Mining,characterization, and exploitation of EST-derived microsatellites in <Emphasis Type="Italic">Gossypium barbadense</Emphasis>

Simple sequence repeats (SSRs) have been widely applied as molecular markers in genetic studies. However, the number of ex-pressed sequence tags (ESTs) and SSR markers from Gossypium barbadense is fewer than those from other cotton species. In this study, EST-SSR distribution from G. barbadense was characterized and new G. barbadense-derived EST-SSR markers were de-termined on the basis of the ESTs obtained by randomly sequencing 2 cDNA libraries associated with fiber development in G. barbadense. By mining 9697 non-redundant ESTs, a total of 638 SSR loci derived from 595 ESTs were observed. In G. barba-dense, the frequency of ESTs containing SSRs was 6.13%, with an average of 1 SSR in every 10.4 kb of EST sequence. Further-more, trinucleotide was found to be the most abundant repeat type among 2–6-nucleotide repeat types. It accounted for 26.6% of the total, followed by the hexanucleotide (26.0%) and pentanucleotide repeats (25.9%). Among all the repeat motifs, (AAG)n accounted for the highest proportion. EST-SSR primer pairs were developed using the Primer3 program, and the redundant primers were removed using the virtual PCR approach. As a result, 380 non-redundant EST-SSR primer pairs were developed and used to detect polymorphisms between the mapping parents G. hirsutum ‘TM-1’ and G. barbadense ‘Hai7124’ for constructing linkage groups in cultivated allotetraploid cotton. Out of these, 98 (25.8%) primer pairs detected polymorphisms. Finally, 95 polymorphic loci from 82 primer pairs were integrated into the backbone genetic map; of these, 42 were mapped into the A subgenome and 53 into the D subgenome. The present work provided the foundation for constructing saturated genetic maps and conducting comparative genomic studies on different cotton species.     

Genome-wide identification of R genes and exploitation of candidate RGA markers in rice

By scanning the whole genomic sequence of japonica rice using 45 known plant disease resistance (R) genes, we identified 2119 resistance gene homologs or analogs (RGAs) and verified that RGAs are not randomly distributed but tend to cluster in the rice genome. The RGAs were classified into 21 families according to their functional domain based on Hidden Markov model (HMM). By comparing the RGAs of japonica rice with the whole genomlc sequence of indica rice, we found 702 RGAs allelic between the two subspecies and revealed that 671 (95.6%) of them have length difference (InDels) in their genomic sequences (including coding and non-coding regions) between the two subspecies, suggesting that RGAs are highly polymorphic between the two subspecies in rice. We also exploited 402 PCR-based and co-dominant candidate RGA markers by designing primer pairs on the regions flanking the lnDels and validating them via e-PCR. The length differences of the candidate RGA markers between the two subspecies are from 1 to 742 hp, with an average of 10.26 hp. All related information of the RGAs is available from our web site(http://ibi.zju.edu.cn/RGAs/index.html).     

Fine mapping of the red plant gene R_1 in upland cotton (Gossypium hirsutum)

Sub 16 is a substitution line with G. hirsutum cv. TM-1 genetic background except that the 16th chro-mosome (Chr. 16) is replaced by the corresponding homozygous chromosome of G. barbadense cv. 3-79, and T586 is a G. hirsutum multiple gene marker line with 8 dominant mutation genes. The R1 gene for anthocyanin pigmentation was tagged in Chr. 16 in T586. The objective of this research was to screen SSR markers tightly linked with R1 by using the F2 segregating population containing 1259 plants derived from t...     

陆地棉LTR反转录转座子的数量分布与功能分析

LTR(Long terminal repeat)反转录转座子是真核生物基因组中普遍存在的一类遗传因子,它们以RNA为媒介在基因组中不断自我复制.在高等植物中,LTR反转录转座子是基因组的重要成分之一.本研究通过多种方法挖掘并注释了陆地棉基因组中的LTR反转录转座子,结果表明陆地棉基因组LTR反转录转座子的Gypsy超家族与基因的分布呈近似的反比关系,而Copia超家族在各染色体的起始端有较多的分布.通过皮尔森相关系数发现陆地棉LTR反转录转座子的拷贝数与染色体大小之间有强相关性.在LTR反转录转座子上游和下游分布的基因具有类似的富集特征,其分子功能主要集中在结合和催化活性等方面.本研究结果加深了对陆地棉LTR反转录转座子的认识,为深入研究棉花基因组提供了重要数据支撑.     

随机扩增多态性DNA技术在生命科学炽的应用

DNA分子标记是DNA水平上遗传变异的直接反映,随机扩增多态性DNA（RAPD）技术,是新发展起来的一种DNA分子标记方法。文中详细阐述了RAPD技术的原理,进一步与限制性片段长度多态性（Restriction FragmentLength Polmorphism,RFLP)技术相比,得出它具有快速,简便和对材料要求不高等特点,最后讨论了RAPD技术在生命科学研究中各个方面的广泛应用,包括种基因组的分子谱图建、系统进化发育以及基因定位研究等。     

分子标记技术在作物育种中的应用与展望

回顾分子标记的发展,介绍了一些有代表性的分子标记在生态学,聚类分析,品种差异性分析以及分子育种中等多方面的应用,并总结了它们的优缺点.随着深度测序技术的发展和多种序列信息库的完善,预测了未来分子标记的发展方向——功能性分子标记(Functional molecular marker),这种新型的分子标记技术利用了基因中的一些功能元件或者重要的单碱基多态性(SNP)位点,提高了在应用中的分辨率和灵敏度.     

单核苷酸多态性及其在作物遗传育种中的应用

单核苷酸多态性（simple nucleotide polym orphism,SNP）是等位基因间序列差异最为普遍的类型,可以作为一种高通量的分子标记.本文主要介绍SNP的定义、几种植物学中常用的检测SNP方法及SNP标记在作物遗传育种中的应用.     

Characterization and mapping of a lesion mimic mutant in rice （Oryza sativa L.）

A rice initiation-type lesion mimic mutant (lmi) was identified, which was isolated from an indica rice Zhongxian 3037 through γ radiation mutagenesis. Trypan blue staining and sterile culture revealed that the mutant spontaneously developed lesions on the leaves in a developmentally regulated and light-dependent manner. Genetic analysis indicated that the lesion mimic trait was controlled by a single resessive locus. Using public molecular markers and an F2 population derived from lmi and 93-11, we mapped the lmi locus to the short arm of chromosome 8, nearby the centromere, between two SSR markers RM547 and RM331. The genetic distance was 1.2 and 3.2 cM, respectively. Then according to the public rice genomic sequence between the two SSR markers, lmi was further finely tagged by three CAPS markers: C4135-8, C4135-9 and C4135-10. And lmi locus was a co-segregated with marker C4135-10, providing a starting point for lmi gene cloning.     

分子标记与小麦群体遗传结构分析

小麦是我国主要的农作物之一,其遗传结构的研究,目前倍受分子生物学家和小麦育种学家的高度重视。现代分子生物学的发展为小麦群体遗传结构的分析提供了一条更新更广阔的途径本文论述了群体遗传结构研究方法的发展,着重讨论几种主要的分子标记及其在小麦群体遗传结构分析中的应用。     

Evaluation of the introgressed lines and screening for elite germplasm in Gossypium

THERE ARE 51 SPECIES IN THE GENUS OF GOSSYPIUM[1]. EXCEPT UPLAND COTTON CULTIVARS, WILD CULTIVARS, SPECIES AND RACE HAVE ABUNDANT GENETIC POLYMORPHISMS DUE TO THEIR VARIOUS ENVIRONMENTAL DISTRIBUTION AND LONG-TERM NATURAL SELECTION. THEREFORE, THEY POSSESS LOTS OF EXCEL- LENT GENES THAT CAN BE USED TO EXPLOIT POTENTIAL TRAITS, SUCH AS DROUGHT RESISTANCE, DISEASE AND INSECT …     

AFLP技术在昆虫分子系统学研究中的应用

概述了AFLP分子标记技术在昆虫分类鉴定、遗传图谱构建、遗传多样性分析、群体遗传结构和分化、生态型分析等分子系统学应用研究方面取得的较大进展．总结了AFLP的改进技术,并提出对相关问题的思考．     

海岛棉ERF族转录因子EREB6基因克隆特征分析

以电子克隆,同源扩增和RACE技术相结合的方法从海岛棉中克隆出了一条新基因,命名为EREB6,它包含一个669 bp长的开放阅读框,预期编码222个氨基酸长的蛋白质.序列分析发现预期蛋白含有一段核定位信号序列,GFP融合蛋白瞬时表达实验证明该蛋白定位于细胞核;含有一个保守的ERF域,属于ERF族;同源分析表明该转录因子...     

Fine mapping of the dominant glandless Gene Gl2^e in Sea-island cotton （Gossypium barbadense L.）

Gle2 is a mutant gene that controls glandless trait in cotton plants and seeds. It is an important gene resource to gossypol-free cottonseed breeding. The objective of this research was to develop SSR markers tightly linked with Gle2 by using the F2 segregating population containing 1599 plants derived from the cross of G. hirsutum genetic standard line TM-1 and G. barbadense glandless mutant line Hai-1. Genetic analysis suggested that the Gle2 was an incomplete dominant gene. Based on the backbone of genetic linkage map from G. hirsutum × G. barbadense BC1 published by our laboratory,Gle2 was lo-cated between CIR362 and NAU2251b,NAU3860b,STV033,with a genetic distance 9.27 and 0.96 cM,respectively. This result is useful for cloning Gle2 gene by map-based cloning method.     

明胶的干燥温度,粘度和分子量分布

通过实验探讨明胶干燥温度对明胶粘度的影响，并从分子量分布和数均分子量变化的角度阐明这种影响的内在原因．实验结果表明：经室温干燥的活性胶、惰胶、复合胶和食用胶再经１０５℃干燥与只经室温干燥相比，其粘度上升；经室温干燥的ＰＡ胶再经１０５℃干燥与只经室温干燥相比，粘度下降．明胶经室温干燥后再经１０５℃干燥，随着干保温度的提高，明胶的分子量分布和数均分子量发生变化，导致宏观上明胶粘度的变化．活性胶、惰胶、复合胶和食用胶经１０５℃干燥后分子量分布向分子量大的方向变化，数均分子量变大；而ＰＡ胶经１０５℃干燥后，分子量分布向分子量小的方向变化，数均分子量变小．     

Characterization and molecular marker screening of a rice bacteria-resistant gene Xa-min(t)

To test the resistant spectrum of the Xa-min(t) gene introgressed from Oryza minuta, thirty-four isolates of different bacterial blight pathogen, Xanthomonas oryzae pv. oryzae (Xoo), from 11 countries were used to inoculate the Xa-min(t) introgression line 78-15. Four rice cultivars, IR24, C64 (IRBB21), Nipponbare and Zhonghua 11 were used as controls. The results showed that the Xa-min(t) gene was broad-spectrum and highly resistant to diverse Xoo isolates. The methods of bulk segregant analysis (BSA), randomly amplified polymorphic DNA (RAPD) and sequence characterized amplified regions (SCAR) were used to analyze F2 individuals of the hybrid IR24×78-15 and molecular genetic markers linked to Xa-min(t) gene were identified. A total of 800 arbitrary decamer oligonucleotide primers were used for RAPD analysis. Two RAPD markers, BE05300 and BE061400, produced by primers BE05 and BE06 respectively, were closely linked to the Xa-min(t) gene. Based on the sequences of these two markers, sequence specific primers were designed and used to screen all F2 plants. One RAPD marker, BE05300, was converted into a stable SCAR marker (ScBE05300). Linkage analysis was carried out using markers ScBE05300 and BE061400 on 948 and 719 F2 individuals of the hybrid IR24×78-15. Our results indicate that the genetic distances from Xa-min(t) to ScBE05300 and BE061400 are 2.2 cM and 3.7 cM respectively on the same side. This study may facilitate the construction of the fine physical map of the Xa-min(t) gene.     

猪凝血酶的分离纯化与鉴定

本文报导以猪血为材料，制备凝血酶，血浆在低离子强度下经等电沉淀得优球蛋白，从该沉淀中采用稀盐溶液提取，氢氧化镁吸附和二氧化碳解吸等步骤获得凝血酶原粗品。后者经脑提取液激活，再经乙醇分级、ＤＥＡＥ－纤维素与磷酸纤维素离子交换层析和ＳｅｐｈａｄｅｘＧ－１００凝胶过滤，得凝血酶制品，经ＳＤＳ－ＰＡＧＥ分析，制品呈单一条带，分子量约为３９ｋＤ，比活达１６１０ＮＩＨＵ／ｍｇ蛋白，以活化的粗品活性为１００％，活性回收率为４８％，纯化倍数约为１０。     

Characterization and mapping of a white panicle mutant gene in rice

A spontaneous white panicle mutant was found from the F6 progenies of an indicajaponica cross.The mutant exhibits white stripes on its basal leaves while the panicles,rachis and pedicel are milky white colored at flowering stage.Genetic analysis in an F2 population from the cross of Zhi7/white panicle mutant indicates that the white panicle phenotype is controlled by a single recessive nuclear gene,tentatively termed as wp(t).Using microsatellite markers,the wp(t) gene was anchored between the markers of SSR101 and SSR63.9 with a map distance of 2.3 and 0.8cM,respectively,and co-segregated with the marker of SSR17 on rice chromosome 1.     

汉中地区的兽类及其资源利用

对汉中地区的兽类及其资源利用作了研究.本地区计有兽类71种,隶属7目24科.其中东洋界种38种,占总种数的53.5%;古北界种17种,占总种数的23.9%;广布种16种,占22.6%.此外,还有我国的特产动物大熊猫、金丝猴、豹、华南虎等.目前应加强资源保护,注重综合利用.