Study On Selection Of Quantitative Trait Determined By Imprinting Major Gene

The genomic imprinting phenomenon is different from the classical Mender's theory. This phenomenon is mainly discussed in this paper. At the beginning, the mechanism of genomic imprinting is illustrated that is due to methylation and demethylation of genetic substance in the copying process of genetic substance, namely, DNA. At the same time, we can regard this imprinting gene as major gene to corresponding trait, and it can control this trait. We analyzed two kinds of situation, that is paternal-imprinting and maternal-imprinting, and researched their different genetic rule in different processes. Here I utilized the method of Monte-Carlo and expressed a kind of trait with a mathematic model, and the phenotypic value is divided into four parts, namely, average value of group, individual breeding value, imprinting effect value and random effect value. My main program was compiled by computer language VBA(Visual Basic for Application), spending about half a year. I designed totally 2400 kinds of parameter aggregates and imitated 1200 processes according to each aggregate including 15 generations. These parameters that are used include heredity, genetic type, initial gene frequency, number of stud retained, proportion of imprinting value occupy trait value. The model program compared the affection of phenotypic value method with BLUP(Best Linear Unbiased Predication) breeding value method and true inbreeding value. The results showed that the phenotypic value method is better than other two methods. After six generations, it was showed that the genetic development appeared fluctuation among three methods, and the BLUP method wasn't good at controlling inbreeding co-efficient.