排序方式： 共有23条查询结果，搜索用时 15 毫秒
1.
单核苷酸多态性（SNP）是指不同个体DNA序列上的单个碱基的差异,是人类基因组中最丰富的遗传变异。单体型是指位于一条染色体上或某一区域的一组相关联的SNP等位基因。研究表明在复杂性疾病研究方面,由多个变异位点组合构成的单体型所携带的信息比单个的SNP数据的信息更有价值,由此衍生了单体型装配问题。文章论述了SNP,单体型,基因型的定义,综述了求解单一个体单体型装配问题的主要模型及算法,同时阐述了求解群体单体型装配问题的5种方法及算法。 相似文献
2.
针对标签SNP选择过程中存在时间复杂度高、重构准确度低以及缺乏生物含义等不足,本文提出了一种基于多位点连锁不平衡的标签SNP选择方法,该方法首先利用最小等位基因频率等指标对数据集进行预处理,排除噪声位点等,然后根据标签SNP选择过程的特点设计并改进了蚁群算法,以获取候选标签子集,最后,为了进一步提高重构准确度,本文以重构准确度为目标,利用支持向量机作为学习模型,采用后向淘汰策略对候选标签子集进行精选。实验结果表明,先过滤再精选的策略,不仅降低了时间复杂度,而且在样本重构准确度也有一定程度优势。 相似文献
3.
MicroRNAs (miRNAs or miRs) are endogenous non-coding RNAs that negatively regulate gene expression by binding to the 3′ non-coding regions of target mRNAs, resulting in their cleavage or blocking their translation. miRNAs may have an impact on cell differentiation, proliferation, and survival, and their deregulation can be inclined to diseases and cancers, including thyroid tumors. The purpose of this review is to summarize the existing findings of deregulated miRNAs in different types of thyroid tumors and to exhibit their potential target genes, especially to demonstrate those involved in tumor invasion and metastasis. In addition, new findings of circulating miRNA expression profiles, single nucleotide polymorphism (SNP) in thyroid tumors, and the correlation of somatic mutations with deregulated miRNA expression in thyroid tumors were all included in this review. 相似文献
4.
5.
Seema P. Todur Tester F. Ashavaid 《Indian journal of clinical biochemistry : IJCB》2013,28(2):116-123
There is an increasing interest to understand the molecular basis of high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) subfractions and their association with coronary artery disease (CAD). The formation of these subfractions is greatly influenced by hepatic lipase (HL) and cholesteryl ester transfer protein (CETP) enzymes. To identify genetic markers influencing LDL and HDL subfractions and their role in CAD we performed a case–control genetic association study on 117 healthy controls and 119 angiographically verified CAD patients. Biochemical analysis was performed using standard assays. HDL-C and LDL-C subfractions were estimated using precipitation methods. Genotyping of C-514T (rs1800588) in the LIPC gene for HL and I405V (rs5882) in the CETP gene was done using PCR-based restriction enzyme analysis and sequencing. Both the polymorphisms were not associated with CAD. The C-514T was associated with increased HDL3-C levels in controls (P = 0.049). The I405V polymorphism was found to be associated with low levels of small dense, LDL (P = 0.038). A multiple regression analysis showed that the effects were dependent on gender and triglyceride levels. We conclude that these polymorphisms are not associated with CAD but are important determinants of HDL-C and small dense LDL particles in our population. 相似文献
6.
以杏花鸡与隐性白洛克鸡为亲本构建的F2代全同胞家系为资源群,分析了鸡1号染色体上一个SNP（rs13651060）的多态性及其与鸡屠体性状的关联性。研究发现,rs13651060的多态性和鸡的腹脂率（%）显著关联。三种基因型的最小二乘均值差异极显著。其加性效应,显性效应,基因的替代效应分别为0.3600、-0.029、0.3654。在10%的水平上,rs13651060的多态性和鸡的腹脂重、脂肪带宽显著关联。rs13651060在鸡脂肪性状的标记辅助选择中可能具有特别的意义,有望对鸡的脂肪性状实现早期选择,缩短世代时间,提高选择强度,并且显著地提高遗传进展。 相似文献
7.
Alex Livy Sayhean Lye Chahil K. Jagdish Nurul Hanis Velapasamy Sharmila Lian Wee Ler Bagali Pramod 《Indian journal of clinical biochemistry : IJCB》2012,27(1):28-33
Buccal cell usage has been shown by many to be a cost effective and safe method to isolate DNA for various biological experiments
especially large epidemiological studies (Garcia-Closas et al. Cancer Epidemiol Biomarkers Prev 10:687–696, 2001). Non-invasive DNA collection methods are preferred over phlebotomy in order to increase study participation and compliance
in research centers and for sick patients in hospital settings. There have been conflicting reports about the methodology
and results obtained from using buccal DNA. It is not very clear if phlebotomy can be confidently replaced by buccal cell
DNA. It is often left for the user to take an intelligent decision. To address this issue, we compared the performance of
buccal and blood DNA from same subjects in a genotyping experiment and this paper reports the results. Cotton swab derived
buccal cells were scraped from the inner side of cheeks from 16 subjects, and blood was also drawn from the same 16 subjects
participating in a genotypic association study of a lipid disease. The DNA quality was assessed by resolving on agarose gels,
checking purity (A260/A280) and finally by microarray hybridization. This study showed that DNA degradation affects the total
yield and performance of the buccal DNA when compared to the blood DNA in microarray based genotyping. Genotyping results
can be seriously compromised if care is not taken to check the quality and yields of such specimens. 相似文献
8.
This paper presents a quick, easy to implement and versatile way of using stochastic simulations to investigate the power and design of using single nucleotide polymorphism (SNP) arrays for genome-wide association studies in farm animals. It illustrates the methodology by discussing a small example where 6 experimental designs are considered to analyse the same resource consisting of 6006 animals with pedigree and phenotypic records: (1) genotyping the 30 most widely used sires in the population and all of their progeny (515 animals in total), (2) genotyping the 100 most widely used sires in the population and all of their progeny (1 102 animals in total), genotyping respectively (3) 515 and (4) 1 102 animals selected randomly or genotyping respectively (5) 515 and (6) 1 102 animals from the tails of the phenotypic distribution. Given the resource at hand, designs where the extreme animals are genotyped perform the best, followed by designs selecting animals at random. Designs where sires and their progeny are genotyped perform the worst, as even genotyping the 100 most widely used sires and their progeny is not as powerful of genotyping 515 extreme animals. 相似文献
9.
10.
张媛华 《渭南师范学院学报》2007,22(2):47-49
研究了硝普纳（Sodium Nitroprusside，SNP）对黄瓜子叶不定根发生的影响．结果表明，SNP促进黄瓜子叶不定根发生的最适浓度和最佳苗龄分别为50μmol／L和3d龄，最适浓度SNP对3d龄黄瓜子叶不定根发生促进效果最好，同时还对子叶近轴面的放置进行了研究，表明子叶近轴面是否向上对生根没有影响． 相似文献