The effect of cryopreservation on the genome of fish reproductive cells

5.00
Hdl Handle:
http://hdl.handle.net/10547/558306
Title:
The effect of cryopreservation on the genome of fish reproductive cells
Authors:
Kopeika, Julia
Abstract:
Cryopreservation has been extensively used in human reproductive medicine, aquaculture and conservation programs for endangered species. Many studies have been devoted to the mechanisms of cryodamage. However, in spite of growing successes of cryopreservation, post-thaw recovery of reproductive and embryonic cells often remains poor. It is known that cryopreservation causes extensive damage to membrane, results in decreased metabolism of cells, and disturbs the bioenergetical processes of cells by damage to mitochondria. Nonetheless, it has not yet been identified clearly if cryopreservation causes some disruption in the genetic integrity of reproductive cells and the safety of this approach still needs to be confirmed. The present study was undertaken on the spermatozoa of weather loach (Misgurnus tassilis) and blastomeres cells of zebrafish (Danio rerio). It was shown that survival was decreased for embryos derived from sperm after cryoprotectant treatment or cryopreservation. Some evidence has emerged that this decrease is more likely to reflect some genetic instability caused by cryopreservation of sperm. The present study showed for the first time that the DNA repair system of oocytes was activated after fertilisation with cryopreserved sperm. The effect of DNA repair system was also studied. It was found that incubation of fertilised eggs in caffeine could reverse the detrimental effects of cryopreservation of loach sperm on subsequent embryo development. On the other hand incubation of fertilised eggs with 3-aminobenzamide - inhibitor of the poly (ADP-ribose) polymerase (PARP)- brought further decrease in the survival of embryos derived from cryopreserved sperm. The effect of individual donors of sperm and eggs on overall embryo survival was also studied and these investigations revealed significant differences between different donors. Effect of cryopreservation on zebrafish blastomeres was studied at the DNA molecular level. Mitochondrial DNA was sequenced after cryopreservation and increased level of frequency of the mutation was observed. This finding showed that cryopreservation might potentially increase the instability of mtDNA genome. The significance of these changes on the subsequent function of the cells is to be elucidated. Meanwhile this study suggests that it is important to be cautious in making judgements on the safety of cryopreservation techniques in reproduction.
Citation:
Kopeika, J. (2003) 'The effect of cryopreservation on the genome of fish reproductive cells'. PhD thesis. University of Luton.
Publisher:
University of Bedfordshire
Issue Date:
Sep-2003
URI:
http://hdl.handle.net/10547/558306
Type:
Thesis or dissertation
Language:
en
Description:
A thesis submitted for the degree of Doctor of Philosophy of the University of Luton
Appears in Collections:
PhD e-theses

Full metadata record

DC FieldValue Language
dc.contributor.authorKopeika, Juliaen
dc.date.accessioned2015-06-22T11:03:20Zen
dc.date.available2015-06-22T11:03:20Zen
dc.date.issued2003-09en
dc.identifier.citationKopeika, J. (2003) 'The effect of cryopreservation on the genome of fish reproductive cells'. PhD thesis. University of Luton.en
dc.identifier.urihttp://hdl.handle.net/10547/558306en
dc.descriptionA thesis submitted for the degree of Doctor of Philosophy of the University of Lutonen
dc.description.abstractCryopreservation has been extensively used in human reproductive medicine, aquaculture and conservation programs for endangered species. Many studies have been devoted to the mechanisms of cryodamage. However, in spite of growing successes of cryopreservation, post-thaw recovery of reproductive and embryonic cells often remains poor. It is known that cryopreservation causes extensive damage to membrane, results in decreased metabolism of cells, and disturbs the bioenergetical processes of cells by damage to mitochondria. Nonetheless, it has not yet been identified clearly if cryopreservation causes some disruption in the genetic integrity of reproductive cells and the safety of this approach still needs to be confirmed. The present study was undertaken on the spermatozoa of weather loach (Misgurnus tassilis) and blastomeres cells of zebrafish (Danio rerio). It was shown that survival was decreased for embryos derived from sperm after cryoprotectant treatment or cryopreservation. Some evidence has emerged that this decrease is more likely to reflect some genetic instability caused by cryopreservation of sperm. The present study showed for the first time that the DNA repair system of oocytes was activated after fertilisation with cryopreserved sperm. The effect of DNA repair system was also studied. It was found that incubation of fertilised eggs in caffeine could reverse the detrimental effects of cryopreservation of loach sperm on subsequent embryo development. On the other hand incubation of fertilised eggs with 3-aminobenzamide - inhibitor of the poly (ADP-ribose) polymerase (PARP)- brought further decrease in the survival of embryos derived from cryopreserved sperm. The effect of individual donors of sperm and eggs on overall embryo survival was also studied and these investigations revealed significant differences between different donors. Effect of cryopreservation on zebrafish blastomeres was studied at the DNA molecular level. Mitochondrial DNA was sequenced after cryopreservation and increased level of frequency of the mutation was observed. This finding showed that cryopreservation might potentially increase the instability of mtDNA genome. The significance of these changes on the subsequent function of the cells is to be elucidated. Meanwhile this study suggests that it is important to be cautious in making judgements on the safety of cryopreservation techniques in reproduction.en
dc.language.isoenen
dc.publisherUniversity of Bedfordshireen
dc.subjectC110 Applied Biologyen
dc.subjectcryopreservationen
dc.subjectzebrafishen
dc.subjectDanio rerioen
dc.subjectMisgurnus tassilisen
dc.subjectweather loachen
dc.subjectspermen
dc.titleThe effect of cryopreservation on the genome of fish reproductive cellsen
dc.typeThesis or dissertationen
dc.type.qualificationnamePhDen_GB
dc.type.qualificationlevelPhDen
dc.publisher.institutionUniversity of Bedfordshireen
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