respect to the other Drosophila chromosomes at ~30%, we hypothesize that the abundance of heterochromatin may be responsible for preventing meiotic crossing over on chromosome 4. To test this hypothesis, a mutant of one the genes responsible for production of heterochromatin, su(var)3-9, was used to understand the effects of decreased heterochromatin levels on the number of cross over events.To begin, we confirmed the presence of a mutation within su(var)3-9 via Sanger sequencing. Next, we created allele-specific primers using the WASP tool and designed a PCR protocol to more accurately identify mutant flies at the molecular level. Forthcoming, we will measure levels of non-disjunction on the X chromosome in wild-type and su(var)3-9 mutants to gain insight into the effect of heterochromatin on meiotic chromosome dynamics.
