Environmental determination of selective significance or neutrality of amylase variants in Drosophila melanogaster.
Environmental determination of selective significance or neutrality of amylase variants in Drosophila melanogaster.
复制标题
果蝇淀粉酶变体选择性显着性或中性的环境测定。
作者：
De Jong;W. Scharloo
在淀粉酶基因座纯合子的菌株来自黑腹果蝇多态的实验室种群。AMY4，6菌株具有比AMY1菌株更高的酶活性。-麦芽糖与淀粉具有相同的营养价值。-淀粉在纯培养中的效果取决于酵母水平。在低酵母水平下，增加淀粉可以提高存活率，在高酵母水平下，增加淀粉可以增加平均干重。这些菌株在纯培养中的存活率或平均干重没有差异。--在混合培养中，在低酵母水平下，当淀粉4，6和AMY1作为幼虫输入50%时，成虫中淀粉4，6的百分比随着麦芽糖的增加而增加。随着淀粉含量的增加，淀粉4，6的比例增加，这一定是由于在幼虫阶段通过竞争食物而在淀粉酶基因座上进行选择。单基因座选择系数由环境决定，可以达到相当高的值。--在淀粉存在下的生活力选择是按照酶活性指示的方向进行的。
Strains homozygous at the amylase locus were derived from a polymorphic laboratory population of Drosophila melanogaster. The Amy4,6 strain has higher enzyme activity than Amy1 strain.-Maltose has the same nutritional value as starch.- The effect of starch in pure culture depends on the yeast level. At low yeast level increasing starch increases survival, at high yeast level increasing starch increases mean dry weight. The strains do not differ in survival or mean dry weight in pure culture.--In mixed cultures at 50% input of Amy4,6 and Amy1 as larvae the percentage Amy4,6 in adults is present with increasing maltose at low yeast levels in mixed culture. The increase in percentage Amy4,6 with increasing starch must be due to selection on the amylase locus working by competition for food in the larval stage. The single locus selection coefficient is determined by the environment and can reach quite high values.--Viability selection in the presence of starch is in the direction indicated by the enzyme activities.