不结球白菜(Brassica campestris ssp. chinensis Makino)种质资源SRAP遗传分化分析

利用SRAP分子标记分析了国内外64份不结球白菜种质资源的DNA遗传多样性和遗传分化。21对引物组合共检测出215个位点，其中112个为多态性位点，多态性比率达52.09%，平均每对引物组合产生10.24个位点和5.33个多态性位点。不结球白菜各类型中普通白菜的Nei’s基因多样性指数（0.1410）和遗传丰富度[(190) 88.37%]最高；各生态区域中江淮流域不结球白菜的Nei’s基因多样性指数（0.1451）和遗传丰富度[(185) 86.05%]最高；国内的Nei’s基因多样性指数(0.1293)和遗传丰富度[(188) 87.44%]分别高于国外。遗传变异估算表明，不结球白菜遗传分化系数58.22%，大部分变异存在于种群间；基因流为0.4031，说明群体间基因流动较少，遗传分化程度较高。以遗传相似系数0.872为截值，可把不结球球白菜分为Ⅵ个类群。     

绥农10号大豆的再生体系研究

为了建立大豆的愈伤组织再生体系,以大豆绥农10号的破坏生长点的茎尖、子叶、真叶、胚轴为外植体,研究了不同激素种类、浓度对大豆愈伤组织形成和芽的再生及生根的影响.结果表明,6-BA对大豆愈伤组织的形成有抑制作用,其中对真叶的抑制作用最大,对破坏生长点的茎尖外植体抑制作用最小:6-BA诱导的大豆芽分化率均较低,其中在2～3...     

胚胎干细胞向神经细胞定向诱导分化方法的研究进展

胚胎干细胞具有自我更新和多向分化潜能,有望成为治疗神经系统疾病重要的种子细胞来源。如何高效地诱导胚胎干细胞向特定神经细胞分化是目前研究的热点。本文就胚胎干细胞定向分化成神经细胞的3种方法:RA诱导法、谱系选择法和SDIA法及其移植研究做一综述。     

冬小麦春生叶片伸展程度与幼穗分化关系的再讨探

试验采用农大139等5～6个冬小麦品种观察表明:春一、二叶伸出4～5 cm 左右时,分别与单棱、二棱两个穗分化始期相对应;春三、四、五、六叶伸出9～10 cm 左右时,分别与小花、雌雄蕊、药隔形成和覆盖器官伸长四个穗分化始期相对应。一般趋势为当每片春生叶片伸出2/5～3/4全长时,分别可与相应的穗分化始期相对应。四分体的分化都在旗叶展开以后;当花药黄绿色、长度为1.5(±0.1)mm 时,发生四分体的机率可在80%以上。     

Genetic diversity decreases as population density declines: Implications of temporal variation in mitochondrial haplotype frequencies in a natural population of Tscherskia triton

Although the spatial genetic differentiation that occurs in animal populations has been extensively studied, information on temporal variations in genetic structure and diversity is still lacking, especially for animals with oscillating populations. In the present study, we used the mtDNA D‐loop sequence to assess the temporal genetic variation in samples from six successive years for the greater long‐tailed hamster, Tscherskia triton. Sampling was carried out between 1998 and 2003 in cropland on the North China Plain, China. A total of 108 individuals were analyzed. The temporal samples showed a high level of genetic diversity. Substantial genetic changes in haplotype frequencies over time were detected for the hamster population. Random genetic drift and migration are likely to be the major factors responsible for the observed temporal pattern. The genetic diversity of the hamster population was higher in years with higher population density, and lower in years with lower population density. The result supports our hypothesis that genetic diversity decreases when population density declines in animals whose population oscillates greatly between years. The combined effects of inbreeding and genetic drift caused by reproduction, dispersal and population size might play important roles in the observed changes in genetic structure and diversity between years.     

猪伪狂犬重组抗原间接ELISA诊断方法的建立

本研究应用重组抗原,成功建立了检测猪伪狂犬病病毒血清抗体的间接ELISA诊断方法。通过方阵滴定确定了抗原最适包被量为1.45μg/孔,血清最适稀释度为1∶80,其作用时间为60 min,酶标抗体最适作用时间为60 min。其阳性临界值为OD≥0.123。此外,该抗原不与猪其他疾病的阳性血清反应,具有良好的特异性;批内重复试验,变异系数小于10%。该方法与进口诊断试剂盒的符合率为96.3%。本研究为现地免疫猪群抗体检测和进行PRV流行病学调查提供了一种简便的血清学诊断方法。     

禽类性别决定与分化相关基因的研究进展

禽类的性别决定机制迄今尚无定论,目前较为公认的有以下几种假说:一是W染色体上携带性别决定基因(类似于哺乳动物的SRY)决定着个体的雌性化发育;二是Z染色体上某些基因的过表达(即不受剂量补偿效应限制)引发了个体的雄性化发育;三是前2种机制共同作用。已知禽类的性别决定候选基因有W染色体上的FET1、ASW和Z染色体上的DMRT1基因。此外,常染色体上的许多基因也参与禽类的性别决定和分化过程,如SOX9,AMH,cFOXL,CYP19A1等。     

Isolation and identification of human fetal bone-derived mesenchymal stem cells and their differentiation to hepatocyte like cells

AIM: To separate and identify the mesenchymal stem cells (MSCs) from human fetal bone and to study their differentiation to hepatocyte like cells under the action of chemical induction.METHODS: The MSCs from human fetal bone were isolated and purified according to the different growth characteristic of attaching to the wall of cell culture flask.The cell cycle and surface markers of MSCs were identified using flow cytometry.The MSCs were pre-induced by adding DMSO,β-Me and 5-aza for 24 h,then adding the inductive medium of H-DMEM and rh-HGF to induce their differentiation to hepatocyte like cells (HLCs).HLCs were identified by the typical morphological change and the expression of special protein with the method of immunocytochemistry.RESULTS: The MSCs derived from human fetal bone expressed adhesion molecules CD29+,CD44+,but not antigens of hematopoietic CD34,CD45,and not antigens related to GVHD,such as HLA-DR,CD80 and CD86.Exposure of these cells to above-mentioned inductive agents resulted in obvious morphological change and an increase in expression of AFP and ALB.CONCLUSION: The results suggest the existence of plentiful MSCs in human fetal bone.MSCs derived from human fetal bone can easily differentiate to HLCs,and they have a lower immunogenic nature,which may provide the ideal source for tissue engineering (bioartificial liver) for cellular therapeutics.     

6-BA、NAA和IAA对黄瓜子叶离体培养分化的影响

以‘津春四号’黄瓜(Cucumis stativus)的幼龄子叶为外植体,比较了不同浓度的6-BA、NAA、IAA对其诱导愈伤组织以及对愈伤组织分化不定芽及不定根的影响。结果表明,黄瓜在组织培养再生完整植株时,只需极低浓度的NAA即能诱导大量愈伤组织;在0.05～0.10mg/L浓度范围内随NAA浓度的提高,出愈率提高,愈伤组织增殖加快;MS 6-BA1.0mg/L NAA0.10mg/L为较适宜的愈伤组织诱导培养基;MS 6-BA1.0mg/L IAA0.05～0.10mg/L为较适宜的芽诱导培养基;1/2MS NAA0.5mg/L培养基对生根诱导效果较好。     

宁夏三个葡萄品种高效再生体系的建立

以宁夏葡萄产业中大量种植的3个葡萄品种为试材建立再生体系.采用花药、茎尖进行愈伤组织诱导,比较了3种葡萄用花药、茎尖培养诱导愈伤组织形成、分化、生根的必须培养条件,获得不定芽分化再生植株.结果表明:葡萄花药愈伤组织形成胚性愈伤组织的能力很低,几乎不能分化成苗;而茎尖愈伤组织形成胚性愈伤组织的能力很高,分化成苗率极高,达100％.B5培养基诱导宁夏葡萄茎尖愈伤组织和分化丛生效果最好;KT有利于愈伤组织分化;茎尖浓度以0.8～1.0 cm最好.