分子遗传学在动物育种中的应用与前景

分子遗传学是微生物学、遗传学、化学、物理等学科相互交叉、相互渗透的学科。它是依据物理、化学的原理来解释遗传现象，并在分子水平上研究遗传机制及遗传物质对代谢过程的调控。实质上，分子遗传学所研究的是基因的本质及其功能和变化。本文综述了转基因技术、遗传标记、基因图谱的构建、基因图谱与QTL定位及动物基因组分析等在动物育种中的应用，并对其前景进行了展望。     

羟甲基尿素及其在畜牧业中的应用

自 1 939年Ｈａｒｔ等[1] 提出非蛋白氮化合物能够被反刍动物瘤胃微生物利用并转化为机体蛋白以来 ,许多国家都在大力开发非蛋白氮作为反刍动物的蛋白饲料。近年来 ,我国畜牧业发展迅速 ,但因蛋白饲料的不足而限制了进一步的发展和生产效率的提高。尿素已广泛用作非蛋白氮饲料添加剂 ,但其安全性较差。 1 954年 ,Ｇｒｉｂｂｉｎｓ[2 ] 发现尿素与甲醛的缩合物可降低氨的释放速度且无毒性 ,但其溶解度太小 ,动物食用后大部分随粪便排出体外而未被利用。 1 976年 ,Ｈｅｌｇｅｒｓｏｎ[3] 发现在催化剂存在下 ,尿素与甲醛的缩合物除大分子量缩…     

牦牛遗传标记及其在育种中的应用

本文系统地论述了牦牛遗传标记的研究概况及其在育种中的应用。     

Ghrelin在危重病中的应用前景

1977年Bowers等人发现人工合成的脑腓肽蛋白类似物能够促进生长激素（GH）的分泌。随后，人们又相继发现了其他促进生长激素分泌的人工化合物，包括生长激素促分泌蛋白-6（growthhormone—releasing peptide，GHRP-6）、GHRP-1、GHRP-2、伊帕瑞林等蛋白化合物，以及L-692、L-429、MK-0677、NN-703等非蛋白化合物，它们被合称为生长激素促分泌素（growth—hormone secretagogues，GHSs）。     

MLVA和SNP分析在炭疽芽孢杆菌基因分型中的应用

炭疽芽孢杆菌是分子多样性较低的革兰阳性菌,具有高度基因单态性。现有的基因分型方法中仅有少数几种适用于该菌株间的基因分型研究,如多位点可变数串联重复序列分析（multiple locus variable number tandem repeat analysis,MLVA）和单核苷酸多态性（single nucleotide polymorphism,SNP）分析等。该文综述了MLVA法和SNP法在炭疽芽孢杆菌菌株间分型中的应用进展。     

应用寡核苷酸芯片技术检测IGF-Ⅱ基因SNP方法的建立及其在运动能力相关基因研究中的应用

目的 :杰出运动能力受控于基因与环境的相互作用 ,由多基因控制。寡核苷酸芯片技术是近年出现的一类基因结构分析技术 ,此项技术出现使基因突变检测更加程序化和规模化。本研究选取与运动能力有关的胰岛素生长因子Ⅱ (IGF -Ⅱ )基因为该方法学及其应用研究的突破点 ,尝试把DNA芯片技术引入体育科研。方法 :寡核苷酸芯片技术。结果 :(1)IGF -Ⅱ基因SNP的分析中 ,基因组DNA采用 1∶2 0的套式扩增 ,杂交液中加氯化四甲氨 ,杂交温度 4 2℃ ,杂交时间 6 0min效果最好 ;(2 )国家自行车队的 6名队员基因型相同。结果表明 :(1)PCR产物可以直接用于检测突变 ,不对称PCR产物杂交阳性点信号更强 ;(2 )由碱基组成计算的Tm值与其实际的Tm值有一定的差距 ,会影响杂交温度 ;(3)有效的DNA载波片的处理效果直接影响杂交结果 ,是芯片制备中关键环节之一 ;(4)IGF -Ⅱ是研究运动能力相关基因的一个很好的候选基因。     

高新技术在国外畜牧业中的应用

近年来,现代生物技术、遥感技术、激光技术、电子计算机和农用机器人等高新技术,在国外畜牧业中的应用日益广泛,畜牧科学研究取得重大进展。 一、种质资源的开发利用 为了挽救濒临灭绝的稀有动植物品种,充分利用特殊种质,如适应性、多胎性、抗病力等,许多国家建立了家畜和牧草资源保存区、种质资源数据库、动物精子和胚胎库等。采用超低温冷冻精子可达30年,冷冻胚胎保种达7年,低温冷库(-18℃)或液氮保存牧草种子20～30年。为了有效地开发利用     

生物技术在畜牧业中的应用前景

新的生物学部门—生物技术和生物技术的两个主要方向,即基因工程和细胞工程在短短的时间内蓬勃地发展起来了。目前,全世界都在大量研究微生物和动植物的基因。现在已创造出基因组的研究方法、个别基因的鉴定和无性繁殖方法、将基因从一个机体转移到另一个机体的研究方法。越来越多的用大肠杆菌基因工程传统对象所获得的研究结果转移到其它的机体。     

冰草种质在哈萨克斯坦共和国草地畜牧业中的地位及应用

本文对哈萨克斯坦共和国冰草种质资源的生物学特性及其在草地畜牧业中地位与应用进行了阐述。由此认为,冰草品质优良、营养丰富、适口性好、饲用价值颇高;抗逆性及适应性均强、栽培幅度宽、抗旱、耐寒、再生性强、耐践踏、是放牧和割草兼用性优良牧草,很适宜在新疆广大牧区的草原和荒漠地带示范推广种植。应重视对冰草品种的引进和区试。     

高分遥感在新疆草地资源与生态研究中的应用前景

新疆草地分布区域广,不仅是草原畜牧业的主要支撑和丰富的生物基因库,也在维护生态安全,保护绿洲和水源涵养地等方面具有重要的生态作用。高分遥感数据因具有很高的空间、时间、光谱和辐射分辨率,为草地分类、草地估产、草地动态检测、草地病虫害检测、国家重大草地生态建设工程的规划、管理及影响和效益评价、精准草业建设等草地资源与生态研究工作提供了丰富、快速和精确的数据支撑。     

维吾尔族和汉族人群RANTES基因多态性特征及其对HIV-1感染的意义

目的　分析RANTES启动子区等位基因在中国维吾尔族和汉族健康人和HIV 1感染者中的分布特点 ,以期阐明RANTES基因突变型和人类免疫缺陷病毒(HIV 1 )感染在不同民族人群的关系。方法　利用PCR RFLP法对维吾尔族和汉族HIV 1感染者和健康人群的 86 5份样品的RANTES 4 0 3、 2 8等位基因进行检测。结果　两个位点在维吾尔族和汉族人群均有较高的等位基因频率 ,分布基本一致 ;RANTES等位基因具有 6个基因表型 ,分别为AC/AC、AC/AG、AC/GC、AG/GC、GC/GC和AG/AG ;从单倍型看 ,汉族和维吾尔族均以GC为最高 ,占 6 2 7% ,AC分别为 2 8 7%和 30 4 % ,AG分别为 8 6 %和 6 8%。但是从单个位点看 ,HIV感染者和健康人、吸毒者差异均无统计学意义(P >0 0 5 ) ;从基因表型分析 ,与AC/AC比较 ,AC/AG、AC/GC、AG/GC、GC/GC的OR值显示都有不同程度的关联(OR =0 33～0 81 )。结论　汉族和维吾尔族中RANTES启动子区 4 0 3/ 2 8均有较高的突变频率 ;与AC/AC比较 ,AC/AG、AC/GC、AG/GC、GC/GC的OR值显示都有不同程度的保护作用     

Performance of ancestry-informative SNP and microhaplotype markers

The use of microhaplotypes (MHs) for ancestry inference has added to an increasing number of ancestry-informative markers (AIMs) for forensic application that includes autosomal single nucleotide polymorphisms (SNPs) and insertions/deletions (indels). This study compares bi-allelic and tri-allelic SNPs as well as MH markers for their ability to differentiate African, European, South Asian, East Asian, and American population groups from the 1000 Genomes Phase 3 database. A range of well-established metrics were applied to rank each marker according to the population differentiation potential they measured. These comprised: absolute allele frequency differences (δ); Rosenberg’s informativeness for (ancestry) assignment (I_n); the fixation index (F_ST); and the effective number of alleles (A_e). A panel consisting of all three marker types resulted in the lowest mean divergence per population per individual (MDPI = 2.16%) when selected by I_n. However, when marker types were not mixed, MHs were the highest performing markers by most metrics (MDPI < 4%) for differentiation between the five continental populations.     

Extended kinship analysis of historical remains using SNP capture

DNA-assisted identification of historical remains requires the genetic analysis of highly degraded DNA, along with a comparison to DNA from known relatives. This can be achieved by targeting single nucleotide polymorphisms (SNPs) using a hybridization capture and next-generation sequencing approach suitable for degraded skeletal samples. In the present study, two SNP capture panels were designed to target ~ 25,000 (25 K) and ~ 95,000 (95 K) nuclear SNPs, respectively, to enable distant kinship estimation (up to 4th degree relatives). Low-coverage SNP data were successfully recovered from 14 skeletal elements 75 years postmortem using an Illumina MiSeq benchtop sequencer. All samples contained degraded DNA but were of varying quality with mean fragment lengths ranging from 32 bp to 170 bp across the 14 samples. SNP comparison with DNA from known family references was performed in the Parabon Fx Forensic Analysis Platform, which utilizes a likelihood approach for kinship prediction that was optimized for low-coverage sequencing data with cytosine deamination. The 25 K panel produced 15,000 SNPs on average, which allowed for accurate kinship prediction with strong statistical support in 16 of the 21 pairwise comparisons. The 95 K panel increased the average SNPs to 42,000 and resulted in an additional accurate kinship prediction with strong statistical support (17 of 21 pairwise comparisons). This study demonstrates that SNP capture combined with massively parallel sequencing on a benchtop platform can yield sufficient SNP recovery from compromised samples, enabling accurate, extended kinship predictions.     

Development of a SNP set for human identification: A set with high powers of discrimination which yields high genetic information from naturally degraded DNA samples in the Thai population

This study describes the development of a SNP typing system for human identification in the Thai population, in particular for extremely degraded DNA samples. A highly informative SNP marker set for forensic identification was identified, and a multiplex PCR-based Invader assay was developed. Fifty-one highly informative autosomal SNP markers and three sex determination SNP markers were amplified in two multiplex PCR reactions and then detected using Invader assay reactions. The average PCR product size was 71 base pairs. The match probability of the 54-SNP marker set in 124 Thai individuals was 1.48 × 10⁻²¹, higher than that of STR typing, suggesting that this 54-SNP marker set is beneficial for forensic identification in the Thai population. The selected SNP marker set was also evaluated in 90 artificially degraded samples, and in 128 naturally degraded DNA samples from real forensic casework which had shown no profiles or incomplete profiles when examined using a commercial STR typing system. A total of 56 degraded samples (44%) achieved the matching probability (PM) equivalent to STR gold standard analysis (successful genotyping of 44 SNP markers) for human identification. These data indicated that our novel 54-SNP marker set provides a very useful and valuable approach for forensic identification in the Thai population, especially in the case of highly to extremely degraded DNA.In summary, we have developed a set of 54 Thai-specific SNPs for human identification which have higher discrimination power than STR genotyping. The PCRs for these 54 SNP markers were successfully combined into two multiplex reactions and detected with an Invader assay. This novel SNP genotyping system also yields high levels of genetic information from naturally degraded samples, even though there are much more difficult to recover than artificially degraded samples.     

SIRT1基因的rs2273773和rs7895833突变与汉族人群冠状动脉疾病风险相关性分析

目的旨在调查汉族人群冠状动脉疾病患者SIRT1基因rs2273773和rs7895833的单核苷酸多态性。方法共纳入77例冠状动脉疾病患者和80例对照者。所有冠状动脉疾病患者通过血管造影术确诊。通过巢式聚合酶链反应测定SIRT1基因rs2273773和rs7895833多态性的基因分型。结果发现在中国汉族人群中,冠状动脉疾病患者和对照组SIRT1基因rs2273773和rs7895833的基因型频率差异无统计学意义（P>0.05）。本研究人群具有相比于发表的荷兰人群rs7895833的显著不同的等位基因频率。结论SIRT1基因遗传变异体rs2273773和rs7895833与中国汉族人群冠状动脉疾病无关。     

基于Luminex悬浮芯片的鼠疫耶尔森菌SNP分型方法研究

目的利用Luminex悬浮芯片技术,基于单核苷酸多态性（single nucleotide polymorphism,SNP）建立我国鼠疫耶尔森菌东方型菌株（以下简称东方型鼠疫菌）的基因分型方法,为进一步研究东方型鼠疫菌多态性并分析其系统发育关系奠定基础。方法利用多重PCR,同时扩增东方型鼠疫菌中18个具有分型意义的SNP位点,扩增产物进行多重等位基因特异性引物延伸（allele specific primer extension,ASPE）反应以及Luminex悬浮芯片技术分析,随后利用MasterPlex GT V2.3软件计算平均荧光强度（median fluorescence intensity,MFI）比值,判断各SNP位点的碱基状态;并对SNP分型方法的重现性进行评价。结果 Luminex多重SNP技术能够快速、高通量地检测出各SNP位点的MFI值,从而在8 h内一次性成功确定东方型鼠疫菌中18个SNP的碱基状态;36株东方型鼠疫菌基于18个SNP可以分为7个基因型。结论本文建立的Luminex多重SNP检测方法作为一种高通量检测SNP的技术平台,为后期的东方型鼠疫菌SNP分型及系统发育分析奠定了基础。     

Robust detection of individual forensic profiles in DNA mixtures

For a forensic identification method to be admissible in international courts, the probability of false match must be quantified. For comparison of individuals against complex mixtures using a panel of single nucleotide polymorphisms (SNPs), the probability of a random man not excluded, P(RMNE) is one admissible standard. While the P(RMNE) of SNP alleles has been previously studied, it remains to be rigorously defined and calculated for experimentally genotyped mixtures. In this report, exact P(RMNE) values were calculated for a range of complex mixtures, verified with Monte Carlo simulations, and compared alongside experimentally determined detection probabilities.     

白细胞介素6基因多态性与河南地区汉族人群脓毒症的关系

目的 探讨白细胞介素6(IL-6)基因-572G/C和-174C/G多态性与中国河南地区汉族人群脓毒症的关系.方法 以人群为基础进行脓毒症病例对照研究,应用PCR-RFLP技术对99例脓毒症患者和260例正常对照的IL-6基因-572C/G和-174G/C多态性进行分析.结果 所有病例和对照基因型分布符合Hardy-W...