Ratner V A, Vasil'eva L A
Genetika. 1992 Dec;28(12):5-17.
The MGEs of Drosophila and other objects contain open reading frames (ORFs) encoding transposition enzymes, and "motifs" similar to functional sites: promoters, enhancers, heat shock regulatory sites, those of reception of different stress external signals and hormones, recombination sites, etc. In other words, MGE play a role of "movable cassettes of regulatory elements" in the genomes. The patterns of genome MGE localization are the important components of polygenic systems of character expression, the subjects of variation and evolution. The summed up density of MGE localization along the genome has probably the upper value corresponding to approx. 1 MGE copy per gene. The transpositional variability of MGE patterns could be random, non-random, self-related and inducible. The MGE patterns are important subjects of microevolution and reconstruction of trees of the pattern similarity is an effective method for its description. The patterns could be changed by selection of limited quantitative characters. The stress induction (temperature, treatment, dysgenic cross, etc.) stimulated the MGE transpositions and excisions, mass in population and multiple in individuals. The temperature induction acts probably through the system of response to heat shock treatment. The totality of MGE patterns make up the genomic system capable of quick reorganizations after stress external and genomic influences. The stress external influences are often correlated with passing of the population through the "bottle-neck" stage. The rate of transpositions has an upper limiting border, so named "boundary of regulation error catastrophe", that corresponds to approx. 1 transposition per genome, per generation. After the stress induction of transpositions this boundary could be exceeded, the state of the population norm becoming disrupted. The changes in MGE patterns are also supposed to accompany the changes of characters of isolation, i.e. to accompany the speciation.
果蝇和其他物种的可移动遗传元件（MGEs）包含编码转座酶的开放阅读框（ORFs），以及与功能位点相似的“基序”：启动子、增强子、热休克调节位点、不同应激外部信号和激素的受体位点、重组位点等。换句话说，MGE在基因组中扮演着“调节元件的可移动盒式结构”的角色。基因组MGE定位模式是性状表达多基因系统的重要组成部分，是变异和进化的研究对象。沿基因组的MGE定位总密度可能有一个上限值，大约对应于每个基因1个MGE拷贝。MGE模式的转座变异性可以是随机的、非随机的、自相关的和可诱导的。MGE模式是微观进化的重要研究对象，模式相似性树的重建是描述它的有效方法。这些模式可以通过对有限数量性状的选择而改变。应激诱导（温度、处理、杂种不育杂交等）会刺激MGE的转座和切除，在群体中大量出现且在个体中多次出现。温度诱导可能通过热休克处理的反应系统起作用。MGE模式的总体构成了一个基因组系统，能够在外部应激和基因组影响后快速重组。外部应激影响通常与群体经历“瓶颈”阶段相关。转座率有一个上限边界，即所谓的“调节错误灾难边界”，大约对应于每代每个基因组1次转座。在转座的应激诱导后，这个边界可能会被突破，群体规范状态被破坏。MGE模式的变化也被认为伴随着隔离性状的变化，即伴随着物种形成。
