)丝状体遗传多样性的比较研究

采用垂直板式聚丙烯酰胺凝胶电泳技术对分别来自中国青岛与日本北海道海带(Laminaria japonica)丝状体的6种酶系统（乙醇脱氢酶、谷氨酸脱氢酶、异柠檬酸脱氢酶、乳酸脱氢酶、山梨醇脱氢酶和超氧化物歧化酶）进行了检测,发现存在22个基因位点,分析了不同来源海带丝状体的遗传多样性与遗传分化程度。结果表明：日本北海道海带丝状体的预期杂合度、每个位点有效等位基因数等遗传参数均大于中国青岛海带丝状体。对日本北海道海带丝状体与中国青岛海带丝状体的遗传相似系数和遗传距离进行了计算分析,显示两者发生了遗传分化。日本北海道海带丝状体的遗传多样性高于中国青岛海带丝状体。研究结果还发现在中国青岛海带丝状体的Idh、Ldh 和Sdh中,以及日本北海道海带丝状体的Adh、Gdh、Idh、Ldh、Sdh和Sod中存在着不同迁移率的不等距双带酶,可能由特殊基因控制,并集中在第3个基因位点上。     

裙带菜同工酶酶谱特征及其遗传多样性的研究

用聚丙烯酰胺凝胶电泳（ＰＡＧＥ）技术对裙带菜丝状体青岛种群和舟山种群的１１种同工酶酶谱特征及其基因表达进行了研究,并作了遗传多样性的检测分析。结果表明：裙带菜丝状体青岛种群遗传多样性水平高于舟山种群：裙带菜丝状体种群还存在哑基因;另外,在裙带菜丝状体的乙醇脱氢酶酶谱中发现２个变异基因控制的２条酶带。     

亚洲小车蝗不同地理种群遗传多样性的等位酶分析

采用等位酶电泳技术对亚洲小车蝗8个地理种群遗传多样性和遗传分化进行了研究,并对8种等位酶系统:苹果酸脱氢酶(MDH)、苹果酸酶(ME)、乙醇脱氢酶(ADH)、谷氨酸脱氢酶(GDH)、谷氨酸-草酰乙酸转氨酶(GOT)、异柠檬酸脱氢酶(IDH)、腺苷酸激酶(AK)和己糖激酶(HK)进行聚丙烯酰胺凝胶电泳分析。结果表明:在亚洲小车蝗8个地理种群中共检测到14个基因位点,其中7个位点为多态位点,检测到25个等位基因;种群总体水平多态位点比率P=42.86%,平均有效基因数A=1.786,平均期望杂合度He=0.072,种群平均遗传距离为0.069～0.235。聚类分析表明,遗传距离与地理距离存在一定相关性。亚洲小车蝗8个种群的遗传分化系数Fst=0.086,基因流Nm=3.142,表明亚洲小车蝗种群间有一定程度的遗传分化及基因交流。     

中华稻蝗四个种群的遗传分化

采用水平淀粉凝胶电泳技术研究中华稻蝗(Oxya chinensis)四个种群的12个基因座位,探讨其遗传分化.这四个种群分别采自内蒙古呼和浩特、山西代县、山西太原和陕西西安.Ck和Mdh-2在四个种群中均为单态,其余的基因座位至少在一个种群内有两个以上的等位基因;在Ldh和Mdh-1的等位基因频率呈现梯度分布趋势.多态基因座位百分率(P)和平均每个基因座位的等位基因数目(A)分别为58.3%-66.7%和2.2-2.8,平均杂合度为Ho=0.173-0.240.除Gpi,Hk-2,Idh,Ldh和Mdh-1在部分蝗虫种群符合Hardy-Weinberg平衡外,其余绝大多数基因座位的基因型频率显著偏离Hardy-Weinberg平衡.四个种群间FST平均值不存在显著差异(FST=0.0510,P＞0.05),结合高的Nei's遗传一致度(I＞0.97)可知,种群之间遗传分化不明显.我们认为人类的农业活动可能促进了种群间的基因交流,从而降低了分化程度[动物学报50(2)187-192,2004].     

四种松毛虫不同地理种群遗传多样性的等位酶分析

【目的】采用等位酶电泳技术对中国松毛虫属Dendrolimus 4种共9个地理种群进行遗传多样性和遗传分化研究。【方法】对6种等位酶系统乳酸脱氢酶（LDH）、苹果酸脱氢酶（MDH）、苹果酸酶（ME）、乙醇脱氢酶（ADH）、甲酸脱氢酶（FDH）、谷氨酸脱氢酶（GDH）进行聚丙烯酰胺凝胶电泳分析。【结果】在4种松毛虫9个地理居群中共检测到10个基因位点,其中4个位点为多态位点,检测到17个等位基因; 种群总体水平多态位点比率P=40%,平均有效基因数A=1.700,平均期望杂合度He=0.151,种群平均遗传距离为0.001～0.285; 其中马尾松毛虫指名亚种Dendrolimu punctatus Walker 6个居群的遗传分化度Fst=0.265,基因流Nm=0.692。4种松毛虫之间遗传关系最近的是落叶松毛虫D. superans Butler和马尾松毛虫的地理亚种赤松毛虫D. punctatus spectabilis Butler,遗传关系最远的是落叶松毛虫D. superans Butler和云南松毛虫D. houi Lajonquiere。【结论】 马尾松毛虫居群间遗传分化程度较大,基因交流较少,遗传漂变已经成为导致该物种种群分化的主要原因之一;遗传距离与地理距离存在一定相关性。     

东北地区中鼩鼱遗传多样性与分子系统地理学

本研究对我国东北地区3个种群（大兴安岭、小兴安岭和长白山山脉）的中鼩鼱（99个样本）Cyt b基因全序列进行分析,共获得81个单倍型。整体单倍型多态性为0.9940,显示东北地区中鼩鼱整体遗传多样性较高,3个种群的遗传多样性无明显差异。分子变异方差分析显示3个种群之间的分化占总分化的2.48%,种群内采样地的分化占总分化的0.34%,采样地内部遗传分化占总分化的97.19%。遗传分化结果显示中鼩鼱遗传分化与地理距离存在非正相关关系。结合GenBank下载欧亚其他地区中鼩鼱Cyt b基因全序列构建系统发生树,分化为3个分支：日本北海道分布的中鼩鼱构成1个小分支;韩国济州岛的中鼩鼱构成1个小分支;我国东北地区和其他欧亚大陆的中鼩鼱构成1个大分支,在这个大支上未显现进一步的遗传分化结构。中介网络分析也暗示除日本北海道和韩国济州岛外,欧亚大陆分布的中鼩鼱没有明显的地理系统分化,表现出遗传分化与地理关联性较弱。种群历史分析显示东北地区中鼩鼱经历过种群扩张。     

利用AFLP分子标记探讨蜡梅种质资源的遗传多样性

利用AFLP分子标记技术,对中国蜡梅种质资源7个野生种群的遗传多样性进行了研究。利用筛选出的3对引物,共扩增出253条谱带,其中218条多态带,多态位点占86.17% ;种群间的基因分化系数为0.2906,说明蜡梅基因多样性主要存在于种群内;种群总的Nei s基因多样性指数为0.2933,Shannon信息多态性指数为0.4487,蜡梅总的遗传多样性水平较高。蜡梅不同种群遗传多样性水平差异较大,种群多态位点百分率在65.44% ～87.16%之间,Nei s基因多样性指数为0.1653 ～0.4012,Shannon信息多态性指数为0.3132 ～0.5603。神农架种群(SN)和保康种群(BK)的遗传多样性水平较高。用NTSYS2.01版软件对样品进行UPGMA聚类分析,结果7个种群并没有按地理距离进行聚类。最后提出要对各蜡梅野生群体采取相应的迁地和就地保护措施。     

苹果属山荆子遗传多样性的RAPD分析

采用RAPD分子标记对东北、华北地区山荆子8个天然居群的137株个体进行了遗传多样性研究,10个引物共得到72个扩增位点,其中多态性位点63个.多态位点百分率为87.50%,有效等位基因数(Ne)为1.602 1,Nei's基因多样性(H)为0.338 6,Shannon信息指数(J)为0.496 1,表明山荆子遗传多样性水平较高.基因流(Nm)为1.735 3,说明山荆子各居群间存在一定的基因交流.居群间基因分化系数(Gst)值为0.223 7,说明虽然山荆子居群的遗传变异主要存在于居群内,但各居群间也存在着较高的遗传分化.     

大叶藻居群微卫星遗传多样性研究

采用4对微卫星引物对大叶藻的7个地理居群进行了遗传多样性与遗传结构分析。扩增148株大叶藻得到57个等位基因, 每个位点平均等位基因数为6, 大叶藻居群的平均期望杂合度(He)为0.687, 平均观测杂合度(Ho)为0.417。青岛湾居群的遗传多样性最高(A=7.750, AR=7.043), 俚岛居群最低(A=4.750, AR=4.543)。从F_st值来看, 7个大叶藻居群间属于中度分化。UPGMA系统发育树显示, 中国4个大叶藻居群聚类到一起, 其遗传分化可能是由于历史大海草场的遗留小片段居群产生, 而中国、韩国、日本和爱尔兰居群间的遗传分化则主要是由于地理隔离造成的。自由交配估计结果支持海草的东亚起源说。青岛湾居群遗传多样性较高, 可优先作为大叶藻移植修复的材料和基因库, 并进行重点保护。     

泡沙参同工酶基因位点的遗传分析

利用聚丙烯酰胺凝胶电泳技术 ,对来自天然群体 (居群 )的泡沙参 (Adenophora potaninii Korsh.)及其人工杂交子代进行了 8种同工酶的电泳检测和谱带遗传分析 ,以确定编码这些酶系统的基因位点和等位基因。选用 4种不同的凝胶缓冲系统 ,对下列不同酶系统进行了酶谱的遗传分析 :天冬氨酸转氨酶 (AAT)、酯酶 (EST)、甲酸脱氢酶 (FDH)、谷氨酸脱氢酶 (GDH)、异柠檬酸脱氢酶 (IDH)、乳酸脱氢酶(LDH)、苹果酸酶 (ME)和超氧化物歧化酶 (SOD)。结果表明 ,这 8种酶系统至少由 1 8个基因位点编码 ,其中 1 2个位点为遗传稳定的等位酶位点 ,是可靠的遗传标记。酶谱的分离式样表明 ,EST为单聚体结构 ,AAT、FDH、IDH、SOD为二聚体结构 ,GDH为六聚体结构。最后对同工酶的器官和发育特异性以及同工酶基因位点的遗传分析进行了讨论     

Genetic variation and population structure of cod, Gadus morhua L., in some fjords in northern Norway

Biochemical genetic polymorphism in cod from several fjords in Troms, northern Norway was analysed. Gene frequencies at several polymorphic loci ( Hb, Pgi, Ldh, Pgm, Gpd and Idh ) are given. Significant variation was found both within and between fjords, and even between samples from the same locality sampled in different years, indicating a mosaic structure of the cod population in the area studied. The results of the haemoglobin variation are compared to similar results obtained more than 20 years ago in the same and adjacent areas. The biochemical genetic variation is discussed in relation to stability of gene frequencies, isolation mechanisms and migration patterns.     

Gene duplication at an isocitrate dehydrogenase locus in Scaphiopus

Spadefoot toads of the subgenus Scaphiopus have two isocitrate dehydrogenase loci, with no intergenic interaction between them. Toads of the subgenus Spea have three Idh loci, with intergenic enzymes formed between two of them, providing strong evidence for their homology and the origin of one through a duplication process. The Idh phenotype of interspecific hybrids is consistent with the theory of a gene duplication.     

ELECTROPHORETIC EVIDENCE FOR INBREEDING IN THE FERN BOTRYCHIUM VIRGINIANUM (OPHIOGLOSSACEAE)

An electrophoretic investigation of Botrychium virginianum was conducted to determine the levels and distribution of genetic variation within and among populations of this species. A total of 18 loci representing seven enzymes was examined. For the four polymorphic loci, observed heterozygosity was substantially lower than expected heterozygosity. Values of F were extremely high, indicating a significant deviation from random mating, probably due to inbreeding. We suggest that the high inbreeding coefficients obtained result from a life cycle involving subterranean gametophytes which restrict sperm movement. The study also demonstrates the value of using F-statistics and gene diversity statistics to analyze genetic subdivision in a fern species. Despite the high chromosome number reported for B. virginianum (n = 90), there is no genetic evidence to support the contention that this species is highly polyploid.     

Allozyme markers for the identification of Lecithochirium rufoviride and Lecithochirium furcolabiatum (Trematoda: Hemiuridae), parasites of Conger conger and Anguilla anguilla from Atlantic Spanish waters

The allozyme variation between 2 sympatric populations of Lecithochirium furcolabiatum and L. rufoviride was examined with the aim to investigate if the 2, morphologically similar, helminths are reproductively distinct. Three enzyme loci, Gpd, Pgm-1, and Idh were found to be diagnostic for the 2 species. These results support the conclusion that the worms are different biological species. Only the Gpi and Gdh loci showed no differences. Marked genetic subdivision was detected at the Idh locus in the L. rufoviride population. Given that the genotypic distribution at Pgm-I showed no significant deviations from Hardy-Weinberg expectations, it does not appear that the absence of heterozygotes for Idh was caused by the reproductive structure of the population. Although there are several other possible reasons for the deficiency of heterozygotes in natural populations, the existence of a new noninterbreeding group within the population studied constitutes a plausible explanation.     

Gene-Centromere Mapping in Rainbow Trout: High Interference over Long Map Distances

Ten enzyme loci were mapped in relation to their centromeres in gynogenetic diploid rainbow trout. Gene-centromere map distances, calculated under the assumption of complete interference, range from 1.1 cM for Ldh4 to 50 cM for Sod1. The Idh2 and Est1 loci are linked on the same chromosome arm.—The observation of close to 100% heterozygous gynogenetic diploids for the Sod1 and Mdh3,4 loci suggests that near-complete interference occurs on the chromosome arms carrying these loci. The high interference observed in this study and in several other species of fish may be related to the small size of fish chromosome arms.—Comparisons of map locations for the Ldh3 and Ldh4 and the Mdh3 and Mdh4 loci, which were duplicated by a tetraploid event in the evolution of salmonid fish, reveal that they are located at similar distances from their centromeres. Comparative mapping of loci duplicated longer ago shows more variation in map location.—The high proportion of heterozygotes for some loci after gynogenesis involving second polar body retention demonstrates that this is not a practical method for producing homozygous inbred lines in rainbow trout; treatments suppressing the first cell division are more promising for this purpose.     

Genetic differentiation of house mice in the south of the Soviet Far East

Electrophoretic analysis of 24 loci specifying a number of enzymatic and non-enzymatic proteins was carried out in populations of Primorye house mice. No variability in Ldh-B, Ldh of testis, fumarase, alpha-Gpd, Aat-2, Sod-2, Gp-1, GP-3 was found. Distribution of the same main variant in all samples is represented by Sdh, Mor-1, Mor-2, Ldh-A, GP-2, Est-D, Gpd-x, Pgl, Ldr and alb. The second variant of these loci was found in one or two animals. Two and more variants encountered with significant frequency were detected for Id-1, Hbb, Aat-1, Est-1, Est-2, Mod-2. Hybrid origin of the Primorye house mouse is assumed. Genogeography of Id-1, Hbb, Aat-1 and Est-1 points to involvement of the Mus-2C castaneus form in development of their gene pool, the effect of Mus-2A musculus being not excluded. Genogeography of Sod-1 confirms the involvement of both castaneus and musculus. Intensive mutual penetration of these forms (more than 300 km from north to south) indicates that they did not achieve the level characteristic of musculus and domesticus in the course of their differentiation.     

Monomorphism of isozyme loci in natural and cultivated amaranth (<Emphasis Type="Italic">Amaranthus</Emphasis> L.) populations

Electrophoretic spectra of alcohol dehydrogenase (ADH), glutamate dehydrogenase (GDH), malate dehydrogenase (MDH), isocitrate dehydrogenase (IDH), and malic enzyme (ME) in different amaranth populations has been studied using a starch gel electrophoresis. 93 populations and 4 cultivars of amaranth have been analyzed. Some populations have been proved to be polymorphic that provided a possibility of a genetic control of the above-mentioned enzymes. The isozyme variability of the studied amaranth populations is low; all studied loci are found to be monomorphic for 73 populations and 4 cultivars. Some populations demonstrate a polymorphism in separate loci (Adh, Mdh 2, Gdh, Idh 1, Idh 2, and Mod 2). The obtained results evidence the presence of a genetic monomorphism in amaranth concerning the loci studied.     

Monomorphism of isoenzyme loci in natural and cultivated amaranth (Amaranthus L.) populations

Starch gel electrophoresis was used for isozyme analysis of ADH, GDH, MDH, IDH, and ME in populations of amaranth. Experiments were performed with 93 populations and 4 cultivars. Some populations proved to be polymorphic, and this fact allowed analysis of the genetic control of the enzymes listed. The populations examined showed poor allozyme variability. Monomorphism for all loci studied was observed in 73 populations and 4 varieties. Starch gel electrophoresis was used for isozyme analysis ofADH, GDH, MDH, IDH, and ME in populations of amaranth. Experiments were performed with 93 populations and 4 cultivars. Some populations proved to be polymorphic, and this fact allowed analysis of the genetic control of the enzymes listed. The populations examined showed poor allozyme variability. Monomorphism for all loci studied was observed in 73 populations and 4 varieties. Only some populations demonstrated rare polymorphism for a single locus each: Adh, Mdh 2, Gdh, Idh 1, Idh 2, or Mod 2. The results demonstrate genetic monomorphism of amaranth for the studied loci.