大豆体细胞胚系培养及其微卫星DNA稳定性研究(简报)

植物离体培养是植物基因操作中的重要一环,也是植物个体发育研究中基因表达研究的有益参考体系。在继代培养过程中发生的遗传变异有时会使再生植株丧失优良的性状而需加以控制和避免。为此,首先需要了解培养过程中的遗传变异情况。     

板栗与锥栗杂交F1代叶片表型变异及杂种优势研究

为探索栗属杂交F₁代幼林期叶片性状遗传变异规律及杂种优势,以板栗、锥栗种内和种间9个杂交组合235个杂交单株及其亲本为研究材料,利用巢式方差分析、Pearson相关性分析及主成分分析等统计学方法对其14个叶表型及光合生理性状进行分析。结果表明:①栗属杂交F₁代叶表型及光合生理性状存在丰富的遗传多样性,14个性状平均变异系数范围为4.40%~27.76%;②性状组合间表型分化系数VST均值为32.32%,组合内变异是主要的变异来源;③性状中亲优势率为-27.16%~90.53%,且不同组合性状杂种优势存在差异;④Pearson相关性分析结果显示14个性状中分别有46对和13对相关性达到极显著(P<0.01)和显著水平(P<0.05),其中叶长、叶宽等5个叶表型性状及叶绿素a、叶绿素b等4个光合生理指标相互间影响较大;⑤利用主成分分析法筛选出“魁栗×YLZ 15号”和“魁栗×YLZ 1号”两个优良杂交组合,其子代叶片具有叶面积大、干物质含量及光合有关色素含量高的特点,可为进一步筛选优良杂交子代提供主要素材。     

微卫星DNA标记技术及其在遗传多样性研究中的应用

微卫星DNA的高突变率、中性、共湿性及其在真核基因组中的普遍性,使其成为居群遗传学研究、种质资源鉴定、亲缘关系分析和图谱构建的优越的分子标记。本研究系统介绍了微卫星DNA在结构和功能上的特点,并对微卫星DNA标记技术应用的遗传学机理和一般方法进行了扼要的阐述。另外,本研究还探讨了微卫星DNA标记技术在遗传多样性研究中的应用现状,并进一步提出其发展前景。     

大熊猫微卫星DNA的筛选及其应用

经ＤｐｎⅡ限制酶消化大熊猫基因组ＤＮＡ后,选取１５０－５００ｂｐ大小的片段构建了ＤＮＡ文库。用合成的（ＣＡ）（１５）探针从这一文库中克隆筛选了１０个大熊猫特异的微卫星ＤＮＡ座位。在测定ＤＮＡ序列的基础上设计并合成了１０个座位特异的引物,以ＰＣＲ技术扩增了７份抽提自组织细胞和６份抽提自毛发的大熊猫ＤＮＡ样品。发现除座位ｇ（００７）外,其余９个座位均呈多态性,而且所有座位均为偶数碱基的长度变异。对有准确谱系记录的家系的研究结果证明,这１０个微卫星ＤＮＡ座位严格按孟德尔方式遗传。因而这些座位能有效地应用于大熊猫的亲子鉴定,从而为建立各地大熊猫谱系和制定有效的繁殖计划提供了一个有效的遗传学手段。根据这１０个微卫星座位的分析,我们澄清了两组未知的父系关系。     

SSR标记用于玉米自交系遗传变异与优势类群划分的研究

采用SSR和杂种优势聚类方法分析我国15个玉米骨干自交系的遗传变异,并初步进行了杂种优势类群划分,从62个SSR引物中筛选的40对有效引物对15个玉米自交系进行了分析,共检测到188个等位基因变异,每个SSR座位的等位基因数2－9个,平均为4．7个,SSR位点的多态信息含量PIC值平均为0．675,分布范围在0．360－0．851之间,根据SSR数据对供试材料进行遗传相似性分析,Nei氏相似性系数分布在0．574－0．777之间,10对多态性高的SSR引物可有效区分15个自交系,应用SSR聚类分析的结果与系谱关系相一致,与杂种优势类法相比较,SSR方法具有效率高,结果可靠,可标准化的特点,对SSR方法在玉米育种实践上的应用进行了初步探讨。     

RAPD分子标记与玉米杂种产量优势预测的研究

以２４个优良玉米自交系统ＮＣⅡ设计组配成１４３个单杂交种为材料，利用的ＲＡＰＤ分子标记技术研究玉米杂种优势群划分，遗传距离与特殊配合力，杂种产量，杂种产量优势的联系。结果表明：（１）ＲＡＰＤ技术可用于玉米杂种优势群划分。（２）亲本遗传距离杂种产量优势，杂种产量，特殊配合畋有一定相关关系，但决定系数很小，分别是１０％，１０％，１５％，利用ＲＡＰＤ技术预测杂种优势，杂种产量作用有限，应进一步研究与杂     

微卫星多态性检测技术及其在保护遗传学中的应用

微卫星是一种新型的分子遗传标记,具有只需极少量样品即可进行PCR扩增等优点,使之极其适合于保护遗传化学研究。阐释了微卫星的结构、微卫星多态检测技术的原理,简要论述了微卫生多态检测技术的优点及其应用,并介绍了一种分离动物微卫星位点的富集方法。     

微卫星序列及其应用

微卫星序列广泛存在于各类真核生物基因组中,一般为散在分布的中等程度重复序列。不同物种中,微卫星序列的含量以及占优势的微卫星序列类型各不相同。复制时,微卫星序列易于发生长度突变,这种突变与微卫星序列的复制滑移有关,同时也受多种因素的影响。微卫星序列可能是原微卫星序列通过复制滑移使序列长度扩增形成的。进化过程中,微卫星序列的长度变化维持在一定的范围内。由于微卫星标记多态性高、重复性好,并且操作简单,因此在基因的定位、人类疾病诊断及预测、亲权分析、品种鉴定、进化研究,以及动植物分子标记辅助选择育种研究等领域中都有着重要的应用价值。 Abstract:Microsatellites,simple sequence repeats (SSR),are abundant and distributed throughout the eukaryote genome.The contents of microsatellites are variant in different creatures.There are also different types of microsatellites,which are dominant in different creatures.One of the most noticeable characters of microsatellites is that they are easy to expand during DNA replication.It is thought to attribute to DNA slippage.This kind of mutation is affected by many factors.It is guessed that microsatellites come from pro-microsatellites,while the pro-microsatellites origin from random point mutations.The length of microsatellites can be maintained under relative conservative ranges during species evolution.As they are abundant,codominatnt,distributed over the euchromatic part of the genome,and have the character of highly polimorphic,microsatellites are useful tools for gene mapping,clinical diagnosis and predicting,paternity or pedigree analysis,evolution study,and marker-assisted breeding.     

3个山羊群体中4个微卫星DNA多态性及其与杂种优势的关系

利用4个微卫星标记（OarFCB11,OarAE101,McM218,McM38）对波尔山羊、太行山羊和河北奶山羊的等位基因频率、群体多态信息含量、有效等位基因数、杂合度和遗传距离进行了遗传检测,并测定了波尔山羊与河北奶山羊及太行山羊的杂交效果。结果表明：4个微卫星标记在波尔山羊、太行山羊和河北奶山羊3个品种中存在多态性,可以用于山羊遗传多样性的评估;从不同品种来看,太行山羊的遗传变异程度最大,而波尔山羊的遗传变异程度相对较小;波尔山羊与河北奶山羊的遗传距离大于与太行山羊,波尔山羊与河北奶山羊的杂种优势高于与太行山羊,与实际杂种优势测定结果相符。 Abstract: Gene frequency, polymorphism information contents, number of effective alleles, heterozygosity and genetic distances were studied in Boer goat, Taihang goat and Hebei dairy goat using four microsatellite markers（OarFCB11,OarAE101,McM218,McM38）. The crossing effects on Hebei dairy goat and Taihang goat with Boer goat were tested. The results indicated that there are genetic polymorphisms at four microsatellite markers in three goat breeds. Four microsatellite markers can be used for genetic diversity evaluation in goat breeds. The genetic variability of Taihang goat is the highest, and Boer goat is the lowest in three goat breeds. Genetic distances between Boer goat and Hebei dairy goat is bigger than that between Boer goat and Taihang goat. The heterosis between Boer goat and Hebei dairy goat is higher than that between Boer goat and Taihang goat. It accords with testing results on actual heterosis.     

微卫星DNA的多态性及其应用

微卫星DNA是广泛存在于各种真核生物基因组中的短串联重复序列,具有突变速率快、多态性高等特点,本分析了微卫星的多态性及其形成机制,并简要介绍其在亲缘关系鉴定、种群遗传结构分析、基因图谱以及基因诊断等方面的应用。     

牛肌肉生长抑制素基因突变的遗传效应与育种应用

肌肉生长抑制素（myostatin,MSTN）基因主要在骨骼肌中表达,参与调控骨骼肌的生长发育。MSTN基因在不同物种中具有极强的进化保守性,同时还具有较多的突变多态性。在牛的不同品种中,存在不同位点的有义突变,突变型牛均表现为骨骼肌发达,呈现双肌表型,生长速度与产肉率显著提高。同时,该基因突变也引起显著的生理性遗传效应。对国内外肉牛的MSTN基因突变类型、突变后遗传效应及在肉牛育种应用等方面作了重点阐述,以期为我国地方品种肉牛改良和选育研究提供参考。     

利用微卫星DNA标记法进行5个肉用绵羊品种的多态性分析和杂种优势率预测

研究选择了与产肉性能相关的5个微卫星标记,分析了这5个位点在杜泊、德国美利奴、特克塞尔、道塞特和右玉本地绵羊5个品种中的遗传多态性.通过遗传分析预测了4个国外引进肉用绵羊品种与右玉本地绵羊的杂种优势,并与实际测定结果进行了比较分析.结果表明,利用微卫星DNA多态性进行品种间杂种优势预测是可行的,杜泊羊与右玉本地绵羊杂交的杂种优势最大,与实际测定结果一致.     

Genetic Variation in FABP4 and Evaluation of Its Effects on Beef Cattle Fat Content

FABP4 is a protein primarily expressed in adipocytes and macrophages that plays a key role in fatty acid trafficking and lipid hydrolysis. FABP4 gene polymorphisms have been associated with meat quality traits in cattle, mostly in Asian breeds under feedlot conditions. The objectives of this work were to characterize FABP4 genetic variation in several worldwide cattle breeds and evaluate possible genotype effects on fat content in a pasture-fed crossbred (Angus-Hereford-Limousin) population. We re-sequenced 43 unrelated animals from nine cattle breeds (Angus, Brahman, Creole, Hereford, Holstein, Limousin, Nelore, Shorthorn, and Wagyu) and obtained 22 single nucleotide polymorphisms (SNPs) over 3,164?bp, including four novel polymorphisms. Haplotypes and linkage disequilibrium analyses showed a high variability. Five SNPs were selected to perform validation and association studies in our crossbred population. Four SNPs showed well-balanced allele frequencies (minor frequency?>?0.159), and three showed no significant deviations from Hardy-Weinberg proportions. SNPs showed significant effects on backfat thickness and fatty acid composition (P?相似文献   

Use of DNA Markers in Prediction of Hybrid Performance and Heterosis for a Three-Line Hybrid System in Rice

Two Cytoplasmic Male Sterile lines were crossed with fourteen restorer lines of rice widely grown in the western regions of Maharashtra, India, to produce 28 F₁ hybrids which were evaluated for eight agronomically important traits, contributing to yield potential, in replicated field trials. The hybrid performance was recorded along with heterosis and heterobeltiosis. All the rice lines under investigation were subjected to marker-based variability analysis. An attempt was made to correlate genetic distance based on specific markers for each trait individually, as well as average genetic distance based on all specific markers, with hybrid performance and heterosis, by regression analysis. Specific markers could cluster the parental lines in different groups and showed significant correlation with hybrid performance. The data also supports the proposition that epistasis is the basis of heterosis. The analysis, however, revealed a lack of significant predictive values for field application.     

玉米光合性能的杂种优势

以4个不同光合速率的玉米自交系及组配的2个杂交种为材料, 在吐丝期进行了光合速率(P_n)、蒸腾速率(T_r)、气孔导度(G_s)、水分利用效率(WUE)等光合性能指标日变化的测定,以探明玉米杂种优势光合性能的日变化规律.结果表明：光合性能中P_n、T_r和G_s 3项指标均呈明显的单峰曲线变化,峰值出现的时间分别为10:00—12:00、12:00和10:00—12:00,其中G_s、P_n早于T_r;WUE日变化规律与其它光合性能指标相反,呈现“V”趋势,低谷值出现在12:00点左右.P_n、T_r的日变化均与G_s密切相关,说明G_s在P_n、T_r日变化中起着重要的调节作用.对光合性能杂种优势率日变化进行分析表明,杂交种P_n、T_r、G_s具有午后优势现象,而WUE杂种优势率表现为上午高于下午,说明午后的环境条件更有利于杂交种抗性的发挥,为筛选高光效品种提供了一项可参考的指标.     

分子标记在油菜杂种优势利用中的研究进展

杂种优势是一种普遍存在的生物学现象,是提高作物产量的重要途径,因而受到越来越广泛的重视。分子标记是近年兴起的一种新型的生物技术,国内外已利用RFLP、RAPD、AFLP、SSR、ISSR和SRAP等多种分子标记技术对油菜的杂种优势进行了广泛的研究,取得了很多有价值的研究成果。本文综述了分子标记在油菜授粉控制系统中关键基因标记、亲本遗传多样性分析、杂种优势群划分、杂种纯度鉴定和杂种优势预测中的研究进展。通过对不同作物间的比较,探讨了分子标记在油菜杂种优势利用中的研究深度,并对分子标记在油菜杂种优势预测中应注意的问题进行了讨论。     

不结球白菜杂种优势及相关分析

以4个不结球白菜不育系与4个父本系以NCⅡ法配制16个杂交组合,研究了16个F1组合的杂种优势表现及其与亲本之间的相关关系,同时对性状间的遗传相关进行分析.结果表明:不结球白菜产量性状杂种优势＞农艺性状杂种优势＞光合性状杂种优势＞品质性状杂种优势.产量性状以超亲优势为主,农艺性状和光合性状以中亲优势为主,品质性状中可溶性糖含量以中亲优势为主, Vc含量和蛋白质含量均为弱的负向优势.亲子相关分析表明,一些性状F1与中亲值、低亲值或高亲值显著相关,因此在亲本选配时,注意亲本差异的同时,中亲值特别是低亲值不能过低,尤其是品质性状.性状间相关分析显示,光合性状与产量性状显著正相关,说明F1高效的光合同化作用是杂种高产的基础.品质性状中,可溶性糖含量与产量显著正相关,但Vc和蛋白质含量与产量负相关,在亲本选配时还应注意二者的协调.     

Heterosis is common and inbreeding depression absent in natural populations of Arabidopsis thaliana

The importance of genetic drift in shaping patterns of adaptive genetic variation in nature is poorly known. Genetic drift should drive partially recessive deleterious mutations to high frequency, and inter‐population crosses may therefore exhibit heterosis (increased fitness relative to intra‐population crosses). Low genetic diversity and greater genetic distance between populations should increase the magnitude of heterosis. Moreover, drift and selection should remove strongly deleterious recessive alleles from individual populations, resulting in reduced inbreeding depression. To estimate heterosis, we crossed 90 independent line pairs of Arabidopsis thaliana from 15 pairs of natural populations sampled across Fennoscandia and crossed an additional 41 line pairs from a subset of four of these populations to estimate inbreeding depression. We measured lifetime fitness of crosses relative to parents in a large outdoor common garden (8,448 plants in total) in central Sweden. To examine the effects of genetic diversity and genetic distance on heterosis, we genotyped parental lines for 869 SNPs. Overall, genetic variation within populations was low (median expected heterozygosity = 0.02), and genetic differentiation was high (median F_ST = 0.82). Crosses between 10 of 15 population pairs exhibited significant heterosis, with magnitudes of heterosis as high as 117%. We found no significant inbreeding depression, suggesting that the observed heterosis is due to fixation of mildly deleterious alleles within populations. Widespread and substantial heterosis indicates an important role for drift in shaping genetic variation, but there was no significant relationship between fitness of crosses relative to parents and genetic diversity or genetic distance between populations.     

Evaluation of Candidate Gene Effects for Beef Backfat via Bayesian Model Selection

Candidate gene approaches provide tools for exploring and localizing causative genes affecting quantitative traits and the underlying variation may be better understood by determining the relative magnitudes of effects of their polymorphisms. Diacyglycerol O-acyltransferase 1 (DGAT1), fatty acid binding protein (heart) 3 (FABP3), growth hormone 1 (GH1), leptin (LEP) and thyroglobulin (TG) have been previously identified as genes contributing to genetic control of subcutaneous fat thickness (SFT) in beef cattle. In the present research, Bayesian model selection was used to evaluate effects of these five candidate genes by comparing competing non-nested models and treating candidate gene effects as either random or fixed. The analyses were implemented in SAS to simplify the programming and computation. Phenotypic data were gathered from a F₂ population of Wagyu × Limousin cattle. The five candidate genes had significant but varied effects on SFT in this population. Bayesian model selection identified the DGAT1 model as the one with the greatest model probability, whether candidate gene effects were considered random or fixed, and DGAT1 had the greatest additive effect on SFT. The SAS codes developed in the study are freely available and can be downloaded at: http://www.ansci.wsu.edu/programs/.Mention of a proprietary product does not constitute a guarantee or warranty of the product by USDA, Montana AES, or the authors and does not imply its approval to the exclusion of other products that may also be suitable.