Ontogenic study of isozymes in giant tiger prawn,Penaeus monodon (Crustacea: Decapoda)

The patterns of isozyme variation throughout the life cycle of the giant tiger prawn,Penaeus monodon were described for ten enzyme systems (G3PD, MDH, LGG, GPI, MPI, FBP, PGM, LDH, PGD, and PROT). The zymograms showed little variation in the number of isozymic loci expressed during larval development compared with results reported for other penaeid prawns. There were specific ontogenic patterns at some loci. As larvae developed beyond the embryonic stage, there was a tendency for intensity of staining and complexity of banding patterns to increase.     

Hybrids between olive flounder Paralichthys olivaceus and stone flounder Kareius bicoloratus: karyotype, allozyme and RAPD analyses

The hybrid between olive flounder Paralichthys olivaceus and stone flounder Kareius bicoloratus was produced by artificial insemination of olive flounder eggs with stone flounder Sperm. Sinistral and dextral are two types of hybrid progeny after metamorphosis. Karyotypes of both hybrid flounders are the same as those of the two parental species. Of the 22 loci examined from 12 allozymes,12 confirmed hybridization of the paternal and matemal loci in hybrids and no difference was found in allozyme patterns of sinistral and dextral hybrid fishes. RAPD patterns of these specimens were also studied with 38 primers selected from 104 tested. Among them, the PCR products of 30 primers showed hybridization of the paternal and maternal bands. Genetic variation between hybrids and their parental stocks was analyzed by RAPD using 10 of the above 38 primers. The average heterozygosity and genetic distance were calculated. The results suggested that the filial generation could inherit a little more genetic materials from paternal fish than that from maternal fish.     

Hybrids between olive flounder Paralichthys olivaceus and stone flounder Kareius bicoloratus： karyotype, allozyme and RAPD analyses

The hybrid between olive flounder Paralichthys olivaceus and stone flounder Kareius bicoloratus was produced by artificial insemination of olive flounder eggs with stone flounder sperm. Sinistral and dextral are two types of hybrid progeny after metamorphosis. Karyotypes of both hybrid flounders are the same as those of the two parental species. Of the 22 loci examined from 12 allozymes, 12 confirmed hybridization of the paternal and maternal loci in hybrids and no difference was found in allozyme patterns of sinistral and dextral hybrid fishes. RAPD patterns of these specimens were also studied with 38 primers selected from 104 tested. Among them, the PCR products of 30 primers showed hybridization of the paternal and maternal bands. Genetic variation between hybrids and their parental stocks was analyzed by RAPD using 10 of the above 38 primers. The average heterozygosity and genetic distance were calculated. The results suggested that the filial generation could inherit a little more genetic materials from paternal fish than that from maternal fish. Supported by National Natural Science Foundation of China (No. 30571445), National High-Technology Research and Development Program (863 Program, No. 2006AA10A404), and Project from the Ministry of Science and Technology of China (No. 2006DKA30470-017)     

The comparison between allozyme and RAPD makers for the population genetic structure analysis of scallop Chlamys farreri

1INTRODUCTION Since the first use in human genetic research in1966,allozyme has become the most popular genetic marker for population genetics studies for almost all groups of animals and plants(Lewontin and Hubby,1966;Murphy et al.,1996).In the past seve…     

基于转录组测序的方斑东风螺单核苷酸多态性位点挖掘及功能注释

【目次】了解方斑东风螺中响应LPS刺激的SNP位点及SNP所在基因SNP-Unigenes的功能。【方法】使用SOAPsnp软件分析不同时间条件下转录组数据中的SNP位点,使用GO、COG和KEGG数据库进行功能注释。【结果】转录组数据中共挖掘到673 782个SNP位点,分布在110 869条SNP-unigenes序列上。SNP类型分析表明,转换位点发生的频率远高于颠换位点,且6种单碱基变异类型中以A/G转换发生概率最大。有5866条SNP-unigenes富集到298个KEGG子集中,其中以"内吞作用"子集中富集的SNP-Unigenes最多,共富集182条。     

紫红笛鲷随机扩增多态性DNA及遗传多样性分析

采用RAPD技术分析了湛江近海紫红笛鲷 (LutjanusargentimaculatusForsk l)的遗传多样性。从 12 0个随机引物中筛选出了 14个引物。 14个引物共检测到 173个位点 ,其中多态位点比例 (P)为 6 8.79%,遗传距离 (D)为 0 .2 2 2 8,遗传多样性指数 (H)为 0 .190 4。结果表明 ,目前湛江近海的紫红笛鲷自然群体的遗传多样性仍然维持在良好水平 ,捕捞尚未对其造成明显影响。     

Development and Characterization of Microsatellite Markers for the Pacific Abalone （Haliotis discus） via EST Database Mining

The EST database of the Pacific abalone (Haliotis discus) was mined for developing mierosatellite markers. A total of 1476 EST sequences were registered in GenBank when data mining was performed. Fifty sequences (approximately 3.4%) were found to contain one or more mierosatellites. Based on the length and GC content of the flanking regions, duster analysis and BLASTN, 13 microsatellite-containing ESTs were selected for PCR primer design. The results showed that 10 out of 13 primer pairs could amplify seorable PCR products and showed polymorphism. The number of alleles ranged from 2 to 13 and the values of Hoand He varied from 0.1222 to 0.8611 and 0.2449 to 0.9311, respectively. No significant linkage disequilibrium (LD) between any pairs of these loci was found, and 6 of 10 loci conformed to the Hardy-Weinberg equilibrium (HWE). These EST-SSRs are therefore potential tools for studies of intraspecies variation and hybrid identification.     

近江牡蛎3个种群生化遗传变异的研究

用同工酶电泳方法研究广东省官渡、阳江和汕尾的近江牡蛎(Ostea rivularis)的遗传变异。分析了11种同工酶20个的位点,其中出现13个位点显示为多态。结果表明官渡、阳江、汕尾种群的多态位点比例分别为0.200、0.200、0.500。官渡和阳江种群间,官渡和汕尾种群间以及阳江和汕尾种群间的遗传距离(D)分别为0.0451,0.1125,0.1088。     

鲤鱼（Cyprinuscarpio L．）体重和体长QTL的定位

利用265个AFLP标记、127个微卫星分子标记、37个EST-SSR标记和16个RAPD标记（共445个标记）对大头鲤／荷包红鲤抗寒品系的F2代雌核发育群体44个个体进行基因型检测,构建鲤鱼（CyprinuscarpioL.）遗传连锁图谱;利用软件WinQTLCart2.5采用复合区间作图法对体重和体长两个性状进行了QTL定位分析。结果共检测到与两个与体重性状相关的QTL,分别定位到LG24连锁群（qBWh-24-1）和LG20连锁群（qBWh-20-1）上,可解释的表型变异分别为7.98％和20.05％;检测到两个与体长性状相关的QTL,分别位于LG2连锁群（qFS-2-1）和LG20连锁群（qFS-20-1）,可解释的表型变异分别为5.69％和12.69％,4个QTL的加性效应均为负值。     

鲤鱼(Cyprinus carpio L.)体重和体长QTL的定位

利用265个AFLP标记、127个微卫星分子标记、37个EST-SSR标记和16个RAPD标记(共445个标记)对大头鲤/荷包红鲤抗寒品系的F2代雌核发育群体44个个体进行基因型检测,构建鲤鱼(Cyprinus carpio L.)遗传连锁图谱;利用软件WinQTLCart2.5采用复合区间作图法对体重和体长两个性状进行了QTL定位分析。结果共检测到与两个与体重性状相关的QTL,分别定位到LG24连锁群(qBWh-24-1)和LG20连锁群(qBWh-20-1)上,可解释的表型变异分别为7.98%和20.05%;检测到两个与体长性状相关的QTL,分别位于LG2连锁群(qFS-2-1)和LG20连锁群(qFS-20-1),可解释的表型变异分别为5.69%和12.69%,4个QTL的加性效应均为负值。     

Isozyme expression of Chinese and Japanese populations of Chlamys farreri and their reciprocal hybrids

Chinese and Japanese population of Chlamys farreri and their reciprocal hybrids were surveyed in isozyme variability at 13 loci by polyacrytamide gel electrophoresis (PAGE). Isozyme banding patterns indicated these hybrids were diploid. Loci that were observed as being monomorphic in inbred populations of C. farreri were also found to be monomorphic in filial progeny; loci that observed to be polymorphic in parental type generations were also polymorphic in hybrid generations. Differences existed among allelic frequency of the four types of cross. Within the reciprocal hybrids the expression of malic enzyme (ME) isozyme was sufficient to distinguishing individual hybrids because of the band, Rf=0.38. However, there were no noticeable variations among all the samples to differentiate one from another. Inbreeding was likely to be the main problem in aquaculture. The introduction of new broodstock can improve the genetic diversity. Hybrid vigor has manifested to a certain extent in the present study.     

The Clam Cyclina sinensis (Gmelin) Phylogeography Study with 28S rRNA Gene and Potential of Nuclear rRNA Genes in Genetic Assessments of Molluscs

Intraspecific diversity of molluscan species is usually studied based on maternally inherited mitochondrial DNA,from which only part of the evolutionary history can be reflected.Some nuclear ribosomal RNA genes such as 28S rRNA represent poten-tial candidates that can be easily applied in phylogeography because of lacking intraindividual variation.However,considering their low polymorphism,genetic appraisals on whether and how they can be used in population studies are necessary.Here,we applied a short 28S rRNA to assess genetic patterns of the clam Cyclina sinensis along the coast of China and compared the results with a for-mer study based on COI and ITS-1 analyses.The results revealed the 28S rRNA data set was characterized by an extremely low level of variation,with only seven haplotypes defined for 93 individuals.Haplotype and nucleotide diversity for each population was al-most the lowest when compared with the other two markers.However,the distribution of two dominant haplotypes showed clear geo-graphic patterns,and significant population differentiation was revealed between the East China Sea and the South China Sea.These patterns were highly concordant with findings of the former study that populations of C.sinensis were historically separated by land bridges among sea basins.Our study suggested that although the nuclear rRNAs have shortcomings such as low variation,they have advantages including lack of intraindividual variation and high amplification rates.Applying rRNA genes can enrich the toolbox of nuclear markers in molluscan phylogeographic studies.     

Genetic variation of natural and cultured stocks of Paralichthys olivaceus by allozyme and RAPD

Population genetics of the left-eyed flounder, Paralichthys olivaceus, including natural and cultured stocks distributed in the coastal waters near Qingdao of eastern maritime China, was analyzed in allozyme and RAPD. The results showed that among total 29 gene loci of 15 isozymes, 9 and 7 were po- lymorphic in natural and cultured stocks, respectively. The status of genetic diversity in P. olivaceus is low in terms of polymorphic loci in chi-square test and genetic departure index of Hardy-Weinberg equi- librium. More alleles in IDHP, CAT, GDH and Ldh-C allozymes were found in the fish, which could be used as markers in assortive breeding and distinguishing stock, population or species evolution. Total 88 and 86 RAPD bands ranging from 200 to 2 500 bp were recognized individually in average of 7.8–8.0 bands per primer. The genetic diversity in cultured stock is lower than that in natural ones showing an ob- viously decreasing genetic divergence. Therefore, effective countermeasures must be taken to protect ge- netic resources of marine cultured fishes. The 2 markers have their own pros and cons. Combining the 2 markers to investigate the genetic variation of populations is suggested. The results provide basic data of this flounder and they are useful for studying genetic improvement and genetic resources of the fish.     

Genetic Variation and Differentiation in Wide Ranging Populations of Razor Clam （Sinonovacula constricta） Inferred from AFLP Markers

The genetic variation and differentiation of the razor clam Sinonovacula constricts distributed along the coast of China were studied through amplified fragment length polymorphism(AFLP)analysis. Six primer combinations generated 193 fragments. The He values varied from 0. 322 to 0. 463 and the percentage of polymorphic loci ranged from 74. 1% to 98. 4%, which indicates a high level of genetic diversity. Cluster analysis by Nei's pairwise distance grouped all specimens by geographical origins. AMOVA consistently showed that genetic variation among populations was 8. 71%, and most of the variation came from the genetic variation within populations(91.29%). Genetic differentiation among the six populations was moderate; pairwise FST ranged from 0. 0282 to0. 1480, which indicated that S. Constricts populations along the coast of China are genetically connected. Among all the six populations, the Beihai population is the mostly differentiated from the others, suggesting that Hainan Island and Leizhou Peninsula act as barriers to gene flow. All populations abide isolation by distance model as indicated by Mantel test, except for ZS(Zhoushan)and YQ(Yueqing)populations. Information obtained in this study will provide guidelines for conservation and fishery management of this species in the future.     

二色裂江珧EST和SOD同工酶组织特异性研究

取二色裂江珧 (Pinna bicolor)的消化盲囊、肾脏、后闭壳肌肌肉、外套膜和鳃等 5种组织 ,用垂直板聚丙烯酰胺凝胶电泳对酯酶 (EST)和过氧化物歧化酶 (SOD)同工酶在上述组织中的表达和分布进行了比较研究 ,并对酶谱表型及位点表达进行了分析。结果表明 ,二色裂江珧组织内的 EST和 SOD存在不同程度的组织特异性 ,EST共检测出 15条酶带 ,SOD检测出 8条酶带 ,且两种同工酶在消化盲囊中活性最高。推测 SOD由 2个座位编码 ,可分为 s- SOD二聚体和 m- SOD四聚体     

Genetic variation assessed with microsatellites in mass selection lines of the Pacific oyster (<Emphasis Type="Italic">Crassostrea gigas</Emphasis>) in China

Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding programs in China were examined at ten polymorphic microsatellite loci to assess the level of allelic diversity and estimate the effective population size. These data were compared with those of their base population. The results showed that the genetic variation of the four generations were maintained at high levels with an average allelic richness of 18.8–20.6, and a mean expected heterozygosity of 0.902–0.921. They were not reduced compared with those of their base population. Estimated effective population sizes based on temporal variances in microsatellite frequencies were smaller to that of sex ratio-corrected broodstock count estimates. Using a relatively large number of broodstock and keeping an equal sex ratio in the broodstock each generation may have contributed to retaining the original genetic diversity and maintaining relatively large effective population size. The results obtained in this study showed that the genetic variation was not affected greatly by mass selection progress and high genetic variation still existed in the mass selection lines, suggesting that there is still potential for increasing the gains in future generations of C. gigas. The present study provided important information for future genetic improvement by selective breeding, and for the design of suitable management guidelines for genetic breeding of C. gigas.     

Tissue Expression and Stock Variation of Isozymes of Stone Flounder （Kareius bicoloratus）

Tissue expression and stock variation of isozymes of stone flounder (Kareius bicoloratus) were analyzed with horizontal starch gel electrophoresis. For the fourteen enzymes assayed, 31 loci were recorded. The results indicated that all the isozymes ex- amined were obviously tissue-specific. The expressions of SOD*, GDH*, G3PDH-2* and ADH-2* were detected only in liver, SDH-1*, MDH-1* and ADH-1* only in muscle, and LDH-B* and LDH-C* only in eyes. In comparison, MDH-2*, GPI-3* and SDH-2* were detected in all tissues examined. Other loci examined were detected in a variety of tissues. Muscle and liver were se- lected to detect the isozyme variation of the two geographic stocks of Qingdao and Weihai, Shandong Province, China. The percent- ages of polymorphic loci (P0.99) were 29.17% and 25.00%, the observed heterozygosities (H0) were 0.028 ± 0.014 and 0.040 ± 0.019, and the expected heterozygosities (He) were 0.039 ± 0.017 and 0.052 ± 0.022 in Qingdao and Weihai stock, respectively. The coeffi- cient of gene differentiation (Fst) and genetic distance (D) between the two stocks was 0.012 and 0.0011, respectively, indicating that the genetic differentiation is low between them. Compared with other species of Pleuronectiformes, both the percentage of polymor- phic loci and the mean heterozygosity of K. bicoloratus were at a middle level.     

Isozyme expression of Chinese and Japanese populations of Chlamys farreri and their reciprocal hybrids

Chinese and Japanese population ofChlamys farreri and their reciprocal hybrids were surveyed in isozyme variability at 13 loci by polyacrytamide gel electrophoresis (PAGE). Isozyme banding patterns indicated these hybrids were diploid. Loci that were observed as being monomorphic in inbred populations ofC. farreri were also found to be monomorphic in filial progeny; loci that observed to be polymorphic in parental type generations were also polymorphic in hybrid generations. Differences existed among allelic frequency of the four types of cross. Within the reciprocal hybrids the expression of malic enzyme (ME) isozyme was sufficient to distinguishing individual hybrids because of the band, Rf=0.38. However, there were no noticeable variations among all the samples to differentiate one from another. Inbreeding was likely to be the main problem in aquaculture. The introduction of new broodstock can improve the genetic diversity. Hybrid vigor has manifested to a certain extent in the present study. Supported by the National “973” Program (G1999012008) and “863” Program (2002AA626020).     

Location of <Emphasis Type="Italic">Vibrio anguillarum</Emphasis> resistance-associated trait loci in half-smooth tongue sole <Emphasis Type="Italic">Cynoglossus semilaevis</Emphasis> at its microsatellite linkage map

A cultured female half-smooth tongue sole (Cynoglossus semilaevis) was crossed with a wild male, yielding the first filial generation of pseudo-testcrossing from which 200 fish were randomly selected to locate the Vibrio anguillarum resistance trait in half-smooth tongue sole at its microsatellite linkage map. In total, 129 microsatellites were arrayed into 18 linkage groups, ≥4 each. The map reconstructed was 852.85 cM in length with an average spacing of 7.68 cM, covering 72.07% of that expected (1 183.35 cM). The V. anguillarum resistance trait was a composite rather than a unit trait, which was tentatively partitioned into Survival time in Hours After V. anguillarum Infection (SHAVI) and Immunity of V. Anguillarum Infection (IVAI). Above a logarithm of the odds (LOD) threshold of 2.5, 18 loci relative to SHAVI and 3 relative to IVAI were identified. The 3 loci relative to IVAI explained 18.78%, 5.87% and 6.50% of the total phenotypic variation in immunity. The microsatellites bounding the 3 quantitative trait loci (QTLs) of IVAI may in future aid to the selection of V. anguillarum-immune half-smooth tongue sole varieties, and facilitate cloning the gene(s) controlling such immunity.