Several studies have suggested that significant genetic variability might exist for some early de... more Several studies have suggested that significant genetic variability might exist for some early developmental traits in the Pacific oyster, C. gigas. However, most studies have examined only limited numbers of families. More critically, these families were rarely replicated, leading to possible bias due to heterogeneous larval rearing conditions among families. To overcome these potential problems, we used a mixed-family approach with subsequent parentage analysis. A recently developed set of three multiplexed microsatellite markers was used to determine parentage in a complete factorial cross between 12 males and 4 females. Larvae were reared at two different temperatures (20 and 26°C) to provide a contrast resembling wild versus hatchery conditions. Samples were collected at the larval stage just before settlement and 2 months later. We observed significant male and female effects on larval growth and survival. More importantly, significant genotype x environment interactions were ...
The 2011 French Bioethics Law regarding disclosure of genetic information within families enables... more The 2011 French Bioethics Law regarding disclosure of genetic information within families enables health professionals to notify any at-risk relatives directly, with the patient’s consent, using a template letter. To assess the impact of this template letter in terms of understanding, personal feelings and intent to contact a health professional, we conducted a study interviewing patients, members of the public and genetic professionals. Although the main response to the letter was anxiety, this was associated with good understanding of the content and most individuals mentioned intention to contact a health professional.
In France, 126 centers for cancer genetics coordinate genetic testing and high-risk cancer survei... more In France, 126 centers for cancer genetics coordinate genetic testing and high-risk cancer surveillance for individuals and their families with hereditary cancer syndromes. Since 2012, the French National Cancer Institute (INCa) supports 17 projects to promote and manage the monitoring of individuals genetically predisposed to cancer. They were assigned 4 missions by INCa including expertise for difficult cases. We initiated a national survey to assess how the oncogenetic clinics responded to the 4th mission for women at high risk of developing breast cancers. We sent the survey to all the French oncogeneticists. We aimed at evaluating the modalities and the extent of implementation of the Multidisciplinary team (MDT) meetings regarding the management of women who have genetically higher risks to develop breast cancer. Fourteen people from 12 administrative regions, who represent 10 of the 17 projects, answered the form. Eleven participants reported the submission of medical cases in Oncogenetics MDT meetings (79 %), 5 in senology MDT meetings (36 %), 5 in MDT meetings dedicated to patients at high risk for breast cancer (36 %) and 2 in network meetings (14 %). Some structures discuss medical cases through different MDT meetings. Although MDT meetings are valuable practices to optimize treatment or management options for patients, its settings might be subject to difficulties to federate the appropriate-number of participants as well as cost-effectiveness issues. This survey thus suggests the need of a standardized process of MDT meetings while taking account specificities of oncogenetics.
We report the case of a 56-year-old Caucasian woman (gravida 2, para 2) diagnosed with ovarian ca... more We report the case of a 56-year-old Caucasian woman (gravida 2, para 2) diagnosed with ovarian cancer, further to abdominal discomfort. Histological examination confirmed a serous papillary adenocarcinoma, poorly differentiated of grade III. A colpo-hysterectomy with bilateral adnexectomy and omentectomy were performed. Simultaneously, oncogenetic consultation was proposed and BRCA 1 & 2 genetic testing completed. According to the family tree, there was no previous history of cancer, making this case presumably isolated. The BRCA1 variant R1699Q (c.5096G>A p.Arg1699Gln) was identified from two independent blood samples. As shown by Spurdle et al. (2013) across multiple assays, this variant displays equivocal functional deficiency that could be associated with intermediate risk of breast and ovarian cancer. Using 30 families in a segregation analysis, the authors estimated for this variant a cumulative risk to age 70 of breast or ovarian cancer of 24%. This case report poses signi...
In Europe, genetic counsellors are employed in specialist genetic centres or other specialist uni... more In Europe, genetic counsellors are employed in specialist genetic centres or other specialist units. According to the European Board of Medical Genetics, the genetic counsellor must fulfil a range of roles, including provision of information and facilitation of psychosocial adjustment of the client to their genetic status and situation. To evaluate the extent to which genetic counsellors fulfil their prescribed roles, we conducted a systematic review of the published relevant scientific evidence. We searched five relevant electronic databases (Medline, CINAHL, SocIndex, AMED and PsychInfo) using relevant search terms and handsearched four subject-specific journals for research-based papers published in English between 1 January 2000 and 30 June 2013. Of 419 potential papers identified initially, seven satisfied the inclusion criteria for the review. Themes derived from the thematic analysis of the data were: (i) rationale for genetic counsellors to provide care, (ii) appropriate rol...
ABSTRACT Oysters, like many other marine bivalves, are characterized by high fertility and low su... more ABSTRACT Oysters, like many other marine bivalves, are characterized by high fertility and low survival rates during the precocious stages. Hatchery reproduction, realised in very different conditions than in their natural habitat (density, food, temperature, etc.), tends to optimize the production of larvae and juveniles. As a consequence, slow growing larvae are systematically culled. Previous results suggest the existence of a genetic variability linked to precocious development. Our approach consists in studying the evolutionary process (genetic drift and selection) linked with hatchery reproduction. Thanks to microsatellite markers enabling us to analyse the relatedness in "mixed" cultivated families, we studied the variability of breeding success in controlled crossbreeding in order (1) to quantify the impact of the larviculture practices on the effective population size, (2) to describe the temporal structuration of the larval population through its development (and thus to try and estimate the potential loss caused by the culling of small larvae) and (3) to look for possible genotype x environment interactions. The first results show a diversity loss linked to larviculture practices, as well as a differential temporal structuration of the larval population, confirming the existence of a genetic variability for the characters related to precocious development in this species. Les huîtres, comme de nombreux bivalves marins, se caractérisent par une très forte fécondité et de faibles taux de survie aux stades précoces. La reproduction en écloserie, réalisée dans des conditions bien différentes de celles du milieu naturel (densité, alimentation, température...), tend à optimiser la production de larves et de juvéniles. Ainsi, les larves présentant des croissances lentes sont systématiquement éliminées. Des résultats précédents suggérant qu'il existe de la variabilité génétique pour les caractères liés au développement précoce, notre démarche consiste à étudier les processus évolutifs (dérive génétique et sélection) liés à la reproduction en écloserie. L'utilisation de marqueurs microsatellites permettant de réaliser des analyses de parenté dans des familles élevées « en mélange », nous avons étudié la variabilité du succès reproducteur dans des croisements contrôlés afin de (1) quantifier l'impact des pratiques d'élevage larvaire sur la taille efficace de la population, (2) de décrire la structuration temporelle de la population larvaire au cours de son développement (et donc d'estimer la part potentiellement perdue par élimination des plus petites larves) et (3) rechercher d'éventuelles interactions génotype x environnement. Les premiers résultats obtenus montrent une perte de diversité liée aux pratiques d'élevage, ainsi qu'une structuration temporelle différentielle de la population larvaire, confirmant qu'il existe de la variabilité génétique pour les caractères liés au développement précoce chez cette espèce.
ABSTRACT Several studies have suggested that significant genetic variability might exist for some... more ABSTRACT Several studies have suggested that significant genetic variability might exist for some early developmental traits in the Pacific oyster, C. gigas. However, most studies have examined only limited numbers of families. More critically, these families were rarely replicated, leading to possible bias due to heterogeneous larval rearing conditions among families. To overcome these potential problems, we used a mixed-family approach with subsequent parentage analysis. A recently developed set of three multiplexed microsatellite markers was used to determine parentage in a complete factorial cross between 12 males and 4 females. Larvae were reared at two different temperatures (20 and 26°C) to provide a contrast resembling wild versus hatchery conditions. Samples were collected at the larval stage just before settlement and 2 months later. We observed significant male and female effects on larval growth and survival. More importantly, significant genotype x environment interactions were also observed for these traits. The potential selective pressures related to intensive rearing practices in commercial hatcheries will be discussed in the light of our findings.
ABSTRACT he European flat oyster (Ostrea edulis L.) is a marine bivalve whose natural geographica... more ABSTRACT he European flat oyster (Ostrea edulis L.) is a marine bivalve whose natural geographical distribution ranges along the European Atlantic coast from Norway to Morocco, in addition to the Mediterranean and Black Sea. Previous studies of allozymes, microsat-ellites and mitochondrial differentiation over the whole range concluded that a significant divergence existed between Mediterranean and Atlantic populations, together with an isolation-by-distance pattern. However, the average mitochondrial haplotypic diversity displayed a high among populations variance, reflecting smaller effective population size in some locations. Additionally, a ten-fold quantitative difference was observed in the same study in Fst between the mitochondrial and the nuclear genomes, which could be due to sex biased differential reproductive success between males and females. In order to further document this hypothesis, two experiments were conducted. First, brooding females were sampled in a wild population and the number of males fertilizing a given female estimated. Then, parentage analyses were achieved under experimental conditions: successive mass spawnings were collected from a population of potential genitors kept in hatchery, whose genotypes were known, in order to infer a posteriori the relative contribution of each genitor. Moreover, we aimed to better understand the reproduction dynamics of this species. Several patterns of spawning could be distinguished: unique, successive or extended in time. The different parental contributions and reproductive behaviors observed in these experiments are discussed in the context of the hypothesis of a variance in the reproductive success of males and females and consequences in local and temporal reduced effective population sizes.
ABSTRACT In order to understand better some fundamental aspects of the bivalve biology, one has t... more ABSTRACT In order to understand better some fundamental aspects of the bivalve biology, one has to pay attention to the variance of their breeding success, the time structure of the populations and their effective size. An abundant literature shows the existence of a heterozygote deficit as well as positive relationships between heterozygoty and fitness components. This last point is the subject of explanatory hypotheses which have never been clearly decided between until now. One of these hypotheses is the possible existence of a certain degree of inbreeding among those populations. This is only possible in the case of separated colonies coming from a small amount of spawners, thus creating blood relations between individuals recruited from the same area, and consequently a restricted local effective stock and the inbreeding of their offspring. In order to go deeper into this hypothesis, the interactions between genetics and demography at a population level have been studied on flat oyster larvae, spats and adults, through the analysis of five microsatellite markers. ... Chez les Bivalves, la variance du succès reproducteur, la structure temporelle des populations et leur taille efficace sont autant d'éléments dont la connaissance est indispensable pour comprendre certains aspects fondamentaux de leur biologie. En particulier, une abondante littérature montre l'existence de déficits en hétérozygotes et de relations positives entre hétérozygotie et composantes de la valeur sélective. Ce dernier point fait l'objet d'hypothèses explicatives qui n'ont pas été clairement départagées jusqu'à présent. Une de ces hypothèses est l'existence possible d'un certain niveau de consanguinité dans les populations. Ceci n'est possible que s'il existe des cohortes séparées issues d'un nombre restreint de géniteurs, créant ainsi de l'apparentement entre individus recrutés au même endroit, et donc un effectif efficace local réduit et de la consanguinité dans leur descendance. Afin d'approfondir cette hypothèse, les interactions entre génétique et démographie à l'échelle de la population ont été étudiées chez des larves, naissains et adultes d'huître plate, grâce à l'analyse de 5 marqueurs microsatellites. Nous avons réalisé trois études complémentaires qui nous ont permis d'étudier : - la variance des fréquences alléliques au cours d'une saison de recrutement dans une population naturelle Les tailles efficaces des populations ont été estimées en comparant la variabilité observée dans les 3 cohortes recrutées à celle observée chez les adultes. - les contributions paternelles en réalisant des échantillonnages de larves non encore émises de femelles incubantes. La variabilité génétique de chaque "portée" (famille maternelle) a été analysée et comparée avec la variabilité observée au sein de la population adulte. - la variance du succès reproducteur individuel au sein d'une population expérimentale en écloserie.
Several studies have suggested that significant genetic variability might exist for some early de... more Several studies have suggested that significant genetic variability might exist for some early developmental traits in the Pacific oyster, C. gigas. However, most studies have examined only limited numbers of families. More critically, these families were rarely replicated, leading to possible bias due to heterogeneous larval rearing conditions among families. To overcome these potential problems, we used a mixed-family approach with subsequent parentage analysis. A recently developed set of three multiplexed microsatellite markers was used to determine parentage in a complete factorial cross between 12 males and 4 females. Larvae were reared at two different temperatures (20 and 26°C) to provide a contrast resembling wild versus hatchery conditions. Samples were collected at the larval stage just before settlement and 2 months later. We observed significant male and female effects on larval growth and survival. More importantly, significant genotype x environment interactions were ...
The 2011 French Bioethics Law regarding disclosure of genetic information within families enables... more The 2011 French Bioethics Law regarding disclosure of genetic information within families enables health professionals to notify any at-risk relatives directly, with the patient’s consent, using a template letter. To assess the impact of this template letter in terms of understanding, personal feelings and intent to contact a health professional, we conducted a study interviewing patients, members of the public and genetic professionals. Although the main response to the letter was anxiety, this was associated with good understanding of the content and most individuals mentioned intention to contact a health professional.
In France, 126 centers for cancer genetics coordinate genetic testing and high-risk cancer survei... more In France, 126 centers for cancer genetics coordinate genetic testing and high-risk cancer surveillance for individuals and their families with hereditary cancer syndromes. Since 2012, the French National Cancer Institute (INCa) supports 17 projects to promote and manage the monitoring of individuals genetically predisposed to cancer. They were assigned 4 missions by INCa including expertise for difficult cases. We initiated a national survey to assess how the oncogenetic clinics responded to the 4th mission for women at high risk of developing breast cancers. We sent the survey to all the French oncogeneticists. We aimed at evaluating the modalities and the extent of implementation of the Multidisciplinary team (MDT) meetings regarding the management of women who have genetically higher risks to develop breast cancer. Fourteen people from 12 administrative regions, who represent 10 of the 17 projects, answered the form. Eleven participants reported the submission of medical cases in Oncogenetics MDT meetings (79 %), 5 in senology MDT meetings (36 %), 5 in MDT meetings dedicated to patients at high risk for breast cancer (36 %) and 2 in network meetings (14 %). Some structures discuss medical cases through different MDT meetings. Although MDT meetings are valuable practices to optimize treatment or management options for patients, its settings might be subject to difficulties to federate the appropriate-number of participants as well as cost-effectiveness issues. This survey thus suggests the need of a standardized process of MDT meetings while taking account specificities of oncogenetics.
We report the case of a 56-year-old Caucasian woman (gravida 2, para 2) diagnosed with ovarian ca... more We report the case of a 56-year-old Caucasian woman (gravida 2, para 2) diagnosed with ovarian cancer, further to abdominal discomfort. Histological examination confirmed a serous papillary adenocarcinoma, poorly differentiated of grade III. A colpo-hysterectomy with bilateral adnexectomy and omentectomy were performed. Simultaneously, oncogenetic consultation was proposed and BRCA 1 & 2 genetic testing completed. According to the family tree, there was no previous history of cancer, making this case presumably isolated. The BRCA1 variant R1699Q (c.5096G>A p.Arg1699Gln) was identified from two independent blood samples. As shown by Spurdle et al. (2013) across multiple assays, this variant displays equivocal functional deficiency that could be associated with intermediate risk of breast and ovarian cancer. Using 30 families in a segregation analysis, the authors estimated for this variant a cumulative risk to age 70 of breast or ovarian cancer of 24%. This case report poses signi...
In Europe, genetic counsellors are employed in specialist genetic centres or other specialist uni... more In Europe, genetic counsellors are employed in specialist genetic centres or other specialist units. According to the European Board of Medical Genetics, the genetic counsellor must fulfil a range of roles, including provision of information and facilitation of psychosocial adjustment of the client to their genetic status and situation. To evaluate the extent to which genetic counsellors fulfil their prescribed roles, we conducted a systematic review of the published relevant scientific evidence. We searched five relevant electronic databases (Medline, CINAHL, SocIndex, AMED and PsychInfo) using relevant search terms and handsearched four subject-specific journals for research-based papers published in English between 1 January 2000 and 30 June 2013. Of 419 potential papers identified initially, seven satisfied the inclusion criteria for the review. Themes derived from the thematic analysis of the data were: (i) rationale for genetic counsellors to provide care, (ii) appropriate rol...
ABSTRACT Oysters, like many other marine bivalves, are characterized by high fertility and low su... more ABSTRACT Oysters, like many other marine bivalves, are characterized by high fertility and low survival rates during the precocious stages. Hatchery reproduction, realised in very different conditions than in their natural habitat (density, food, temperature, etc.), tends to optimize the production of larvae and juveniles. As a consequence, slow growing larvae are systematically culled. Previous results suggest the existence of a genetic variability linked to precocious development. Our approach consists in studying the evolutionary process (genetic drift and selection) linked with hatchery reproduction. Thanks to microsatellite markers enabling us to analyse the relatedness in "mixed" cultivated families, we studied the variability of breeding success in controlled crossbreeding in order (1) to quantify the impact of the larviculture practices on the effective population size, (2) to describe the temporal structuration of the larval population through its development (and thus to try and estimate the potential loss caused by the culling of small larvae) and (3) to look for possible genotype x environment interactions. The first results show a diversity loss linked to larviculture practices, as well as a differential temporal structuration of the larval population, confirming the existence of a genetic variability for the characters related to precocious development in this species. Les huîtres, comme de nombreux bivalves marins, se caractérisent par une très forte fécondité et de faibles taux de survie aux stades précoces. La reproduction en écloserie, réalisée dans des conditions bien différentes de celles du milieu naturel (densité, alimentation, température...), tend à optimiser la production de larves et de juvéniles. Ainsi, les larves présentant des croissances lentes sont systématiquement éliminées. Des résultats précédents suggérant qu'il existe de la variabilité génétique pour les caractères liés au développement précoce, notre démarche consiste à étudier les processus évolutifs (dérive génétique et sélection) liés à la reproduction en écloserie. L'utilisation de marqueurs microsatellites permettant de réaliser des analyses de parenté dans des familles élevées « en mélange », nous avons étudié la variabilité du succès reproducteur dans des croisements contrôlés afin de (1) quantifier l'impact des pratiques d'élevage larvaire sur la taille efficace de la population, (2) de décrire la structuration temporelle de la population larvaire au cours de son développement (et donc d'estimer la part potentiellement perdue par élimination des plus petites larves) et (3) rechercher d'éventuelles interactions génotype x environnement. Les premiers résultats obtenus montrent une perte de diversité liée aux pratiques d'élevage, ainsi qu'une structuration temporelle différentielle de la population larvaire, confirmant qu'il existe de la variabilité génétique pour les caractères liés au développement précoce chez cette espèce.
ABSTRACT Several studies have suggested that significant genetic variability might exist for some... more ABSTRACT Several studies have suggested that significant genetic variability might exist for some early developmental traits in the Pacific oyster, C. gigas. However, most studies have examined only limited numbers of families. More critically, these families were rarely replicated, leading to possible bias due to heterogeneous larval rearing conditions among families. To overcome these potential problems, we used a mixed-family approach with subsequent parentage analysis. A recently developed set of three multiplexed microsatellite markers was used to determine parentage in a complete factorial cross between 12 males and 4 females. Larvae were reared at two different temperatures (20 and 26°C) to provide a contrast resembling wild versus hatchery conditions. Samples were collected at the larval stage just before settlement and 2 months later. We observed significant male and female effects on larval growth and survival. More importantly, significant genotype x environment interactions were also observed for these traits. The potential selective pressures related to intensive rearing practices in commercial hatcheries will be discussed in the light of our findings.
ABSTRACT he European flat oyster (Ostrea edulis L.) is a marine bivalve whose natural geographica... more ABSTRACT he European flat oyster (Ostrea edulis L.) is a marine bivalve whose natural geographical distribution ranges along the European Atlantic coast from Norway to Morocco, in addition to the Mediterranean and Black Sea. Previous studies of allozymes, microsat-ellites and mitochondrial differentiation over the whole range concluded that a significant divergence existed between Mediterranean and Atlantic populations, together with an isolation-by-distance pattern. However, the average mitochondrial haplotypic diversity displayed a high among populations variance, reflecting smaller effective population size in some locations. Additionally, a ten-fold quantitative difference was observed in the same study in Fst between the mitochondrial and the nuclear genomes, which could be due to sex biased differential reproductive success between males and females. In order to further document this hypothesis, two experiments were conducted. First, brooding females were sampled in a wild population and the number of males fertilizing a given female estimated. Then, parentage analyses were achieved under experimental conditions: successive mass spawnings were collected from a population of potential genitors kept in hatchery, whose genotypes were known, in order to infer a posteriori the relative contribution of each genitor. Moreover, we aimed to better understand the reproduction dynamics of this species. Several patterns of spawning could be distinguished: unique, successive or extended in time. The different parental contributions and reproductive behaviors observed in these experiments are discussed in the context of the hypothesis of a variance in the reproductive success of males and females and consequences in local and temporal reduced effective population sizes.
ABSTRACT In order to understand better some fundamental aspects of the bivalve biology, one has t... more ABSTRACT In order to understand better some fundamental aspects of the bivalve biology, one has to pay attention to the variance of their breeding success, the time structure of the populations and their effective size. An abundant literature shows the existence of a heterozygote deficit as well as positive relationships between heterozygoty and fitness components. This last point is the subject of explanatory hypotheses which have never been clearly decided between until now. One of these hypotheses is the possible existence of a certain degree of inbreeding among those populations. This is only possible in the case of separated colonies coming from a small amount of spawners, thus creating blood relations between individuals recruited from the same area, and consequently a restricted local effective stock and the inbreeding of their offspring. In order to go deeper into this hypothesis, the interactions between genetics and demography at a population level have been studied on flat oyster larvae, spats and adults, through the analysis of five microsatellite markers. ... Chez les Bivalves, la variance du succès reproducteur, la structure temporelle des populations et leur taille efficace sont autant d'éléments dont la connaissance est indispensable pour comprendre certains aspects fondamentaux de leur biologie. En particulier, une abondante littérature montre l'existence de déficits en hétérozygotes et de relations positives entre hétérozygotie et composantes de la valeur sélective. Ce dernier point fait l'objet d'hypothèses explicatives qui n'ont pas été clairement départagées jusqu'à présent. Une de ces hypothèses est l'existence possible d'un certain niveau de consanguinité dans les populations. Ceci n'est possible que s'il existe des cohortes séparées issues d'un nombre restreint de géniteurs, créant ainsi de l'apparentement entre individus recrutés au même endroit, et donc un effectif efficace local réduit et de la consanguinité dans leur descendance. Afin d'approfondir cette hypothèse, les interactions entre génétique et démographie à l'échelle de la population ont été étudiées chez des larves, naissains et adultes d'huître plate, grâce à l'analyse de 5 marqueurs microsatellites. Nous avons réalisé trois études complémentaires qui nous ont permis d'étudier : - la variance des fréquences alléliques au cours d'une saison de recrutement dans une population naturelle Les tailles efficaces des populations ont été estimées en comparant la variabilité observée dans les 3 cohortes recrutées à celle observée chez les adultes. - les contributions paternelles en réalisant des échantillonnages de larves non encore émises de femelles incubantes. La variabilité génétique de chaque "portée" (famille maternelle) a été analysée et comparée avec la variabilité observée au sein de la population adulte. - la variance du succès reproducteur individuel au sein d'une population expérimentale en écloserie.
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