MOLECULAR GENETIC VARIATION IN NATURAL POPULATIONS

在大多数的核苷酸中，有很高的比例，可能是1% 近亲繁殖的生物，包括人类、老鼠和果蝇， 在普通个体中是杂合子。的相对作用 决定这些的突变、迁徙和自然选择 多态现象是群体遗传学中的基本问题。 迁徙与选择在决定性别差异中的作用 酒精中等位酶频率的地理分布 正在对果蝇脱氢酶基因座进行测试 通过比较DNA序列单倍型的分布 许多种群中的变种与几个人预测的 迁移对基因频率影响的理论模型。这个 果蝇白色基因座的分子遗传变异 也进行了非常详细的测量。两人之间的关系 数量和类型(碱基对替换、删除等)的 基因结构和功能的变异是 调查的主要重点。复制品 已知果蝇中的金属硫蛋白基因可以提供 对重金属毒性的抗性。频率和 这些复制的特性与环境的关系 目前正在对重金属水平进行调查。

A high proportion, perhaps 1%, of all nucleotides in most outbreeding organisms, including humans, mice and Drosophila, are heterozygous in an average individual. The relative roles of mutation, migration and natural selection in determining these polymorphisms is the fundamental issue in population genetics. The roles of migration versus selection in determining the geographic cline in allozyme frequencies at the alcohol dehydrogenase locus in Drosophila melanogaster are being tested by comparing the distribution of the DNA sequence haplotype variants in many populations with that predicted by several theoretical models of migration effects on gene frequency. The molecular genetic variation in the white locus in Drosophila has also been measured in great detail. The relationships of the amounts and types (base pair substitutions, deletions, etc.) of variation to the structure and function of the gene are the primary focus of investigation. Duplications of the metallothionein gene in Drosophila are known to afford resistance of heavy metal toxicity. The frequencies and properties of these duplication in relationship to environmental levels of heavy metals are being investigated.