mtDNA D-loop of Chinese main indigenous sheep breeds using PCR-RFLP

The polymorphism of mitochondrial DNA (mtD-NA) D-loop of 83 individuals from nine Chinese indigenous sheep breeds and two imported sheep breeds was studied with five endonucleases, Hinf I, Msp I, Sau3 A I, Xsp I and Taq I, using PCR-RFLP. The results indicated that there existed two basic haplotypes in the region of mtDNA D-loop. It could be inferred that Chinese indigenous sheep breeds originated from two maternal ancestors. The average polymorphic degree (π value = 0.0421%) of mtDNA D-loop showed that the genetic diversity of mtDNA of Chinese indigenous sheep breeds was very low. Translated from Hereditas, 2006, 28(2): 165–170 [译自: 遗传]     

用RAPD方法分析六个品种猪的亲缘关系

用１４０个１０碱基随机引物对外来猪种杜洛克猪、斯格猪、长白猪、大约克夏猪及地方猪种蓝塘猪、大花白猪的基因组ＤＮＡ进行ＲＡＰＤ分析，其中２３个引物无扩增产物，６６个引物的扩增产物表现为多态，５１个引物的扩增产物表现为单态，扩增产物的电泳条带数在１～１１条之间，平均为４２条。从相似系数及聚类分析结果可以看出，斯格猪与长白猪、蓝塘猪与大花白猪的相似系数较高，亲缘关系也较近，而２个地方猪种与４个外来猪种之间则相应地较低、较远；在４个外来猪种中，除杜洛克猪外，另３个外来猪种又因曾直接或间接地引用过中国地方猪种作为育种素材，因而表现出与地方猪种相对较近的亲缘关系。     

Effects of livestock breed and grazing intensity on biodiversity and production in grazing systems. 2. Diet selection

Reduction in grazing intensity and the use of traditional instead of commercial breeds have frequently been recommended to meet biodiversity and production goals in sustainable grazing systems. The impact of such practices within a range of contrasting grassland vegetation types was studied. This paper describes the effects on foraging behaviour in a study conducted over three years on mesotrophic or semi-natural grasslands in UK (steers), Germany (steers), France (heifers) and Italy (sheep). Three treatments were performed: (i) a moderate grazing intensity using a commercial breed, (ii) a more lenient grazing intensity with a commercial breed and (iii) a more lenient intensity with a traditional breed. Livestock at all sites preferentially selected bites containing legumes and forbs, and also short rather than tall vegetative patches. Grazing intensity affected not only diet consumed, largely reflecting the different availabilities of dietary components, but also some differences in diet selection. Livestock grazing the more productive mesotrophic grasslands more frequently exploited short patches of higher nutritive value, which is expected to reinforce the spatial heterogeneity of the pastures. Studies in the UK and Germany also revealed that steers showed a more pronounced selection for short patches at the lenient grazing intensity. More homogeneous grazing by livestock on the semi-natural grasslands with fine-scale heterogeneity is likely to decrease their spatial heterogeneity. There were few differences in the choices made by commercial and traditional breed livestock. North Devon steers in the UK expressed a greater selection for tall grass-forb bites than Charolais × Holstein crossbreds, whereas traditional breeds appeared slightly less selective than commercial breeds at the other three sites.     

山东省地方畜禽品种资源的保护与利用研究

山东省地方畜禽品种资源丰富。有地方畜禽品种32个,已对烟台黑猪、莱芜黑猪等5个猪种、鲁西黄牛、德州驴、小尾寒羊、洼地绵羊、黑耳兔等19个畜种资源按照标准进行了主产地、分布区域、群体规模的描述。采集耳组织、血细胞样本800余个,并对这些样本进行了DNA提取和基因组学的分析,初步建立了山东地方家畜遗传资源库。利用地方良种历经10余年已经培育出了鲁烟白猪新品种和鲁农Ⅰ号猪配套系。     

5个猪品种3个拷贝数变异区的多态性分析

为了探究拷贝数变异(copy number variation,CNV)在不同猪品种间的多态性,本试验根据猪SNP60芯片检测结果,以大白猪、香猪、柯乐猪、糯谷猪、荣昌猪为主要研究对象,采用实时荧光定量PCR方法,对5个猪品种基因组中3个CNV区域(CNVR91、CNVR92和CNVR143)的拷贝数进行测定。结果显示,香猪的CNVR91以拷贝数缺失为主,其他4个猪品种的拷贝数以正常为主;香猪、大白猪、柯乐猪、荣昌猪的CNVR92以拷贝数缺失为主,糯谷猪以拷贝数正常为主;香猪和糯谷猪的CNVR143以拷贝数增加为主,其他3个猪品种以拷贝数正常为主。表明3个拷贝数变异区在5个猪品种之间具有多态性,可能通过剂量效应影响香猪、糯谷猪和柯乐猪等相关基因的表达和生理功能。     

3个贵州地方鸡种NKX2-5基因多态性及生物信息学分析

以高脚鸡、威宁鸡、乌蒙乌骨鸡(含白壳蛋鸡和绿壳蛋鸡)3个贵州地方鸡种为研究对象,构建品种DNA池,扩增NKX2-5基因第1外显子全部序列及第2内含子部分序列,采用直接测序法对3个品种(4个群体)的NKX2-5基因进行单核苷酸多态性检测,利用生物信息学软件预测不同多态性位点对NKX2-5基因mRNA二级结构、蛋白质二级结构的影响.结果表明,在3个品种(4个群体)中共检测到G108A、T288C、C400T、T420G和G429A 5个SNPs位点,其中,G108A位于非编码区;T288C、C400T位于第1外显子区;T420G和G429A位于内含子区.T288C和C400T均为错义突变,T288C突变导致丝氨酸(Ser)变为脯氨酸(Pro)、C400T突变导致丙氨酸(Ala)变为缬氨酸(Val),SNPs位点对于NKX2-5基因mRNA二级结构、蛋白质二级结构有一定影响.     

鸡肉品质分析及关键风味物质和基因的筛选

【目的】对不同品种鸡肉中的风味物质和基因进行筛选,为开展品种选育及鸡肉产品的开发利用等研究提供科学依据。【方法】首先对消费者购买肉鸡的主要选择因素进行市场调查。其次分别选取上市日龄的地方品种鸡（文昌鸡、鹿苑鸡）、培育品种鸡（817肉鸡、花山鸡）、引进白羽肉鸡（罗斯308）,每个品种选取接近平均体重的30只鸡（公母各15只）屠宰,屠宰后迅速取两侧胸肌,用于品尝评定、常规肉品质、肌纤维特性、肌苷酸、脂肪酸、氨基酸含量及相关基因表达的测定。最后通过偏最小二乘法（partial least squares,PLS）将品尝评定结果与理化测定结果进行关联分析,挖掘影响品尝评定的风味物质。【结果】（1）风味是消费者购买肉鸡的主要选择因素。文昌鸡肉的甜味、鲜味显著高于罗斯308(P≤0.05)。（2）文昌鸡、鹿苑鸡平均肌纤维面积显著低于其他品种（P≤0.05）,平均肌纤维直径显著低于花山鸡、罗斯308(P≤0.05)。文昌鸡肌苷酸含量显著高于其他品种（P≤0.05）。文昌鸡、鹿苑鸡饱和脂肪酸含量显著高于其他品种（P≤0.05）,罗斯308不饱和脂肪酸含量显著高于文昌鸡、鹿苑鸡、817肉鸡（P≤0.05...     

Genetic diversity of mtDNA D-loop sequences in four native Chinese chicken breeds

1. To explore the genetic diversity of Chinese indigenous chicken breeds, a 585 bp fragment of the mitochondrial DNA (mtDNA) region was sequenced in 102 birds from the Xichuan black-bone chicken, Yunyang black-bone chicken and Lushi chicken. In addition, 30 mtDNA D-loop sequences of Silkie fowls were downloaded from NCBI. The mtDNA D-loop sequence polymorphism and maternal origin of 4 chicken breeds were analysed in this study.

2. The results showed that a total of 33 mutation sites and 28 haplotypes were detected in the 4 chicken breeds. The haplotype diversity and nucleotide diversity of these 4 native breeds were 0.916 ± 0.014 and 0.012 ± 0.002, respectively. Three clusters were formed in 4 Chinese native chickens and 12 reference breeds. Both the Xichuan black-bone chicken and Yunyang black-bone chicken were grouped into one cluster. Four haplogroups (A, B, C and E) emerged in the median-joining network in these breeds.

3. It was concluded that these 4 Chinese chicken breeds had high genetic diversity. The phylogenetic tree and median network profiles showed that Chinese native chickens and its neighbouring countries had at least two maternal origins, one from Yunnan, China and another from Southeast Asia or its surrounding area.