Intraspecific DNA methylation polymorphism in the non-edible oilseed plant castor bean

Investigation of the relationships of phenotypic and epigenetic variations might he a good way to dissect the genetic or molecular basis of phenotypic variation and plasticity in plants, Castor bean （Ricinus cornraunis L）, an important non-edible oilseed crop, is a mono-species genus plant in the family Euphorbiaceae. Since it displays rich phenotypic variations with low genetic diversity, castor bean is a good model to investigate the molecular basis of phenotypic and epigenetic variations. Cytosine DNA methylation represents a major molecular mechanism of epigenetic occurrence. In this study, epigenetic diversity of sixty landrace accessions collected worldwide was investigated using the methylation- sensitive amplification polymorphism （MSAP） technique, Results showed that the epigenetic diversity （based on the polymorphism of DNA methylated loci） exhibited a medium variation （Ne = 1.395, He = 0.242, I = 0.366） at the population level though the variation was great, ranging from 3,80% to 3431% among accessions. Both population structure analysis and the phylogenetic construction （using the neighbor-joining criteria） revealed that the two main clades were identified, but they did not display a distinct geographic structure, After inspecting the location of polymorphic methylated loci on genome we identified that the polymorphic methylated loci occur widely in nuclear and organelle genomes. This study provides new data to understand phenotypic and epigenetic variations in castor bean,

NOD2,IL23R and ATG16L1 polymorphisms in Lithuanian patients with inflammatory bowel disease

AIM:To investigate the frequency of NOD2, IL23R and ATG16L1 genetic variants in a case-control panel for inflammatory bowel disease (IBD) from Lithuania.METHODS: One hundred and eighty unrelated IBD pa- tients [57 Crohn's disease (CD) and 123 ulcerative colitis (UC)] and 186 healthy controls were genotyped for the following known genetic susceptibility variants:NOD2-Arg702Trp (rs2066844), Gly908Arg (rs2066845) and Leu1007insC (rs2066847), as well as IL23R-Arg381Gln (rs11209026) and ATG16L1-Thr300Ala (rs2241880).RESULTS:The effect that carriership of at least one NOD2 risk allele predisposes to CD was replicated in the Lithuanian population (41.1% CD vs 16.9% controls, P=2×10-4, OR=3.48,95% CI:1.81-6.72). In the allelic single marker analysis, Leu1007insC was strongly associated with CD (21.4% CD vs 4.7% controls, P=3.687×10-8, OR=5.54, 95% CI:2.85-10.75). Neither the other two NOD2 variants, nor the known variants in IL23R and ATG16L1 were found to be risk factors for CD, UC or IBD. However, our relatively small study population was underpowered to demonstrate such weak to moderate disease associations.CONCLUSION: The results support a strong association between CD susceptibility and the Leu1007insC variant in NOD2 in the Lithuanian study population.

Polymorphism and association analysis of a drought-resistant gene TaLTP-s in wheat

Lipid transfer protein （LTP） is a kind of small molecular protein, which is named for its ability to transfer lipid between cell membranes. It has been proved that the protein is involved in the responding to abiotic stresses. In this study, TaLTP-s, a genomic sequence of TaLTP was isolated from A genome of wheat （Triticum aestivum L）. Sequencing analysis exhibited that there was no diversity in the coding region of TaLTP-s, but seven single nucleotide polymorphisms （SNPs） and 1 bp insertion/deletion （InOel） were detected in the promoter regions of different wheat accessions. Nucleotide diversity （T1） in the region was 0.00033, and linkage disequilibrium （LD） extended over almost the entire TaLTP-s region in wheat. The dCAPS markers based on sequence variations in the promoter regions （SNP-207 and SNP-1696） were developed, and three haplotypes were identified based on those markers. Association analysis between the haplotypes and agronomic traits of natural population consisted of 262 accessions showed that three haplotypes of TaLTP-s were significantly associated with plant height （PH）. Among the three haplotypes, Haplll is considered as the superior haplotype for increasing plant height in the drought stress environments. The G variance at the position of 207 bp could be a superior allele that significantly increased number of spikes per plant （NSP）. The functional marker of TaLTP-s provide a tool for marker-assisted selection regarding to plant height and number of spikelet per plant in wheat.

TCF7L2 rs7903146 polymorphism is associated with gastric cancer: a case-control study in the Venezuelan population

AIM: To explore the association between TCF7L2 rs12255372 and rs7903146 single nucleotide polymorphisms (SNPs) and gastric cancer risk in Venezuelan patients.METHODS: We performed a case-control study including 122 paraffin-embedded archived intestinal-type gastric cancer samples and 129 biopsies obtained by superior endoscopy from chronic gastritis patients. Gastric cancer samples were classified according the degree of carcinoma differentiation. Genomic DNA was extracted from tissues, and the two SNPs of TCF7L2 gene (rs12255372 and rs7903146) were genotyped by polymerase chain reaction-restriction fragment length polymorphism reactions. Multiple regression analysis with adjustments for age and gender were performed and best-fitting models of inheritance were determined. Statistic powers were post-hoc calculated.RESULTS: After adjusting for age and sex the TCF7L2 rs7903146 TT genotype was associated with gastric cancer risk under the recessive genetic model (OR = 3.11, 95%CI: 1.22-7.92, P = 0.017). We further investigated the distribution of rs12255372 and rs7903146 genotypes according gastric cancer stratified by degree of differentiation, and we observed that carriers of rs7903146 T allele (CT + TT vs CC) had a significantly increased risk of moderate/well differentiated gastric cancer (dominant model, OR = 2.55, 95%CI: 1.35-4.80, P = 0.004), whereas the rs7903146 TT genotype was associated with poorly differentiated gastric cancer in the recessive model (OR = 3.65, 95%CI: 1.25-10.62, P = 0.018). We did not find association between rs12255372 SNP and the susceptibility of developing gastric cancer.CONCLUSION: TCF7L2 rs7903146 polymorphism is associated with gastric cancer risk in the Venezuelan population, and could be related to determine the degree of differentiation of tumor cells.

江浙地区菱品种遗传多样性的SLAF-seq分析

利用SLAF-seq技术对江浙地区17个主要的栽培菱品种和1个野生菱种质进行高通量测序,获得445594个SLAF标签,鉴定到多态性SLAF标签95931个。通过序列分析,获得269338个SNP标记,并基于这些SNP构建18份菱样品的遗传发育树及进行群体结构分析。结果表明,SLAF-seq技术能高效地开发出大量可用于群体遗传分析的SNP标记,基于SNP标记构建的进化树能较好地区分不同类型的菱品种。该结果对开展菱种质资源鉴定和菱种质遗传演化研究具有重要参考价值。

CDKAL1基因rs7756992位点A>G多态性与2型糖尿病易感性的meta分析

目的系统评价CDKAL1基因rs7756992位点A>G多态性与2型糖尿病(T2DM)易感性的关系。方法制定原始文献的纳入、排除标准及检索策略,通过检索学术期刊全文数据库(CNKI)、万方数据库及EMBASE、PubMed、ScienceDirect等数据库,收集有关CDKAL1基因rs7756992位点A>G多态性与T2DM易感性的病例对照研究,以病例组与对照组CDKAL1基因rs7756992位点各种基因模型的比值比(OR)及其95%置信区间(CI)为效应指标进行meta分析,并根据研究人群种族不同进行亚组分析。结果本研究共纳入15篇文献,T2DM组和对照组病例数分别为24 315例和35 132例。Meta分析显示,CDKAL1基因rs7756992位点A>G多态性与T2DM易感性有关联[等位基因模式(G vs A):OR=1.171,95%CI1.122~1.223,P<0.001;共显性模式(GG vs AA):OR=1.380,95%CI1.258~1.515,P<0.001;共显性模式(AG vs AA):OR=1.131,95%CI 1.089~1.176,P<0.001;显性模式(AG+GG vs AA):OR=1.168,95%CI 1.101~1.240,P<0.001;隐性模式(GG vs AA+AG):OR=1.343,95%CI 1.282~1.405,P<0.001]。亚组分析显示,亚洲人群和白种人群中携带CDKAL1基因rs7756992位点G等位基因的人群发生T2DM的风险增加(P<0.05);而非洲人群中携带CDKAL1基因rs7756992位点G等位基因与A等位基因的人群发生T2DM风险的差异无统计学意义。结论在亚洲人群及白种人群中CDKAL1基因rs7756992位点A>G等位基因的突变可能是T2DM发病的危险因素之一。

冠心病患者L-选择素基因多态性分析

目的观察中国汉族人群L-选择素(L-selectin,SELL)基因4个单核苷酸多态性(single nucleotide polymorphism,SNP)与冠心病(coronary artery disease,CAD)的相关性。方法应用荧光标记单碱基延伸及寡核苷酸微阵列芯片杂交技术检测SELL基因rs964555,rs2205848,rs4987318和rs2298900的基因型。结果对照组和CAD组间4个SNP的基因型频率和等位基因频率无统计学差异(P>0.05),由rs964555,rs2205848和rs2298900构成的单倍型以CAT型为主,各单倍型频率在两组间无统计学差异(P>0.05)。结论本研究中SELL基因的4个SNP与CAD的易感性无关。

铝毒胁迫下甘蓝型油菜种子萌发期相关性状的QTL定位

随着土壤酸化的日益加重,铝毒已成为影响作物种子萌发质量以及作物产量的重要胁迫因子之一。作物耐铝相关性状的QTL定位和候选基因筛选已有许多报道,但铝胁迫下甘蓝型油菜萌发期相关性状的QTL定位报道较少。本文以80μg mL^-1的铝胁迫浓度处理重组自交系(10D130×中双11号)群体进行种子萌发试验,处理3 d时调查发芽势,7 d时调查发芽率,测定其根长、芽长和干重,并计算各性状相对值。基于6K SNP芯片,结合高密度遗传连锁图谱对油菜萌发期的5个性状进行QTL定位,共检测到23个QTL。其中与相对发芽势、相对发芽率、相对根长、相对芽长和相对干重相关的QTL分别有9个、1个、4个、5个和4个,覆盖了A、C基因组,LOD值介于3.00~5.26,可解释的表型变异为7.70%~13.10%。根据各QTL置信区间序列筛选,与铝胁迫相关的候选基因共30个。ALMT1基因和MATE基因与有机酸的合成和分泌有关,主要通过苹果酸、柠檬酸和草酸等有机酸的分泌来增强植物的耐铝性;STOP1基因、NAC基因和RAP2.4基因均属于转录激活因子,通过诱导耐铝基因的表达增强植株的抗性;ABC转运蛋白、膜蛋白转运体、GDSL脂肪酶通过减少有毒物质在质膜上的积累或将有毒物质排出体外等途径增强植物的耐铝性;过氧化物酶和细胞色素P450均属于氧化胁迫相关基因,具有防止植物细胞氧化损伤、抵御逆境胁迫的功能;另外,还有部分编码逆境蛋白的基因,均在各种胁迫反应中起重要作用。本研究的结果将为培育耐铝油菜品种及后续基因的功能研究提供理论依据。

蓖麻LPAAT基因序列的SNPs及与油脂的相关性

LPAAT对蓖麻储存油脂(triacylglycerols,TAG)的合成调控具有重要作用。为了研究蓖麻LPAAT的多态性,参考GenBank中编码蓖麻LPAAT的基因组序列设计引物,对来自32个不同地区蓖麻种质的LPAAT进行测序,获得长约804 bp的基因组序列。多态分析表明:在804 bp的区间内共发现2个SNP和3个InDel,SNP频率为1/161 bp,多样性指数Pi为0.000 67。在外显子区域,有1个SNP和2个InDel,其中2个为同义突变,1个为错意突变。结果表明,基因LPAAT的exon10与种子油脂含量有明显相关性。

凡纳滨对虾CTSL基因与生长相关的SNP位点的特征

对3个凡纳滨对虾品系的CTSL基因进行单核苷酸多态性(single nucleotide polymorphism,SNP)筛查,发现在生长指标差异的对虾中存在特征较为显著的7个SNP位点,其中3个属于外显子上的突变,4个属于内含子上的突变.B210对虾品系体重月平均生长量约为7.58 g,体长月平均生长量约为2.31 cm,B310对虾品系体重月平均生长量约为3.96 g,体长月平均生长量约为1.48cm,HNTT对虾品系体重月平均生长量约为3.04 g,体长月平均生长量约为2.18 cm.从市场价值来看,B210和B310品系比HNTT品系生长相对好些.进一步的PCR产物直接测序比较分析表明在生长指标较好的对虾品系,这7个SNP位点表现为纯合子;而在生长指标较差的对虾品系,在这7个SNP位点上31.6%表现为杂合子.虽然国内外有不少关于CTSL基因SNP位点的报道,但是与生长快慢的相关分析还鲜有报道,且这些SNP位点与前人发现的位点有所不同.本研究发现的CTSL基因的SNP位点与对虾生长快慢相关,将为凡纳滨对虾生长研究提供有用信息,从而有助于为对虾选育提供可靠的分子标记.

L-选择素基因多态性在2型糖尿病肾病家系中的相关性分析

目的:初步探讨L-选择素基因rs4987318、rs2229569、rs4656697、rs78261125单核苷酸多态性(SNP)与一家族性2型糖尿病肾病的相关性,为个体化治疗糖尿病肾病提供基础资料。方法:应用聚合酶链式反应(PCR)-基因测序技术检测同一家系中6名糖尿病肾病患者和13名健康成员L-选择素基因多态性。结果:rs4987318位点基因型在该家系中基因型全部为AA,rs2229569位点基因型在该家系中基因型全部为CC,rs4656697位点在该家系中有GG、GC和CC型,患者组基因型频率为GG(50%),GC(50%)对照组基因型频率为GG(61.54%),GC(30.77%),CC(7.69%),应用Fisher精确检验差异无统计学意义(P>0.05)。rs78261125位点在该家系中有GG和GC,病例组基因型频率为GG(33.33%),GC(66.67%),对照组基因型频率为GG(69.23%),GC(30.77%),应用Fisher精确检验差异无统计学意义(P>0.05)。结论:L-选择素基因rs4987318位点与rs2229569位点在该家系内无多态性;rs4656697位点与rs78261125位点多态性与该家族二型糖尿病肾病之间未发现相关性。

dCAPS markers developed for nitrate transporter genes TaNRT2L12s associating with 1000-grain weight in wheat

Nitrate transporters(NRTs)are regulators of nitrate assimilation and transport.The genome sequences of TaNRT2L12-A,-B and-D were cloned from wheat(Triticum aestivum L.),and polymorphisms were analyzed by sequencing.TaNRT2L12-D in a germplasm population was highly conserved.However,38 single nucleotide polymorphisms(SNPs)in TaNRT2L12-A coding region and 11 SNPs in TaNRT2L12-B coding region were detected.Two derived cleaved amplified polymorphic sequences(dCAPS)markers A-CSNP1 and A-CSNP2 were developed for TaNRT2L12-A based on SNP-351 and SNP-729,and three haplotypes were identified in the germplasm population.B-CSNP1 and B-CSNP2 were developed for TaNRT2L12-B based on SNP-237 and SNP-1227,and three haplotypes were detected in the germplasm population.Association analyses between the markers and agronomic traits in 30 environments and phenotypic comparisons revealed that A-CSNP2-A is a superior allele of shorter plant height(PH),length of penultimate internode(LPI)and peduncle length(PL),B-CSNP2-G is a superior allele of higher grain number per spike(GNS).Hap-6B-1 containing both superior alleles B-CSNP1-C and B-CSNP2-A is a superior haplotype of 1 OOO-grain weight(TGW).Expression analysis showed that TaNRT2L12-B is mainly expressed in the root base and regulated by nitrate.Therefore,TaNRT2L12 may be involved in nitrate transport and signaling to regulate TGW in wheat.The superior alleles and dCAPS markers of TaNRT2L12-A/B are beneficial to genetic improvement and germplasm enhancement with molecular markers-assisted selection.

A dCAPS marker developed from a stress associated protein gene TaSAP7-B governing grain size and plant height in wheat

Stress associated proteins（SAPs） are the A20/AN1 zinc-finger proteins which confer to abiotic stresses in plants. In this study, TaSAP7-B, including two AN1 domains, was isolated from B genome of wheat（Triticum aestivum L.）. Sequencing analysis on TaSAP7-B illustrated one In Del（insertion-deletion） and one SNP（single nucleotide polymorphism） in the promoter region while no diversity was observed in the coding region. On the basis of SNP in the promoter region（–260 bp）, a dCAPS（derived cleaved amplified polymorphic sequences） marker SNP-260 was developed for TaSAP7-B. Using a natural population consisting of 262 wheat accessions, significant associations were detected between the marker SNP-260 and agronomic traits, such as plant height（PH）, peduncle length（PL）, length of penultimate internode（LPI）, number of spike per plant（NSP）, and 1 000-grain weight（TGW）. Two genotypes were identified using marker SNP-260 in the natural population. Among them, the genotypes possessing C allele exhibited a higher TGW and shorter PH than the T genotypes. Hence, base C was considered as the superior allele. The dCAPS marker of TaSAP7-B can be instrumental for marker-assisted selection for high grain size and short plant height.

茶树新梢中香叶醇樱草糖苷含量的全基因组关联分析

香叶醇是茶树中含有的一种重要的挥发性单萜醇,在茶树与环境互作中起重要作用,也是茶叶中关键呈香成分之一,茶树新梢中的香叶醇主要以香叶醇樱草糖苷形式存在。发掘香叶醇樱草糖苷含量性状显著关联的SNP位点与候选基因,对香叶醇樱草糖苷含量的遗传调控机制研究与茶树遗传改良具有重要意义。以169个茶树种质为研究对象,连续3年对其新梢香叶醇樱草糖苷含量进行鉴定,基于SLAF简化基因组测序技术开发SNP标记,然后利用一般线性模型(GLM)对茶树新梢香叶醇樱草糖苷含量性状进行GWAS分析,发掘该性状显著关联的SNP位点与候选基因,最后对极端含量材料间的候选基因编码区碱基差异及其上游顺式作用元件进行分析。结果表明,参试群体在3个环境下香叶醇樱草糖苷含量变异系数范围为77.6%~81.8%,广义遗传力为62.6%。香叶醇樱草糖苷含量性状在基因型、环境间均呈现显著差异,变异受遗传影响为主。3个环境下共检测到340个SNP与香叶醇樱草糖苷含量显著相关,其中2个环境下重复检测到65个SNP。基于参考基因组与连锁不平衡衰减距离,获得重复检测到的SNP两侧各100 kb范围内的基因共88个,包含信号蛋白、激酶、磷酸酶、离子转运蛋白、转录因子、热激蛋白、激素相关蛋白、抗性蛋白、萜类代谢酶、糖基转移酶、糖苷酶,从中初筛出10个与香叶醇樱草糖苷含量相关的候选基因。极端含量材料之间的候选基因编码区序列均存在SNP非同义突变,多数候选基因上游2 kb区域存在不同数量的与环境胁迫和激素相关的顺式作用元件。本研究为阐明茶新梢中香叶醇樱草糖苷含量的遗传调控机制提供了新的视角,为分子标记辅助选择茶树新品种提供了标记与基因资源。

QTL mapping for yield components of Brassica napus L. using double haploid and immortalized F_2 populations

Effective silique number per plant(ESN), seeds per silique(SS), thousand seeds weight(TSW), silique length(SL) and silique density(SD) are important seed yield potential determinant traits in rapeseed(Brassica napus L.), which are controlled by quantitative trait loci(QTL). Mapping QTL to delimited chromosomal region offers an effective method for genetic dissection of these traits. A set of 96 double haploid(DH) lines were developed by crossing 2 Brassica napus lines R1 and R2, and an immortalized F_2(IF_2) population containing 124 combinations was developed by crossing those DH lines. DH populations were planted at 2 locations for 2 years and IF_2 populations were planted in 2 locations for 1 year. Based on the established 2,217.2 cM length high density genetic map, 42 QTLs were identified, with 26 QTLs detected repeatedly in different environments or populations, including 8 for SL, 7 for TSW, 4 for ESN, 4 for SS and 3 for SD. Among these identified QTLs, 3, 4, 1, 1 and 3 QTLs were considered as major QTLs for SL, TSW, ESN, SS and SD, respectively. In addition, 2 QTLs on A9 chromosome which control multiple traits were identified. These results warrant further study of fine mapping for yield and yield components.

茶树CHS基因结构及编码区单核苷酸多态性分析

【目的】通过试验获得茶树CHS基因(CsCHS)gDNA序列,以进一步确定CsCHS基因结构;研究CsCHS编码区单核苷酸多态性,并结合茶树多酚含量进行关联分析,寻找基因中可能存在的与茶多酚含量存在显著或极显著相关关系的SNP位点。【方法】根据NCBI数据库中已有CsCHS序列设计特异性引物,再分别以基因组DNA和cDNA为模板进行PCR扩增,经克隆、测序获得CsCHS1、CsCHS2、CsCHS3三个基因的gDNA和cDNA全长序列,通过序列比对方法确定CsCHS结构。利用Compute pI/Mw、SOPMA等软件对所得序列进行生物信息学分析,预测和比较CsCHS1、CsCHS2和CsCHS3三者蛋白质结构。以茶多酚含量差异较大的57份茶树品种为材料,分别以57份材料的cDNA为模板,用特异性引物进行PCR扩增,然后利用PCR产物直接测序法筛查CsCHS编码区序列的单核苷酸多态性。结合CsCHS编码区序列单核苷酸多态性和57份材料多酚含量,利用软件TASSEL进行关联分析,筛选基因中可能与茶多酚含量存在显著或极显著相关关系的SNP位点。【结果】试验获得CsCHS1、CsCHS2和CsCHS3的cDNA序列长度分别为1 277、1 320和1 242 bp,各自均包含一个长度为1 170 bp的开放阅读框;CsCHS1、CsCHS2和CsCHS3的gDNA序列长度分别为1 600、1 330和1 607 bp。通过gDNA序列和cDAN序列比对,结合真核生物内含子GT-AG法则,确定CsCHS1、CsCHS3分别包含2个外显子和1个内含子,内含子大小分别为323和356 bp,CsCHS2可能没有内含子。根据CsCHS1、CsCHS2和CsCHS3 cDNA序列推导三者对应氨基酸序列,比较三条氨基酸序列发现三者氨基酸同源性较高,达到92.6%—95.4%,CHS蛋白亚家族中的特征性保守位点在这三条序列中都能找到,生物信息学分析结果显示CsCHS1、CsCHS2和CsCHS3三者蛋白质结构高度相似。CsCHS1编码区序列中共发现71个SNP位点,SNP出现频率为1SNP/16.48 bp,无Indel,基因核苷酸多样性(π)值为0.01088;CsCHS2编码区序列中共发现55个SNP位点,SNP出现频率分别为1SNP/21.27 bp,CsCHS2核苷酸多样性(π)值(0.00530)明显低于CsCHS1;因扩增CsCHS3 cDNA序列的PCR反应成功率低,未对该基因遗传多样性进行分析。通过关联分析分别从CsCHS1和CsCHS2中找到2个和4个与茶叶多酚含量相关的SNP位点。【结论】CsCHS1和CsCHS3属于保守型CHS基因,且CsCHS1、CsCHS2和CsCHS3蛋白质结构高度相似,推测三者可能在茶树的不同部位或不同生长阶段发挥类似作用;CsCHS1和CsCHS2活跃,二者编码区内可能存在突变热点区。

不同性别类型黄瓜ACC合酶基因的单核苷酸多态性标记和酶切扩增长度多态性标记

黄瓜的性别分化与乙烯密切相关,1-氨基环丙烷-1-羧酸(ACC)合酶是乙烯生物合成过程中的关键酶.根据ACC合酶基因家族的保守序列设计PCR引物,从8个不同性别类型(雌雄同株、强雌性和全雌性)黄瓜品种中克隆了长度为1188bp的ACC合酶基因(CS-ACS2)片段(GenBank登记号为:DQ115884～DQ115886和DQ115875～DQ115879).经测序分析,3个雌雄同株性别类型品种的序列完全相同.与之相比,5个强雌性和全雌性品种中存在8个单核苷酸多态性(SNPs)标记,SNPs标记为4个A←→G和4个T←→C之间的转换.在8个SNPs中,有1个SNP位于内含子区域,其余7个SNPs都位于外显子区域.在7个位于外显子区域的SNPs中,有3个为非编码区的SNPs,4个为cSNPs.而在4个cSNPs中,有3个导致了编码的氨基酸序列改变.研究结果表明,与雌雄同株性别类型相比,雌性系中均存在单核苷酸的变异,这提示ACC合酶基因CS-ACS2的单核苷酸变异可能与黄瓜雌性系的发生形成有关.另一方面,根据SNP多态性还发展了一个酶切扩增长度多态性(CAPS)标记C-MT700.利用CAPS标记C-MT700能将强雌性优良品种MT-705与其他黄瓜品种相区别,该标记在黄瓜育种生产上具有一定的应用价值.此外,研究获得的SNPs标记和CAPS标记丰富了黄瓜的分子标记种类.

小麦果聚糖合成酶基因6-SFT-A单核苷酸多态性分析及其定位

【目的】小麦果聚糖合成酶基因6-SFT是果聚糖合成过程中的关键酶基因,研究6-SFT-A的多态性,分析其与小麦苗期抗旱性的关系,并进行遗传定位。【方法】以苗期抗旱性不同的30份六倍体小麦和4份小麦A基因组供体种乌拉尔图小麦为材料,通过直接测序分析6-SFT-A的单核苷酸多态性(SNP)及其与抗旱性的关系;开发基因分子标记,利用RIL群体(偃展1号×内乡188)对该基因进行遗传定位。【结果】在30份六倍体小麦材料中检测到14个核苷酸多态性位点,包括13个SNP和1个InDel,平均234 bp检测到一个多态性位点,仅在1 727和1 781 bp 2个位点检测到非同义突变;在4份乌拉尔图小麦中检测到28个SNP和4个InDel,其频率明显高于普通小麦。该基因的内含子1、2、3和外显子3为变异富集区,其它区域变异较小,外显子2变异最小,π值为0。34份材料分为3种单倍型,HaplⅠ主要包括中等抗旱材料和水敏感材料,HaplⅢ中主要包括强抗旱材料和中等抗旱材料。利用RIL群体将该基因定位于染色体4A的标记Xcwm-27与Xwpt688之间,遗传距离分别为5.3和7.9 cM。【结论】单倍型分析表明,小麦果聚糖合成酶基因6-SFT-A单倍型与小麦苗期抗旱性有一定的相关性。

欧洲黑杨基因资源材性关联基因的SNP分析

以115个欧洲黑杨(Populus nigra L.)无性系为材料,利用TaqMan技术分析了欧洲黑杨基因资源参与木质素和纤维素合成的酶(4CL、PAL和CesA2)的单核苷酸多态性,并对分型的SNPs与木材材性性状(物理性状:基本密度、纤维长、纤维宽、微纤丝角;化学性状:木质素含量、纤维素含量、α纤维素含量等)进行了相关分析。结果如下:(1)在对4CL、PAL和CesA2等3个基因进行检测时,共获得27个SNPs标记,对其中转换(A-G,C-T)有17个位点,颠换(A-C,G-C,G-T,A-T等)有10个位点;(2)对其中的3个SNPs进行了分型,分别记作SNP1、SNP2和SNP3;(2)对已经分型SNPs位点与材性性状进行方差分析,结果显示,3个SNPs中只有SNP1与4年生欧洲黑杨综纤维素含量显著相关,表现为负效应,贡献率为11.11%;(3)对欧洲黑杨4CL基因的SNP1标记的不同基因型所对应的材性性状进行方差分析,结果显示基因型为CC和CT的欧洲黑杨相对于基因型为TT的欧洲黑杨有较高的纤维素含量。

核桃JrCBF基因的克隆与表达和单核苷酸多态性分析

根据CBF基因氨基酸保守序列设计简并引物,运用cDNA末端快速扩增(RACE)技术克隆核桃JrCBF基因cDNA全长序列。用实时荧光定量PCR分析JrCBF基因在低温胁迫下的表达模式,并分析JrCBF基因的单核苷酸多态性。结果获得长度为879 bp的CBF基因cDNA全长序列,编码214个氨基酸,命名为JrCBF;低温能诱导JrCBF基因的表达,4℃处理2 h后表达量开始增加,8 h后达到最大值;自然越冬条件下,JrCBF基因在花芽中表达量呈现先上升后下降的趋势,在寒冬时期(1月份)表达量最高;单核苷酸多态性分析JrCBF基因序列中有28个SNPs位点和7个Indels标记,存在2个突变热点区;单倍型分析显示15份材料可分为9个单倍型,单倍型多样性为0.9238。本研究为通过基因工程手段培育抗寒核桃品种和分子标记辅助育种提供了帮助。