Date of Completion

Spring 5-1-2024

Thesis Advisor(s)

Kazumasa Takemoto; Rahul Kanadia; Thomas Abbott

Honors Major

Molecular and Cell Biology

Disciplines

Cell and Developmental Biology | Developmental Biology | Genetics and Genomics

Abstract

The minor spliceosome is composed of the unique small nuclear RNAs (snRNA), U11, U12, U4atac, and U6atac, and is necessary for the splicing of less than 0.5% of introns, termed minor introns. Minor intron containing genes (MIGs) regulate diverse processes, one of which is spermatogenesis. Specifically, 111 testis-specific MIGs have been identified, suggesting that minor splicing is necessary for spermatogenesis. To interrogate the role of minor splicing in spermatogenesis, we conditionally ablated the Rnu11 gene, which encodes for the U11 snRNA, in the developing testes via Stra8-iCre, creating a Rnu11Flx/Flx::Stra8-Cre+ mutant. We found, at postnatal day (p) 42, the mutant testes are smaller than the wildtype (WT). Assay for cell death confirmed that U11 ablation results in cell death in the mutant at 6 weeks of age. Lastly, we found that our mutant resulted in varying spermatogenesis defects, such as an increase of asynchronous meiosis and a decrease in differentiating cells. Despite this, meiotic recombination can still occur in these mutants, concluding that U11 is important but not essential for meiotic recombination. This work is the first study to assess the importance of minor splicing in spermatogenesis which is underscored by the phenotype observed when the minor spliceosome is inhibited. Furthermore, the importance of studying spermatogenesis is highlighted by a decrease in sperm count over the last decades, which contributes to rising rates of male infertility.

Download

Share

COinS