Life Sciences Commons^™

Investigating The Roles Of Ndj1 And Tid1 In Crossover Assurance In Saccharomyces Cerevisiae, Rianna Knowles

Master's Theses

Meiosis is the specialized process of cell division utilized during gametogenesis in all sexually reproducing eukaryotes, which consists of one round of DNA replication followed by two rounds of chromosome segregation and results in four haploid cells. Crossovers between homologous chromosomes promote proper alignment and segregation of chromosomes during meiosis.

Crossover interference is a genetic phenomenon in which crossovers are non-randomly placed along chromosomes. Crossover assurance ensures that every homologous chromosome pair obtains at least one crossover during Prophase I. Crossovers physically connect homologous pairs, allowing spindle fibers to attach and separate homologs properly. However, some organisms have shown an …

Studies On The Mechanism Of Homolog Pairing In Drosophila Male Meiosis, Jui-He Tsai

Doctoral Dissertations

Drosophila male is an example of achiasmatic meiosis which lacks crossingover and chiasmata during meiosis. Previous studies showed that homologous pairing of both euchromatin and centromeres is lost during middle prophase I, however, homologs are still connected as they form bivalents. The X-Y pair utilizes a specific repeated sequence within the heterochromatic ribosomal DNA blocks as a pairing site. No pairing sites have yet been identified for the autosomes. To search for such sites, we utilized probes specifically targeting heterochromatin regions to assay pairing sequences and behavior in meiosis by fluorescence in situ hybridization (FISH). We found that the fourth …