Estimation of the carcass composition from a cross-section of the rib-loin from crossbred Japanese Black × Limousin F2 cattle by computer image analysis

The carcass composition of crossbred Japanese Black × Limousin F2 cattle was examined in order to find an accurate carcass composition equation. The test animals included 17 steers and 17 heifers. The 28 image measurements from the area encircling the vertical line to the thoracic vertebra and the line from the thoracic vertebra between the sixth and seventh rib‐bones were measured by computer image analysis. The relationships between the 29 parameters that added the carcass left side weight of the animal and the carcass composition were suggested. The carcass composition included muscle weight, muscle ratio, fat weight and fat ratio. The carcass composition from steers was estimated by an equation composed of these three or four parameters (R² = 90.80%, 79.30%, 90.75% and 73.70%, respectively). The selected parameters were measured without cutting the thoracic vertebra. The carcass composition from heifers was estimated by an equation composed of two to four parameters (R² = 96.15%, 90.98%, 93.60% and 88.22%, respectively). The parameters for the estimation of the muscle and fat weight, and muscle and fat ratio are very similar. Furthermore, the equations using the parameters could estimate the carcass composition from the Japanese Black × Limousin cattle resource population.     

Evaluation of association between polymorphism within the thyroglobulin gene and milk production traits in dairy cattle

In dairy cattle, many studies have reported quantitative trait loci (QTL) on the centromeric end of chromosome 14 that affect milk production traits. One of the candidate genes in this QTL region – thyroglobulin (TG) – was previously found to be significantly associated with marbling in beef cattle. Thus, based on QTL studies in dairy cattle and because of possible effects of this gene on fat metabolism, we investigated the association of TG with milk yield and composition in Holstein dairy cattle. A total of 1279 bulls from the Cooperative Dairy DNA Repository Holstein population were genotyped for a single nucleotide polymorphism in TG used previously in beef cattle studies. Analysis of 29 sire families showed no significant association between TG variants and milk production traits. Within‐sire family analysis suggests that TG is neither the responsible gene nor a genetic marker in association with milk production traits.     

Genome-wide Association Study on Alive Litter Size Trait in Bama Xiang Pigs

In order to identify the molecular markers related to alive litter size of Bama Xiang pigs,the genome-wide association study (GWAS) was used to map and screen the candidate genes affecting the alive litter size trait.Ear tissue samples of 297 Bama Xiang pigs with multiple parity records were collected,and DNA was extracted and genotyped by porcine 50K SNP beadchip.After quality control and genotype imputation,the alive litter size of Bama Xiang pigs were GWAS by Tassel.The results showed that the average number born alive per litter of Bama Xiang pigs increased gradually with the increasing of parity in the range of 1-9 parities.A total of 32 816 SNPs were obtained after quality control and filtration.8 SNPs related to alive litter size of Bama Xiang pigs were screened by genome-wide association analysis,which were significant at genome or chromosome level.Based on the enrichment analysis of the coding genes in the region between 500 kb upstream and downstream of the associated significant SNP loci,and the QTL regions and gene functions related to porcine reproductive traits,4 genes (CAPZB,MSH3,CITED2 and HSD17B7) were finally identified to be candidate genes related to alive litter size of Bama Xiang pigs.     

抗盐酸克伦特罗单链抗体基因的克隆、序列分析及表达

提取分泌抗盐酸克伦特罗单克隆抗体杂交瘤细胞株的总RNA,通过RT-PCR技术,扩增VH和VL,用一段柔性肽链-(G4S)3将VH和VL连接成ScFv。测序后经NCBI Blast分析,所得ScFv具有重组功能性鼠抗体可变区基因的特征。将所得目的基因与pET-22b( )连接,转化E.coli BL21,用IPTG诱导表达,表达蛋白经SDS-PAGE分析,37℃培养5 h表达量较大,25℃诱导表达以可溶性为主。     

基因芯片及其在病原微生物检测中的应用

基因芯片是近年来迅速发展的一门生物高新技术,它以其能够快速、高效、大规模地同步检测生物遗传信息的卓越功能而得到发展。在基因测序、基因表达分析、药物筛选、基因诊断等领域显示出重要的理论和实用价值。作者就基因芯片技术的原理、技术要点以及在病原微生物检测中的应用作一综述。     

应用基因芯片检测动物性食品中主要致病菌

依据16SrDNA、23SrDNA上的恒定区和可变区设计7种致病菌的通用引物和特异性寡核苷酸探针，并对探针5’端进行氨基化修饰进行基因芯片共价结合，然后优化杂交反应液、芯片点样及后处理程序，研制出一种可同时检测动物性食品中7种主要致病菌的基因芯片。结果表明，7种致病菌的基因芯片杂交检测灵敏度可达10^2cfu／g，与经典传统检测方法及分子生物学、免疫学方法相比该方法特异性强，准确率高，可同时检测动物性食品中7种致病菌。     

鸭生长激素(GH)基因编码区及调控区多态性分析

根据鸭生长激素基因编码区及调控区的序列设计8对引物,利用PCR-SSCP方法对北京鸭、西湖野鸭、樱桃谷鸭、金定鸭、山麻鸭、荆江鸭、绍兴鸭、缙云麻鸭等8个鸭种进行单核苷酸多态性分析。结果共发现3个突变位点,分别为230处（C→G）、244处（C→A）和3 701处（C→T）。前两处突变位于5′调控区,3 701处突变位于编码区第4外显子,但该编码区的突变是沉默突变,3′调控区表现了高度的保守性。统计结果发现：⑴在5′调控区基因座上,金定鸭的等位基因B频率显著高于其他品种;⑵在外显子4基因座上,基因型频率的分布与品种有关,且肉用型鸭的CC基因型频率显著高于蛋用型。可以推测,本研究所检测到的基因座可能与生产性能相关。     

感染鸡日龄对球虫单卵囊分离的影响

选用5、8、11日龄的雏鸡进行鸡球虫单卵囊分离试验,研究不同感染日龄对鸡球虫单卵囊分离的影响。结果表明:在其他条件一致的情况下,从感染成功率、潜伏期、高峰期的出现时间及持续时间和从每只感染雏鸡收集到的球虫卵囊数量等指标进行综合判定,发现感染11日龄的雏鸡单卵囊分离成功率最高。     

基因芯片在百合无症病毒检测中的应用

设计百合无症病毒、植物18SrRNA基因的特异扩增引物和各种对照的探针，将探针固定在醛基化玻璃片基上，完成植物基因芯片制备。提取百合种球总RNA，经RT-PCR扩增相应区段并用Cy3dCTP进行标记，用标记的PCR产物与芯片杂交，扫描仪对杂交结果进行扫描，GenePixProd．0软件对杂交图像进行分析。结果从荷兰进口的百合种球中检测出百合无症病毒，证明了该实验研制的植物病毒基因芯片的准确性和灵敏性。     

水处理设备的单片微机控制器

介绍了用 89C2 0 51单片机系统对水处理设备工作的控制 ,使水处理设备能全面、可靠、无人值守地工作 ,达到智能的档次 .文中描述了水处理设备控制器的软件设计和硬件设计