不同地区及不同季节的柞蚕寄生蝇RAPD分析

利用RAPD技术对不同地区及不同季节发生危害的柞蚕寄生蝇进行了遗传多态性研究。选取11个随机引物对14份供试材料的基因组DNA进行扩增,共扩增出140条稳定条带,其中128(91.43%)条为多态性条带,表明柞蚕饰腹寄蝇(Blepharipa tibialis)、秋柞蚕寄生蝇(未命名)及栗蚕寄生蝇(未命名)间具有丰富的多态性。各材料间的遗传距离在0.0214~0.5143之间,利用UPGMA法进行聚类分析,14份供试材料可聚为两大类:栗蚕(Dic-tyoplocajaponica)寄生蝇与寄生柞蚕的寄生蝇各聚为一类,其中来自河南省的柞蚕饰腹寄蝇自成一类,来自东北地区的柞蚕饰腹寄蝇与秋柞蚕寄生蝇又各自聚为一类。     

Molecular detection and characterization of unclassified bovine enteric caliciviruses in South Korea

The unclassified bovine enteric calicivirus (BEC) is a new bovine enteric calicivirus that is different from bovine norovirus, and causes diarrhea and pathologies in the small intestine of calves. This virus includes Nebraska (NB)- and Newbury agent 1 (NA1)-like strains. The prevalence of this BEC and its genetic characterization has only been reported in the UK and the USA. This study examined the prevalence and genetic diversity of these BECs in diarrheic calves in South Korea. Among a total of 645 diarrheic fecal specimens obtained from 629 cattle herds, these unclassified BECs were detected in 59 (9.1%) diarrheic fecal samples from 57 herds (9.3%) by either RT-PCR or nested PCR. Sequence and phylogenetic analyses of the partial RdRp gene showed that all the Korean BECs clustered together and were closely related to the NB-like viruses (80.9-88.1% nucleotide and 84.5-98.4% amino acid) but not to the NA1-like viruses (75.8-78.4% nucleotide and 79.7-82.8% amino acid). Although these viruses could not be classified into NA1- and NB-like viruses from the sequence and phylogenetic data of the entire capsid gene, all the Korean BECs clustered together on a branch separate from the other known BECs. These results show that these BEC infections are endemic in diarrheic calves in South Korea. The infecting strains are genetically closer to the NB-like viruses but have a distinct evolutionary pathway.     

沂蒙山中华蜜蜂微卫星DNA遗传多样性分析

利用19对微卫星标记对山东省中华蜜蜂群体遗传多样性进行分析,共检测到100个等位基因,等位基因数目从3-9不等。平均等位基因数为5.26;所有位点平均的期望杂合度和PIC值分别为0.6666和0.6136。表明沂蒙山中蜂是多态性丰富的群体。     

中国家鸡和红色原鸡mtDNA控制区遗传多态性及系统进化分析

通过线粒体DNA控制区的结构和多态性来研究中国家鸡和红色原鸡的遗传多态性与系统进化。测定14个中国地方鸡种和红色原鸡2个亚种的256个个体线粒体DNA控制区部分序列约560bp,结果表明,A、C、G、T这4种核苷酸的平均比例分别为25．∞％、37．40％、4．40％和33．20％。共发现44个变异位点,约占分析位点总数的7．86％,没有观测到插入／缺失,颠换和转换之比为0．13;共具有32种单倍型,9种为共享单倍型;16个群体内单倍型多样度从0到0．964,单倍型变异度总体为0．909±0．014,整体的平均核苷酸差异数为7．276,核苷酸多样度为1．851％。群体间核苷酸分歧度（Dxy）在0．747％～3．125％之间变化,核苷酸净遗传距离（Da）为0．015％～2．633％。16个群体表现出较高水平的遗传多态性,群体间表现出显著的遗传分化。群体遗传多态性和亲缘关系分析表明,一些中国家鸡的群体（如固始鸡和仙居鸡）起源于泰国红色原鸡Gallus gallu sgallus亚种,一些中国家鸡的群体（如茶花鸡和藏鸡等）起源于中国红色原鸡Gallus gallus spadiceus亚种,在一些中国地方鸡种还同时具有这2种红色原鸡的遗传贡献;认为中国家鸡起源于泰国或单纯起源于中国的观点都是不全面的。     

柴达木绒山羊八个微卫星位点遗传多样性分析

以柴达木绒山羊为研究对象,对其8个微卫星位点进行遗传多样性分析,计算各位点的等位基因频率(P)、杂合度(H)、多态信息含量(PIC)和有效等位基因数(N)。结果表明:8个微卫星位点在柴达木绒山羊均呈高度的多态性(PIC>0.5);位点LSCV 24基因杂合度、有效等位基因和多态信息含量都最高(H=0.796,N=6.916,PIC=0.766);位点BM 3413的基因杂合度、多态信息含量都最小(H=0.676,PIC=0.615);位点MAF-70的有效等位基因最小(N=0·7672)。因此,柴达木绒山羊群体中遗传背景复杂,遗传多样性较丰富;这8个微卫星位点也可用于柴达木绒山羊羊绒性状的进一步研究。     

退化草地生态修复技术试验研究

采用草地生态学、恢复生态学、农业栽培学、畜牧学等多学科理论,应用宏观与微观相结合的方法,对退化草地的生态修复重建技术进行了系统研究。试验研究结果表明：围栏封育、施肥、松土补播均是退化草地修复的有效措施,封育使草地四度一量分别提高1.97倍、1.18倍、3.31倍、5.11倍、1.85倍;施肥使草产量提高21.62%-80.00%;补播提高5.40%-62.16%,退化草地修复后优良植物群落、营养成份明显提高,植物多样性、丰富度、均匀度明显改善,土壤侵蚀量仅为对照草地的13.46%-33.99%。     

采用PCR-SSCP技术分析蚯蚓粪便的微生物群落结构

通过SDS/蛋白酶的方法抽提蚯蚓粪便微生物总DNA,以总DNA为模板,采用通用引物分别成功扩增细菌16S rRNA基因的V4-V5可变区,真菌18S rRNA基因的V8-V9可变区,应用单链构象多态性技术（SSCP）分析了蚯蚓粪便中不同空间层次的微生物种群的多样性。结果表明,在粪便的不同空间层次上呈现出明显的空间分布多样性,并且与纯蚯蚓粪微生物种群的多样性有很大的差别。为进一步的蚯蚓粪生态学功能研究提供了有益的指导。     

Selection on multiple QTL with control of gene diversity and inbreeding for long-term benefit

The purpose of this study was to develop and investigate selection strategies that aim at maximizing long-term genetic response while conserving gene diversity and controlling inbreeding in populations of limited effective size, assuming complete knowledge of all genes affecting a quantitative trait. Three selection strategies were proposed to select on 100 quantitative trait loci (QTL) and compared with truncation selection on breeding value. Alternative selection strategies aimed at maximizing the average breeding value of parents with a penalty on (1) the number of unfavourable QTL genotypes among parents (OS-I), (2) the negative of the logarithm of the frequency of the favourable allele at each QTL among parents (OS-II), and (3) the average pedigree relationship among parents (OS-III). When all QTL and their effects were known, the strategies examined were able to obtain extra long-term responses, conserve QTL diversity and reduce inbreeding, compared with truncation selection. Strategy OS-II was the most effective in conserving QTL diversity and OS-III in reducing inbreeding. By changing the magnitude of the penalties applied, the impact on long-term response, inbreeding and diversity can be controlled. Extra long-term responses over truncation selection of OS-I and OS-II were even greater when effects of QTL were estimated rather than assumed known, indicating the applicability of results to practical strategies for marker-assisted selection. Extra responses are expected to be reduced for larger population sizes.     

贺兰山地区冬季鸟类物种多样性调查

2006年和2007年的11～12月,采用固定样线统计法连续2 a对贺兰山地区冬季鸟类组成进行了调查。共记录鸟类7目17科72种,约占全国鸟类种数(1 319种)的5.46%,占宁夏鸟类种数(320种)的22.50%。在地理区划上,古北界鸟类61种,占该地区鸟类种数的84.72%;广布种类11种,占15.28%;未观测到东洋界鸟类。其中,留鸟51种,占70.83%;冬候鸟11种,占15.28:旅鸟10种,占13.89%。具有明显集群生活方式的有41种,占56.94%。山地草原带出现的鸟类种类最多,有40种,其次是山地疏林草原带和山地针叶林带,分别有34种和35种,亚高山灌丛和草甸带最少,仅有5种。贺兰山冬季有国家Ⅰ级重点保护野生鸟类3种,有国家Ⅱ级重点保护野生鸟类14种。     

T-RFLP技术及其在动物胃肠道微生物群落多样性研究中的应用

随着分子生物学技术的飞速发展,越来越多的新兴研究手段应用于胃肠道微生态系统的研究之中。介绍了末端限制性片段长度多态性技术(T-RFLP)的基本原理、操作流程和优缺点,并总结了该技术在动物胃肠道微生态研究中的应用现状。