Polymorphism of GDF9 and BMPR1B genes and their association with litter size in Markhoz goats

The main objective of this study was to investigate the polymorphism of GDF9 and BMPR1B genes and their relationship with litter size in Markhoz goats. The polymorphism of GDF9 and BMPR1B genes as well‐documented genes regarding fecundity in sheep and goat was investigated using RFLP‐PCR and a tetra‐primer amplification refractory mutation system‐PCR (T‐ARMS‐PCR) in Markhoz goats. The 164 blood samples were collected from the raised goats in Sanandaj Markhoz goat Performance Testing Station. The DNA extraction was carried out by salting‐out procedure, and then, PCR was performed using four and two pairs of primers to detect polymorphism in GDF9 and BMPR1B genes, respectively. To disclose GDF9 loci polymorphism, PCR products were digested with SspI (G3288A), PvuII (G423A), MvaI (A959C) and MspI (G1189A) restriction enzymes. The results showed that these mutations are available in tested animals. Parity had no significant effect on litter size. Also, the effects of different genotypes of GDF9 and BMPR1B had no significant effect on litter size. Further studies with a high number of animals with minimum relatedness for testing the association of these SNPs and others in the fecundity genes with reproductive traits may be worthwhile.     

Seismic Assessment of RC Frame Structure Based on New Design Codes

The national structural codes GB50010-2002 and GB 50011-2001 have been modified in many aspects compared with the old ones. To verify the effectiveness of structural capacity design provisions in the new codes, firstly, two typical RC frame structures of Grade 2 in intensity-category 8 and Grade 1 in intensity-category 9 are designed according to the new codes. Then, nonlinear dynamic analyses of the two structures are carried out under excitations of several ground motions with the fortification and rare intensity levels. With the analysis results the availability of strong column weak beam is checked carefully, which is desirable with capacity design measures of RC frame in Chinese new structural design code. The conclusions drawn from the analysis are helpful to structural design and local modification of the codes.     

Loop-mediated isothermal amplification: an emerging technology for detection of fish and shellfish pathogens

Fish and shellfish diseases are a constant threat to the sustainability and economic viability of aquaculture. Early diagnosis plays a vital role in management of fish and shellfish diseases. Traditionally, various biochemical and serological tests have been used for fish disease diagnosis. However, the time and expertise required for such diagnoses makes it difficult for aquaculturists to easily adopt them under production conditions. Polymerase chain reaction and probe-based nucleic acid detection have become increasingly popular in fish and shellfish diagnostics. Recently, a novel technique called loop-mediated isothermal amplification (LAMP) has been developed, which is highly sensitive and rapid. LAMP has been used for the detection of bacterial, viral, fungal and parasitic diseases in both animal and plants. In aquaculture, LAMP-based detection of pathogens like Edwardsiella tarda, E. ictaluri, Nocardia seriolae, Tetracapsuloides bryosalmonae, white spot syndrome virus and infectious haematopoietic necrosis virus have been reported. In this review, the application of LAMP for the detection of aquaculture-associated pathogens is discussed.     

苹果RAPD标记的引物筛选与RAPD校正

为筛选适宜苹果的RAPD引物，以苹果富士与舞姿的杂交后代为试材，依据RAPD校正方法、利用引物OPAl3构建了苹果的RAPD校正图谱；在520个RAPD引物中找出了扩增稳定、条带清晰的246个引物，其中扩增条带数在8个以上的有91个引物，可用于苹果的遗传分析。探讨了RAPD-PCR反应条件与RAPD校正的关系，RAPD校正能够提高RAPD-PCR的扩增能力。     

盐芥ThNHX1基因的3′RACE

以盐芥为材料,依据拟南芥AtNHX1基因的序列信息设计引物,扩增出盐芥中ThNHX1基因的部分序列,然后使用快速扩增cDNA3′末端(3′RACE)方法,从盐芥中克隆到ThNHX13′cDNA序列。该序列全长680 bp,编码104个氨基酸,其编码序列、氨基酸序列与拟南芥AtNHX1基因的相应序列同源性分别为91%和91.5%,而盐芥ThNHX1基因3′端非翻译区序列与拟南芥相应序列的同源性为68.5%,明显低于编码区。     

利用小麦SSR标记追踪大赖草染色体Lr.2、Lr.7、Lr.14及其片段

定位于小麦7个部分同源群上的337对SSR引物中有113对SSR引物可检测到大赖草与普通小麦基因组间多态性，对小麦一大赖草Lr．2、Lr．7和Lr.14的异附加系和易位系的进一步分析表明，小麦7BL上的SSR引物gwm112在大赖草染色体Lr．2上具有特异扩增位点，可用来追踪Lr．2；5AS上的SSR引物gwm205、5AL的gwml56和5DL上的gwm212在Lr．7和Lr．14中均有特异扩增产物，可用于追踪Lr．7和Lr．14；而7AL上的SSR引物gwm63仅在大赖草染色体Lr．7上具有扩增位点。这不仅揭示了Lr．7可能存在第5和第7部分同源群染色体重排，而且也表明将引物gwm205、gwm156、gwm212与gwm63相结合可分别追踪大赖草Lr.7和Lr．14染色体及其片段。利用这些SSR引物可追踪同一植株中不同的大赖草染色体；与簇毛麦染色体6V上的SCAR标记相结合，能追踪同一植株中的大赖草和簇毛麦染色体片段。     

魔芋灰霉病病原菌的分子鉴定

[目的]对魔芋灰霉病病原菌进行分子鉴定。[方法]通过提取DNA、PCR扩增、电泳检测以及魔芋灰霉病病原菌rDNA的ITS序列分析。[结果]采用CTAB法得到的DNA产量较高且纯度较好;以其为模板进行PCR扩增,条带清晰;ITS序列测序证实魔芋灰霉病病原菌属于富氏葡萄孢盘菌(Botryotinica fuckeliana),Genbank登陆号KF802809。[结论]该致病菌在魔芋种芋储藏期间和设施繁育过程中危害极为严重,属首次报道,为魔芋灰霉病的防治提供理论依据。     

肠炎沙门氏菌SDA-琼脂糖凝胶电泳检测技术研究

[目的]建立肠炎沙门氏菌的SDA快速检测方法。[方法]根据肠炎沙门氏菌invA基因片段设计链置换扩增(SDA)引物,建立肠炎沙门氏菌的SDA快速检测方法,并对设计的引物的灵敏度和特异性进行研究。[结果]成功建立了肠炎沙门氏菌的SDA快速检测方法,SDA反应成功扩增了目标序列。建立的SDA检测技术对肠炎沙门氏菌的检测灵敏度达到7.0×103cfu/ml,且特异性良好。[结论]试验选取的序列和引物具有较高的特异性,可用于肠炎沙门氏菌的特异性检测。     

基于CODEHOP克隆杉木种子14-3-3基因片段

对于未测序的物种,利用常规的引物设计很难扩增出蛋白质组获得的蛋白质基因。利用CODEHOP设计杉木种子14-3-3蛋白质的简并引物来进行反转录PCR,从杉木未成熟的种子中扩增出1 000 bp左右的产物。将PCR产物构建p MD-19Vector载体上并转化JM109菌感受态细胞中,菌落PCR扩增测序。结果显示,利用CODEHOP方法设计简并引物扩增的目标片段的大小及序列与预期的一致。这将为杉木其他蛋白质基因的克隆和研究提供参考。     

Distribution and biodiversity of soybean rhizobia in the soils of Shennongjia forest reserve,China

Soil samples were collected at an altitude of 500, 1,060, 1,500, 1,950, 2,400 and 3,100 m, respectively, from Shennongjia, a forest reserve in Hubei province (central China). Their corresponding pHs were 5.50, 4.91, 5.64, 5.28, 5.49 and 4.60. By using a plant trap method, a total of 25 soybean rhizobia were isolated from the soil above an altitude of 1,500 m and all identified to be Sinorhizobium fredii. Their genetic biodiversity was characterized by 16S–23S rDNA internally transcribed spacer (ITS) region polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and random amplification DNA (RAPD) analysis. All the tested strains produced a 2.1 kb 16S–23S rDNA ITS fragment. After digestion with three restriction endonucleases (HaeIII, MspI and CfoI), respectively, great variations in 16S–23S rDNA ITS PCR-RFLP patterns were observed. The tested strains could be differentiated into 11 ITS genotypes. The genotypes of rhizobia were not related to geographical location. Twelve primers were applied to RAPD analysis and a dendrogram was obtained, showing that all the strains (including reference strain S. fredii USDA205) were divided into two diverging groups. Moreover, each group could be further divided into two subgroups. Both RAPD and 16S–23S rDNA ITS PCR-RFLP analysis indicated that a high degree of genetic diversity existed among S. fredii strains isolated from Shennongjia virgin soils. Since Shennongjia is an unexploited forest region in central China and the gene centre of soybean is located in China, the symbiotic genes harboured by these strains may be of great importance and the rich diversity of these strains might contribute to the adaptation of soybean to an alpine environment.