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1.
金钱鱼(Scatophagus argus)是我国东南沿海名优养殖鱼类, 具有 XY 性别决定系统, Dmrt1 是其性别决定候选基因。金钱鱼生长具有性别二态性, 雌鱼生长快于雄鱼。目前缺乏快速鉴定金钱鱼遗传性别的分子标记, 阻碍了其性别控制育种技术的建立。本研究以公布的金钱鱼基因组数据, 在 Dmrt1 附近设计多对标记引物, 并通过 PCR 扩增验证标记的性别特异性。其中, 标记引物 Dmrt1-Marker-4-F/R 在雌鱼中仅扩增出一条 593 bp X 染色体条带, 而在雄鱼中能扩增出 593 bp 和 693 bp 两条条带, 分别来自 X 和 Y 染色体, 表明该标记为共显性标记。利用该标记检测我国南海沿岸 3 个不同地理群体 213 尾金钱鱼的遗传性别与表型性别完全一致。此外, 快速 DNA 提取试剂盒提取的片段较短 DNA 样品也可用于该对标记引物准确鉴定遗传性别。本研究建立了一种快速、准确、经济可靠的金钱鱼遗传性别鉴定方法, 将旨为促进金钱鱼性别控制育种技术的建立, 并为金钱鱼性别决定与分化机制研究提供依据。  相似文献   

2.
A non‐destructive procedure based on nested RT‐PCR and dot‐blot hybridization has been developed for the detection of asymptomatic IPNV‐carrier fish. The pair of primers designed for RT‐PCR amplified a 599‐bp fragment of the pVP2 region within the polyprotein gene, resulting in the detection of IPNV genotype III.1. The use of a nested RT‐PCR allowed the amplification of IPNV genotypes III.1 and I.2. In addition, a 191‐bp probe was designed for hybridization studies used in combination with the nested RT‐PCR. The application of the nested RT‐PCR to analyse blood samples from asymptomatic redbanded seabream, Pagrus auriga, and common seabream, P. pagrus, specimens showed a 53.1% and 77.8% prevalence of IPNV‐carriers, respectively. The combination of nested RT‐PCR and dot‐blot hybridization increased the detection rates up to 100% for redbanded seabream and 94.4% for common seabream. Therefore, the protocol described in this study is highly sensitive and specific for the detection of IPNV in asymptomatic carrier fish, and, in addition, the results demonstrate the carrier state in two newly cultured sparid species in southern Spain.  相似文献   

3.
To determine the genotype with better traits for aquaculture practices of the loach, factorial crosses were made among diploid (D), tetraploid (T) dojo loach, Misgurnus anguillicaudatus, and large‐scale loach, Paramisgurnus dabryanus (P), producing DD, DT, DP, TD, TT, TP, PD, PT, and PP genotypes (female listed first). The growth performance and survival of different genotypes in culture were evaluated through a 48‐wk rearing trail. The average fertilization rate in genotypes with P. dabryanus as female parental was significantly higher than those of M. anguillicaudatus as female parental. The average fertilization level of sperm from P. dabryanus was about the same as diploid M. anguillicaudatus but significantly higher than tetraploid M. anguillicaudatus. The highest survival rate was found in DD group (52.77%) and PP group (50.31%) (P > 0.05). The intergenetic crosses between P. dabryanus and M. anguillicaudatus, especially for PD (19.05%), DP (17.89%), and PT (15.44%) groups, exhibited poor survival rates. Under the similar rearing conditions, PP group showed significant growth advantage. Growth rates of the interspecific hybrid progenies were found to be intermediate in comparison with the parental species. According to these results, the PP genotype is more suitable for aquaculture practice .  相似文献   

4.
White spot disease (WSD) caused by white spot syndrome virus (WSSV) creates severe epizootics in shrimp aquaculture industry worldwide. Despite several efforts, no such permanent remedy was yet developed. Selective breeding using DNA markers would be a cost‐effective strategy for long‐term solution of this problem. In the present investigation, out of 30 random primers, only one primer produced a statistically significant (< 0.01) randomly amplified polymorphic DNA (RAPD) marker of 502 bp, which provided a good discrimination between disease resistant and disease susceptible populations of Penaeus monodon from three geographical locations along the East coast of India. Because RAPD markers are dominant, a sequence characterized amplified region (SCAR) marker was developed by cloning and sequencing of 502 bp RAPD fragment, which generates a single 457 bp DNA fragment after PCR amplification only in the disease resistant shrimps. Challenge experiment was also conducted to validate this 457 bp SCAR marker, and the results suggested that the WSSV loads were 2.25 × 103 fold higher in disease susceptible than that in disease resistant shrimps using real‐time PCR. Therefore, this 457 bp DNA SCAR marker will be very valuable towards the development of disease‐free shrimp aquaculture industry.  相似文献   

5.
Luo  Wei  Zhang  Ning  Wang  Dongjie  Xu  Zhou  Wang  Tianzhu  Zhang  Xiaoyang  Gao  Tong  Liao  Min  Long  Yuejin  Du  Zongjun 《Aquaculture International》2021,29(3):1331-1341

Misgurnus anguillicaudatus and Paramisgurnus dabryanus hybrids were generated via full diallel crosses between the Meishan (M_M) and Fuyang (M_F) populations of M. anguillicaudatus and Meishan (P_M) and Ziyang (P_Z) populations of P. dabryanus. The purebred and hybrid offspring were co-cultured in a pool for 4 months, and 96.5% of the offspring could be assigned to a single parental pair based on nine potentially cross-species polymorphic microsatellites. The average body weight (BW) of the P_M × P_Z (female × male, in this order hereafter) hybrids was the highest (4.88 g), followed by that of the P_Z × P_M and P_M × P_M hybrids. The general combining abilities (GCA) of BW from both the sires and dams of P_M and P_Z were high, and that from M_M and M_F were low. The specific combining ability (SCA) of P_M × P_Z was the largest (16.61), followed by that of P_Z × P_M, M_F × M_M, and M_M × M_F (?15.89). The combination of M_F × P_M, M_F × P_Z, and P_M × M_F showed > 10% heterosis. This is the first study to use microsatellite-based parentage assignment in hybrid fish and lays foundation for loach crossbreeding.

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6.
许兰馨  周亮  危起伟 《水产学报》2023,47(2):029304-029304
归纳了白鲟、长江鲟、中华鲟近40年自然资源量变化情况,统计了长江鲟和中华鲟人工增殖放流数据,评估了增殖放流成效。因物种特性和分布的差异,放流无效的原因迥异。过度捕捞使人工放流长江鲟在放流后6个月之内难逃被“误捕”,而中华鲟放流数量不足及长江和近海过度捕捞导致中华鲟人工增殖放流的贡献甚微,其结果是长江鲟和中华鲟增殖放流均无法达到自然繁殖群体的补充水平。本文探究了近40年来白鲟、中华鲟和长江鲟在保护、管理和决策上存在的误区和不足,提出在生态大保护的背景下,(1)应编制和实施《长江鲟拯救行动计划》优先项目;(2)应以《中华鲟拯救行动计划》为指引,在就地保护、迁地保护和遗传多样性保护方面提出更具有可操作性的优先计划;(3)应设立中华鲟和长江鲟物种拯救行动计划专项,对现有涉栖息地或保护区生态补偿项目进行优化整合。唯有以恢复长江鲟和中华鲟自然繁殖为核心,才有望延续和恢复其自然种群,实现人与自然的和谐共处,推动长江流域社会经济绿色可持续发展。  相似文献   

7.
Abstract. Penaeus monodon -type baculovirus (MBV) was isolated and purified from the hepatopancreases of MBV-infected Penaeus monodon Fabricius. MBV DNA was extracted and used as a template in a polymerase chain reaction (PCR). The primers were chosen from conserved regions of the polyhedrin gene of Autographa californica nuclear polyhedrosis virus (AcNPV). One DNA fragment (674 base pairs) was amplified after PCR. There was a 65% homology between the predicted amino acid sequence of this PCR product with that of the polyhedrin polypeptide of AcNPV. Nucleotide sequence analysis indicated that the amplified DNA is the open reading frame of the MBV polyhedrin gene. This 674 bp DNA fragment was subsequently used as a probe in a dot blot analysis. The probe was able to hybridize with the DNA extracted from the purified MBV and from the MBV-infected P. monodon , but not from the MBV uninfected P. monodon.  相似文献   

8.
Pacific bluefin tuna (PBF), Thunnus orientalis, is commercially one of the most important species of tuna. In this study, amplified fragment length polymorphism (AFLP) screening was conducted to find the growth‐related polymorphic DNA in cultured PBF. Fish hatched in 2007 were harvested at an age of 818–1994 days. They were categorized into superior, average and inferior growth groups, depending on their growth score at the time of harvest. On AFLP screening of 24 fish, with eight fish from each group, 215 polymorphic DNA fragments were observed. A second amplification, with EcoRI + ACC and MseI + CCC primers, generated a polymorphic fragment of 630 bp at a rate of 80.0% (n = 15) in the superior, 56.3% (n = 16) in the average and 20.0% (n = 15) in the inferior growth groups. Polymerase chain reaction (PCR) primers, which could amplify both AFLP‐positive and AFLP‐negative loci, were developed using the consensus sequence outside the AFLP target fragment. Eleven haplotypes were obtained by sequence analysis of the PCR product at the AFLP target loci. Among those, haplotype 1 was statistically significant in the superior and average growth groups and could be used as a molecular marker for distinguishing the individuals with superior and average growth from those with inferior growth.  相似文献   

9.
White spot disease caused by white spot syndrome virus (WSSV) poses major problems that result in huge economic losses each year in shrimp aquaculture throughout the world. In the present study, microsatellite‐based DNA fingerprints have been compared between naturally occurring WSSV disease‐resistant and susceptible populations of giant black tiger shrimp, Penaeus monodon, to find DNA markers. For the first time, we report here a microsatellite locus, which, after amplification by polymerase chain reaction, provides a highly statistically significant DNA fingerprint of 71 bp, only in disease susceptible populations but not in disease‐resistant shrimp populations, whereas a 317 bp band is common in both. The absence of the former DNA marker will be very useful to identify disease‐resistant broodstock of P. monodon for marker‐assisted selection in breeding programs to generate disease‐free shrimps (P. monodon) in the aquaculture industry.  相似文献   

10.
Artificial and natural hybridization of dojo loach Misgurnus anguillicaudatus (2N = 50, DD for short) and large-scale loach Paramisgurnus dabryanus (2N = 48, PP for short) are well-grown. However, these hybrid loaches have not yet been examined for fertility and ploidy of gametes. Here, histological observations, artificial propagation, observations of embryonic development, larval morphology, and ploidy analyses were conducted to determine the fertility and ploidy of gametes of allodiploid (DP for short) and allotriploid (DDP for short) loaches, produced by DD females × PP males and induced from fertilized eggs of DD females × PP males by cold shock to prevent the second polar body release, respectively. The ovaries of DP and DDP included smaller number of eggs when compared with those of the control DD, while full-grown oocytes were observed. Testes of these two loaches were delayed-developed without spermatids or mature spermatozoa. Results obtained here showed that DP and DDP were fertility-weakened female and sterile male. Moreover, DP females and DDP females could, respectively, produce few viable haploid eggs and few viable haploid and diploid eggs. This study will provide valuable information for fish hybrid researches.  相似文献   

11.
A sex‐associated amplified fragment length polymorphism and a strain‐specific random amplified polymorphic DNA marker were identified from Asian arowana (dragonfish; Scleropages formosus Müller & Schlegel) by screening pooled genomic DNA samples from three different strains as well as males and females respectively. Both markers were cloned, sequenced and successfully converted into sequence‐tagged‐site (STS) markers. The strain‐specific STS marker could be applied to differentiate the Indonesian golden strain of Asian arowana from the green and blood‐red strains before the stage when colours become identifiable. Individuals from the green strain could be sexed with an efficiency of 82.7% using the sex‐associated STS marker. Thus, populations with preferred sex ratios can be formed without the need of rearing a large number of fish.  相似文献   

12.
Identification of masu salmon Oncorhynchus masou masou and amago salmon O. m. ishikawae was accomplished using a random amplified polymorphic DNA (RAPD) technique. Of 80 primers screened, three primers amplified subspecies-specific fragments (OPA11-1095 *, OPB5-1618* and OPD5-2038 *). Based on fragment patterns, 33 hybrids were detected among 150 upstream-migrating individuals in the Jinzu River, central Japan, a long-time habitat of masu salmon, to which amago salmon were recently introduced. All of the individuals examined in the 2000–2002 cohorts were identified as F 1 and F x as well as pure masu and amago forms. These results indicated continuing hybridization, the genetic pollution of the native masu salmon population by amago salmon possibly being a serious problem in the Jinzu River. Both standard length and body weight in F 1 hybrids tended to be less than in pure masu salmon. However, F x hybrids showed similar body sizes to masu salmon.  相似文献   

13.
Abstract. The plasmid content of 18 isolates of Edwardsiella ictaluri found in channel catfish was analysed by agarose gel electrophoresis. Each isolate contained an identical set of plasmids. This set consisted of two prominent plasmids of 5.2 and 4.4 kilobase pairs, and three smaller and less apparent plasmids. One plasmid (the 5.2 kilobase plasmid) was radiolabelled and used to probe a blot of DNA from all isolates. All plasmids were hybridized but no chromosomal DNA was labelled. These plasmids must share some homologous regions. DNAs from other bacteria, including the related Edwardsiella tarda, were also probed and no hybridization was seen. It is suggested that a plasmid probe may be a sensitive, specific probe for detection of E. ictaluri in channel catfish  相似文献   

14.
The matrinch? Brycon amazonicus, a commercially important freshwater fish resource, has no heteromorphic sex chromosomes so far described. In the present study, we performed a screening of sex-associated DNA markers in this species, through the use of a random amplified polymorphic DNA (RAPD) assay and a genomic DNA restriction digestion analysis. DNA digestions evidenced no differences between sexes. Sixty-six random primers were used in pooled and individual DNA samples of males and females, and the analysis of the RAPD fingerprints revealed one female sex-associated band. Cloning and sequencing of this band led to the identification of two distinct DNA segments. While one of the isolated fragments showed a significant identity with a described protein gene (phosphatidylinositol glycan anchor biosynthesis, class W), the other fragment, composed of 535?bp, corresponds to a novel DNA marker. Further experiments were performed with this second DNA fragment in order to verify its sex-specificity. Data on dot blot hybridization, using total DNA of both sexes, confirmed its female-specificity in B. amazonicus. A primer set was designed based on its sequence data and used in PCR with DNA samples of this species, leading to diagnose the animals' sexes with a 100?% overall accuracy through a sequence characterized amplified region approach. No amplification results were found for two other species of the genus-B. orbignyanus and B. lundii. The obtained data can lead to the hypothesis that B. amazonicus may present heteromorphic sex chromosomes that should be in an early phase of differentiation.  相似文献   

15.
以奥利亚罗非鱼Oreochromis aureus为实验材料,通过对800多条随机引物的筛选,获得了1个奥利亚罗非鱼雌性特异性的、长度为1 488 bp的RAPD标记片段RAPD71699-1488,经琼脂糖凝胶电泳后回收、克隆、测序,并根据测序结果设计PCR特异引物,再经PCR条件优化,成功地将该RAPD标记片段转化为实验结果稳定、操作简便的SCAR标记,即SCAROaF1488。采用双重PCR技术,以mtDNA 16S rRNA基因片段为PCR扩增阳性对照,对该标记的有效性在两个群体共200个个体(雌、雄各100个)中进行验证。结果显示,标记检测结果与表型性别的符合度为100%。SCA-ROaF1 488标记的获得为奥利亚罗非鱼遗传性别鉴定及标记辅助选择提供了有效工具,为深入研究鱼类性别相关基因及性别决定机制提供了重要线索和新的思路。  相似文献   

16.
长江流域泥鳅与大鳞副泥鳅种质资源调查与研究   总被引:2,自引:1,他引:1  
对长江流域泥鳅和大鳞副泥鳅野生群体进行了系统资源调查,结果显示,二倍体泥鳅(2n)与多倍体泥鳅(3n,4n,5n)在长江流域均有分布,其中二倍体泥鳅数目占有绝对优势,少量多倍体泥鳅集中分布于长江流域中游地区及若干湖泊。此外,显著性分析表明,泥鳅和大鳞副泥鳅的雌性个体都显著大于雄性个体,两物种间个体大小无显著性差异。二倍体泥鳅的体长与体质量明显小于三倍体泥鳅及四倍体泥鳅,而三倍体泥鳅与四倍体泥鳅间无显著性差异。野生群体中,泥鳅雌性个体所占比例从上游到下游逐渐减少,大鳞副泥鳅无明显变化。相关性分析显示,泥鳅体质量与地域经度呈负相关,大鳞副泥鳅体质量与地域经度无显著相关性。研究表明,长江流域多倍体泥鳅和大鳞副泥鳅物种资源丰富。  相似文献   

17.
The sequence‐related amplified polymorphism (SRAP) technique was applied to identify the genetic difference between the ‘Whole Red’ (‘WR’) population and the ‘Whole White’ (‘WW’) population. The specific SRAP band, namely SR2,7173 bp (SR indicates the first two letters of SRAP) from ‘WR’ and ‘WW’, was identified from the amplified bands of 12 primer pairs (PP) screened from 88 SRAP PP. After gel extraction, cloning and sequencing of specific band from the two populations, the sequence was submitted to database of Genome Sequence Survey. blast analysis showed that this SRAP fragment shared high similarity to functional genes of Danio rerio. Four primers (22–26 bases) were designed according to the sequence information. Then, polymerase chain reaction amplification was carried out in the two populations. The experimental results also showed that among four sequence‐characterized amplified region (SCAR) markers, only SC‐3 (154 bp) developing from SR2,7173 bp (me2‐em7) showed specificity to ‘WR’. Examination with a large sample size showed that SCAR 3 (SC‐3) could be positively amplified with 85% frequency in the ‘WR’ population rather than in the ‘WW’ population. The results indicated that the SC‐3 marker could be used as a specific molecular marker for population identification, providing an effective, easy and rapid method for discriminating different populations and conducting genetic analysis.  相似文献   

18.
19.
Abstract. A digoxigenin-labelled DNA probe was used for in situ detection of the Penaeus monodon -type baculovirus (MBV) derived from cloned MBV polyhedrin genome in cultured Penaeus monodon Fabricius. First, the specificity of the probe against MBV DNA with dot blot hybridization analysis was verified. This probe indicated that cloned MBV polyhedrin fragment can be used as an MBV-specific probe. This was then used to microscopically examine sections of MBV-infected tissues for a blue-purple precipitate indicative of a positive reaction for MBV. MBV-positive cells were located only in the epithelium of the hepatopancreatic tubules and of the midgut. Furthermore, comparison of the susceptibility to MBV infection among several life-stages of the shrimp showed that the MBV genome was found in the zoea, mysis, post-larva, and adult stages, whereas MBV DNA was not detected in either eggs or nauplii. The results were quantified from in situ hybridization with an image analyser to compare the degree of cell infection among groups of cultured P. monodon collected from various farms in Taiwan.  相似文献   

20.
UV性别决定系统在一些低等生物生活史的单倍体阶段展现出特定的进化和遗传特性.实验构建了一个海带雌配子体基因组的细菌人工染色体(BAC)文库,结果显示,该文库包含31872个克隆,插入片段平均长为115 kb,覆盖6.57倍的海带基因组.利用海带雌配子体特异性的标记FRML-1488的序列为探针筛选BAC文库,获得4个阳...  相似文献   

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