Estimation of Epistatic Variance Components and Heritability in Founder Populations and Crosses
نویسندگان
چکیده
Genetic association studies have explained only a small proportion of the estimated heritability of complex traits, leaving the remaining heritability "missing." Genetic interactions have been proposed as an explanation for this, because they lead to overestimates of the heritability and are hard to detect. Whether this explanation is true depends on the proportion of variance attributable to genetic interactions, which is difficult to measure in outbred populations. Founder populations exhibit a greater range of kinship than outbred populations, which helps in fitting the epistatic variance. We extend classic theory to founder populations, giving the covariance between individuals due to epistasis of any order. We recover the classic theory as a limit, and we derive a recently proposed estimator of the narrow sense heritability as a corollary. We extend the variance decomposition to include dominance. We show in simulations that it would be possible to estimate the variance from pairwise interactions with samples of a few thousand from strongly bottlenecked human founder populations, and we provide an analytical approximation of the standard error. Applying these methods to 46 traits measured in a yeast (Saccharomyces cerevisiae) cross, we estimate that pairwise interactions explain 10% of the phenotypic variance on average and that third- and higher-order interactions explain 14% of the phenotypic variance on average. We search for third-order interactions, discovering an interaction that is shared between two traits. Our methods will be relevant to future studies of epistatic variance in founder populations and crosses.
منابع مشابه
Estimation of Genetic Components and Inheritance of Bread Wheat Agronomic Traits Using Regression Method Through Generation Mean Analysis
Studying the genetic structure of crops, including wheat, has always been one of the research priorities to increase the efficiency of breeding methods. In order to genetic analysis of some agronomic traits of bread wheat using generation mean analysis (GMA), all produced generations along with relevant parents of the two populations (Marvdasht × Rasoul and Marvdasht × Shahpasand) were evaluate...
متن کاملThe genetic basis of photoperiodism and its evolutionary divergence among populations of the pitcher-plant mosquito, Wyeomyia smithii.
We measured the additive genetic variance within populations and the composite additive, dominance, and epistatic effects contributing to differentiation of photoperiodic response between two southern (ancestral) and each of four progressively more northern (derived) populations of the pitcher-plant mosquito, Wyeomyia smithii. Critical photoperiod and its additive genetic variance but not its h...
متن کاملEstimation of Combining Ability and Gene Effects in Forage Maize (Zea mays L.) Using Line × Tester Crosses
Abstract Determination of gene effects and combining abilities is a critical stage in maize hybrid breeding. In the present study, 20 S6 lines as female and three S6 inbred lines (K18, K19 and K1264/5-1) as tester were crossed and the resulting test cross progenies were evaluated in a randomized complete block design with three replications in 2008. During the growing period, several agronomi...
متن کاملGenetic Analysis of Grain Yield and Yield Components in Bread Wheat using Hayman's Diallel Method
Extended Abstract Introduction and Objective: By progeny trial after a diallel crossing, the function of genes and inheritance of quantitative traits can be estimated. This increases the ability to select parental lines, to participate in crosses, and determines the management of generations in the segregating populations. Material and Methods: In order to understand the genetic structure of ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 198 شماره
صفحات -
تاریخ انتشار 2014