CORRELATED CHARACTERS IN COMPLEX GENETIC SYSTEMS

相关基因变异、选择和进化的分析方法 字符将被开发并应用于不同的感兴趣的系统 给生物学家。具体目标涉及统计的使用 分子多态之间的关联(连锁不平衡) 标记基因和其他基因来解决动植物育种中的问题， 人类遗传学和进化论： (一)提高人工选择的效率 农作物和家养动物的重要经济性状。 这将涉及到最佳选择标准的推导(选择 指数)结合了来自传统表型的信息 测量和来自统计上的分子标记基因座 与重要的数量性状相关。的约束条件 分子标记辅助选择在长期育种计划中的效率将 通过数学和计算机模拟进行分析，包括一个时间 选择的最大反应极限，繁殖的大小 人口，获得分子和表型的相对成本 信息，遗传显性和上位性的影响，以及 种群的交配系统。 (Ii)精细绘制特定基因的图谱，例如那些导致人类 遗传性疾病，形态差异或生殖隔离 在物种之间。方法同时使用来自 将开发多个标记基因座以克服统计限制 以前的方法只利用一到两个连锁不平衡 一次打记分牌。这应该有助于定位特定的基因 对小于1厘米的染色体区域感兴趣，便于 随后通过DNA测序对基因进行鉴定。 (Iii)遗传学在保护生物学中的应用；协会和 分子标记座位、近亲交配基因间的相互作用 抑郁症(如隐性致死突变)和数量性状基因座 将被分析为逐渐或突然 在数量上减少。了解分子遗传学的情况 基因多态与近亲交配抑郁或适应性无关 潜在的(人口灭绝的风险)将有助于减少滥用 保护生物学中的遗传学。

Methods for analyzing variation, selection and evolution of correlated characters will be developed and applied to different systems of interest to biologists. Specific aims involve the utilization of statistical associations (linkage disequilibria) between polymorphisms at molecular marker loci and other genes to solve problems in animal and plant breeding, human genetics, and evolution: (i) Augmenting the efficiency of artificial selection in the improvement of economically important characters of crop plants and domesticated animals. This will involve the derivation of optimal selection criteria (selection indices) incorporating information both from traditional phenotypic measurements and from the molecular marker loci that are statistically associated with important quantitative traits. Constraints on the efficiency of marker-assisted selection in long-term breeding programs will be analyzed mathematically and by computer simulation, including a time limit for the maximum response to selection, the size of the breeding population, the relative cost of obtaining molecular and phenotypic information, the influence of genetic dominance and epistasis, and the mating system of the population. (ii) Fine-scale mapping of particular genes, such as those causing human genetic diseases, and morphological difference or reproductive isolation between species. Methods that simultaneously employ information from multiple marker loci will be developed to overcome statistical limitations of previous methods that utilize linkage disequilibria with only one or two markers at a time. This should help to localize a particular gene of interest to a chromosomal region of less that one centimorgan, facilitating subsequent identification of the gene by DNA sequencing. (iii) Applications of genetics in conservation biology,. Associations and interactions among molecular marker loci, genes contributing to inbreeding depression (e.g. recessive lethal mutations) and quantitative trait loci will be analyzed for populations that have been gradually or suddenly reduced in numbers. Understanding situations in which molecular genetic polymorphism is not correlated with inbreeding depression or adaptive potential (risk of population extinction) will help to curtail the misuse of genetics in conservation biology.