基于实验的果蝇伴性遗传数学模型

Mathematical Model and Analysis of Sex-linked Inheritance of Drosophila Melanogaster Based on Experiments

以果蝇眼色伴性遗传实验结果为基础,计算了F_2代果蝇中X^W、X^+的基因频率以及X^+X^+、X^+Y和X^WY的基因型频率,并与理论值对比,分析了误差产生的原因。通过概率分析,建立了第n+1代果蝇X^+、X^W基因频率与X^+X^+、X^+X^W和X^WX^W基因型频率的数学模型。应用白眼雌蝇和红眼雌蝇的遗传规律,验证了模型的正确性和可靠性。研究发现,F_(n+1)代果蝇的X^+和X^W基因频率与第三代果蝇的对应基因频率呈线性关系,X^WX^W、X^+X^+和X^+X^W的基因型频率是雌蝇和雄蝇X^+和X^W基因频率的二次函数。算例分析表明,实验误差对后代基因型频率计算有较大影响。

Both the genetic structures and the sex-linked inheritance depend on the genes of sex chromosomes. In this work,the gene frequency of XW,X＋and the genotype frequencies of X^＋X^＋,X^＋Y and X^WY are computed based on the results of sex-linked inheritance experiments of drosophila melanogaster. Comparing with the results obtained by theoretical analysis,we evaluated the errors of experimental results. Mathematical models of X^＋ and X^W gene frequency and X^＋X^＋,X^＋X^W and X^WX^Wgenotype frequencies are set up by applying the probability analysis. The exactitude and reliability are verified by the melanogaster inheritances of female drosophila. It is found that XWand X＋gene frequencies of Fn ＋ 1drosophila are proportional to the homologous gene frequencies of the third generation drosophila. And the X^＋X^＋,X^＋X^W and X^WX^Wgenotype frequencies in the n ＋ 1 generation drosophila are the quadratic functions of X^W and X^＋gene frequencies of F_3 drosophila. The example analysis indicates that experimental errors have dominant influence on the gene and genotype frequencies of drosophila posterity obtained by use of this model.