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Possible links between MH polymorphism and resistance to AGD in Atlantic salmon Salmo salar
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Abstracts / Aquaculture 272S1 (2007) S238–S321
used in our laboratory. This system can also be applied with other genetic markers, for example, in construction of a genetic linkage map of Atlantic cod.
fish) makes this approach feasible for broodstock management in commercial aquaculture operations. doi:10.1016/j.aquaculture.2007.07.201
doi:10.1016/j.aquaculture.2007.07.200
Microsatellite DNA assignment of progeny to parents enables communal freshwater rearing in an Atlantic salmon selective breeding program a
a
b
b
R.E. Withler , J. Supernault , B. Swift , R. Peterson , S. Fukui c a Pacific Biological Station Fisheries and Oceans Canada 3190 Hammond Bay Road Nanaimo, B.C. Canada V9T 6N7 b TRI-GEN Fish Improvement 2244 Wilson Road Agassiz, B.C. Canada V0M 1A1 c Mainstream Canada #203-919 Island Highway Campbell River, B.C. Canada V9W 2C2 Environmental effects introduced among families by rearing in individual freshwater tanks prior to marking can impede progress in selection for increased growth rate and size in domesticated salmonids. Accurate and inexpensive genetic methods of identifying progeny to parents in selective breeding programs would enable communal freshwater rearing of families. We developed a cost-effective suite of eight microsatellite loci to assign progeny from 135 fullsib families of domesticated Atlantic salmon to parents. Approximately 150 progeny from each family were communally reared for 8 months and sampled for genetic analysis upon transfer to seawater. Maximum-likelihood assignment of 3000 progeny to fullsib families and comparison of reconstructed with known parental genotypes enabled the identification of all 135 families. An unplanned application of the methodology involved another year class of the same strain in which the tagged broodstock group was lost and family brands on a backup group proved unreadable. This backup group of ‘progeny’ had been reared in seawater for 3 years and parental tissue samples were available for only 91 of the 146 families originally transferred to seawater. Microsatellite analysis of 2911 ‘progeny’ and assignment to families with known (87 families) and unknown (53 families) parental genotypes was conducted within 3 weeks. Quantitative genetic analysis (BLUP) of weight and growth was based on the microsatellite assignment to family rectified problems (nonconvergence) encountered when the analysis was based on family assignment by brandreading. The cost of automated analysis (∼$12 U.S. per
Associations between differential gene expression and increased AGD resistance in Atlantic salmon Salmo salar J.W. Wynne a, M.T. Cook a, B. Nowak b, D. Lovell c, M. O'Sullivan c, G. Stone c, N.G. Elliott a a CSIRO Food Futures Flagship, CSIRO Marine and Atmospheric Research, Hobart, Tasmania, Australia b School of Aquaculture, Univeristy of Tasmania, Aquafin CRC, Launceston, Tasmania, Australia c CSIRO Mathematical and Information Sciences, North Ryde, New South Wales, Australia Previous research suggests that resistance to amoebic gill disease (AGD) is to some extent genetically controlled. As a consequence of these findings, developing selective breeding programs to increase AGD resistance have become a major focus in Tasmania. In order to gain maximum efficiency from such breeding programs, genes which influence resistance must be identified. This study aimed to identify such genes by comparing differential gene expression between fish displaying high and low levels of AGD resistance. Briefly, a population of Atlantic salmon were experimentally challenged with AGD over a 19 day period. Following challenge all individuals were euthanised, organs dissected and the gills processed for routine histology. Next, the severity of AGD infection was determined by histopathological examination of the infected gill tissue. Differential gene expression was then assessed within the gill tissue using a 16K salmonid cDNA microarray with real time quantitative PCR validation. Preliminary results from this work will be presented and future research directions discussed. doi:10.1016/j.aquaculture.2007.07.202
Possible links between MH polymorphism and resistance to AGD in Atlantic salmon Salmo salar J.W. Wynne a, M.T. Cook a, B.F. Nowak b, N.G. Elliott a a CSIRO Food Futures Flagship, CSIRO Marine and Atmospheric Research, Hobart, Tasmania, Australia b School of Aquaculture, Univeristy of Tasmania, Aquafin CRC, Launceston, Tasmanian, Australia
Abstracts / Aquaculture 272S1 (2007) S238–S321
Amoebic gill disease (AGD) is the most significant health problem affecting the culture of Atlantic salmon in Australia. Research is underway to determine if AGD resistance is a heritable trait and therefore if there is potential to enhance resistance by selective breeding. In an attempt to accelerate the possible gains from future breeding programs we have undertaken a search for genes that may control or influence genetic resistance. Identifying such genes may allow the development of QTL for AGD resistance. The major histocompatibility (MH) class genes offer good candidates due to their important role in the immune system, high polymorphism and previous associations with resistance to other salmonids diseases. Within this study, Atlantic salmon were experimentally challenged with AGD over a 19 day period. Histopathological scoring of gill tissue was employed to determine the severity of AGD in all individuals. Fish were then genotyped for a MH class I microsatellite (UBA) and MH class II minisatellite (DAA) located within the 3′ untranslated regions of their respective genes. This facilitated the examination of a link between the presence of specific MH alleles and the histopathological severity of AGD. Preliminary results from this analysis will be presented and their implications for a marker assisted selective breeding program discussed. doi:10.1016/j.aquaculture.2007.07.203
Identification and mapping of AFLP markers linked to shell color in the bay scallop, Argopecten irradians Q. Yanjie a, L. Xiao a, G. Zhang a, X. Guo b a Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China b Haskin Shellfish Research Laboratory, Institute of Marine and Coastal Sciences, Rutgers University, Port Norris, NJ, USA Twenty-five AFLP primer pairs were used to study the inheritance of shell color in Argopecten irradians in an F1 family, 37 orange and 51 white. They were produced by two scallops with orange and white shells respectively. Six loci had significantly (P b 0.05) different frequencies between the white and orange progeny. They were mapped to one linkage group with a minimum LOD threshold of 3.0 and a maximum recombination fraction of 0.40. One of the loci, F1f335, is completely linked to the shell color gene, which we designated as Orange1, without any recombination in the progeny we sampled. The linkage group that carried Orange1 was 54.8 cM in
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length with a marker density of 11 cM. Marker I6f550 and I2f680 flanked Orange1 and F1f335 at a distance of 6.6 cM and 29.9 cM, respectively. Other markers present on this linkage group were I5f180, H5f348 and H7f305, which were 15.9 cM, 19.3 cM and 35.5 cM away from Orange1, respectively. The close linkage between F1f335 and Orange1 was also tested using bulk association analysis in an inbred line and two natural populations, and all our data indicate that F1f335 is specific for the shell color gene, Orange1. This study provides genomic mapping of a shell color gene in the bay scallop. This is probably the first time that a shell color gene is mapped in a mollusc. The mapping of shell color genes improves our understanding of shell color inheritance and helps us to breed molluscs with desired shell color. doi:10.1016/j.aquaculture.2007.07.204
Fertilization, hatching, metamorphosis and growth of two Pacific abalone populations and their reciprocal crosses D. Yuewen, X. Liu, G. Zhang Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China A 2 × 2 factorial cross between two wild populations [Dalian population (A) in China and Iwate population (B) in Japan] of Pacific abalone Haliotis discus hannai Ino was carried out to compare fertilization, hatching, metamorphosis and growth of the parental populations (AA and BB) and their reciprocal crosses (AB and BA) and investigate the magnitude of maternal effects and heterosis. Fertilization, hatching and metamorphosis rates, which respectively ranged from 89.9% to 97.5% (mean 93.6%), 52.7% to 61.6% (mean 57.3%) and 57.3% to 69.5%(mean 64.4%), were significantly different among the four crosses (P b 0.05). The growth of the four crosses was significantly different on Days 8, 20, 43, 160 and 330 (P b 0.05). Cross AB grew consistently faster than the rest crosses at ages except for on Day 8. Maternal effects were significant on fertilization, hatching, metamorphosis, and growth on Days 8 and 20 (P b 0.05), but they became insignificant on growth on Days 43, 160 and 330 (P N 0.05). Heterosis for fertilization, hatching and metamorphosis rates of cross AB was 5.41%, 7.41% and 7.57% respectively, while that of cross BA was − 0.45%, − 8.18% and − 1.58% respectively. Heterosis for growth of the crosses AB and BA at ages ranged from − 2.30% to
Abstracts / Aquaculture 272S1 (2007) S238–S321
used in our laboratory. This system can also be applied with other genetic markers, for example, in construction of a genetic linkage map of Atlantic cod.
fish) makes this approach feasible for broodstock management in commercial aquaculture operations. doi:10.1016/j.aquaculture.2007.07.201
doi:10.1016/j.aquaculture.2007.07.200
Microsatellite DNA assignment of progeny to parents enables communal freshwater rearing in an Atlantic salmon selective breeding program a
a
b
b
R.E. Withler , J. Supernault , B. Swift , R. Peterson , S. Fukui c a Pacific Biological Station Fisheries and Oceans Canada 3190 Hammond Bay Road Nanaimo, B.C. Canada V9T 6N7 b TRI-GEN Fish Improvement 2244 Wilson Road Agassiz, B.C. Canada V0M 1A1 c Mainstream Canada #203-919 Island Highway Campbell River, B.C. Canada V9W 2C2 Environmental effects introduced among families by rearing in individual freshwater tanks prior to marking can impede progress in selection for increased growth rate and size in domesticated salmonids. Accurate and inexpensive genetic methods of identifying progeny to parents in selective breeding programs would enable communal freshwater rearing of families. We developed a cost-effective suite of eight microsatellite loci to assign progeny from 135 fullsib families of domesticated Atlantic salmon to parents. Approximately 150 progeny from each family were communally reared for 8 months and sampled for genetic analysis upon transfer to seawater. Maximum-likelihood assignment of 3000 progeny to fullsib families and comparison of reconstructed with known parental genotypes enabled the identification of all 135 families. An unplanned application of the methodology involved another year class of the same strain in which the tagged broodstock group was lost and family brands on a backup group proved unreadable. This backup group of ‘progeny’ had been reared in seawater for 3 years and parental tissue samples were available for only 91 of the 146 families originally transferred to seawater. Microsatellite analysis of 2911 ‘progeny’ and assignment to families with known (87 families) and unknown (53 families) parental genotypes was conducted within 3 weeks. Quantitative genetic analysis (BLUP) of weight and growth was based on the microsatellite assignment to family rectified problems (nonconvergence) encountered when the analysis was based on family assignment by brandreading. The cost of automated analysis (∼$12 U.S. per
Associations between differential gene expression and increased AGD resistance in Atlantic salmon Salmo salar J.W. Wynne a, M.T. Cook a, B. Nowak b, D. Lovell c, M. O'Sullivan c, G. Stone c, N.G. Elliott a a CSIRO Food Futures Flagship, CSIRO Marine and Atmospheric Research, Hobart, Tasmania, Australia b School of Aquaculture, Univeristy of Tasmania, Aquafin CRC, Launceston, Tasmania, Australia c CSIRO Mathematical and Information Sciences, North Ryde, New South Wales, Australia Previous research suggests that resistance to amoebic gill disease (AGD) is to some extent genetically controlled. As a consequence of these findings, developing selective breeding programs to increase AGD resistance have become a major focus in Tasmania. In order to gain maximum efficiency from such breeding programs, genes which influence resistance must be identified. This study aimed to identify such genes by comparing differential gene expression between fish displaying high and low levels of AGD resistance. Briefly, a population of Atlantic salmon were experimentally challenged with AGD over a 19 day period. Following challenge all individuals were euthanised, organs dissected and the gills processed for routine histology. Next, the severity of AGD infection was determined by histopathological examination of the infected gill tissue. Differential gene expression was then assessed within the gill tissue using a 16K salmonid cDNA microarray with real time quantitative PCR validation. Preliminary results from this work will be presented and future research directions discussed. doi:10.1016/j.aquaculture.2007.07.202
Possible links between MH polymorphism and resistance to AGD in Atlantic salmon Salmo salar J.W. Wynne a, M.T. Cook a, B.F. Nowak b, N.G. Elliott a a CSIRO Food Futures Flagship, CSIRO Marine and Atmospheric Research, Hobart, Tasmania, Australia b School of Aquaculture, Univeristy of Tasmania, Aquafin CRC, Launceston, Tasmanian, Australia
Abstracts / Aquaculture 272S1 (2007) S238–S321
Amoebic gill disease (AGD) is the most significant health problem affecting the culture of Atlantic salmon in Australia. Research is underway to determine if AGD resistance is a heritable trait and therefore if there is potential to enhance resistance by selective breeding. In an attempt to accelerate the possible gains from future breeding programs we have undertaken a search for genes that may control or influence genetic resistance. Identifying such genes may allow the development of QTL for AGD resistance. The major histocompatibility (MH) class genes offer good candidates due to their important role in the immune system, high polymorphism and previous associations with resistance to other salmonids diseases. Within this study, Atlantic salmon were experimentally challenged with AGD over a 19 day period. Histopathological scoring of gill tissue was employed to determine the severity of AGD in all individuals. Fish were then genotyped for a MH class I microsatellite (UBA) and MH class II minisatellite (DAA) located within the 3′ untranslated regions of their respective genes. This facilitated the examination of a link between the presence of specific MH alleles and the histopathological severity of AGD. Preliminary results from this analysis will be presented and their implications for a marker assisted selective breeding program discussed. doi:10.1016/j.aquaculture.2007.07.203
Identification and mapping of AFLP markers linked to shell color in the bay scallop, Argopecten irradians Q. Yanjie a, L. Xiao a, G. Zhang a, X. Guo b a Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China b Haskin Shellfish Research Laboratory, Institute of Marine and Coastal Sciences, Rutgers University, Port Norris, NJ, USA Twenty-five AFLP primer pairs were used to study the inheritance of shell color in Argopecten irradians in an F1 family, 37 orange and 51 white. They were produced by two scallops with orange and white shells respectively. Six loci had significantly (P b 0.05) different frequencies between the white and orange progeny. They were mapped to one linkage group with a minimum LOD threshold of 3.0 and a maximum recombination fraction of 0.40. One of the loci, F1f335, is completely linked to the shell color gene, which we designated as Orange1, without any recombination in the progeny we sampled. The linkage group that carried Orange1 was 54.8 cM in
S319
length with a marker density of 11 cM. Marker I6f550 and I2f680 flanked Orange1 and F1f335 at a distance of 6.6 cM and 29.9 cM, respectively. Other markers present on this linkage group were I5f180, H5f348 and H7f305, which were 15.9 cM, 19.3 cM and 35.5 cM away from Orange1, respectively. The close linkage between F1f335 and Orange1 was also tested using bulk association analysis in an inbred line and two natural populations, and all our data indicate that F1f335 is specific for the shell color gene, Orange1. This study provides genomic mapping of a shell color gene in the bay scallop. This is probably the first time that a shell color gene is mapped in a mollusc. The mapping of shell color genes improves our understanding of shell color inheritance and helps us to breed molluscs with desired shell color. doi:10.1016/j.aquaculture.2007.07.204
Fertilization, hatching, metamorphosis and growth of two Pacific abalone populations and their reciprocal crosses D. Yuewen, X. Liu, G. Zhang Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China A 2 × 2 factorial cross between two wild populations [Dalian population (A) in China and Iwate population (B) in Japan] of Pacific abalone Haliotis discus hannai Ino was carried out to compare fertilization, hatching, metamorphosis and growth of the parental populations (AA and BB) and their reciprocal crosses (AB and BA) and investigate the magnitude of maternal effects and heterosis. Fertilization, hatching and metamorphosis rates, which respectively ranged from 89.9% to 97.5% (mean 93.6%), 52.7% to 61.6% (mean 57.3%) and 57.3% to 69.5%(mean 64.4%), were significantly different among the four crosses (P b 0.05). The growth of the four crosses was significantly different on Days 8, 20, 43, 160 and 330 (P b 0.05). Cross AB grew consistently faster than the rest crosses at ages except for on Day 8. Maternal effects were significant on fertilization, hatching, metamorphosis, and growth on Days 8 and 20 (P b 0.05), but they became insignificant on growth on Days 43, 160 and 330 (P N 0.05). Heterosis for fertilization, hatching and metamorphosis rates of cross AB was 5.41%, 7.41% and 7.57% respectively, while that of cross BA was − 0.45%, − 8.18% and − 1.58% respectively. Heterosis for growth of the crosses AB and BA at ages ranged from − 2.30% to