Boussy I A, Itoh M, Rand D, Woodruff R C
Dept. of Biology, Loyola University of Chicago, Illinois 60626, USA.
Genetica. 1998;104(1):45-57. doi: 10.1023/a:1003469131647.
The latitudinal cline in P transposable element-associated characteristics in eastern Australian populations of Drosophila melanogaster has changed between 1986 and 1991-1994. New collections were made in 1991-1994 from localities along the eastern coast of Australia. P element-associated properties of 256 isofemale lines from 43 localities were evaluated using gonadal dysgenesis and/or singed-weak hypermutability assays. The overall results indicate that both P activity and P susceptibility have declined, with all populations showing a tendency towards a state with little P activity potential but with P repressor function (neutral or 'Q'). P repressor function is strong in all populations except some of the most southernly. P activity potential peaks at about 27 degrees SLat, and drops off to the south (as in 1983-1986 collections) and to the north (in contrast to 1983-1986 collections); thus the cline is no longer a simple P-to-Q-to-M pattern from north to south, but is now Q-P-Q-M. A mtDNA RFLP that putatively distinguishes North American and European populations varies in frequency among the populations but the frequency does not vary clinically with latitude, ruling out massive introductions from North America and Europe as causing the cline.
1986年至1991 - 1994年间，澳大利亚东部黑腹果蝇种群中与P转座因子相关的特征的纬度渐变发生了变化。1991 - 1994年从澳大利亚东海岸各地进行了新的样本采集。使用性腺发育不全和/或焦刚毛弱超突变检测评估了来自43个地点的256个同雌系的P因子相关特性。总体结果表明，P活性和P易感性均有所下降，所有种群都呈现出一种P活性潜力低但具有P抑制功能（中性或“Q”）的状态趋势。除了最南端的一些种群外，P抑制功能在所有种群中都很强。P活性潜力在南纬约27度处达到峰值，然后向南（如1983 - 1986年的样本）和向北（与1983 - 1986年的样本相反）下降；因此，渐变不再是从北到南简单的P - Q - M模式，而是现在的Q - P - Q - M模式。一种推测可区分北美和欧洲种群的线粒体DNA限制性片段长度多态性在种群间频率有所不同，但该频率在临床上并不随纬度变化，排除了来自北美和欧洲的大量引入导致这种渐变的可能性。
