Mammalian sperm-egg fusion: The rat egg has complementary sites for a sperm protein that mediates gamete fusion

Rat epididymal protein DE is localized on the fusogenic region of the acrosome-reacted spermatozoa and has a potential role in sperm-egg fusion. We investigated the presence of DE binding sites on the egg surface by co-incubating zona-free eggs and capacitated sperm in different concentrations of pu...

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Autores principales: Rochwerger, L., Cohen, D.J., Cuasnicú, P.S.
Formato: JOUR
Materias:
egg
rat
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00121606_v153_n1_p83_Rochwerger
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spelling todo:paper_00121606_v153_n1_p83_Rochwerger2023-10-03T14:10:17Z Mammalian sperm-egg fusion: The rat egg has complementary sites for a sperm protein that mediates gamete fusion Rochwerger, L. Cohen, D.J. Cuasnicú, P.S. protein animal cell article cell fusion egg female fertilization gamete male nonhuman oocyte priority journal rat spermatozoon Amino Acid Sequence Animal Binding Sites Female Glycoproteins Male Membrane Fusion Membrane Glycoproteins Molecular Sequence Data Ovum Rats Rats, Inbred Strains Sperm-Ovum Interactions Spermatozoa Support, Non-U.S. Gov't Animalia Mammalia Mammalia Rat epididymal protein DE is localized on the fusogenic region of the acrosome-reacted spermatozoa and has a potential role in sperm-egg fusion. We investigated the presence of DE binding sites on the egg surface by co-incubating zona-free eggs and capacitated sperm in different concentrations of pure DE. Results indicate that DE produced a concentration-dependent decrease in egg penetration by sperm (fusion), with almost complete inhibition at 200 μg/ml. This inhibition was not due to an effect of DE on initial sperm binding to the egg membrane, since the presence of this protein did not affect the percentage of oocytes with bound sperm nor the number of bound sperm per egg. Those sperm that failed to penetrate the egg in the presence of DE became able to do so after transfer of the eggs to protein- and sperm-free medium, indicating a role for DE in an event subsequent to binding and leading to fusion. Indirect immunofluorescence using a polyclonal antibody against DE revealed a patchy labeling over the entire egg surface, with the exception of the area overlying the second metaphase spindle. This conclusion was supported by the disappearance of the DE-negative area on the fertilized egg. Zona-free eggs, incubated with DE at 4°C or fixed before exposure to DE displayed a uniform staining, suggesting that the patchy labeling resulted from aggregation of DE binding sites by the purified protein. The aggregation of these egg components may represent a necessary step of the fusion process. To our knowledge, this is the first study reporting the existence and localization of complementary sites to a specific sperm protein on the plasma membrane of the mammalian egg. © 1992. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00121606_v153_n1_p83_Rochwerger
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic protein
animal cell
article
cell fusion
egg
female
fertilization
gamete
male
nonhuman
oocyte
priority journal
rat
spermatozoon
Amino Acid Sequence
Animal
Binding Sites
Female
Glycoproteins
Male
Membrane Fusion
Membrane Glycoproteins
Molecular Sequence Data
Ovum
Rats
Rats, Inbred Strains
Sperm-Ovum Interactions
Spermatozoa
Support, Non-U.S. Gov't
Animalia
Mammalia
Mammalia
spellingShingle protein
animal cell
article
cell fusion
egg
female
fertilization
gamete
male
nonhuman
oocyte
priority journal
rat
spermatozoon
Amino Acid Sequence
Animal
Binding Sites
Female
Glycoproteins
Male
Membrane Fusion
Membrane Glycoproteins
Molecular Sequence Data
Ovum
Rats
Rats, Inbred Strains
Sperm-Ovum Interactions
Spermatozoa
Support, Non-U.S. Gov't
Animalia
Mammalia
Mammalia
Rochwerger, L.
Cohen, D.J.
Cuasnicú, P.S.
Mammalian sperm-egg fusion: The rat egg has complementary sites for a sperm protein that mediates gamete fusion
topic_facet protein
animal cell
article
cell fusion
egg
female
fertilization
gamete
male
nonhuman
oocyte
priority journal
rat
spermatozoon
Amino Acid Sequence
Animal
Binding Sites
Female
Glycoproteins
Male
Membrane Fusion
Membrane Glycoproteins
Molecular Sequence Data
Ovum
Rats
Rats, Inbred Strains
Sperm-Ovum Interactions
Spermatozoa
Support, Non-U.S. Gov't
Animalia
Mammalia
Mammalia
description Rat epididymal protein DE is localized on the fusogenic region of the acrosome-reacted spermatozoa and has a potential role in sperm-egg fusion. We investigated the presence of DE binding sites on the egg surface by co-incubating zona-free eggs and capacitated sperm in different concentrations of pure DE. Results indicate that DE produced a concentration-dependent decrease in egg penetration by sperm (fusion), with almost complete inhibition at 200 μg/ml. This inhibition was not due to an effect of DE on initial sperm binding to the egg membrane, since the presence of this protein did not affect the percentage of oocytes with bound sperm nor the number of bound sperm per egg. Those sperm that failed to penetrate the egg in the presence of DE became able to do so after transfer of the eggs to protein- and sperm-free medium, indicating a role for DE in an event subsequent to binding and leading to fusion. Indirect immunofluorescence using a polyclonal antibody against DE revealed a patchy labeling over the entire egg surface, with the exception of the area overlying the second metaphase spindle. This conclusion was supported by the disappearance of the DE-negative area on the fertilized egg. Zona-free eggs, incubated with DE at 4°C or fixed before exposure to DE displayed a uniform staining, suggesting that the patchy labeling resulted from aggregation of DE binding sites by the purified protein. The aggregation of these egg components may represent a necessary step of the fusion process. To our knowledge, this is the first study reporting the existence and localization of complementary sites to a specific sperm protein on the plasma membrane of the mammalian egg. © 1992.
format JOUR
author Rochwerger, L.
Cohen, D.J.
Cuasnicú, P.S.
author_facet Rochwerger, L.
Cohen, D.J.
Cuasnicú, P.S.
author_sort Rochwerger, L.
title Mammalian sperm-egg fusion: The rat egg has complementary sites for a sperm protein that mediates gamete fusion
title_short Mammalian sperm-egg fusion: The rat egg has complementary sites for a sperm protein that mediates gamete fusion
title_full Mammalian sperm-egg fusion: The rat egg has complementary sites for a sperm protein that mediates gamete fusion
title_fullStr Mammalian sperm-egg fusion: The rat egg has complementary sites for a sperm protein that mediates gamete fusion
title_full_unstemmed Mammalian sperm-egg fusion: The rat egg has complementary sites for a sperm protein that mediates gamete fusion
title_sort mammalian sperm-egg fusion: the rat egg has complementary sites for a sperm protein that mediates gamete fusion
url http://hdl.handle.net/20.500.12110/paper_00121606_v153_n1_p83_Rochwerger
work_keys_str_mv AT rochwergerl mammalianspermeggfusiontherategghascomplementarysitesforaspermproteinthatmediatesgametefusion
AT cohendj mammalianspermeggfusiontherategghascomplementarysitesforaspermproteinthatmediatesgametefusion
AT cuasnicups mammalianspermeggfusiontherategghascomplementarysitesforaspermproteinthatmediatesgametefusion
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