The sex determination of the oyster Crassostrea gigas : from phenotype to underlying molecular factors
Knowledge about the mode of reproduction and the sex determination of the cupped oyster Crassostrea gigas remains limited. As a sequential hermaphroditic species, sex determination takes place several times during its lifetime. As part of this thesis, the sexual phenotypes of the first 6 years of li...
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fttriple:oai:gotriple.eu:10670/1.mvanb6 2023-05-15T15:57:45+02:00 The sex determination of the oyster Crassostrea gigas : from phenotype to underlying molecular factors Le déterminisme sexuel de l'huître crassostrea gigas : du phénotype aux facteurs moléculaires sous-jacents Broquard, Coralie Normandie Martinez, Anne-Sophie 2019-12-12 http://www.theses.fr/2019NORMC264/document fr fre 10670/1.mvanb6 http://www.theses.fr/2019NORMC264/document other Theses.fr Déterminisme sexuel Facteurs moléculaires Sex determination Hermaphroditism Growth Molecular factors C. gigas anthro-se psy Thesis https://vocabularies.coar-repositories.org/resource_types/c_46ec/ 2019 fttriple 2023-01-22T17:57:35Z Knowledge about the mode of reproduction and the sex determination of the cupped oyster Crassostrea gigas remains limited. As a sequential hermaphroditic species, sex determination takes place several times during its lifetime. As part of this thesis, the sexual phenotypes of the first 6 years of life of oysters were identified in two cohorts. Thus, the sex ratio was biased towards females from the first sexual maturity, as well as for all subsequent years. After six years of sexing, 42%, 32%, 19%, 5%, 1% and 0.1% of oysters showed 0, 1, 2, 2, 3, 4 and 5 sex changes. The frequency of sex changes also decreased with age (34% between years 1-2 to 9% between years 5-6). This thesis work has also sought to determine the influence of sex and sex change on the morphological parameters of individuals. Thus, a sexual dimorphism was identified for the total weight as well as the length, width and thickness of the shell, in favour of female oysters, including those that have changed sex in the male to female direction. Finally, a transcriptomic analysis of the gonad of individuals with contrasted phenotypes ("true" females and "true" males) was to provide further knowledge on the molecular factors of sex determination. Thus, this approach made it possible (i) to identify the expression patterns of homologs of sex-determining genes, over the entire period of this mechanism and (ii) to identify new molecular actors of interest, overexpressed specifically in one sex during sex determination. Each expression pattern obtained in "true" males or "true" females could thus be interpreted in the light of the most probable future phenotype of the sex, despite sequential hermaphroditism. This approach allowed to refine hypotheses about the role of various factors in determining the sex of this cupped oyster. Le savoir relatif au mode de reproduction et au déterminisme sexuel de l’huître creuse Crassostrea gigas demeure limité. Etant une espèce hermaphrodite séquentielle, la détermination de son sexe a lieu plusieurs fois au cours ... Thesis Crassostrea gigas Unknown |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
French |
topic |
Déterminisme sexuel Facteurs moléculaires Sex determination Hermaphroditism Growth Molecular factors C. gigas anthro-se psy |
spellingShingle |
Déterminisme sexuel Facteurs moléculaires Sex determination Hermaphroditism Growth Molecular factors C. gigas anthro-se psy Broquard, Coralie The sex determination of the oyster Crassostrea gigas : from phenotype to underlying molecular factors |
topic_facet |
Déterminisme sexuel Facteurs moléculaires Sex determination Hermaphroditism Growth Molecular factors C. gigas anthro-se psy |
description |
Knowledge about the mode of reproduction and the sex determination of the cupped oyster Crassostrea gigas remains limited. As a sequential hermaphroditic species, sex determination takes place several times during its lifetime. As part of this thesis, the sexual phenotypes of the first 6 years of life of oysters were identified in two cohorts. Thus, the sex ratio was biased towards females from the first sexual maturity, as well as for all subsequent years. After six years of sexing, 42%, 32%, 19%, 5%, 1% and 0.1% of oysters showed 0, 1, 2, 2, 3, 4 and 5 sex changes. The frequency of sex changes also decreased with age (34% between years 1-2 to 9% between years 5-6). This thesis work has also sought to determine the influence of sex and sex change on the morphological parameters of individuals. Thus, a sexual dimorphism was identified for the total weight as well as the length, width and thickness of the shell, in favour of female oysters, including those that have changed sex in the male to female direction. Finally, a transcriptomic analysis of the gonad of individuals with contrasted phenotypes ("true" females and "true" males) was to provide further knowledge on the molecular factors of sex determination. Thus, this approach made it possible (i) to identify the expression patterns of homologs of sex-determining genes, over the entire period of this mechanism and (ii) to identify new molecular actors of interest, overexpressed specifically in one sex during sex determination. Each expression pattern obtained in "true" males or "true" females could thus be interpreted in the light of the most probable future phenotype of the sex, despite sequential hermaphroditism. This approach allowed to refine hypotheses about the role of various factors in determining the sex of this cupped oyster. Le savoir relatif au mode de reproduction et au déterminisme sexuel de l’huître creuse Crassostrea gigas demeure limité. Etant une espèce hermaphrodite séquentielle, la détermination de son sexe a lieu plusieurs fois au cours ... |
author2 |
Normandie Martinez, Anne-Sophie |
format |
Thesis |
author |
Broquard, Coralie |
author_facet |
Broquard, Coralie |
author_sort |
Broquard, Coralie |
title |
The sex determination of the oyster Crassostrea gigas : from phenotype to underlying molecular factors |
title_short |
The sex determination of the oyster Crassostrea gigas : from phenotype to underlying molecular factors |
title_full |
The sex determination of the oyster Crassostrea gigas : from phenotype to underlying molecular factors |
title_fullStr |
The sex determination of the oyster Crassostrea gigas : from phenotype to underlying molecular factors |
title_full_unstemmed |
The sex determination of the oyster Crassostrea gigas : from phenotype to underlying molecular factors |
title_sort |
sex determination of the oyster crassostrea gigas : from phenotype to underlying molecular factors |
publishDate |
2019 |
url |
http://www.theses.fr/2019NORMC264/document |
genre |
Crassostrea gigas |
genre_facet |
Crassostrea gigas |
op_source |
Theses.fr |
op_relation |
10670/1.mvanb6 http://www.theses.fr/2019NORMC264/document |
op_rights |
other |
_version_ |
1766393448119664640 |