High Genetic Load in the Pacific Oyster Crassostrea gigas
Abstract The causes of inbreeding depression and the converse phenomenon of heterosis or hybrid vigor remain poorly understood despite their scientific and agricultural importance. In bivalve molluscs, related phenomena, marker-associated heterosis and distortion of marker segregation ratios, have b...
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Oxford University Press (OUP)
2001
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Online Access: | http://dx.doi.org/10.1093/genetics/159.1.255 https://academic.oup.com/genetics/article-pdf/159/1/255/42033946/genetics0255.pdf |
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croxfordunivpr:10.1093/genetics/159.1.255 2024-10-13T14:06:46+00:00 High Genetic Load in the Pacific Oyster Crassostrea gigas Launey, Sophie Hedgecock, Dennis 2001 http://dx.doi.org/10.1093/genetics/159.1.255 https://academic.oup.com/genetics/article-pdf/159/1/255/42033946/genetics0255.pdf en eng Oxford University Press (OUP) https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model Genetics volume 159, issue 1, page 255-265 ISSN 1943-2631 journal-article 2001 croxfordunivpr https://doi.org/10.1093/genetics/159.1.255 2024-09-17T04:30:48Z Abstract The causes of inbreeding depression and the converse phenomenon of heterosis or hybrid vigor remain poorly understood despite their scientific and agricultural importance. In bivalve molluscs, related phenomena, marker-associated heterosis and distortion of marker segregation ratios, have been widely reported over the past 25 years. A large load of deleterious recessive mutations could explain both phenomena, according to the dominance hypothesis of heterosis. Using inbred lines derived from a natural population of Pacific oysters and classical crossbreeding experiments, we compare the segregation ratios of microsatellite DNA markers at 6 hr and 2–3 months postfertilization in F2 or F3 hybrid families. We find evidence for strong and widespread selection against identical-by-descent marker homozygotes. The marker segregation data, when fit to models of selection against linked deleterious recessive mutations and extrapolated to the whole genome, suggest that the wild founders of inbred lines carried a minimum of 8–14 highly deleterious recessive mutations. This evidence for a high genetic load strongly supports the dominance theory of heterosis and inbreeding depression and establishes the oyster as an animal model for understanding the genetic and physiological causes of these economically important phenomena. Article in Journal/Newspaper Crassostrea gigas Pacific oyster Oxford University Press Pacific Genetics 159 1 255 265 |
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Open Polar |
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Oxford University Press |
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croxfordunivpr |
language |
English |
description |
Abstract The causes of inbreeding depression and the converse phenomenon of heterosis or hybrid vigor remain poorly understood despite their scientific and agricultural importance. In bivalve molluscs, related phenomena, marker-associated heterosis and distortion of marker segregation ratios, have been widely reported over the past 25 years. A large load of deleterious recessive mutations could explain both phenomena, according to the dominance hypothesis of heterosis. Using inbred lines derived from a natural population of Pacific oysters and classical crossbreeding experiments, we compare the segregation ratios of microsatellite DNA markers at 6 hr and 2–3 months postfertilization in F2 or F3 hybrid families. We find evidence for strong and widespread selection against identical-by-descent marker homozygotes. The marker segregation data, when fit to models of selection against linked deleterious recessive mutations and extrapolated to the whole genome, suggest that the wild founders of inbred lines carried a minimum of 8–14 highly deleterious recessive mutations. This evidence for a high genetic load strongly supports the dominance theory of heterosis and inbreeding depression and establishes the oyster as an animal model for understanding the genetic and physiological causes of these economically important phenomena. |
format |
Article in Journal/Newspaper |
author |
Launey, Sophie Hedgecock, Dennis |
spellingShingle |
Launey, Sophie Hedgecock, Dennis High Genetic Load in the Pacific Oyster Crassostrea gigas |
author_facet |
Launey, Sophie Hedgecock, Dennis |
author_sort |
Launey, Sophie |
title |
High Genetic Load in the Pacific Oyster Crassostrea gigas |
title_short |
High Genetic Load in the Pacific Oyster Crassostrea gigas |
title_full |
High Genetic Load in the Pacific Oyster Crassostrea gigas |
title_fullStr |
High Genetic Load in the Pacific Oyster Crassostrea gigas |
title_full_unstemmed |
High Genetic Load in the Pacific Oyster Crassostrea gigas |
title_sort |
high genetic load in the pacific oyster crassostrea gigas |
publisher |
Oxford University Press (OUP) |
publishDate |
2001 |
url |
http://dx.doi.org/10.1093/genetics/159.1.255 https://academic.oup.com/genetics/article-pdf/159/1/255/42033946/genetics0255.pdf |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Crassostrea gigas Pacific oyster |
genre_facet |
Crassostrea gigas Pacific oyster |
op_source |
Genetics volume 159, issue 1, page 255-265 ISSN 1943-2631 |
op_rights |
https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model |
op_doi |
https://doi.org/10.1093/genetics/159.1.255 |
container_title |
Genetics |
container_volume |
159 |
container_issue |
1 |
container_start_page |
255 |
op_container_end_page |
265 |
_version_ |
1812812984344379392 |