Importance of over-dominance as the genetic basis of heterosis in rice

In populations derived from commercial hybrid rice combination Shanyou 10, F₁ heterosis and F₂ inbreeding depression were observed on grain yield (GYD) and number of panicles (NP). Using marker loci evenly distributed on the linkage map as fixing factors, the F₂ population was divided into sub-populations. In a large number of sub-populations, significant correlations were observed between heterozygosity and GYD, and between heterozygosity and NP. This was especially true in type III sub-populations in which the genotype of a fixing factor was heterozygotes. In type III sub-populations, 15 QTL for GYD and 13 QTL for NP were detected, of which the majority exhibited over-dominance effects for increasing the trait values. This study showed that over-dominance played an important role in the genetic control of heterosis in rice.     

Cloning, mapping and mutation analysis of human gene GJB5 encoding gap junction protein b-5

By homologous EST searching and nested PCR a new human gene GJB5encoding gap junction protein b-5 was identified. GJB5 was genetically mapped to human chromosome 1p33-p35 by FISH. RT-PCR revealed that it was expressed in skin, placenta and fetal skin. DNA sequencing of GJB5 was carried out in 142 patients with sensorineural hearing impairment and probands of 36 families with genetic diseases, including erythrokeratodermia (5 families), Charcot-Marie-Tooth disease (13), ptosis (4), and retinitis pigmentosa and deafness (14). Two missense mutations (686A→G, H229R; 25C→T, L9F) were detected in two sensorineural hearing impairment families. A heterologous deletion of 18 bp within intron was found in 3 families with heredity hearing impairment, and in one of the 3 families, a missense mutation (R265P) was identified also. But the deletion and missense mutation seemed not segregating with hearing impairment in the family. No abnormal mRNA or mRNA expression was detected in deletion carriers by RT-PCR analysis in skin tissue. Mutation analysis in 199 unaffected individuals revealed that two of them were carriers with the same 18 bp deletion.     

角质酶在生物可降解聚酯聚己二酸/对苯二甲酸丁二醇酯降解中的应用

随着废弃塑料带来的环境污染越来越严重,生物可降解聚酯已成为大众关注的焦点。聚己二酸/对苯二甲酸丁二醇酯[poly(butylene adipate-co-terephthalate),PBAT]是脂肪族和芳香族共聚形成的生物可降解聚酯,兼具两者的优异性能。针对PBAT在自然条件下对降解环境要求严格且降解周期长的不足之处,本研究探究了角质酶在PBAT降解中的应用和对苯二甲酸-丁二醇酯(butylene terephthalate,BT)含量对PBAT生物降解性的影响,以实现对PBAT降解速率的提升。选取5种不同来源的聚酯降解酶对PBAT进行降解应用并比较出降解效果最优的酶,并测定了含有不同BT含量的PBAT聚酯的降解效率。结果表明,角质酶ICCG为降解效果最好的酶,且BT含量越高PBAT的降解率越低。此外,还确定了角质酶ICCG对高BT含量的PBAT(H)降解的最适温度、最适缓冲液类型、最适pH、最适E/S(enzyme to substrate)和最适底物浓度比分别为75℃、Tris-HCl、9.0、0.4%和1.0%。本研究结果可为角质酶在PBAT降解中的应用提供一定的理论依据和实验...     

雌二醇对成年大鼠肺表面活性物质分泌的影响

采用离体非灌流肺模型,观察了雌二醇(E_2)对成年大鼠肺表面活性物质(PS)分泌的影响,并探讨了前列腺素(PG)在其中的作用。结果显示:E_2(10~(-6)mol/L)可使肺磷脂释放指数和肺磷脂释放量增多,分别为对照组的150.0％(P<0.05)及160.7％(P<0.01),表明E_2可促进成年大鼠PS的分泌;PG合成抑制剂消炎痛(10~(-5)mol/L)可以抑制E_2促进肺磷脂释放的效应,表明PG在E_2促进PS分泌中起介导作用。以上结果提示E_2可能参与成年动物PS分泌的调控。     

无前恙螨属二新种(蜱螨目:恙螨科)

本描述了采自江苏黑线姬鼠体上的无前恙螨属二新种,即长盾无前恙螨Walchia(Walchia)longiscuta Xia et Chen,sp．nov．和孟氏无前恙螨Walchia(Walchia)meni Xiaet Chen,sp．nov．。模式标本保存于复旦大学上海医学院寄生虫学教研室。     

武汉大学校园流浪猫行为生态学初步研究

随着宠物猫在人们生活中越来越普及,流浪猫的问题也日渐突显;它们可能携带多种人畜共患寄生虫,对本地生态系统造成干扰,并带来公共安全隐患。因此,开展流浪猫的调查,并制定相应的管理措施,对于缓解这一问题显得尤为重要。2021年9月——2022年12月,采用样线法对武汉大学校园地区流浪猫进行了种群调查,根据重捕法及其模型估算种群规模;通过定位项圈跟踪20只流浪猫,确定它们的家域范围;基于流浪猫的社交亲人行为等级,对流浪猫的行为差异进行了分析。结果显示,武汉大学的流浪猫密度约为1只/hm²,绝育率较低,校园流浪猫的家域范围为(4.99±0.84)hm²;校园流浪猫85%的时间都在喂食点半径100 m以内活动,且喂食点密度越高,流浪猫的活动范围越小;在不同性别上,雄性流浪猫的活动范围大于雌性,而绝育与否不影响其活动范围;在社交亲人行为方面,校园流浪猫社交亲人性高于一般的流浪猫,即分布在城市和乡村中的流浪猫,随着喂食点密度增加,其社交亲人等级随之升高。研究表明,武汉大学校园流浪猫数量较多,绝育率低,家域范围小,且主要分布在喂食点附近。此外,喂食点密度对流浪...     

抗虫耐除草剂玉米GH5112E-117C定性PCR检测方法

转基因抗虫耐除草剂玉米GH5112E-117C是由北京奥瑞金公司研发的转mG2-aroA基因和mcry1Ah基因抗虫耐除草剂玉米新品系,对玉米螟、粘虫等鳞翅目害虫具有抗性、耐草甘膦除草剂的转基因玉米,在我国具有重要产业化应用前景。本文研发了GH5112E-117C转基因玉米的定性PCR检测方法,该方法能特异性地检测转基因抗虫耐除草剂玉米GH5112E-117C,在每个反应引物浓度为0.2 μmol/L、Taq DNA 聚合酶0.625 U、DNA模板50 ng,退火温度为58℃的条件下,检测灵敏度可稳定达到0.1%。该方法为转基因抗虫耐除草剂玉米GH5112E-117C的精准检测提供了一种新的技术手段,为农业转基因监管提供技术支撑。     

Study of the interaction of sulfur dioxide derivative with cardiac sodium channel

The effects of sulfur dioxide (SO(2)) derivatives (bisulfite and sulfite, 1:3 M/M) on voltage-dependent sodium channel in isolated rat ventricular myocyte were studied using the whole cell patch-clamp technique. SO(2) derivatives increased sodium current (I(Na)) in a concentration-dependent manner. SO(2) derivatives at 10 microM significantly shifted steady-state inactivation curve of I(Na) to more positive potentials, but did not affect the activation curve. SO(2) derivatives markedly shifted the curve of time-dependent recovery of I(Na) from inactivation to the left, and accelerated the recovery of I(Na). SO(2) derivatives also significantly shortened the activation and inactivation time constants of I(Na). These results indicated that SO(2) derivatives produced concentration-dependent stimulation of cardiac sodium channels, which due mainly to the interaction of the drug with sodium channels in the inactivated state.     

老虎感染猫传染性鼻—结膜炎病毒的研究

用猫肾传代细胞从发病虎的病料中分到了一株杯状病毒粒子样病毒。该病毒大小为３５～３９ｎｍ、无囊膜、在胞浆中病毒前体呈晶格状排列,抗乙醚、不能被５－ＩＵＤＲ所抑制,能被来源于标准疫苗的猫传染性鼻－结膜炎病毒（或杯状病毒Ｆｅｌｉｎｅ ｃａｌｉｃｉｖｉｒｕｓ,ＦＣＶ）抗血清所中和,人工感染猫出现典型的ＦＣＶ感染症状。ＲＴ－ＰＣＲ能扩增出与设计值相符的电泳带,ＰＣＲ产物直接测序结果与Ｇｅｎｅｂａｎｋ发表的Ｆ     

pLNCX-pemt2重组载体的构建及pemt2基因在大鼠肝癌CBRH-7919细胞中的表达

为进一步研究 pemt2对肝癌细胞生长抑制的作用机制提供方便的实验模型 ,构建了p LNCX- pemt2重组体 .将目的基因 pemt2连接入含有 neo抗性基因的真核细胞表达载体 p LNCX中 ,构建 p LNCX- pemt2重组子 ,并用磷酸钙沉淀法将其转入大鼠肝癌 CBRH- 791 9细胞中 ,应用PCR、Western印迹及 [3 H]SAM参入等技术对其转染、表达及活性进行鉴定 .转染 p LNCX- pemt2的大鼠肝癌细胞 ,PEMT2成功表达 (分子量为 2 2 .5k D) ;高表达克隆 PEMT2的表达量比对照组高约 5倍 ,其活性比对照组高 2 .1倍 ;细胞生长的倍增时间从 2 1 .54± 7.0 8h延长到 43.2 2± 7.1 1h.结果表明 ,p LNCX- pemt2重组体转入肝癌细胞后 ,PEMT2蛋白得到高效表达 ,明显抑制肝癌细胞生长 .