POTENTIAL FOR SELECTION AMONG NEARLY NEUTRAL ALLOZYMES OF 6-PHOSPHOGLUCONATE DEHYDROGENASE IN ESCHERICHIA-COLI
POTENTIAL FOR SELECTION AMONG NEARLY NEUTRAL ALLOZYMES OF 6-PHOSPHOGLUCONATE DEHYDROGENASE IN ESCHERICHIA-COLI
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DOI：
10.1073/pnas.78.10.6344
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发表时间：
1981-01-01
期刊：
影响因子：
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通讯作者：
DYKHUIZEN, DE
中科院分区：
文献类型：
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作者：
HARTL, DL;DYKHUIZEN, DE
6个编码天然存在的6-磷酸葡萄糖酸脱氢酶的等位基因[6-磷酸- d -葡萄糖酸：NAD(P)+ 2-氧化还原酶，EC 1.1.1.43]通过转导转移到大肠杆菌K-12的遗传背景中，并检测了它们在葡萄糖酸盐限制的趋化剂中的选择作用。其中4个等位基因明显是中性或接近中性的，因为它们的选择效应（如果有的话）低于该程序的分辨率极限，即0.5%/h或0.75%。1% /的一代。一个等位基因对限制葡萄糖酸盐有害但对限制葡萄糖或果糖无害。另一个等位基因与tonA具有有害的、密度依赖性的上位性相互作用。6个等位基因在自然种群中均为中性或接近中性，但在功能上并不等同；它们的功能差异可能很重要，因为在适当的环境或遗传背景条件下，它们可以表现为适合度的差异。在这些条件下，原本中性的等位基因可能成为选择的对象。
Six gnd alleles coding for naturally occurring allozymes of 6-phosphogluconate dehydrogenase [6-phospho-D-gluconate:NAD(P)+ 2-oxidoreductase, EC 1.1.1.43] were transferred by transduction into the genetic background of E. coli K-12 and examined for their selective effects in chemostats in which gluconate was limiting. Four of the alleles are evidently neutral or nearly neutral, inasmuch as their selective effects, if any, fall below the limit of resolution of the procedure, 0.5%/h or .apprx. 1%/generation. One allele is detrimental in limiting gluconate but not in limiting glucose or fructose. Another allele has a detrimental, density-dependent, epistatic interaction with tonA. All 6 alleles are neutral or nearly neutral in natural populations but they are not functionally equivalent; their functional differences are potentially important because they can become expressed as differences in fitness under the appropriate conditions of environment or genetic background. Under these conditions, otherwise neutral alleles can become subject to selection.