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81.
金乌贼(Sepia esculenta)繁殖模式的分子学鉴定   总被引:1,自引:0,他引:1  
我国金乌贼自然资源日渐衰退,为制定相应的保护措施,需要对金乌贼的繁殖模式进行分析研究。本实验在青岛海域采捕活体金乌贼成体22只,进行室内繁育。根据形态学判定参与受精产卵雌性有2只(F8,F18)雄性18只。为了进一步探索金乌贼的繁殖模式,对雌体F2纳精囊处交配后留下的精荚中的精子进行了微卫星DNA标记检测,发现至少2个雄性参与交配行为;同时,随机选取子代幼体87只,利用8个DNA微卫星位点进行亲权鉴定。结果表明:F8个体是42只幼体的母本,而剩余45只的母本是F18,由F8产卵孵化的幼体潜在父本是M4和M5,由F18产卵孵化的幼体潜在父本是M12和M13,每一个雌性可能与至少2个潜在雄性交配并受精。分析结果显示金乌贼繁殖模式存在一雌多雄关系,为科学维持和保护原种基因库,有的放矢地进行繁育、增养殖和人工放流工作提供重要支撑。  相似文献   
82.
Genetic diversity is the basis for adaptation and therefore of primary scientific interest, especially in species that are threatened by anthropogenic challenges, e.g. climate change and/or pollution. Coral reefs are among the most threatened but also the most diverse ecosystems and have therefore been studied quite extensively. So far, most investigations have focused on scleractinian corals while the equally important reef builders, the hydrozoans, have been less considered. Here we provide the first study of genotypic variability as well as intra‐colonial genetic variability, the co‐occurrence of more than one genotype within a single colony, in Milleporidae based on microsatellites. We analysed two geographically distinct populations from the Millepora dichotoma complex, one from the Red Sea and one from the Great Barrier Reef. Additionally, a population of Millepora platyphylla was analysed from French Polynesia. We compared microsatellite multilocus genotypes and cytochrome c oxidase subunit I haplotypes for each of the three field sites to detect levels of genotypic diversity at the intra‐ and inter‐specific levels. Furthermore, we examined all species for the occurrence of intra‐colonial genetic variability, a recently described mechanism in scleractinian corals that might enhance the adaptive potential of sessile organisms. We found both species and all field sites to be genotypically variable. Twelve mitochondrial haplotypes and 27 multilocus microsatellite genotypes were identified. In addition, intra‐colonial genetic variability was detected in the M. dichotoma complex from the Great Barrier Reef as well as in M. platyphylla from French Polynesia. All of the intra‐colonial genetically variable colonies consisted of one main genotype and a second divergent genotype caused by somatic mutations (mosaicism). Our study proves that Milleporidae are genetically variable and that the phenomenon of intra‐colonial genetic variability also occurs in this important reef‐building family.  相似文献   
83.
为探究不同地理条件下斑节对虾天然群体的遗传多样性和遗传分化水平, 选用14对简单重复序列(simple sequence repeat, SSR)特异引物对广东湛江、海南三亚、海南琼海的斑节对虾天然群体共计90尾个体进行微卫星标记分析, 每对引物检测出的等位基因数为2~4不等, 平均2.7。3个群体(湛江、三亚、琼海)平均有效等位基因分别为1.9081、1.9715和2.0185, 平均多态信息含量分别为0.3864、0.3926和0.4078, 总的平均期望杂合度(0.4605 )明显高于观测杂合度(0.4046), 表明3个群体遗传多样性水平为中等, 且存在杂合度缺失的现象。种群分化指数和遗传距离分析表明, 在不同群体间已产生了遗传分化, 但是分化较小; 三亚群体和琼海群体之间的亲缘关系最近, 而与湛江群体的亲缘关系最远。分子方差分析表明, 群体间的遗传变异指数为8%, 群体内个体间的遗传变异指数为92%, 基因分化主要发生在群体内, 而不是群体之间。  相似文献   
84.
本研究采用生物信息学方法分析比较了黑鲷、真鲷及其两种杂交子代基因编码区(Coding sequence.CDS)中微卫星序列(简单重复序列.SSR)的分布规律及密码子偏好性。结果表明:(1)黑鲷、真鲷及其两种杂交子代微卫星序列均以三碱基重复类型为主,其次为二碱基重复,片段长度大多数在12—20bp之间。(2)黑鲷与反交(黑鲷♀×真鲷♂)在三、五碱基中优势基元类型相同,真鲷与正交(真鲷♀×黑鲷♂)在三碱基中优势基元类型相同,而黑鲷与正交在四碱基中优势基元类型相同。(3) UUC、UAC等28个密码子为黑鲷、真鲷及其两种杂交子代基因编码区的偏好性密码子,偏爱使用以C或G结尾的密码子,且第三位密码子碱基的GC含量(GC3s)均高于基因编码区平均GC含量。(4)真鲷与正交的密码子使用的偏好性相似,一定程度上说明黑鲷、真鲷杂交子代偏母系遗传。分析结果将为研究鲷科鱼类微卫星标记、研究其群体遗传多样性、构建转基因表达系统和开展分子遗传育种提供理论基础。  相似文献   
85.
真江蓠是原产于西北太平洋的重要经济红藻。我们利用10对微卫星引物检测中国黄渤海地区真江蓠的群体遗传多样性和结构。10个微卫星位点在12个群体中共检测到65个等位基因,每个位点的等位基因(Na)为1~28,有效等位基因(Ne)为1.0~9.6。每个群体的平均等位基因(Na)、平均有效等位基因(Ne)、平均香浓指数(I)、平均观察杂合度(Ho)和平均预期杂合度(He)分别为2.4、1.6、0.419、0.133和0.227,显示较低的群体遗传多样性。中国黄渤海12个真江蓠群体间遗传分化较大(Fst=0.398 7),基因流有限(Nm=0.377 1),近交系数为正(Fis=0.391 3,Fit=0.634 0),表明可能存在近交和杂合子缺失现象。Structure和UPGMA系统进化分析一致将12个群体分为两个遗传组,并在黑石礁群体(HS)和石岛群体(SD)中发现明显的遗传混杂现象。AMOVA分析显示遗传变异主要来自于群体内(73.27%)。该研究可为黄渤海地区真江蓠自然资源保护和管理提供科学依据。  相似文献   
86.
近年来,长江下游进行了大规模鲢(Hypophthalmichthys molitrix)增殖放流活动,而增殖放流对鲢资源的贡献如何,成为亟待探究的科学问题.本研究基于已开发的11对微卫星引物,标记8个主要原良种场(为江苏省各地政府放流工作提供苗种的单位)鲢繁殖亲本群体,利用微卫星亲子鉴定技术,评估2016-2017年长江江苏段鲢增殖放流对鲢在江群体的资源贡献率.研究结果显示,621尾繁殖亲本群体和475尾长江捕捞鲢群体共检测出191种等位基因,每个座位的等位基因种类数、观测杂合度、期望杂合度范围分别为9~36、0.536~0.793、0.597~0.941;对应平均值分别为17.36、0.656、0.794.11个座位均表现出高度的多态性,每个座位的多态信息含量范围为0.560~0.938,平均值为0.771,证明选用的11对微卫星引物可作为亲子鉴定的有效工具.亲子鉴定结果表明,在亲本性别未知的情况下,非亲排除率(NEP)范围为2.4%~42.4%,累积非亲权排除率(CEP)在99.99%以上; 475尾长江鲢群体中,鉴定出39尾鲢个体来自于原良种场鲢亲本群体所繁殖的后代,即回捕率为8.21%.综合分析可见,2016-2017年,长江江苏段增殖放流对鲢资源量有较好的补充作用.  相似文献   
87.
2019~2020年在三峡库区巫山(WS)、万州(WZ)、丰都(FD)、涪陵(FL)4个采样点采集到新建短颌鲚(Coilia brachygnathus)种群153尾个体,基于鳞片和10个微卫星DNA标记进行年龄结构、生长特征与遗传多样性分析。结果显示,短颌鲚种群体长分布范围为102.1~301.6mm,平均体长(196.6±40.0)mm;体重分布范围为1.90~79.70g,平均体重(17.70±13.06)g。短颌鲚种群年龄组为1~5龄,其中2龄和3龄为优势年龄组,占总个体数的82.35%。体长-体重呈幂函数指数关系,属于正异速生长类型。微卫星DNA标记分析结果显示,10个微卫星位点共检测到82个等位基因,各群体平均等位基因数(Na)为5.600 0~7.300 0,平均有效等位基因数(Ne)为3.541 4~3.831 5,平均观测杂合度(Ho)为0.617 7~0.700 0,平均期望杂合度(He)为0.682 3~0.702 9之间,平均多态信息含量(PIC)为0.628 5~0.648 4。4个群体的遗传多样性水平均较高,呈现出由三峡库区下游至上游逐渐减小的特点。遗传结构分析结果显示,群体间遗传分化水平很低,遗传变异主要来源于个体内部。结果表明,三峡库区短颌鲚种群处于快速扩张阶段,4个群体均具有较丰富的遗传多样性,遗传结构未发生显著群体分化,群体间基因交流频繁。由此提示,三峡库区短颌鲚很可能来源于三峡大坝下种群扩张迁入三峡库区水域而繁殖建群。  相似文献   
88.
Pacific whiteleg shrimp(Litopenaeus vannamei) is an economically relevant shrimp species in many Asian countries. The specific objective of the current research was to assess microsatellite markers in screening the fastgrowth of domesticated L. vannamei stocks to establish a founder population for breeding-selection plans. The postlarvae produced by the reproduction of second generation broodstock were cultured in the same conditions throughout a five months growing period. Ninety juvenile shrimp were selected from the slow-, medium- and the fast-growth groups, and ten microsatellite markers were used to investigate their genetic diversity, and to understand the improvement of a breeding-selection scheme. Ten polymorphic loci(markers)(M1–M10) were produced at ten loci in this sample, among them Primer M8 was the highest polymorphic locus and M7 was the lowest one. A specific locus was found in the fast-growth group using Primer M5. The longest genetic distance(0.481) was determined between the fast- and medium-growth groups and the shortest(0.098) was between the slow- and medium-growth groups; therefore, the largest genetic identity(0.946) was observed between the slowand medium-growth groups and the smallest(0.667) was observed between the medium- and fast-growth groups.The Unweighted Paired Group with Arithmetic Average(UPGMA) dendrogram based on Nei's genetic distances provided two different groups; the first consist of the slow- and medium-growth groups and the second the fastgrowth group. Selection response and realized heritability for growth were 11.55% and 31.26%, respectively.Therefore, this set of microsatellite markers would provide a useful tool in shrimp breeding schemes.  相似文献   
89.
It has been proposed that the elkhorn coral Acropora palmata is genetically separated into two distinct provinces in the Caribbean, an eastern and a western population admixing in Western Puerto Rico and around the Mona Passage. In this study, the genetic structure of A. palmata sampled at 11 Puerto Rican localities and localities from Curaçao, the Bahamas and Guadeloupe were examined. Analyses using five microsatellite markers showed that 75% of sampled colonies had unique genotypes, the rest being clone mates. Genetic diversity among genets was high (HE = 0.761) and consistent across localities (0.685–0.844). FST ranged from ?0.011 to 0.047, supporting low but significant genetic differentiation between localities within the previously reported eastern and western genetic provinces. Plots of genetic per geographic distances and significant Mantel tests supported isolation‐by‐distance (IBD) within Puerto Rico. Analysis with the software STRUCTURE favored a scenario with weak differentiation between two populations, assigning Eastern Puerto Rican locations (Fajardo and Culebra), Guadeloupe and Curaçao to the Caribbean eastern population and Western Puerto Rican locations (west of Vega Baja and Ponce), Mona and the Bahamas to the Caribbean western population. Vieques and San Juan area harbored admixed profiles. Standardized FST per 1000 km unit further supported higher differentiation between localities belonging to different STRUCTURE populations, with IBD being stronger within Puerto Rico than on larger regional scales. This stronger genetic transition seems to separate localities between putative eastern and western provinces in the Eastern Puerto Rican region, but not around the Mona Passage.  相似文献   
90.
以黄口荔枝螺转录组测序所得到的拼接序列为基础,利用MISA软件进行微卫星分析,利用Primer5.0设计引物160对。结果显示,83对引物能够成功扩增,引物在黄口荔枝螺渔山列岛群体多态性检测中发现,37个SSR位点能够表现出多态性,一共获得了129个等位基因,各位点等位基因数为2~5个,平均每个位点等位基因数为3.49个,观测杂合度H_o,期望杂合度H_e,多态信息含量PIC范围分别介于0.000~0.800、0.146~0.645、0.139~0.573之间,有9个表现为高度多态,20个表现为中度多态,8个表现为低度多态。实验结果进行Hardy-Weinberg平衡检测后,利用Bonferroni correction法进行校正,有29个位点显著偏离,结果表明渔山列岛黄口荔枝螺群体总体遗传多样性水平较低。  相似文献   
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