抗稻瘟病基因Pi-2(t)紧密连锁的SSR标记的筛选与应用

根据已报道的双侧连锁标记并利用已公布的水稻基因组序列信息,在广谱抗稻瘟病基因Pi-2(t)的附近找到了一个新的SSR标记,记为SRM24,估计它与Pi-2(t)间的距离大约只有0.5 cM或43 kb 。利用该标记,成功地将Pi-2(t)从供体材料5173导入到迄今广泛使用的雄性不育保持系珍汕97B中,获得了一批携有Pi-2(t)的珍汕97B近等基因系。

水稻稻瘟病抗性基因Pi-2(t)的精细定位

利用重组自交系群体对水稻稻瘟病抗性基因 Pi- 2 (t)进行精细定位 ,将 Pi- 2 (t)定位于分子标记 RG6 4和 AP2 2之间 ,遗传距离分别为 0 .9c M和 1.2 c M。该研究建立了 Pi- 2 (t)基因和分子标记之间的紧密连锁 ,为提高分子标记辅助选择育种的效率 ,以及克隆该基因奠定了基础。

水稻抗稻瘟病基因Pi-2(t)物理图谱的构建

应用BAC文库，采用基于分子标记的染色体着陆（marker-based chromosome landing）和染色体步查（chromosome walking）等手段，建立了包含有水稻抗稻瘟病基因Pi-2（t）的物理图谱，该物理图谱由22个BAC克隆组成，遗传跨度8cM，而物理距离为925kb，该物理图谱的构建不仅为进一步分离和克隆该基因打下了基础，同时也可为分子标记辅助选择育种选择抗稻瘟病新材料提供新的标记。

与Pi-2(t)基因连锁的栽培稻BAC克隆在药用野生稻和栽培稻中的比较物理定位

用栽培稻遗传图第 6连锁群中与 Pi- 2 ( t)紧密连锁的 RFL P标记 RG64及其筛选出来的 BAC克隆3 8D17作为探针 ,对药用野生稻和栽培稻进行荧光原位杂交 ( FISH) ,供试探针 RG64及 BAC克隆 3 8D17均被定位于药用野生稻和栽培稻第 6染色体 .药用野生稻杂交信号的百分距离分别为 4 4 .87± 5 .3 3和 4 6.5 0± 4 .5 7,而栽培稻则为 3 5 .85± 3 .0 6和 3 6.0 5± 2 .4 4 ,信号检出率相应地为 7.14 %、4 2 .5 3 %、8.0 9%和 4 0 .78% .BAC克隆和RFL P探针杂交位置几乎一致 ,由此推知 ,与抗性基因 Pi- 2 ( t)连锁的 BAC克隆在药用野生稻中的同源顺序就在第6染色体杂交信号出现的相应位置 .在未封阻的情况下 ,药用野生稻多个染色体上具有信号 ,这表明它和栽培稻的Cot- DNA重复序列在一定的程度上具有同源性 .文中讨论了栽培稻 BAC克隆对药用野生稻原位杂交物理作图的可行性和 Cot- DNA的制备所涉及的一些技术问题 .

黑龙江省主栽水稻品种抗稻瘟病基因Pi-2(t)的SSR检测分析

为合理搭配种植水稻品种,利用与抗稻瘟病基因Pi-2(t)紧密连锁的SSR标记AP22和SRM24检测49份黑龙江省主栽水稻品种(系)抗瘟基因Pi-2(t)的分布情况。结果表明:用2个与抗稻瘟病基因Pi-2(t)紧密连锁的SSR标记同时对抗瘟基因Pi-2(t)的检测是非常有效的方法,龙粳8号、绥粳4号、龙D99-709和垦676共4个水稻品种(系)检测出含有Pi-2(t)抗稻瘟病基因,并了解了该基因在黑龙江省水稻品种资源中的分布情况。

Increased Expression of PI-3K in Asthmatic Rat T Lymphocytes

In order to explore the expression of PI-3K in T lymphocytes of asthmatic rats and the relationship between PI-3K and activation of T lymphocytes, 24 Wistar rats were randomly divided into 4 groups： normal control group, asthmatic one-week group, asthmatic two-week group and asthmatic four-week group. T cells were purified from blood of each rat and the expression of PI-3K was observed by immunocytochemical fluorescence staining, the serniquantitative fluorescence intensity was measured by HPIAS-2000 analytic software, and the expression of IL-4 in supernatants was detected by ELISA. The results showed that the fluorescence intensity of T lymphocytes in asthmatic groups was significantly higher than that in normal control （P〈0.001）, indicating that the expression of PI-3K in T lymphocytes of asthmatic rats was significantly higher than that in those of normal controls, and the difference between acute and chronic stage asthmatic groups was significant （P〈0.05）. The expression levels of IL-4 protein in supernatants of asthmatic T lymphocytes were significantly higher than those in the normal controls （P〈0.05）. There was a significant positive correlation between the expression of PI-3K in T lymphocytes and the IL-4 protein expression in supernatants （r=0.583, P〈0.01）. It was suggested that PI-3K signal pathway may participate in the processes of activation and other cytological effects of asthmatic T lymphocytes, thus may play an important roles in the pathogenesis of asthma.