基因多态性与牛疾病相关性的研究进展

基因多态性是指基因组序列上的变异,它是决定家畜对疾病易感性与抵抗力、疾病临床表现多样性以及不同个体对药物反应性的重要因素.研究基因多态性有利于定位和鉴定致病基因和疾病易感基因,使得从遗传学的角度控制疾病成为可能,从而达到减少家畜疾病防治的成本,改良家畜品种,为人类提供健康的动物产品的目的.笔者主要从抗病育种的角度综述了近年来基因多态性与牛疾病易感性和抗性的相关研究,并结合遗传信息学和表观遗传学,阐述家畜疾病控制的新进展.     

Correlation between intraventricular pressure and early phase proto-oncogene expression in volume overload rats

AIM: To investigate the effect of intraventricular pressure change by volume overload (VOL) on expression of proto-oncogene c-fos,c-jun,c-myc and egr-1. METHODS: Left ventricular systolic pressure(LVSP) and left ventricular end diastolic pressure (LVEDP) of rat with VOL induced by aortacaval fistula operation and rats of control group were measured at 30 min, 1, 4, 6, 12 and 48 h after the operation,these mRNAs at the foregoing time points were measured by slot bloting method and quantified with densitometry. RESULTS: Be compared with the control group, VOL rats LVSP decreased (P＜0.05) and declined most remarkably at 48 h,LVEDP elevated significantly at 30 min (P＜0.05), reached a maximal value at 12 h and the levels of control group at 48 h (P＞0.05) after the operation.The proto-oncogene expression signals were not detected in the control,negative controls and VOL rats at 30 min after the operation. The c-fos,c-jun and egr-1 mRNA signals appeared earlier,at 1 h, and c-myc mRNA increased later at 4 h.All reached peak value at 4 h and then declined gradually.The c-fos mRNA were not detected at 48 h. The c-myc,c-0jun and egr-1 mRNA persisted throught the entire observation period from 1 h to 48 h. CONCLUSIONS: During VOL early phase the overload have effect on expression of the proto-oncogene mRNA,c-fos,c-jun and egr-1 mRNA appear earlier, c-myc later,egr-1,c-jun and c-myc persist longer period, but the expressions do not strengthen with the ventricule wall load increase.This sequential induction pattern may reflect the time course regularity of the proto-oncogenes expression induced by VOL,and indicate the proto-oncogenes expression initiate while the heart load accumulate some extent and duration and the load magnitude may not play a critical role.     

Relating tradable credits for biodiversity to sustainability criteria in a dynamic landscape

Tradable biodiversity credit systems provide flexible means to resolve conflicts between development and conservation land-use options for habitats occupied by threatened or endangered species. We describe an approach to incorporate the influence of habitat fragmentation into the conservation value of tradable credits. Habitat fragmentation decreases gene flow, increases rates of genetic drift and inbreeding, and increases probabilities of patch extinction. Importantly, tradable credit systems will change the level of fragmentation over time for small and/or declining populations. We apply landscape equivalency analysis (LEA), a generalizable, landscape-scale accounting system that assigns conservation value to habitat patches based on patch contributions to abundance and genetic variance at landscape scales. By evaluating habitat trades using two models that vary the relationship between dispersal behaviors and landscape patterns, we show that LEA provides a novel method for limiting access to habitat at the landscape-scale, recognizing that the appropriate amount of migration needed to supplement patch recruitment and to offset drift and inbreeding will vary as landscape pattern changes over time. We also found that decisions based on probabilities of persistence alone would ignore changes in migration, genetic drift, and patch extinction that result from habitat trades. The general principle of LEA is that habitat patches traded should make at least equivalent contributions to rates of recruitment and migration estimated at a landscape scale. Traditional approaches for assessing the “take” and “jeopardy” standards under the Endangered Species Act based on changes in abundance and probability of persistence may be inadequate to prevent trades that increase fragmentation.     

白菜型油菜双显性核不育896AB恢复系基因型的鉴定

以白菜型油菜双显性核不育896AB为材料，采用成对兄妹交和相应可育株自交，验证显性不育基因的遗传;用恢复系与全不育系测交，测交一代与临保系复交，验证显性恢复基因的抑制作用，并区分F2代育性分离为3:1和13:3的遗传类型。经4个年度的研究认为，育性是由一对显性不育基因MSMS和一对显性可育基因RfRf互作控制，且显性可育基     

Gene Expression of Enzymes for Starch and Sucrose Metabolism and Transport in Leaf Sheaths of Rice (Oryza sativa L.) during the Heading Period in Relation to the Sink to Source Transition

Abstract

Leaf sheaths of rice plants are known to temporarily accumulate starch prior to heading, which is subsequently remobilized and transported into the panicle after heading. We investigated the time course for both carbohydrate content and steady state mRNA levels of enzymes related to starch and sucrose metabolism in the rice leaf sheath (Oryza sativa L. cv. Nipponbare). Leaf sheaths from the second leaf below the flag leaf accumulated high levels of starch before heading but they rapidly decreased after heading. In contrast, the flag leaf sheath did not accumulate as much starch. In the second leaf sheath, the mRNA levels of enzymes involved in starch synthesis, ADP glucose pyrophosphorylase (EC 2. 7. 7. 27), soluble starch synthase (EC 2. 4. 1.21) and branching enzyme (EC 2. 4. 1. 18) were high before heading, which coincided with rapid accumulation of starch. The mRNA levels of sucrose synthesis enzymes, cytosolic FBPase (EC 3. 1. 3. 11) and sucrose phosphate synthase (EC 2. 4. 1. 14), and the sucrose transporter (OsSUTI) increased at the time of heading, which was largely coincident with a decrease in the mRNA levels of starch synthesis enzymes. In the flag leaf sheaths, changes in mRNA levels of starch synthesis enzymes were not pronounced, however mRNA levels of sucrose synthesis enzymes and the sucrose transporter showed a clear increase throughout the heading period. The different characteristics observed between the two leaf sheaths will be discussed in relation to the sink to source transition.     

Advances in the ABCB4 gene in cholestatic disorders

The ABCB4 gene, also called MDR3, encodes the MDR3 protein which is localized to the hepatocyte canalicular membrane and is demonstrated to be a phosphatidylcholine translocase. The recent study showed that ABCB4 deficiency was associated with several cholestatic disorders, but the pathogenesis is not clear. This review highlights recent advances in the structure and function of ABCB4 gene, and the relationship between ABCB4 gene and cholestatic diseases.     

草莓果实外源基因瞬时表达系统的建立

将东北红豆杉紫杉烷13α-羟基化酶(Taxane13α-hydroxylase,13OH)基因全长cDNA正向插入到pCAMBI-A1304,构建其植物表达载体pCT13OH;将水稻小RNA169d(microRNA169d,miRNA169d)基因前体(precursor)全长DNA正向插入到pCAMBIA1305.1,构建其植物表达载体pCO169d。用电击法把它们导入根癌农杆菌GV3101,获得有关工程菌株。用1mL无菌注射器分别将这2种工程农杆菌悬浮液注射到草莓(Fragaria×ananassa)授粉后1周、2周、3周的果实中,发现授粉后2周果实适宜注射,可用于瞬时表达。对授粉后2周的果实进行不同注射部位、根癌农杆菌不同活化时期和根癌农杆菌悬浮液不同注射量试验,以蒂部注射、根癌农杆菌活化12h和0.5mL悬浮液注射量的效果最好,与结构基因13OH和调节基因miRNA169d相融合的GUS基因都得到表达,瞬时表达成功。     

介绍1个新的短蔓西瓜基因

对在长蔓西瓜材料5-6y中发现的1株短节间突变体的研究显示,其受制于1对隐形基因。这1新的短蔓突变体(系)暂命名为d5-6y,它既不与已知的dw-1和dw-2等位,也无法与dw-3进行测定,建议将这一新的短蔓基因命名为dw-4。     

光核桃AmSO基因初克隆及生物信息学分析

为了初步探索光核桃（Amygdalus mira）亚硫酸盐氧化酶（Sulfite oxidase，SO）的蛋白结构与功能，以1 a生光核桃叶片cDNA为模板，采用分子克隆技术获得光核桃AmSO基因全长为1 182 bp的开放阅读框（ORF），共编码393个氨基酸，相对分子质量是43.45 ku。生物信息学分析结果显示，AmSO蛋白是一种能在细胞核内发挥生物学作用的稳定碱性亲水蛋白，二级结构由无规则卷曲、α-螺旋和延伸链构成。蛋白结构域的预测及氨基酸序列同源性比对发现，编码氨基酸序列的N端具有氧化钼结构域，常存在于氧化还原酶中，可以与钼辅因子结合；在C端具有钼钴（Mo-co）二聚体结构域，该结构域参与二聚体的结合，并且能够参与硫、氮和碳循环中的氧化还原反应，二者在进化过程中高度保守。系统进化树分析表明AmSO与碧桃PpSO亲缘性最近，进化相对保守。对光核桃AmSO蛋白进行生物信息学预测，有助于进一步系统研究光核桃 AmSO基因在生物学上的功能，为进一步了解其对非生物胁迫的响应机制奠定基础。