Date of Award

Fall 1997

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Committee Director

Gary D. Hodgen

Committee Member

Susan Lanzendorf

Committee Member

Mary C. Mahony

Committee Member

R. James Swanson

Committee Member

James P. Toner

Abstract

The human hemizona has been demonstrated to select spermatozoa with good motility, normal morphology, and the capacity to undergo the zona-induced acrosomal reaction. The studies conducted here are directed at using the human hemizona to investigate two key questions: (1) whether human X-chromosome bearing spermatozoa (X-sperm) and Y-chromosome bearing spermatozoa (Y-sperm) differ in their functional survival time (assessed by their capacity to bind to the human zona pellucida) after prolonged in vitro incubation, and (2) whether hemizona-bound spermatozoa have a reduced aneuploidy rate compared to unbound (and therefore, unselected) spermatozoa?

In the functional survival study, donor spermatozoa were held in vitro for up to 72 hours using two systems: at 4°C refrigeration and at 37° incubation. At each 24 hour storage interval, spermatozoa were coincubated with human hemizona, and the total numbers of zona-bound X-sperm and Y-sperm were determined using fluorescence in situ hybridization. The analysis revealed that although equal proportions of X-sperm and Y-sperm survived functionally throughout the 72 hours at 4°C refrigeration, the proportions differed after 48 hours incubation when the storage took place at 37°C, with significantly more Y-sperm surviving functionally than X-sperm.

Spermatozoa from subfertile patients were used in the aneuploidy study. This study demonstrated that zona-bound spermatozoa had a significantly lower chromosomal aneuploidy rate compared to unbound spermatozoa. This indicates that hemizona has the potential to be used clinically to improve the genetic quality of zygotes fertilized using intracytoplasmic sperm injection.

Comments

A Dissertation Submitted to the Faculty of Old Dominion University and Eastern Virginia Medical School in Partial Fulfillment of the Requirement for the Degree of Doctor of Philosophy in Biomedical Sciences.

DOI

10.25777/2hfq-tk58

ISBN

9780591631845

Share

COinS