小麦B染色体组双端体旗叶光合能量转换参数的研究

在旗叶一生中,各供试双端体材料叶绿素含量均于叶片全展前后达到最大值,以后呈逐渐降低的趋势。研究表明,染色体臂1BL,2BL,6BL,7BL,2BS和7BS对叶绿素含量有正效应;1BS,3BS,4BS和5BS对其有负效应。光合能量转换参数Hill反应和光合磷酸化活力也随叶片衰老进程逐渐降低,总的来看,染色体臂1BL,7BL,1BS,4BS,5BS和6BS对上述参数有负效应;2BL,6BL,2BS和3BS对其有正效应。各供试材料光合能量转换参数对光合作用的影响主要表现在叶片老化后期。     

猪瘟疫苗研究进展

简要地追求了猪瘟疫苗研究的历史沿革，结合猪瘟病毒基因组图主要囊膜糖蛋白生物学特性，重点介绍了猪瘟新型疫苗的研究现状，并依据现行养猪业猪瘟检疫、防制中存在的种种问题，对猪瘟新型疫苗应用和发展趋势作了初步探讨和展望。     

东乡野生稻核基因组SSLP分析

利用SSLP标记对东乡野生稻进行了多态性分析 ,结果表明 :在 1 4对SSLP标记引物中 ,1 2对引物扩增的产物产生多态 ,总共扩增出了 70条多态性带 ,平均每对引物扩增的多态性带数为 5.83。聚类分析结果表明 :取自同一居群的部分材料遗传差异较小 ,甚至有些材料完全相同 ,但也有些材料遗传差异较大 ,不同程度地分布在各个类群组。这些结果表明“东野”9个居群的天然小群体可能就是一个大的群落。阐述了对“东野”原生地现有居群进行保护的紧迫性。     

利用新的外植体建立棉花高效转化系统的研究

利用陆地棉 (Gossypium hirsutum cv.Cok-er3 1 2和 G.hirsutum.晋棉 7号 ,冀合 3 2 1 ) 8～1 2 d无菌苗侧根 1 0 mm切段作为新的外植体与农杆菌 L BA440 4 p BK9(3 5 s∶∶ LUC∶∶ Nos)共培养将外源基因导入棉花 ,成功的获得转基因工程植株 ,提高了愈伤组织和转基因工程植株的转化效率。 p BK9质粒上携带的萤光素酶基因 [Lucif-erous(lux) ]为报告基因 (reporter gene) ,新霉素磷酸转移酶基因 (npt II)为选择标记基因 (markergene) ,经选择获得的转基因工程植株通过 VedioImage System进行整株活体萤光素酶基因 (lux)活性表达检测 ,获得 To 代和 T1代萤光素酶基因(lux)阳性表达植株。进行 DNA分子杂交 (South-ern blot)分析 ,证明外源基因已经整合到棉花基因组中。转基因工程植株萤光素酶基因 (lux)和新霉素磷酸转移酶基因 (npt II)在自交后代中得到保持 ,外源基因呈核基因单一位点显性遗传。     

家禽基因组研究

本文从方法学和应用效果两方面概要评述了针对家禽(尤其是鸡)的重要经济性状改良的基因组研究,包括基因组分析的内容及其对家禽育种的作用、鸡的基因组概述、鸡的微卫星标记、鸡数量性状位点(QTL)检测检测的试验设计及其研究进展.     

Whole‐genome resequencing to identify candidate genes for the QTL for oleic acid percentage in Japanese Black cattle

In our previous study, we detected a QTL for the oleic acid percentage (C18:1) on BTA9 in Japanese Black cattle through a genome‐wide association study (GWAS). In this study, we performed whole‐genome resequencing on eight animals with higher and lower C18:1 to identify candidate polymorphisms for the QTL. A total of 39,658 polymorphisms were detected in the candidate region, which were narrowed to 1993 polymorphisms within 23 genes based on allele differences between the high and low C18:1 groups. We subsequently selected three candidate genes, that is, CYB5R4, MED23, and VNN1, among the 23 genes based on their function in fatty acid metabolism. In each candidate gene, three SNPs, that is, CYB5R4 c.*349G > T, MED23 c.3700G > A, and VNN1 c.197C > T, were selected as candidate SNPs to verify their effect on C18:1 in a Japanese Black cattle population (n = 889). The statistical analysis showed that these SNPs were significantly associated with C18:1 (p < 0.05), suggesting that they were candidates for the QTL. In conclusion, we successfully narrowed the candidates for the QTL by detecting possible polymorphisms located within the candidate region. It is expected that the responsible polymorphism can be identified by demonstrating their effect on the gene's function.     

3株鸭乙型肝炎病毒全基因组克隆与序列分析

对河南南阳、安徽亳州、湖北潜江三地鸭血清样本用PCR进行鸭乙型肝炎病毒(DHBV)检测,并从三地经检测为DHBV阳性的样本中各挑选1份进行DHBV全基因的扩增、克隆、测序及序列分析。结果显示,河南南阳、安徽亳州、湖北潜江三地的鸭乙型肝炎自然感染率分别为17.6%、13.6%、16.1%,差异不显著(P>0.05)。河南南阳、安徽亳州、湖北潜江3株DHBV基因组全长分别为3024、3027、3024bp,均含有编码P、S和C蛋白的3个开放阅读框。通过各开放阅读框氨基酸同源性比较,发现编码P蛋白的区域差异较大。全基因序列分析显示,3株DHBV核苷酸同源性为95.1%~97.4%,与选取的25株参考株同源性为90.3%~96.2%。遗传进化分析及P蛋白关键位点分析结果表明,3株均为类中国基因型,湖北潜江的DHBV毒株P蛋白3位-345位关键氨基酸残基位点与中国毒株基因型相同,在367位-771位关键氨基酸残基位点与西方毒株基因型相同,推测其产生了重组。结果表明,成功克隆了华中地区的3株鸭DHBV全基因序列,为DHBV的分子流行病学调查提供参考。     

Reinfection with Streptococcus suis analysed by whole genome sequencing

A butcher with chronic dermatitis presented with a second episode of Streptococcus suis meningitis, 8 years after the first episode. To distinguish between reinfection and persistent carriage, we compared the two S. suis isolates using whole genome sequencing. We investigated whole genome sequences of the S. suis isolates by means of substitution rates and population structure of closely related strains in addition to available clinical information. Genome‐wide analyses revealed an inserted region consisting of 12 genes in the first isolate and the calculated substitution rate between the isolates suggested infections were caused by highly similar, but unrelated strains. Continuous occupational exposure likely resulted in reinfection with S. suis in a butcher.     

Genome sequence of an Australian strain of canid alphaherpesvirus 1

Objective

Characterisation of a complete genome sequence of an Australian strain of canid alphaherpesvirus 1 (CHV‐1) and its phylogenetic relationship with other varicellovirus species.

Methods

Standard pathology and PCR methods were used to initially detect herpesvirus in hepatic tissue from an infected 4‐week‐old Labrador Retriever puppy. The complete CHV‐1 genome was sequenced using next‐generation sequencing technology followed by de novo and reference assembly, and genome annotation.

Results

The CHV‐1 genome was 125 kbp in length and contained 74 predicted open reading frames encoding functional proteins, all of which have counterparts in other alphaherpesviruses. Phylogenetic analysis using the DNA polymerase gene revealed that the newly sequenced CHV‐1 clustered with canid alphaherpesvirus isolated from the UK and shared a 99% overall nucleotide sequence similarity.

Conclusion

This is the first complete genome of an Australian strain of CHV‐1, which will contribute to our understanding of the genetics and evolution of herpesvirus.     

Full genome characterization of Iranian H5N8 highly pathogenic avian influenza virus from Hooded Crow (Corvus cornix), 2017: The first report

During 2014–2017 Clade 2.3.4.4 H5N8 highly pathogenic avian influenza viruses (HPAIVs) have spread worldwide. In 2016, an epidemic of HPAIV H5N8 in Iran caused mass deaths among wild birds, and several commercial poultry farms and captive bird holdings were affected and continue to experience problems. Several outbreaks were reported in 2017. One of them is related to Hooded crow (Corvus cornix) in a national park in Esfahan province in 2017. Whole genome sequencing and characterization have been done on the detected H5N8 sample. Based on HA sequencing results, it belongs to 2.3.4.4 clade, and the cleavage site is (PLREKRRKR/G). Phylogenetic analysis of the HA gene showed that the Iran 2017 H5N8 virus clustered within subgroup Russia 2016 2.3.4.4 b of group B in H5 clade 2.3.4.4 HPAIV.On the other hand, the NA gene of the virus is placed in group C of Eurasian lineage. Complete genome characterization of this virus revealed probable reassortment of the virus with East-Asian low-pathogenic influenza viruses. Furthermore, the virus possessed some phenotypic markers related to the increased potential for transmission and pathogenicity to mammals at internal segments. This study is the first full genome characterization H5N8 HPAIV in Iran. The data complete the puzzle of molecular epidemiology of H5N8 HPAIV in Iran and the region. Our study provides evidence for fast and continuing reassortment of H5 clade 2.3.4.4 viruses, that might lead to changes in virus structural and functional characteristics such as the route and method of transmission of the virus and virus infective, pathogenic and zoonotic potential.