Molotova-Besedina N G, Iliadi N N, Bragina Iu V, Kamysheva E A, Soboleva S A, Iliadi K G, Kamyshev N G
Genetika. 2009 Jan;45(1):50-8.
The Drosophila mutant P124, carrying insertion of P(lacW) vector in the second chromosome on the background of the w mutation in the X chromosome, was previously isolated as showing memory deficiency after courtship conditioning. Here we report additional features of the mutant phenotype: (1) abnormal adaptation to dark-light transition; (2) impaired perception by males of nuances of visual image of a female, specifically, of her fine movements such as preening and ovipositor extrusion; (3) subnormal performance index after odor-shock conditioning. These abnormalities are not related to a deficit of the eye screening pigments because they are also revealed on the background of the normal w+ allele in the X chromosome. The visual and cognitive impairments are independent pleiotropic effects of the mutation. The mutation is caused by insertion of the P vector 12 nucleotides upstream of the transcription start of the gene Ent2 (equilibrative nucleoside transporter 2). Ent2(P124) is the second mutant allele of this gene found in Drosophila. The genetic variability in Ent2 locus should be considered as a factor of risk for development of mental retardation and disorders of visual perception.
果蝇突变体P124在X染色体上w突变的背景下，其第二条染色体插入了P(lacW)载体，此前被分离出来，因为它在求偶条件反射后表现出记忆缺陷。在此，我们报告该突变体表型的其他特征：(1)对明暗转换的异常适应；(2)雄性对雌性视觉图像细微差别，特别是对其诸如梳理和产卵器伸出等精细动作的感知受损；(3)气味-电击条件反射后的表现指数低于正常水平。这些异常与眼筛选色素缺乏无关，因为在X染色体上正常w+等位基因的背景下也能观察到这些异常。视觉和认知障碍是该突变的独立多效性效应。该突变是由P载体插入Ent2基因（平衡核苷转运体2）转录起始位点上游12个核苷酸处引起的。Ent2(P124)是在果蝇中发现该基因的第二个突变等位基因。Ent2基因座的遗传变异性应被视为智力发育迟缓及视觉感知障碍发生风险的一个因素。
