利用RT-PCR技术验证基于小鼠外显子芯片发现的缺血相关基因的表达

目的:利用RT-PCR技术验证并确认基于小鼠外显子芯片发现的部分缺血相关基因的表达,以鉴定候选基因的外显子是否发生可变剪接,从而实现对外显子芯片结果的鉴定。方法:根据生物信息学分析结果,选取小鼠外显子芯片中的3个基因(Ube3c,6330439K17Rik,Atp7a),在预测发生可变剪接的外显子两侧设计上下游引物,PCR后进行凝胶回收,再克隆到载体中进行测序。结果:RT-PCR及测序结果表明,Ube3c基因在6号外显子、6330439K17Rik基因在12号外显子、Atp7a基因在3号外显子发生可变剪接,与芯片预测结果一致。结论:RT-PCR技术可针对外显子芯片的结果进行可靠性验证,为可变剪接基因表达研究提供了一种有效手段。     

利用靶定基质蛋白基因m的小干扰RNA抑制2009甲型H1N1流感病毒的复制

目的:设计、构建并筛选针对流感病毒基质蛋白基因m的小干扰RNA(siRNA),检测其对2009甲型H1N1流感病毒复制的抑制效果。方法:设计3条针对流感病毒m基因的siRNA,并克隆到短发夹型(shRNA)siRNA表达载体pSilencer2.1-U6-hygro上;经测序证明构建成功后,将表达3种siRNA的质粒和阴性对照质粒psiRNA-control分别转染MDCK细胞,用潮霉素筛选稳定表达细胞株,用H1N1流感病毒感染细胞,通过Real-time PCR和Western印迹检测干扰效果。结果:构建了3个针对流感病毒m基因的siRNA表达质粒,3种siRNA均使m基因的mRNA水平降低,其中M1-306的抑制效率达60%;3种siRNA均使流感病毒NA蛋白的表达量降低,M2-25、M1-105的抑制效率明显,M1-306略低。结论:针对m基因的siRNA可以有效抑制流感病毒在MDCK细胞中的复制。     

Study on Tandem Repeat Sequence Variation in Sheep mtDNA D-loop Region

The 75-nt-long tandem repeat sequence in the control region of mtDNA of 77 individuals, of which 69 were from different indigenous sheep breeds in China and 8 were from imported breeds, was sequenced and analyzed to investigate the origin and differentiation of Chinese indigenous sheep breeds and also the genetic diversities and relationships among them. A total of 28 variable sites were detected within 309 repeated sequences, among which 7 sites were singleton variable sites with two variants, 1 site was a singleton variable site with three variants, and 20 sites were parsimony informative sites with two variants. A total of 63 haplotypes were sorted from 28 polymorphic sites, among which two main and basic haplotypes, namely, Hap 1 and Hap 3 were present at a much higher proportion, at 12.94% and 30.42%, respectively. It could be inferred that Chinese indigenous sheep breeds originated from two maternal ancestors because of the maternal inheritance characteristics of the mtDNA. Altay sheep and Kazakstan sheep are closely related and do not differentiate significantly. Mongolian sheep and Ujumuqin sheep also share a close relationship. Tibetan sheep, Mongolian sheep, and Ujumuqin sheep have lower genetic diversity than Altay sheep and Kazakstan sheep.     

Effects of the MyoG Gene on the Partial Growth Traits in Pigs

Single-nucleotide polymorphisms of the MyoG gene were tested using PCR-SSCP in different pig breeds including Landrace, Large White, Duroc, Shanxi Black, and Mashen pigs, and the effects of the MyoG gene on the birth weight, the weaning weight, the 6-month body weight, and the backfat thickness were also analyzed. On the basis of the published sequence of the porcine MyoG gene, ten pairs of primers were designed, and one polymorphism was found in the PCR product amplified with In2-3 primers. The results showed that: (1) the Landrace, the Large White, and the Duroc breeds differ significantly (P < 0.05) in genotype distribution from the Shanxi Black and the Mashen breeds; (2) On the basis of the fixed effect model, significant differences were found in the birth weight and the backfat thickness among the different MyoG genotypes, whereas no significant differences existed in the weaning weight and the 6-month body weight; (3) Using least square analysis, it was seen that individuals of the BB genotype had significantly less (P < 0.01) birth weight than those of the AA and AB genotypes, with the order being AA>AB>BB; the pigs of the AA genotype had significantly lower (P < 0.01) backfat thickness than those of the AB and BB genotypes, with the order being AA<AB<BB. These results suggest that the genotype has significant effects on the individual birth weight and the backfat thickness, and that the selection of the A allele is favored with regard to the birth weight and the backfat thickness.     

褐藻裙带菜中PSⅡ复合物及其亚复合物的分离和特性研究

用不连续梯度蔗糖密度超离心,从经Triton X-100增溶的褐藻裙带菜类囊体膜中分离到3种色素蛋白复合物条带,分别是捕光复合物、具有光氧化活性的PSⅡ复合物颗粒（区带Ⅱ）以及PSⅠ（区带Ⅲ）。PSⅡ颗粒经毛地黄皂苷增溶后,再次超离心分离得到3条PSⅡ的亚复合物条带。吸收和荧光激发谱显示其中的区带Ⅱ-1为墨角藻黄素-Chl a／c-蛋白复合物,区带Ⅱ-2为Chl a／c-蛋白复合物,两者都只含20kDa多肽;而鲜绿色的区带Ⅱ-3为不含捕光复合物的活性PSⅡ核心。     

细胞分裂素在果实及种子发育中的作用

就最近几年来细胞分裂素与果实及种子发育的研究进展作简要介绍。     

玉米黄尾球跳甲的发生与防治

调查研究玉米黄尾球跳甲Sphaeroderma apicaleBaly的自然种群动态、自然种群生命表并对其药剂防治策略进行探讨。结果表明:玉米黄尾球跳甲在湖北宜昌1年发生1~2代,以成虫和蛹越冬。越冬代成虫4月中旬始现于田边的杂草,5月上旬迁入大田。百株成虫高峰出现在6月15日和8月7日;性比为0.491;卵始现于5月19日,产卵高峰出现在6月18日;平均卵量123.5粒,单雌最大卵量212粒;6月22日出现最高百株幼虫量。自然种群增长指数(I)为16.20。在发生盛期、高峰期、盛末期,玉米黄尾球跳甲被异角短胸姬小蜂Hemiptarsenus variconisGirault的寄生率分别为14.6,33.6和77.0%。马.辛硫磷1 000倍液和毒死蜱1 000倍液是防治玉米黄尾球跳甲比较理想的农药,校正防治效果分别为76.3%和66.5%;卵和1、2龄幼虫对化学药剂敏感性高,3龄幼虫对化学药剂敏感性低。结合以上的研究,提出玉米黄尾球跳甲的防治策略。     

外源基因转染导致小鼠体细胞过快衰老 及p16INK4a表达水平变化

对小鼠胎儿成纤维细胞进行外源基因转染时发现, 外源基因转染后的小鼠体细胞染色体端粒的长度以每代47 bp碱基缩短; 在转染后的衰老细胞中, 或细胞随着增龄, p16^INK4a 5′-调控区DNA甲基化程度逐渐降低; 利用RT-PCR与Northern blot证明, 衰老细胞与年轻细胞中的p16^INK4a基因的表达水平存在显著差异, 传代45代的细胞和外源基因转染后的衰老细胞p16^INK4a基因的表达水平大约是原代细胞的12~16倍, 而原代细胞与20代细胞间的差异很小。外源基因转染后的衰老细胞核移植后能支持克隆胚胎的体外早期发育。     

栲属(壳斗科)植物的现代和地史分布

根据文献资料和标本馆及化石记录,讨论了壳斗科栲属植物的现代分布和地史分布。现代栲属植物有110～134种,主要分布在东亚及东南亚,其中印度支那地区有82种栲属植物,是世界栲属植物分布最集中的地区,马来西亚地区是栲属特有种最丰富的事实是支持马来西亚地区与其它地区的区系交流十分有限的论据。中国栲属植物最丰富的地区是滇黔桂地区（29种）。栲属植物现代多样化中心在马来西亚和中南半岛。排除Chrysolepis后,栲属的分布类型应属热带亚洲分布。栲属在地质历史上有着比现在广泛的分布,最早、最可靠的栲属化石记录发现于北美始新世地层,欧洲和日本始新世也有栲属的化石记录,化石记录表明栲属起源的时间不晚于古新世,所有的壳斗科及栲属的化石都发现于北半球,现代分布也主要在北半球,壳斗科及栲属起源于北半球可以确认,由于化石证据与现代植物学的研究结果有较大差异以及关键地区化石证据的不足,具体的起源地尚不能肯定。     

松科冷杉属植物的化石历史和现代分布

冷杉是北半球阴暗针叶林的优势种和建群种,现全世界共有52种1亚种12变种,在北半球形成南欧、北美和东亚三个分布中心,这三个地区也是冷杉属化石最丰富的地区。在垂直分布上,冷杉集中分布于1000～2000m（15种）和2500～4000m（13种）两个海拔地段。在中国,冷杉植物呈南北间断分布,集中分布在横断山地区。冷杉属的特有现象和孑遗分布现象都十分突出,有7个种呈孑遗分布。根据冷杉属的地史分布和现代分布的研究并结合最新的系统演化资料,本文推测冷杉属于白垩世中期起源于北半球的中高纬度地区,始新世以后,随着全球气候的变冷,逐步向南迁移,由于喜马拉雅山脉、阿尔卑斯山、落基山脉抬升及东亚季风气候的出现以及第四纪冰期的影响而形成了现代间断的分布格局。冷杉与银杉、金钱松等其它松科植物的形成模式十分相似。