Ratner V A, Vasil'eva L A
Genetika. 1996 Jul;32(7):933-44.
Localization patterns of mobile genetic element (MGE) Dm412 were compared in chromosomes of ten isogenic lines and a heterogeneous control line riC of Drosophila. Isogenization was shown to induce MGE transpositions and excisions. Rates of induced transpositions and excisions were, respectively, 0.35 and 0.13 per site per haploid genome per isogenization, which is significantly (by two to three orders of magnitude) higher than corresponding rates in the control line. These values are also higher by an order of magnitude than previously obtained rates of transposition induction by means of heat shock treatment and gamma-irradiation of isogenic lines. In the average haploid genome of the original line, nc = 22.14 of the occupied Dm412 sites correspond to 11.9 transpositions and 4.6 excisions generated by isogenization. Calculated for the genomic system of copia-like MGE, these rates are approximately 105 and 39 events per approximately 300 initial MGE positions. Apparently, these rates exceed the "catastrophic limit of transpositions and excisions." A hypothesis on the role of inbreeding as genomic stress in induction of transpositions and excisions was proposed. Inbreeding is assumed to increase cell concentration of defective proteins, acting via the system of heat shock response-a general system of cell response to external and physiological stresses.
在果蝇的十个同基因系和一个异质对照系riC的染色体中，比较了移动遗传元件（MGE）Dm412的定位模式。结果表明，同基因化会诱导MGE转座和切除。每个位点每单倍体基因组每次同基因化诱导的转座率和切除率分别为0.35和0.13，这比对照系中的相应比率显著高（两到三个数量级）。这些值也比之前通过对同基因系进行热休克处理和γ射线照射获得的转座诱导率高一个数量级。在原始品系的平均单倍体基因组中，nc = 22.14个被占据的Dm412位点对应于同基因化产生的11.9次转座和4.6次切除。对于类copia MGE的基因组系统计算，这些比率约为每约300个初始MGE位置105次和39次事件。显然，这些比率超过了“转座和切除的灾难性极限”。提出了关于近亲繁殖作为基因组应激在转座和切除诱导中的作用的假说。近亲繁殖被认为会增加缺陷蛋白的细胞浓度，通过热休克反应系统起作用——这是细胞对外部和生理应激的一般反应系统。
