Forsdyke D R
Department of Biochemistry, Queen's University, Kingston, Ontario, Canada.
J Theor Biol. 1996 Feb 21;178(4):405-17. doi: 10.1006/jtbi.1996.0038.
Radio can be used as a metaphor for the transmission of information by DNA through time and space. Just as different radio transmitters broadcast at different wavelengths to prevent interference, so different biological species "broadcast" their DNAs at different (G+C)% "wavelengths" to prevent recombination. It is postulated that species differences in (G+C)% prevent recombination. First, evidence is presented supporting the early Crick-Sobell stem-loop model for genetic recombination, which proposes that the rate-limiting step in recombination is the recognition ("kissing") of complementary sequences in the loops of stem-loop structures extruded from supercoiled DNA. Then, various ways in which differences in (G+C)% might impede complementary loop interactions are outlined. The strength of the postulate is that it brings together a variety of disparate observations in fields that have not previously been seen as related. Thus, explanations are apparent for why most mutations are not selectively neutral (the "neutralist/selectionist" debate), why introns were present in the earliest genes (the "introns-early/introns-late" debate), and the origin of species.
无线电可被用作一个比喻,来描述DNA在时空上传递信息的过程。就如同不同的无线电发射器以不同波长进行广播以防止干扰一样,不同的生物物种也以不同的(G+C)%“波长”“广播”它们的DNA,以防止重组。据推测,(G+C)%的物种差异会阻止重组。首先,给出了支持早期克里克-索贝尔遗传重组茎环模型的证据,该模型提出重组中的限速步骤是超螺旋DNA挤出的茎环结构环中互补序列的识别(“亲吻”)。然后,概述了(G+C)%差异可能阻碍互补环相互作用的各种方式。该假设的优势在于,它将以前未被视为相关领域的各种不同观察结果汇集在一起。因此,对于为什么大多数突变不是选择性中性的(“中性论者/选择论者”之争)、为什么内含子存在于最早的基因中(“内含子早期/内含子晚期”之争)以及物种的起源,都有了明显的解释。