Date Thesis Awarded

4-2020

Access Type

Honors Thesis -- Access Restricted On-Campus Only

Degree Name

Bachelors of Science (BS)

Department

Biology

Advisor

Diane Shakes

Committee Members

Shanta Hinton

Lisa Landino

Matthew Wawersik

Abstract

During cell division, accurate segregation of chromosomes into two daughter cells is essential to avoid catastrophic consequences. Segregation of the sex chromosomes is particularly important, as it plays a primary role in sex determination. Furthermore, unequal segregation of the sex chromosome during gamete formation can lead to skewed sex ratios. Nematodes are powerful models to study this process because many nematodes employ an XX/XO sex determination pattern, where XX animals are feminine and animals with a single X (no Y) are male. In the nematode species, Auanema rhodensis, meiotic X chromosome segregation fails to follow the normal laws of genetics and instead varies by sex and by gamete. Here, we report X chromosome segregation and cellular component partitioning patterns in an A. rhodensis tra mutant, where males have two X chromosomes that follow non-standard patterns of X chromosome segregation as part of their normal developmental mechanism. X chromosome segregation in tra (XX) males is highly variable due to unique modulations during anaphase I. Post-meiotic partitioning varies with respect to X chromosome segregation. These variations in meiosis and post-meiosis result in the production of more than one type of sperm.

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