分子生物学数据库及相关软件的开发利用

生物大分子序列和结构测定技术的完善和应用,使核酸及蛋白质序列数据库及蛋白质结构数据库迅速增长.面对不断增长的分子生物信息,很多生物学工作者又在此基础上构建了具有特殊生物学意义和专门用途的二次数据库,使得数据库的内容和种类更加丰富和具体,为生物学各个领域的深入研究提供了坚实的信息基础.     

小麦背景中簇毛麦6V染色体的遗传稳定性及其在配子中的传递

小麦－簇毛麦６Ｖ二体附加系,６Ａ（６Ｖ）二体代换系,６Ａ＾Ｌ．６Ｖ＾ｓ二体易位系在细胞学上是基本稳定的６Ｖ,６Ａ＾Ｌ．６Ｖ＾ｓ染色体能够通过配子稳定地传递给后代,在杂合状态下,带有６Ｖ的配子传递率普遍显著下降,在单体附加系（２１”Ｗ＋６Ｖ）中,６Ｖ通过雌配子的传递率（１１．３％）高于通过雄配子的传递率（５．９％）,在单体代换系（２０”Ｗ＋６Ａ－６Ｖ）中,６Ｖ通过雌配子的传递率（１０．４％）低于通过     

小麦-簇毛麦属间染色体易位系的高效诱导

利用60Coγ射线以不同剂量照射硬粒小麦-簇毛麦双二倍体即将成熟的花粉,将其授于母本中国春,创造出一批包含小麦-簇毛麦易住染色体的材料,对这些材料用中国春进行连续回交或自交,可有效保留簇毛麦染色体片段,实现外源基因的转移.研究结果表明,60Coγ射线照射花粉后产生易位染色体的频率因剂量不同而有显著差异,12 Gy和8 Gy剂量照射后杂交的M1群体中,产生小麦-簇毛麦易位染色体的单株分别占调查总数的76.7%和50.0%,均显著高于用其他方法创造易住的频率,并且12 Gy较8 Gy产生了更优的易住类型;创制的易位染色体有67.6%可以从M1传递到BC1,BC1的易位染色体有96.4%可传递到BC,;在回交后代中,加以人为选择,整条簇毛麦染色体很快丢失,至BC2F2即有纯合易位株出现.     

具一对双随体染色体的硬粒小麦—簇毛麦双二倍体的合成,抗病性及 …

通过幼胚培养和秋水仙碱处理,人工合成了具有一对双随体染色体的硬粒小麦－簇毛麦双二倍体（ＡＡＢＢＶＶ）。根尖细胞染色体数目２ｎ＝４２;花粉母细胞减数分裂中期Ｉ,２ｎ＝２１″的细胞占６９．９４％,染色体构型为１．０＇＋２０．４７″＋０．０２＇″。天然和自交结实率分别为４９．０７％和３９．２３％。籽粒蛋白质含量为２０．９８％。抗白粉、条锈、叶锈和赤霉病。     

小麦-簇毛麦易位系 6VS/6AL中6VS的遗传传递及其所携Pm21基因的遗传稳定性分析

以簇毛麦(Haynaldiavillosa(L.)Schur)物种专化重复序列探针pHv62及小麦(TriticumaestivumL.)第六部分同源群短臂专化RFLP探针Psr113对扬94_138(“扬麦158”的改良品系)与易位系92R149配制的F2群体进行分析,观察到易位系中的6V短臂在杂交后代中的传递率为69.5%,接近75%的理论值。对来自同一个F1的另外147株F2群体以6个白粉菌菌株进行苗期抗病性测定,检测结果表明6VS上所携Pm21基因在向“扬麦158”小麦基因型转移时,按显性单基因遗传,并能很好地表达。     

小麦—簇毛麦易位系6VS—6AL中6VS的遗传传递及其所携Pm21基因的 …

以簇毛麦（Ｈａｙｎａｌｄｉａ ｖｉｌｌｏｓａ（Ｌ．）Ｓｃｈｕｒ）物种专化重复序列探针ｐＨｖ６２及小麦（Ｔｒｉｔｉｃｕｎ ａｅｓｔｉｖｕｍ Ｌ．）第六部分同源群短臂专化ＲＦＬＰ探针Ｐｓｒ１１３对肠９４－１３８（“扬麦１５８”的改良品系）与易位系９２Ｒ１４９配制的Ｆ２群体进行分析,观察到易位系中的６Ｖ短臂在杂交后代中的传递率为６９．５％,接近７５％的理论值。     

具一对双随体染色体的硬粒小麦-簇毛麦双二倍体的合成、抗病性及细胞遗传学研究

通过幼胚培养和秋水仙碱处理,人工合成了具有一对双随体染色体的硬粒小麦——簇毛麦双二倍体（ＡＡＢＢＶＶ）。根尖细胞染色体数目２ｎ＝４２;花粉母细胞减数分裂中期Ⅰ,２ｎ＝２１″的细胞占６９．９４％,染色体构型为１．０′＋２０．４７″＋０．０２。天然和自交结实率分别为４９．０７％和３９．２３％。籽粒蛋白质含量为２０．９８％。抗白粉、条锈、叶锈和赤霉病。     

簇毛麦NBS类R基因相关序列的分子标记开发及其染色体定位

小麦近缘种簇毛麦携带许多尚未克隆的抗病(R)基因。NBS-LRR类型的R基因占已克隆植物R基因的绝大多数,因此,本研究根据NBS-LRR类型R基因的保守序列设计引物,从簇毛麦基因组DNA和cDNA中扩增获得23条相关序列。基于其中5条抗病基因同源序列(RGAs)H-56/d6、H-66/b2和CDS40设计引物,对小麦、簇毛麦、硬-簇双二倍体及其杂种以及已知携带个别簇毛麦染色体或染色体臂的小麦材料进一步进行PCR扩增,结果表明:3对引物均可对簇毛麦、硬-簇双二倍体进行特异扩增;同时,源于序列H-66/b2的引物可对1VL和6VL染色体臂进行特异扩增;源于序列CDS40的引物可在同时携带1VL和2VS或同时携带2VS和4V的小麦材料以及具有6VL的小麦材料中特异扩增,而H-56/d6的引物在携带1VL、2VS、4V和6V染色体臂或染色体的小麦背景中都不能获得目的片段的扩增。这些结果不仅为外源染色体臂在小麦背景中的追踪与鉴定提供了新的分子标记,而且这些标记还与外源染色体或染色体臂上的抗病基因或抗病基因同源物紧密连锁或共分离。     

不同小麦背景小簇麦双二倍体的品质、抗病性及分子细胞遗传学研究

对不同小麦（Triticum aestivum 2n=42 AABBDD）背景的4个小簇麦双二倍体进行了分子细胞遗传学分析。结果表明,经过自交7代选育,小簇麦双二倍体的遗传逐渐趋于稳定。其中V852cd和V853cd的遗传稳定性相对较好,RTC M,2m=56的植株分别占100％和83.33%,PMC MI,2n=28Ⅱ的频率分别为73.34%和70.72%,相对紊乱系数分别为0.021和0.022;用簇毛麦（Haynaldia villosa 2n=14 VV)DNA作探针进行原位杂交时,V851cd、V852cd和V853cd的体细胞中都有14条簇毛麦染色体,其染色体组成为2n=56=42W 14V,V854cd中有12条簇毛麦染色体,其染色体组成为2n=56=42W 12V 2T(W/V)。4个双二倍体籽粒蛋白质含量为19.28％－20.52%;V851cd,V852cd和V853cd对条锈病免疫或近免疫,高抗白娄病和叶锈病,中抗雪霉病和赤霉病。     

Analyses of genetic change-over in Drosophila populations

Genetic change-overs in Drosophila populations similar to those frequently observed in microbial ones maintained in chemostats are described. In two cases, the change-overs were revealed by an abrupt and sustained increase in the probability that two independently sampled lethal chromosomes proved to be allelic. These favored lethals (or closely linked non-lethal elements) were estimated to have fitnesses 1.30–1.35 in combination with “ordinary” lethals or 1.05–1.10 in combination with non-lethal chromosomes (fitness 1.00 is assigned to carriers of non-lethal chromosomes only). A decrease in the frequency of lethal chromosomes in a third population was adequately explained by postulating the origin of a non-lethal “favored” element whose relative fitness was 1.25, a value similar to those estimated above. Genetic change-over in populations is discussed in relation to biochemical and morphological conservatism.     

簇毛麦染色体组特异性RAPD标记的筛选、定位和应用

以普通小麦中国春、中国春－簇毛麦二体附加系以及不同来源的簇毛麦为材料,用100个10碱基随机引物进行RAPD扩增。引物OPF02能在不同来源的簇毛麦及所有中国春－簇毛麦二体附加系中扩增出一条长约750bp的片段OPF02 750。普通小麦和硬粒小麦不能扩增出该片段。因此,OPF02 750为分布于簇毛麦所有染色体上的一个簇毛麦染色体组特异片段。用引物OPF02对普通小麦－簇毛麦双二倍体、硬粒小麦－簇毛麦双二倍体以及几个普通小麦的簇毛麦二体代换系、二体附加系进行检测,发现NAU302已经丢失了其所附加的簇毛麦3V染色体。     

对苞萱草的核型研究

本文报道用光学显微镜观察对苞萱草Ｈｅｍｅｒｏｃａｌｉｓｆｕｌｖａ（Ｌ．）Ｌ．ｖａｒ．ｏｐ ｐｏｓｉｔｉｂｒａｃｔｅａｔａＨ．ＫｏｎｇｅｔＣ．Ｊ．Ｗａｎｇ,ｖａｒ．ｎｏｖ．的染色体,按全国第一次植物染色体学术讨论会建议的标准进行核型分析。研究结果表明,对苞萱草体细胞染色体数目２ｎ＝２２,核型公式ｋ（２ｎ）＝２２＝１２ｍ＋６ｓｍ＋４ｓｔ,属于Ｓｔｅｂｂｉｎｓ核型的２Ｂ型。甘肃萱草属植物的核型可分为两大类群,对苞萱草的核型属于第二类群。对苞萱草与萱草Ｈ．ｆｕｌｖａ（Ｌ．）Ｌ．的核型较接近,为新变种的确立提供了细胞学方面的依据。     

New tools for the high throughput characterization of rat genomic DNA samples

Linkage studies and positional cloning projects for the identification of disease related genes require the genetic characterization of large numbers of genomic DNA samples. The application of spotting robots enables the production of high density filters representing several thousand DNA probes. To take full advantage of the potential of these filters we have established a new, hybridization based Interspersed Repetitive Sequence (IRS-)marker system for the rat genome. This marker panel was shown to be useful for rapid genotyping of many multigenic crosses as well as high throughput characterization of large insert genomic libraries.     

Clinical findings and cytogenetic analysis of small supernumerary ring chromosomes 7: report of two new cases

Two new patients, mosaic for a small supernumerary ring chromosome 7 are described. There are only seven published reported concerning supernumerary ring chromosome 7 and we reviewed the previously reported cases in an attempt to establish genotype-phenotype correlations, which are particularly important for genetic counselling and clinical genetics. Our first case was a 20 months old girl who was referred for a mild motor developmental delay, an asymmetric facial appearance, a plagiocephaly and a short nose with anteverted nostrils. Our second case was a 9 years old boy who was referred for a IQ at the lower end of the normal range (? 80), obesity, hyperactivity and some dysmorphic features including hypertelorism and down slanting palpebral fissures. In both cases, chromosome analysis after G and R banding and FISH showed a small ring chromosome 7 in respectively 76% and 50% of consecutively scored metaphases. Both ring chromosomes were labelled by FISH using the Williams Syndrome locus probe (Elastin Gene D7S486). Comparison between these two cases and previously published cases allowed to delineate frequent clinical findings. A mild mental retardation was found in the majority of patients. which is an important data for genetic counselling.