雄性核不育水稻育性转换的光周期效应指数值(PE)和温度效应指数值(TE)的遗传性初步研究

对比考察了农垦５８ｓ与７００１ｓ、８９０２ｓ与培矮６４ｓ及８９０２ｓ与安农Ｓ１等３个光（温）敏核不育水稻杂交组合的双亲、Ｆ１、Ｂ１、Ｂ２和Ｆ２世代的样本及每一个体的ＰＥ和ＴＥ的变异。无论双亲核不育基因的等位程度及栽培环境的光、温周期如何,在多数情况下都显示了如下的规律：（１）后代样本ＰＥ、ＴＥ的大小虽然形形色色,但都取决于其双亲。Ｆ１表示完全显性甚至超显性。（２）Ｆ２个体的ＰＥ或ＴＥ、尤其同一个体ＰＥ与ＴＥ的集成类型发生有规律的分离和超亲分离,产生形形色色的育性转换类型。在纯粹由雄性不育个体组成的Ｆ２不育分样本中也发生同样分离。（３）ＰＥ或ＴＥ的广义遗传力的估值都大于５０％。据此推断ＰＥ、ＴＥ是两个可遗传并可供选择的独立性状;并对育性转换现象的遗传机制也进行了讨论。     

表达barstar基因及bar基因的转基因油菜的研究

从细菌Ｂａｃｉｌｕｓａｍｙｌｏｌｉｑｕｅｆａｃｉｅｎｓ染色体ＤＮＡ中克隆了ｂａｒｎａｓｅ抑制剂ｂａｒｓｔａｒ的基因,构建了带有ＴＡ－２９基因５′调控区（－１３００－＋３）与ｂａｒｓｔａｒ基因编码区、ＣａＭＶ３５Ｓ启动子与除草剂抗性基因ｂａｒ两个表达框架的植物表达质粒ｐＢＢＳ。以“双低”油菜“５－４”的子叶柄为受体,通过农杆菌介导的遗传转化,获得了在含有１０ｍｇ／Ｌ卡那霉素和２０ｍｇ／ＬＰＰＴ的筛选培养基上再生的转基因植株。ＰＣＲ分析结果表明,ｂａｒｓｔａｒ基因已整合到油菜染色体上;Ｎｏｒｔｈｅｒｎｂｌｏｔ检测表明,ｂａｒｓｔａｒ基因及ｂａｒ基因在转基因植物中得到了正确的调控与表达。以转基因油菜“５－４”为父本授粉给表达ｂａｒｎａｓｅ基因的雄性不育植株,不育株能正常结实。     

小鼠基因组研究进展

小鼠基因组研究进展李善如１,２王冬平１陈永福２（１．军事医学科学院实验动物中心,北京１０００７１）（２．中国农业大学生物学院,北京１０００９４）ＴｈｅＤｅｖｅｌｏｐｍｅｎｔｏｆＭｏｕｓｅＧｅｎｏｍｅＲｅｓｅａｒｃｈＬＩＳｈａｎｒｕ１,２ＷＡＮＧＤｏｎ...     

转基因植物生产动物疫苗的研究及应用

转基因植物生产动物疫苗的研究及应用范国昌１,２山松１钱凯先２沈桂芳１（１．中国农业科学院生物技术研究中心,北京１０００８１）（２．浙江大学生物科学与技术系,杭州３１００２７）ＲｅｓｅａｒｃｈａｎｄＡｐｐｌｉｃａｔｉｏｎｏｎＴｒａｎｓｇｅｎｉｃＰｌａｎ...     

哺乳动物的核移植

哺乳动物的核移植陆长富卢光（湖南医科大学人类生殖工程研究室,长沙４１００７８）ＮｕｃｌｅａｒＴｒａｎｓｐｌａｎｔａｔｉｏｎｉｎＭａｍｍａｌｉａｎＬＵＣｈａｎｇｆｕＬＵＧｕａｎｇｘｉｕ（ＨｕｍａｎＲｅｐｒｏｄｕｃｔｉｖｅＥｎｇｉｎｅｒｉｎｇＬａｂｏｒ...     

Mechanism of low‐temperature‐induced pollen failure in rice

Low‐temperature stress during microspore development alters cellular organization in rice anthers. The major cellular damage includes unusual starch accumulation in the plastids of the endothecium in postmeiotic anthers, abnormal vacuolation and hypertrophy of the tapetum, premature callose (1,3‐β‐glucan) breakdown and lack of normal pollen wall formation. These cellular lesions arise from damage to critical biochemical processes that include sugar metabolism in the anthers and its use by the microspores. Failure of utilization of the callose breakdown product and other microspore wall components like sporopollenin can also be considered as critical. In recent years, considerable progress has been made in the understanding of major biochemical processes including the expression of critical genes that are sensitive to low temperature in rice and cause male sterility. This paper combines a discussion of cellular organization and associated biochemical processes that are sensitive to low temperatures and provides an overview of the potential mechanisms of low‐temperature‐induced male sterility in rice.     

Fine mapping of S32(t), a new gene causing hybrid embryo sac sterility in a Chinese landrace rice (Oryza sativa L.)

Ketan Nangka, the donor of wide compatibility genes, showed sterility when crossed to Tuanguzao, a landrace rice from Yunnan province, China. Genetic and cytological analyses revealed that the semi-sterility was primarily caused by partial abortion of the embryo sac. Genome-wide analysis of the linkage map constructed from the backcross population of Tuanguzao/Ketan Nangka//Ketan Nangka identified two independent loci responsible for the hybrid sterility located on chromosomes 2 and 5, which explained 18.6 and 20.1% of phenotypic variance, respectively. The gene on chromosome 5 mapped to the previously reported sterility gene S31(t), while the gene on chromosome 2, a new hybrid sterility gene, was tentatively designated as S32(t). The BC₁F₂ was developed for further confirmation and fine mapping of S32(t). The gene S32(t) was precisely mapped to the same region as that detected in the BC₁F₁ but its position was narrowed down to an interval of about 1.9 cM between markers RM236 and RM12475. By assaying the recombinant events in the BC₁F₂, S32(t) was further narrowed down to a 64 kb region on the same PAC clone. Sequence analysis of this fragment revealed seven predicted open reading frames, four of which encoded known proteins and three encoded putative proteins. Further analyses showed that wide-compatibility variety Dular had neutral alleles at loci S31(t) and S32(t) that can overcome the sterilities caused by these two genes. These results are useful for map-based cloning of S32(t) and for marker-assisted transferring of the neutral allele in hybrid rice breeding.     

小麦光温敏雄性不育相关基因的DDRT－PCR分析及功能预测

 以小麦光温敏雄性不育系BS210为试材,分别在北京顺义（可育环境）和安徽阜阳（不育环境）两种诱导育性表现的生态环境下种植,并于雌雄蕊分化期、药隔形成期、花粉母细胞形成期、四分体期和单核期5个时期提取小穗组织的RNA,利用DDRT-PCR方法分离不育系在光、温因子诱导下的差异表达mRNA,并通过反向Northern 进行验证.对获得的20条差异表达的EST进行了测序和BLAST分析,得到了4个候选基因的片段,对其进行5′Race 扩增、序列分析及功能预测.结果表明：它们分别与水稻的DNA修复重组蛋白基因rad50、小麦穗部表达的LRR重复序列型类受体激酶基因、玉米叶片坏死斑点L1s1基因的序列相似性分别为89%、89%和88%,另外还筛选到1个未知功能的新基因片段,它和rad50分别在可育和不育环境下表达的mRNA具有相同的5′端编码区,但3′端非编码区