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Document Type:Latin Dissertation
Language of Document:English
Record Number:55406
Doc. No:TL25360
Call number:‭3314468‬
Main Entry:Jennifer J. Venditti
Title & Author:Localization, stability, and functional role of sperm associated α-L-fucosidaseJennifer J. Venditti
College:Lehigh University
Date:2008
Degree:Ph.D.
student score:2008
Page No:90
Abstract:Novel isoforms of α-L-fucosidase are found in both the seminal plasma and membrane system of human sperm. Association of α-L-fucosidase with the human sperm membrane system suggests a role in fertilization. This investigation first refined the subcellular localization of membrane associated αL-fucosidase in washed, capacitated, and acrosome reacted human spermatozoa using immunolocalization and confocal microscopy. These experiments revealed sperm associated α-L-fucosidase was widely distributed throughout the membrane system of human sperm with enrichment in the equatorial segment. Secondly, this project investigated the functional distribution and stability of α-L-fucosidase using fluorometry. If α-L-fucosidase is required during fertilization, substantial amounts of the enzyme should be present in acrosome reacted cells and considerable activity should remain for at least 24 hours at body temperature (37°C). Data from direct fluorometric enzyme assays revealed high amounts of α-L-fucosidase activity in capacitated and acrosome reacted human sperm that remained actively stable for up to 72 hours. Thirdly, this project evaluated the role(s) of α-L-fucosidase in fertilization using a Syrian hamster in vitro system. Two hypotheses were tested using a Syrian hamster model system. The first is α-L-fucosidase is required for binding and/or penetration of the zona pellucida (ZP); therefore pretreatment of sperm with DFJ, α-L-fucosidase competitor, will inhibit binding and/or penetration of the ZP. No significant difference was found between the average number of tightly bound sperm per oocyte for oocytes inseminated with control or DFJ pre-treated sperm. Additionally, both control and DFJ pre-treated sperm could penetrate the ZP. These results provided direct evidence that sperm associated α-L-fucosidase is not required for binding and/or penetration of the zona pellucida. The second hypothesis is α-L-fucosidase is required for membrane-membrane fusion between sperm and oocyte, therefore pretreatment of sperm with DFJ will inhibit fertilization at the membrane level. Pre-treatment of sperm with 5 mM DFJ significantly reduced the percent of 2-cell embryos compared to the control group. Taken together, the results indicated sperm associated α-L-fucosidase functions during hamster fertilization. Understanding the role of sperm associated α-L-fucosidase could lead to the possible development of infertility treatments and/or clinical diagnostic tools for evaluating patient fertility.
Subject:Biological sciences; Fertilization; Fucosidase; Sperm; Zona pellucida; Molecular biology; Cellular biology; 0307:Molecular biology; 0379:Cellular biology
Added Entry:Lehigh University