Heritability and genetic and phenotypic correlations were estimated for juvenile growth traits of Pacific abalone Haliotis discus hannai Ino. The estimates were calculated from shell length and shell width measurement...Heritability and genetic and phenotypic correlations were estimated for juvenile growth traits of Pacific abalone Haliotis discus hannai Ino. The estimates were calculated from shell length and shell width measurements on progeny resulting from 12 half-sib families and 36 full-sib families obtained using artificial fertilization of mating three females to each male. The measurements were taken at 10, 20 and 30 d after fertilization. It was found that heritability estimates based on sire component ranged from 0.23 to 0.36 for shell length and 0.21 to 0.32 for shell width. Heritability estimates from dam component were larger than those from sire component at three ages, indicating presence of maternal effects, non-additive genetic effects and common environmental effects. Phenotypic correlations were significant at three ages （P 〈 0.05）, with values of 0.92, 0.93 and 0.92, respectively. Genetic correlations from the paternal half-sib correlation analysis were highly positive at three ages, with values of 0.50, 0.78 and 0.81, respectively. The results suggest that selective breeding is an effective approach to improving growth traits of Pacific abalone stocks.展开更多
We conducted a complete diallel cross among three geographically isolated populations of Pacific abalone Haliotis discus hannai Ino to determine the heterosis and the combining ability of growth traits at the spat sta...We conducted a complete diallel cross among three geographically isolated populations of Pacific abalone Haliotis discus hannai Ino to determine the heterosis and the combining ability of growth traits at the spat stage.The three populations were collected from Qingdao(Q) and Dalian(D) in China,and Miyagi(M) in Japan.We measured the shell length,shell width,and total weight.The magnitude of the general combining ability(GCA) variance was more pronounced than the specific combining ability(SCA) variance,which is evidenced by both the ratio of the genetic component in total variation and the GCA/SCA values.The component variances of GCA and SCA were significant for all three traits(P<0.05),indicating the importance of additive and non-additive genetic effects in determining the expression of these traits.The reciprocal maternal effects(RE) were also significant for these traits(P<0.05).Our results suggest that population D was the best general combiner in breeding programs to improve growth traits.The DM cross had the highest heterosis values for all three traits.展开更多
Heat shock protein 70 （Hsp70） is one important member of heat shock protein （Hsp） family that is responsible for various stresses, especially thermal stress. Here we examined the response of Hsp70 gene to both chr...Heat shock protein 70 （Hsp70） is one important member of heat shock protein （Hsp） family that is responsible for various stresses, especially thermal stress. Here we examined the response of Hsp70 gene to both chronic and acute thermal exposure in Pacific abalone （Haliotis discus hannai Ino）. For the chronic exposure, abalones were maintained at 8, 12, 20, and 30∩ for four months and their mRNA levels were measured. The highest mRNA level of Hsp70 gene relative to actin gene was detected in the 30~C-acclimated group, followed by the 8~C-acclimated group and then the 12~C- and 20~C-acclimated groups. After the long-term acclimation, gills from each of the above acclimation groups were dissected and exposed to different temperatures between 8~C and 38~C for 30 min. Hsp70 expression in gills acclimated to different temperatures responded differentially to the same temperature exposure. The incubation temperature that induced maximum Hsp70 mRNA expression was higher in the higher temperature acclimation groups than lower temperature groups. Pacific abalones could alter the expression pattern of Hsp70 gene according to environmental thermal conditions, through which they deal with the stress of thermal variations.展开更多
A2 × 2 factorial cross between two populations of Pacific abalone Haliotis discus hannai Ino, collected separately from Dalian （D） in China and Miyagi （M） in Japan, was conducted to compare performances in fe...A2 × 2 factorial cross between two populations of Pacific abalone Haliotis discus hannai Ino, collected separately from Dalian （D） in China and Miyagi （M） in Japan, was conducted to compare performances in fertilization rate, hatching rate, metamorphosis rate and growth at days 20, 43, 160 and 330 between purebreds （DD and MM） and crossbreds （DM and MD） and investigate the magnitude of heterobeltiosis （better parent） and heterosis （mid-parent）. Heterobeltiosis and heterosis for all the traits analyzed were evidently different between crossbreds DM and MD. Heterobeltiosis in the crossbred DM varied among traits, with values of 2.5% for the fertilization rate, 2.2% for the hatching rate, - 1.9% for the metamorphosis rate and 7.4% for the growth at the day 330. The crossbred DM displayed positive heterotic values for fertilization rate （5.4%）, hatching rate （7.4%）, metamorphosis rate （7.6%） and growth （ 12.0% ） at the day 330. However, both heterobeltiosis and heterosis for all the traits in the crossbred MD were negative except those for the growth at days 20 and 43. The results indicate the importance of selecting superior hybrid varieties if the exploitation of hybrid vigor is considered in the Pacific abalone breeding program.展开更多
A study was conducted to evaluate the effects of dietary carbohydrates on triglyceride, cholesterol and fatty acid concentrations in abalone, Haliotis discus hannai Ino. Six semi-purified diets with different carbohyd...A study was conducted to evaluate the effects of dietary carbohydrates on triglyceride, cholesterol and fatty acid concentrations in abalone, Haliotis discus hannai Ino. Six semi-purified diets with different carbohydrates （dextrin, heat-treated wheat starch, wheat starch, corn starch, tapioca starch and potato starch, respectively）, all containing a carbohydrate level of 33.5%, were fed to abalone （initial shell length： 29.98mm±0.09mm; initial weight. 3.42g±0.02g） for 24 weeks in a recirculation system. The results indicate that serum triglyceride concentrations were significantly （P〈0.05） higher in the abalone fed with dextrin, heat-treated wheat starch and wheat starch than those fed with corn starch, and serum cholesterol concentrations were significantly （P〈0.05） higher in the abalone fed with dextrin, heat-treated wheat starch than those fed with corn starch. Fatty acid C20：4n-6 in the foot mus- cles were significantly （P〈0.05） lower in the abalone fed with dextrin than those fed with wheat starch, corn starch, tapioca starch and potato starch. Fatty acid C20：4n-6 in hepatopancreas was significantly （P〈0.05） lower in abalone fed with heat-treated wheat starch than those fed with corn starch, tapioca starch and potato starch. Fatty acid C22：6n-3 in the foot muscles were significantly （P 〈 0.05） lower in the abalone fed with dextrin and beat-treated wheat starch than those fed with wheat starch and potato starch.展开更多
From 2007 to 2009, large-scale blooms of green algae (the so-called "green tides") occurred every summer in the Yellow Sea, China. In June 2008, huge amounts of floating green algae accumulated along the coa...From 2007 to 2009, large-scale blooms of green algae (the so-called "green tides") occurred every summer in the Yellow Sea, China. In June 2008, huge amounts of floating green algae accumulated along the coast of Qingdao and led to mass mortality of cultured abalone and sea cucumber. However, the mechanism for the mass mortality of cultured animals remains undetermined. This study examined the toxic effects of Ulva (Enteromorpha) prolifera, the causative species of green tides in the Yellow Sea during the last three years. The acute toxicity of fresh culture medium and decomposing algal effluent of U. prolifera to the cultured abalone Haliotis discus hannai were tested. It was found that both fresh culture medium and decomposing algal effluent had toxic effects to abalone, and decomposing algal effluent was more toxic than fresh culture medium. The acute toxicity of decomposing algal effluent could be attributed to the ammonia and sulfide presented in the effluent, as well as the hypoxia caused by the decomposition process.展开更多
A genetic linkage map of Pacific abalone(Haliotis discus hannai) was constructed using AFLP markers based on a two-way pseudo-testcross strategy in a full-sib family. With 33 primer combinations,a total of 455 markers...A genetic linkage map of Pacific abalone(Haliotis discus hannai) was constructed using AFLP markers based on a two-way pseudo-testcross strategy in a full-sib family. With 33 primer combinations,a total of 455 markers(225 from the female parent and 230 from the male parent) segregated in a 1:1 ratio,corresponding to DNA polymorphism:heterozygous in one parent and null in the other. The female framework map consisted of 174 markers distributed in 18 linkage groups,equivalent to the H. discus hannai haploid chromosome number,and spanning a total length of 2031.4 cM,with an average interval of 13.0 cM between adjacent markers. The male framework map consisted of 195 markers mapped on 19 linkage groups,spanning a total length of 2273.4 cM,with an average spacing of 12.9 cM between adjacent markers. The estimated coverage for the framework linkage maps was 81.2% for the female and 82.1% for the male,on the basis of two estimates of genome length. Fifty-two markers(11.4%) remained unlinked. The level of segregation distortion observed in this cross was 20.4%. These linkage maps will serve as a starting point for linkage studies in the Pacific abalone with potential application for marker-assisted selection in breeding programs.展开更多
Simple sequence repeat (SSR) markers were developed from the expressed sequence tags (ESTs) of Pacific abalone (Haliotis discus hannai).Repeat motifs were found in 4.95% of the ESTs at a frequency of one repeat every ...Simple sequence repeat (SSR) markers were developed from the expressed sequence tags (ESTs) of Pacific abalone (Haliotis discus hannai).Repeat motifs were found in 4.95% of the ESTs at a frequency of one repeat every 10.04 kb of EST sequences,after redundancy elimination.Seventeen polymorphic EST-SSRs were developed.The number of alleles per locus varied from 2-17,with an average of 6.8 alleles per locus.The expected and observed heterozygosities ranged from 0.159 to 0.928 and from 0.132 to 0.922,respectively.Twelve of the 17 loci (70.6%) were successfully amplified in H.diversicolor.Seventeen loci segregated in three families,with three showing the presence of null alleles (17.6%).The adequate level of variability and low frequency of null alleles observed in H.discus hannai,together with the high rate of transportability across Haliotis species,make this set of EST-SSR markers an important tool for comparative mapping,marker-assisted selection,and evolutionary studies,not only in the Pacific abalone,but also in related species.展开更多
Defensin is one of preserved ancient host defensive materials formed in biological evolution. As a regulator and effector molecule, it is very important in animals＇ acquired immune system. This paper reports the defe...Defensin is one of preserved ancient host defensive materials formed in biological evolution. As a regulator and effector molecule, it is very important in animals＇ acquired immune system. This paper reports the defensin gene from the mixed liver and kidney cDNA library of abalone Haliotis discus hannai Ino. Sequence analysis shows that the gene sequence of full-length cDNA encodes 42 mature peptides （including six Cys）, molecular weight of 4 323 Da, and pI of 8.02. Amino acid sequence homology analysis shows that the peptides are highly similar （70% in common） to other insects defensin. Because of a typical insect-defensin structural character of mature peptide in the secondary structure, the polypeptide named Haliotis discus defensin （hd-def）, a novel of antimicrobial peptides, belongs to insects defensin subfamily. The RT-PCR result of Haliotis discus defensin shows that the gene can be expressed only in the hepatopancreas by Gram-negative and positive bacteria stimulation, which is ascribed to inducible expression. Therefore, it is revealed that the Haliotis discus defensin gene expression was related to the antibacterial infection of Haliotis discus hannai Ino.展开更多
Growth rates, measured as shell length and body weight daily growth, were studied in the eight families of Pacific abalone, Haliotis discus hannai Ino, reared at 12, 16 and 20 ℃for 40 d respectively. The results show...Growth rates, measured as shell length and body weight daily growth, were studied in the eight families of Pacific abalone, Haliotis discus hannai Ino, reared at 12, 16 and 20 ℃for 40 d respectively. The results show that J1Rh family grew the best at 12 ℃, with growth rates of (32.88±4.66) μm/d and (5.24±1.84) mg/d. C1Jm family had the highest growth rates of (58.00±2.00) μm/d and (9.71±1.21) mg/d at 16 ℃. J1Jm family ranked the first at 20 ℃, with growth rates of (66.00±1.76) μm/d and (10.99±0.34) mg/d. RjRh family had the slowest growth rates at all three temperatures. Shell length growth rates were 18.25, 33.00 and 43.13 μm/d respec- tively, while body weight growth rates were 2.47, 2.56 and 4.75 mg/d respectively. Both temperature and family had significant effect on growth rates (P< 0.05). At 16 and 20 ℃, maternal effects on growth rates were not significant (P> 0.05), but paternal effects on growth rates were significant (P< 0.05). Results of this study indicate genetic difference among the families and importance of select- ing male breeders in the commercial hatchery.展开更多
基金The study was supported by the National High Technology Development Project of China under contract No.2006AA10A407the National Natural Science Foundation of China under contract No.30371117.
文摘Heritability and genetic and phenotypic correlations were estimated for juvenile growth traits of Pacific abalone Haliotis discus hannai Ino. The estimates were calculated from shell length and shell width measurements on progeny resulting from 12 half-sib families and 36 full-sib families obtained using artificial fertilization of mating three females to each male. The measurements were taken at 10, 20 and 30 d after fertilization. It was found that heritability estimates based on sire component ranged from 0.23 to 0.36 for shell length and 0.21 to 0.32 for shell width. Heritability estimates from dam component were larger than those from sire component at three ages, indicating presence of maternal effects, non-additive genetic effects and common environmental effects. Phenotypic correlations were significant at three ages （P 〈 0.05）, with values of 0.92, 0.93 and 0.92, respectively. Genetic correlations from the paternal half-sib correlation analysis were highly positive at three ages, with values of 0.50, 0.78 and 0.81, respectively. The results suggest that selective breeding is an effective approach to improving growth traits of Pacific abalone stocks.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (No2006AA10A407)the National Natural Science Foundation of China (No30371117)
文摘We conducted a complete diallel cross among three geographically isolated populations of Pacific abalone Haliotis discus hannai Ino to determine the heterosis and the combining ability of growth traits at the spat stage.The three populations were collected from Qingdao(Q) and Dalian(D) in China,and Miyagi(M) in Japan.We measured the shell length,shell width,and total weight.The magnitude of the general combining ability(GCA) variance was more pronounced than the specific combining ability(SCA) variance,which is evidenced by both the ratio of the genetic component in total variation and the GCA/SCA values.The component variances of GCA and SCA were significant for all three traits(P<0.05),indicating the importance of additive and non-additive genetic effects in determining the expression of these traits.The reciprocal maternal effects(RE) were also significant for these traits(P<0.05).Our results suggest that population D was the best general combiner in breeding programs to improve growth traits.The DM cross had the highest heterosis values for all three traits.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (Nos. 2006AA10A407, 2012AA100812)
文摘Heat shock protein 70 （Hsp70） is one important member of heat shock protein （Hsp） family that is responsible for various stresses, especially thermal stress. Here we examined the response of Hsp70 gene to both chronic and acute thermal exposure in Pacific abalone （Haliotis discus hannai Ino）. For the chronic exposure, abalones were maintained at 8, 12, 20, and 30∩ for four months and their mRNA levels were measured. The highest mRNA level of Hsp70 gene relative to actin gene was detected in the 30~C-acclimated group, followed by the 8~C-acclimated group and then the 12~C- and 20~C-acclimated groups. After the long-term acclimation, gills from each of the above acclimation groups were dissected and exposed to different temperatures between 8~C and 38~C for 30 min. Hsp70 expression in gills acclimated to different temperatures responded differentially to the same temperature exposure. The incubation temperature that induced maximum Hsp70 mRNA expression was higher in the higher temperature acclimation groups than lower temperature groups. Pacific abalones could alter the expression pattern of Hsp70 gene according to environmental thermal conditions, through which they deal with the stress of thermal variations.
基金The National High-Technology Research and Development Plan under contract No.2006AA10A407the National Natural Science Foundation of China under contract No.30371117
文摘A2 × 2 factorial cross between two populations of Pacific abalone Haliotis discus hannai Ino, collected separately from Dalian （D） in China and Miyagi （M） in Japan, was conducted to compare performances in fertilization rate, hatching rate, metamorphosis rate and growth at days 20, 43, 160 and 330 between purebreds （DD and MM） and crossbreds （DM and MD） and investigate the magnitude of heterobeltiosis （better parent） and heterosis （mid-parent）. Heterobeltiosis and heterosis for all the traits analyzed were evidently different between crossbreds DM and MD. Heterobeltiosis in the crossbred DM varied among traits, with values of 2.5% for the fertilization rate, 2.2% for the hatching rate, - 1.9% for the metamorphosis rate and 7.4% for the growth at the day 330. The crossbred DM displayed positive heterotic values for fertilization rate （5.4%）, hatching rate （7.4%）, metamorphosis rate （7.6%） and growth （ 12.0% ） at the day 330. However, both heterobeltiosis and heterosis for all the traits in the crossbred MD were negative except those for the growth at days 20 and 43. The results indicate the importance of selecting superior hybrid varieties if the exploitation of hybrid vigor is considered in the Pacific abalone breeding program.
基金support by the National Natural Science Foundation of China (NNSFC, grant No. 30671630)
文摘A study was conducted to evaluate the effects of dietary carbohydrates on triglyceride, cholesterol and fatty acid concentrations in abalone, Haliotis discus hannai Ino. Six semi-purified diets with different carbohydrates （dextrin, heat-treated wheat starch, wheat starch, corn starch, tapioca starch and potato starch, respectively）, all containing a carbohydrate level of 33.5%, were fed to abalone （initial shell length： 29.98mm±0.09mm; initial weight. 3.42g±0.02g） for 24 weeks in a recirculation system. The results indicate that serum triglyceride concentrations were significantly （P〈0.05） higher in the abalone fed with dextrin, heat-treated wheat starch and wheat starch than those fed with corn starch, and serum cholesterol concentrations were significantly （P〈0.05） higher in the abalone fed with dextrin, heat-treated wheat starch than those fed with corn starch. Fatty acid C20：4n-6 in the foot mus- cles were significantly （P〈0.05） lower in the abalone fed with dextrin than those fed with wheat starch, corn starch, tapioca starch and potato starch. Fatty acid C20：4n-6 in hepatopancreas was significantly （P〈0.05） lower in abalone fed with heat-treated wheat starch than those fed with corn starch, tapioca starch and potato starch. Fatty acid C22：6n-3 in the foot muscles were significantly （P 〈 0.05） lower in the abalone fed with dextrin and beat-treated wheat starch than those fed with wheat starch and potato starch.
基金Supported by the National Key Technology R&D Program (No. 2008BAC49B01)the National Basic Research Program of China (973 Program) (No. 2010CB428705)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No. 40821004)
文摘From 2007 to 2009, large-scale blooms of green algae (the so-called "green tides") occurred every summer in the Yellow Sea, China. In June 2008, huge amounts of floating green algae accumulated along the coast of Qingdao and led to mass mortality of cultured abalone and sea cucumber. However, the mechanism for the mass mortality of cultured animals remains undetermined. This study examined the toxic effects of Ulva (Enteromorpha) prolifera, the causative species of green tides in the Yellow Sea during the last three years. The acute toxicity of fresh culture medium and decomposing algal effluent of U. prolifera to the cultured abalone Haliotis discus hannai were tested. It was found that both fresh culture medium and decomposing algal effluent had toxic effects to abalone, and decomposing algal effluent was more toxic than fresh culture medium. The acute toxicity of decomposing algal effluent could be attributed to the ammonia and sulfide presented in the effluent, as well as the hypoxia caused by the decomposition process.
基金The study was supported by grants from the Chinese Ministry of Education(NCET-04-0640)the National Natural Science Foundation of China(No.30571442).
文摘A genetic linkage map of Pacific abalone(Haliotis discus hannai) was constructed using AFLP markers based on a two-way pseudo-testcross strategy in a full-sib family. With 33 primer combinations,a total of 455 markers(225 from the female parent and 230 from the male parent) segregated in a 1:1 ratio,corresponding to DNA polymorphism:heterozygous in one parent and null in the other. The female framework map consisted of 174 markers distributed in 18 linkage groups,equivalent to the H. discus hannai haploid chromosome number,and spanning a total length of 2031.4 cM,with an average interval of 13.0 cM between adjacent markers. The male framework map consisted of 195 markers mapped on 19 linkage groups,spanning a total length of 2273.4 cM,with an average spacing of 12.9 cM between adjacent markers. The estimated coverage for the framework linkage maps was 81.2% for the female and 82.1% for the male,on the basis of two estimates of genome length. Fifty-two markers(11.4%) remained unlinked. The level of segregation distortion observed in this cross was 20.4%. These linkage maps will serve as a starting point for linkage studies in the Pacific abalone with potential application for marker-assisted selection in breeding programs.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (No. 2007AA09Z433)the Cultivation Fund of the Key Scientific and Technical Innovation Project Ministry of Education of China (No. 707041)
文摘Simple sequence repeat (SSR) markers were developed from the expressed sequence tags (ESTs) of Pacific abalone (Haliotis discus hannai).Repeat motifs were found in 4.95% of the ESTs at a frequency of one repeat every 10.04 kb of EST sequences,after redundancy elimination.Seventeen polymorphic EST-SSRs were developed.The number of alleles per locus varied from 2-17,with an average of 6.8 alleles per locus.The expected and observed heterozygosities ranged from 0.159 to 0.928 and from 0.132 to 0.922,respectively.Twelve of the 17 loci (70.6%) were successfully amplified in H.diversicolor.Seventeen loci segregated in three families,with three showing the presence of null alleles (17.6%).The adequate level of variability and low frequency of null alleles observed in H.discus hannai,together with the high rate of transportability across Haliotis species,make this set of EST-SSR markers an important tool for comparative mapping,marker-assisted selection,and evolutionary studies,not only in the Pacific abalone,but also in related species.
基金Supported by the National High Technology Research and Development Program of China (863 program)(No.2006AA100309)
文摘Defensin is one of preserved ancient host defensive materials formed in biological evolution. As a regulator and effector molecule, it is very important in animals＇ acquired immune system. This paper reports the defensin gene from the mixed liver and kidney cDNA library of abalone Haliotis discus hannai Ino. Sequence analysis shows that the gene sequence of full-length cDNA encodes 42 mature peptides （including six Cys）, molecular weight of 4 323 Da, and pI of 8.02. Amino acid sequence homology analysis shows that the peptides are highly similar （70% in common） to other insects defensin. Because of a typical insect-defensin structural character of mature peptide in the secondary structure, the polypeptide named Haliotis discus defensin （hd-def）, a novel of antimicrobial peptides, belongs to insects defensin subfamily. The RT-PCR result of Haliotis discus defensin shows that the gene can be expressed only in the hepatopancreas by Gram-negative and positive bacteria stimulation, which is ascribed to inducible expression. Therefore, it is revealed that the Haliotis discus defensin gene expression was related to the antibacterial infection of Haliotis discus hannai Ino.
基金supported financially by the National High-Technology R&D Plan of China under the contract Nos 2001AA621070 and 2002AA629030,the National Natural Science Foundation of China.under contract No.30371117.
文摘Growth rates, measured as shell length and body weight daily growth, were studied in the eight families of Pacific abalone, Haliotis discus hannai Ino, reared at 12, 16 and 20 ℃for 40 d respectively. The results show that J1Rh family grew the best at 12 ℃, with growth rates of (32.88±4.66) μm/d and (5.24±1.84) mg/d. C1Jm family had the highest growth rates of (58.00±2.00) μm/d and (9.71±1.21) mg/d at 16 ℃. J1Jm family ranked the first at 20 ℃, with growth rates of (66.00±1.76) μm/d and (10.99±0.34) mg/d. RjRh family had the slowest growth rates at all three temperatures. Shell length growth rates were 18.25, 33.00 and 43.13 μm/d respec- tively, while body weight growth rates were 2.47, 2.56 and 4.75 mg/d respectively. Both temperature and family had significant effect on growth rates (P< 0.05). At 16 and 20 ℃, maternal effects on growth rates were not significant (P> 0.05), but paternal effects on growth rates were significant (P< 0.05). Results of this study indicate genetic difference among the families and importance of select- ing male breeders in the commercial hatchery.
