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1.
为分析罗非鱼群体的遗传多样性以及筛选与罗非鱼性别相关的微卫星标记。应用24对微卫星引物,使用常规PCR及聚丙烯酰胺凝胶电泳的方法在两个尼罗罗非鱼(Oreochromis niloticus)群体和两个奥利亚罗非鱼(O.aureus)群体中初步筛选到UNH931、GM128、GM201、GM258、GM597以及UNH898共6个与性别相关的微卫星标记。然后使用降落PCR以及毛细管电泳的方法在两个尼罗罗非鱼群体、两个奥利亚罗非鱼群体以及ZY 1、WY 1、YY 1和YY 2型罗非鱼群体中进一步扩增这6个微卫星标记,统计各群体的遗传多样性参数:6个微卫星标记在上述群体共297个样本中检测到95个等位基因,其大小在97~302 bp之间,各位点在各群体等位基因数在1~13个之间,各群体平均观测等位基因数为2.167~9.333,平均有效等位基因数为1.624~4.966,平均观测杂合度为0.324~0.983,平均期望杂合度为0.329~0.782,平均多态信息含量为0.275~0.753;两个尼罗罗非鱼群体、WY 1和YY 2群体达到高度多态(PIC>0.5),两个奥利亚罗非鱼群体、ZY 1和YY 1群体为中度多态(0.25相似文献   

2.
文章采用微卫星标记技术,对吉富品系尼罗罗非鱼(GIFT strain Oreochromis niloticus)抗病群体和易感病群体进行了遗传差异分析。结果显示:在30个微卫星位点中20个能扩增出多态性高、重复性好和扩增条带清晰;抗病群体和易感病群体的平均等位基因数分别为2.5和2.4个;观测杂合度和期望杂合度分别为0.476和0.453,0.44和0.457;多态信息含量PIC分别为0.359和0.379;UNH845和UNH189位点在抗病群体中偏离Hardy-Weinberg平衡(P0.05),GM180位点在易感病群体偏离Hardy-Weinberg平衡,两个群体间的遗传距离和遗传分化指数0.055和0.054。此外GM251和GM462位点的差异等位基因片段(135bp和198bp)与抗病性状存在一定的连锁关系。以上结果表明,吉富品系尼罗罗非鱼抗病群体与易感病群体之间的遗传多样性差异不明显,筛选出2个与抗病性状相关的微卫星标记,为开展吉富品系尼罗罗非鱼抗病品种分子标记辅助选育奠定了基础。  相似文献   

3.
用33对在尼罗罗非鱼(Oreochromis niloticus)中能有效扩增的微卫星引物,对橙色莫桑比克罗非鱼(Oreochromis mossambicus)进行PCR扩增,结果有32对引物能获得稳定的特异性条带,占总数的97.0%,其中15个微卫星位点具多态性,表明大部分尼罗罗非鱼的微卫星位点存在于橙色莫桑比克罗非鱼中。用具多态性的15个微卫星位点,对橙色莫桑比克罗非鱼30尾个体进行扩增分析,结果共检测到44个等位基因,大小在113~232bp之间,平均多态信息含量(PIC)为0.4308,平均观测杂合度(鼠)为0.5489,平均期望杂合度(垃)为0.5248,个体间平均遗传距离为0.3132,表明所选橙色莫桑比克罗非鱼群体遗传多样性较丰富,种群结构比较合理。本研究还对尼罗罗非鱼和橙色莫桑比克罗非鱼间特异位点进行了分析,发现有7个位点(UNH899、UNH208、UNH853、UNH876、UNH222、UNH933、UNH773)可有效区分莫桑比克罗非鱼和尼罗罗非鱼,可作为罗非鱼种质鉴定的分子标记。[中国水产科学,2008,15(3):400-406]  相似文献   

4.
根据罗非鱼微卫星遗传图谱,在不同的连锁群上随机选择30个微卫星位点,研究它们在192尾不同家系吉富罗非鱼(Genetically Improved Fanned Tilapia,GIFT)中的遗传多样性及这些位点与体质量、体形性状的相关性.结果表明,30个位点共检测出126个等位基因,片段长度124~310 bp.各位点等位基因数为1~7个,平均等位基因数4.2个;多态信息含量(P1C)为0.259 4~0.716 7,平均0.580 8;杂合度(H)为0.306 4~0.753 1,平均0.632 2,表明该吉富罗非鱼群体遗传多样性比较丰富.最小二乘方差分析结果显示,位点GM041、GM542和GM304与吉富罗非鱼雌鱼体质量相关;位点GM041、UNH860、GM519和GM304与雄鱼体质量相关,位点UNH952与雄鱼体形相关.位点GM041、UNH860、GM304的AA基因型和位点GM519的DE基因型都有可能作为以体质量为选育目标的辅助标记,其中UNH860和GM304的AA基因型有望成为作为以体质量为选育目标的首选辅助标记.实验结果说明,吉富罗非鱼具有与体质量相关的标记越多,体质量也越大.  相似文献   

5.
应用微卫星标记对尼罗罗非鱼(Oreochromis niloticus)♀×萨罗罗非鱼(Sarotherodon melanotheron)♂杂交后代(F1、F2)的遗传分离情况进行了初步研究.在86对微卫星引物中,筛选出21对在尼罗罗非鱼和萨罗罗非鱼中存在差异等位基因的特异性引物,共检测出59个等位基因,包含32个尼罗罗非鱼和24个萨罗罗非鱼特异等位基因.F1观测杂合度(Ho=0.998)大于 F2(Ho=0.739), F2有效等位基因数(Ne=2.48)、平均多态信息含量(PIC=0.497)与 F1的(Ne=2.45、PIC=0.489)相似.F1中所有位点均表现为尼罗罗非鱼与萨罗罗非鱼杂合基因型.F2中位点等位基因分离情况各异,通过卡方检验,有18个位点符合孟德尔遗传(P>0.05),2个位点GM145、UNH003表现为偏离孟德尔遗传(P<0.05),1个位点GM276不分离.在18个孟德尔遗传位点中, F2中尼罗罗非鱼特异等位基因频率为48.3%,萨罗罗非鱼特异等位基因频率为47.7%;基因型出现F1型、尼罗罗非鱼型、萨罗罗非鱼型的比例分别为58.2%、19.9%、21.9%.结果表明, F2较好地继承了F1的遗传杂合性,但也存在一定程度的分离.  相似文献   

6.
刺参微卫星标记与生长性状体重、体长的相关分析   总被引:1,自引:0,他引:1  
运用单标记分析法分析了10个微卫星位点与控制体重、体长数量性状的QTL的连锁关系。10对微卫星引物在8月龄具有生长性状差异的60个刺参个体基因组DNA中扩增得到50个等位基因,每个微卫星位点等位基因数3~7个,平均有效等位基因个数5.0。10个微卫星位点的多态信息含量为0.268 0~0.825 6不等,观测杂合度为0.083 3~0.666 7。采用SPSS软件对刺参的体重、体长生长性状和微卫星位点相关性进行分析,结果显示,微卫星位点AjSSR02基因型AB、AD、CD与体重和体长相关,AjSSR04标记中等位基因A对生长性状有正面影响,位点AjSSR06基因型FF个体仅平均体重与其他基因型个体显著差异,AjSSR09标记的A和B等位基因分别对生长性状具有正面和负面不同影响。  相似文献   

7.
草鱼生长相关的微卫星标记在选育群体中的验证   总被引:1,自引:0,他引:1       下载免费PDF全文
生长性状是水产动物遗传育种中的重要经济性状,利用与性状相关的分子标记与育种相结合的手段,可以大大加速育种进程。在对草鱼生长性状的前期研究中,采用数量性状位点(QTL)定位的方法,在1号连锁群中发现了2个与生长相关的QTL。在此基础上,实验利用这2个QTL侧翼的2对微卫星标记(CID391_2、CID1512、CID973_1和CID254_1),对长江草鱼选育群体的480个个体进行分析,以期基于草鱼QTL定位结果,对草鱼生长相关的微卫星标记在选育群体中进行验证。结果显示:(1)4个微卫星标记在该群体中均具有高度多态性,其中各位点观测等位基因数(N_a)为12~23个,有效等位基因数(N_e)为4~12个,观测杂合度(H_o)为0.607~0.904,期望杂合度(H_e)为0.751~0.902;(2)利用方差分析及多重比较对4个多态性的微卫星标记与选育草鱼群体的生长性状(体质量和体长)进行关联分析,发现CID391_2在雌性个体中,各基因型与体质量和体长之间均无显著差异;而在雄性个体中,各基因型与体质量和体长之间差异显著。CID1512、CID973_1和CID254_1在雌性或雄性个体中,各基因型与体质量和体长之间均具有显著差异。研究表明,对草鱼生长相关的微卫星标记在选育群体中的验证结果,为进一步开展草鱼生长性状QTL定位研究和基于QTL结果的分子标记辅助育种(MAS)实践奠定理论基础。  相似文献   

8.
本研究利用SPSS 19.0的GLM模型分析28个微卫星标记与半滑舌鳎Cynoglossus semilaevis生长性状的相关性,结果获得14个与半滑舌鳎体质量(BWe)、体长(BL)或体宽(BWi)显著相关的微卫星标记。与雄性个体生长性状显著相关的7个标记中,cse56与体质量、体长和体宽3个性状均显著相关(P0.05);csou24、hncyse68、hncyse147和hncyse148与体质量和体宽显著相关(P0.05)。与雌性个体生长性状显著相关的10个标记中,cse151和csou56与3个性状均显著相关(P0.05);csou33、csou39和hncyse108等5个标记与其中2个性状显著相关(P0.05)。csou24、hncyse147和hncyse148在雄、雌群体中均表现出与生长性状的相关性。本研究共筛选出17个对雄性个体生长具有显著正面影响的优势基因型,29个雌性个体的优势基因型。  相似文献   

9.
驯养、选育条件下尼罗罗非鱼群体的选择压力分析   总被引:1,自引:1,他引:0  
家养动物是研究长期人工选择对动物基因组产生选择效应机制的独特对象,尼罗罗非鱼(Oreochromis niloticus)是一种受人工干预(驯养、选育)历史较短的优良养殖对象,可作为研究新近发生的人工干预对动物基因组产生影响的遗传机制的良好模型。本研究以1个尼罗罗非鱼埃及野生群体为对照组,以4个"新吉富"罗非鱼选育系群体、2个企业自主选育群体和5个驯养群体为实验组,采用3种模型分析方法(岛屿模型、分级岛屿模型和贝叶斯似然法),在12个微卫星位点上进行F_(ST)-离群值点检测(F_(ST)-outlier test)。结果显示,在本研究所分析的12个微卫星位点中,4个"新吉富"罗非鱼选育系群体在2个微卫星位点(OMO043,OMO114)受到了显著的正向选择压力(P0.01),2个企业自主选育群体在另外2个微卫星位点(OMO049,OMO100)受到显著的正向选择压力(P0.01),而5个驯养群体只在1个微卫星位点(OMO013)受到了显著的正向选择压力(P0.01)。由此可见,选育群体受到的正向选择位点数明显多于驯养群体,选育群体与驯养群体受到正向选择的位点各异,不同选育群体间受到正向选择的位点也各不相同。本研究结果表明,不同的人工干预途径从不同的方向上对尼罗罗非鱼基因组产生了影响。  相似文献   

10.
草鱼EST-SSRs标记的筛选及其与生长性状相关分析   总被引:2,自引:1,他引:1  
利用草鱼(Ctenopharyngodon idella)EST(expressed sequence tags)数据库开发的18个EST-SSR标记,对草鱼群体进行基因型与生长性状关联分析和群体遗传多样性分析,结果表明:关联分析得到6个微卫星位点(13118、13305、24017、25085、35939和40698)与体重,体长和体高显著或极显著相关(P<0.05或P<0.01)。对其进行多重比较获得有利基因型分别为13118位点的BB、13305位点的AD、24017位点的AC、25085位点的BE、35939位点的BB和40698位点的BB。将6个微卫星位点上的EST序列与GenBank数据库进行BLAST比对,其中24017序列与鲤鱼自然杀伤细胞增强因子(NCEF)同源性水平高达86%,25085序列与草鱼反应元件结合蛋白(CREB)的基因同源性水平达到80%。应用这18个微卫星位点对草鱼养殖群体进行遗传多样性分析,共检测到82个等位基因,平均等位基因4.556个,每个位点检测到的等位基因数为2~9个,群体的平均观测杂合度为0.452 9,平均期望杂合度和平均多态信息含量分别为0.457 1和0.401 7,表明该群体遗传多样性处于低水平。  相似文献   

11.
To develop an effective system for parentage analysis in gynogenetic and clonal progeny of Nile tilapia, Oreochromis niloticus L., polymorphic microsatellite loci and amplified fragment length polymorphisms (AFLPs) were investigated in several gynogenetic families and clonal lines. Six microsatellite loci were screened in two meiotic gynogenetic families to look for loci with high gene–centromere recombination rates, which can be used to discriminate meiotic from mitotic gynogenetics. Microsatellite loci UNH189 and UNH211 showed 96.7% and 92.0% heterozygosity, respectively, in these families, while other loci showed lower recombination frequencies. Scoring both UNH189 and UNH211 would give a very low probability of an individual meiotic gynogenetic being homozygous for both loci. Multiplex polymerase chain reaction of microsatellite loci was used to verify parentage in four families of mitotic gynogenetics and five fully inbred clonal lines. The genotype of each clonal line should serve as a unique identifier. Twelve AFLP primers were also investigated and 26 diagnostic AFLP bands were identified to follow inheritance in mitotic gynogenetic individuals. Amplified fragment length polymorphisms were found to be effective for this purpose but microsatellites were more appropriate since they are co‐dominant, while AFLPs are dominant markers. A multiplex of the microsatellite loci used in this study would be useful for general parental assignment as well as for the analysis of the products of chromosome set manipulations.  相似文献   

12.
A genome scan, searching for quantitative trait loci (QTL) for the traits cold tolerance and body weight in tilapia, was performed on a cross between a (Oreochromis niloticus×Sarotherodon galilaeus) male and a (O. mossambicus×O. aureus) female. Fifty‐four microsatellites and 23 amplified fragment length polymorphism (AFLP) primer combinations were genotyped and tested for marker–trait associations. Sex‐specific linkage maps were constructed from this data. Twenty‐three point‐wise significant marker–trait associations were found in the genome scan, and putative QTL were subsequently tested in another (On×Sg) × (Om×Oa) family. None of the putative QTL from the first experiment were significant in the second experiment. However, one microsatellite, UNH130, found to be associated to weight in the first experiment, was found to be strongly associated to cold tolerance in the second experiment. Since QTL for cold tolerance and body weight were recently found on the linkage group containing UNH130 (linkage group 23) in another study, this linkage group was investigated more closely using interval mapping. The results provide indications, but not conclusive evidence, of a QTL for cold tolerance on linkage group 23.  相似文献   

13.
Two control (C1 or first control generation, and C4 or fourth control generation) and three selected (S1 or first selected generation, S2 or second selected generation, S4 or fourth selected generation) stocks of Chitralada Nile tilapia were analysed for microsatellite variation to determine the effect of size‐specific mass selection on genetic variability. Genetic variation based on five microsatellite loci (UNH123, UNH147, UNH172, UNH222 and UNH216) showed a slightly higher allelic diversity in the selected stocks (7.4–10 alleles) than in the control stocks (6.8–8.8 alleles). Apparent reductions in the mean number of alleles and He values were noted in successive generations of both control and selected lines. Significant deviations from Hardy–Weinberg equilibrium because of an excess of homozygotes indicated inbreeding in all control and selected stocks. Although estimated inbreeding levels were not significantly different among selected and control lines based on Welch's t‐tests, the increase in the degree of inbreeding within the selected line was higher (107.9%) than the control line (64.2%) after four generations. The implications of these results on the management and conservation of genetic diversity in improved breeds are discussed, while the importance of monitoring and minimizing inbreeding are likewise emphasized.  相似文献   

14.
以吉富罗非鱼与奥利亚罗非鱼为繁育亲本,采用完全双列杂交繁育4组F1,将初始规格基本一致的4组罗非鱼饲养100 d后,运用“加性-显性”遗传分析模型,分析了4组F1罗非鱼8个生长相关性状杂种优势、遗传效应以及与性状间的相关性.结果表明:(1)F1群体平均优势为0.129 4~0.368 4.除尾柄长超亲优势较大外,其他性状的群体超亲优势较小或表现出负向超亲优势.(2)8个性状的广义遗传率(HB)为0.714 2~0.995 3,表明加性效应和显性效应对性状的遗传变异影响极显著(P<0.01).除尾柄长外,其他性状的狭义遗传率(HN)介于0.469 4~0.737 9,表明加性遗传方差在表型方差中所占比率较高.(3)体质量、全长、体长、体高、体宽、头长、尾柄长、尾柄高性状之间表型相关在0.776 6~0.999 7范围内,而遗传相关在0.994 1~1.000 0之间,表明这些性状间都存在极显著的正相关.取样结束后,采用3.95×106 CFU/mL的海豚链球菌菌液进行腹腔感染,吉富罗非鱼自繁组F1代12 h后出现死亡,而奥利亚罗非鱼自繁组F1192 h后才出现死亡.384 h后,吉富罗非鱼自繁组F1死亡率为40%,正反交组F1分别为20%和23.3%,奥利亚罗非鱼自繁组F1死亡率最低,为6.67%.研究结果表明,除尾柄长外,杂交F1的其他性状不具备超亲优势,然而杂交可以提高选育后代的抗病力.  相似文献   

15.

 利用线粒体DNA控制区部分序列对中国8个尼罗罗非鱼 (Oreochromis niloticus) 养殖群体(埃及、吉拉达、美国、鹭业、吉诺玛、宝路、广东、新吉富)的遗传多样性和相互间遗传关系进行了分析。在所分析的237个样本中, 可归结为15种单倍型, 其中单倍型BL1为宝路(BL)、埃及(EGY)、吉拉达(GLD)、吉诺玛(GNM)和鹭业(LY) 5个群体所共享, 但没有一个单倍型为所有群体共享。8群体内的核苷酸多态位点数(S)4~83, 平均核苷酸差异数(K)的范围为0.50~37.26, 单倍型多样性(h)0.190 8~0.802 3, 核苷酸多样性(π)0.000 8~0.056 9AMOVA分析与群体间两两比较的遗传分化指数(FST)表明, 这些罗非鱼群体存在显著的遗传分化与差异(P<0.01)。利用Kimura two-parameter模型分析的系统发育关系表明: 宝路、广东和新吉富3个群体亲缘关系较近, 它们聚为一大支; 埃及、美国、吉拉达、鹭业、吉诺玛这5个群体聚为另一大支。单倍型网络(NETWORK)结果显示, 8个群体并没有明显的谱系分化。本研究结果旨为尼罗罗非鱼种质资源的聚合利用奠定基础。


  相似文献   

16.
从40个随机引物中分别筛选出15和18个,对奥利亚罗非鱼和尼罗罗非鱼雌、雄群体进行RAPD分析,结果显示:奥利亚罗非鱼雌性群体的多态位点比例为56.25%,基因多样性指数为0.2358,Shannon氏指数为0.3417,群体内的遗传相似指数为0.8625;雄性群体的多态位点比例为57.50%,基因多样性指数为0.2356,Shannon氏指数为0.3418,群体内的遗传相似指数为0.8375。尼罗罗非鱼雌性群体的多态位点比例为47.44%,基因多样性指数为0.1788,Shannon氏指数为0.2637,群体内的遗传相似指数为0.7667;雄性群体的多态位点比例为64.10%,基因多样性指数为0.2347,Shannon氏指数为0.3486,群体内的遗传相似指数为0.6769。试验结果表明,奥利亚罗非鱼雌、雄性群体的遗传多样性程度接近,而尼罗罗非鱼雄性群体的遗传多样性要比雌性群体丰富,遗传变异比雌性群体大。  相似文献   

17.
Flesh characteristics comprising chemical composition (protein, fat and moisture percentages and pH) as well as a sensory attribute (colour) were measured in 1951 fillet samples from two generations of two populations (a selection line, selected for increased harvest weight, and a control line, selected for average breeding values for harvest weight) of the genetically improved farmed tilapia (GIFT) strain of Nile tilapia. These data were jointly analysed with 5331 harvest weight records from three generations to estimate genetic parameters and correlated selection responses. Multiple trait animal models were used in the analyses. The potential for correlated responses was evaluated by estimating heritabilities and genetic correlations between body traits (weight, length, depth and width) and fillet traits (weight and yield) with the above mentioned flesh characteristics. The heritabilities for protein%, fat% and colour were low (0.06–0.11), whereas for moisture% and pH they were moderate (0.15–0.20). Genetic correlations among some flesh characteristics (moisture% with protein%, fat% and pH and with fat%) as well as between body and fillet traits with flesh characteristics, were significantly different from zero but low (?0.34 to 0.31). Correlated responses were evaluated by comparing the least squares means between the Selection and Control lines. Our results indicate that selection for high growth increased harvest weight in the Selection line relative to the Control line but it did not change the flesh characteristics of the GIFT strain.  相似文献   

18.
This study was designed to determine whether l -carnitine supplementation is necessary in a tilapia diet containing low-fish meal and a high lipid level, which is beneficial economically and for the environment. The effects of dietary l -carnitine on the growth, body composition, blood traits and post-thaw drip from muscle in hybrid tilapia were investigated. Five isonitrogenous and isocaloric diets were fed to the fish with a mean body weight of 141.7 g for 168 days. The control diet contained fish meal as the major protein source with 7% lipid. Other diets contained 7% or 12% lipid, in which fish meal was largely replaced by plant proteins, and supplemented with l -carnitine or not. Results showed that supplemental dietary l -carnitine did not affect the growth performance, feed efficiency or protein efficiency ratio, while the supplementation significantly reduced the mesenteric fat ratio. Whole body and muscle proximate compositions were unaltered by any dietary treatment. The total plasma lipid, triacylglycerol and cholesterol values of tilapia fed diets with alternative plant proteins were significantly lower than those of the control fish, whereas increasing the dietary lipid content increased the aforementioned blood traits. A decrease in plasma ammonia and an increase in urea were observed in dietary l -carnitine-supplemented fish. Post-thaw drip from muscle was reduced in fish fed supplemental dietary l -carnitine. The observations of this study revealed that neither the growth performance nor the feed utilization of hybrid tilapia was improved by a dietary l -carnitine treatment, but that it did lead to a reduced mesenteric fat ratio, altered nitrogen metabolism and improved meat quality.  相似文献   

19.
The strain by nutrition interaction in body weight and survival rate was examined by testing three genetic groups (Selection and Control lines of the GIFT strain, and Red tilapia) at two levels of protein in the diet (28% and 34%). The GIFT strain of Nile tilapia (Oreochromis niloticus) has been selected for high‐breeding values for body weight, whereas the Control was contemporaneously maintained and selected for breeding values of body weight close to the population mean. The Red tilapia (Oreochromis spp) was unselected at the time of the experiment. There were a total of 6000 fish at stocking in the study (2000 fish per genetic group). During the grow‐out period of 147 days, within each genetic group, the fish were randomly assigned to either a 28% or a 34% protein diet. Survival rate during grow‐out averaged 72%. A total of 4335 fish were harvested, with individual body measurements and survival recorded. The effect of genetic group accounted for the largest proportion of variation in body weight and survival, followed by sex and protein level. Across the two dietary protein levels, the GIFT strain had the highest growth. The difference in body weight between the Control and Red tilapia was not statistically significant (P > 0.05). Responses in growth to dietary protein levels also differed between genetic groups. No differences (P > 0.05) in body weight were found in the GIFT selection and Control fish fed 28% or 34% protein diets. However, body weight of Red tilapia was greater in the high‐ than in the low‐protein diet. In contrast to body weight, survival rate from stocking to harvest was affected by protein level. The high‐protein diet significantly improved survival rate, averaging 24% across the three strains. The overall results indicate significant effects of genetic group and dietary protein level on both body weight and survival rate; however, the interaction between strain and dietary protein levels was small and possibly unimportant for these traits. It is concluded that the 28% protein diet used in the selection programme for the GIFT strain results in the selection of genotypes that can perform well under commercial feeds.  相似文献   

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