Fabergé A C
Mol Gen Genet. 1983;192(3):354-60. doi: 10.1007/BF00392174.
It is pointed out that in some species it is very difficult or even apparently impossible to get genetic visible marker mutants by means of ionizing radiation. Such results are not as a rule published. Species in which no mutants at all could be obtained, after what seem to be adequate efforts by several geneticists are Limnaea peregra, Rhynchosciara angelae, Coelopa frigida, Oncopeltus fasciatus, Dermestes maculatus. Published data on Sciara, Tribolium, Blattella, in which a relative difficulty in getting mutants is reported, are discussed and compared to many other forms in which obtaining marker mutants is on the contrary easy. What appears to be very abnormal mutagenesis is described in Drosophila busckii, which yielded an unusual frequency of autosomal dominants, and Drosophila nebulosa, in which only very poor mutants could be obtained. Possible reasons for all these departures from the usual are discussed. No firm conclusions are reached, but one is led to consider the possible effects of overall chromosome structure, presence or absence of heterochromatin, and multiplicity at the single locus or single polytene band level. There seems to be no relation between the rates of induction of dominant lethality and of point mutation for visible markers.
有人指出，在某些物种中，通过电离辐射获得遗传可见标记突变体非常困难，甚至明显不可能。通常情况下，这样的结果不会发表。经过几位遗传学家看似充分的努力后，完全无法获得突变体的物种有静水椎实螺、安琪拉黑腹果蝇、寒栖大蚊、红斑蝽、黄斑皮蠹。文中讨论了关于果蝇、拟谷盗、德国小蠊的已发表数据，这些数据表明获得突变体存在相对困难，并将其与许多其他获得标记突变体反而容易的物种进行了比较。巴氏果蝇出现了异常高频率的常染色体显性突变，星云果蝇只能获得非常少的突变体，文中描述了这两种果蝇中似乎非常异常的诱变情况。讨论了所有这些与通常情况不同的可能原因。虽然没有得出确凿的结论，但促使人们考虑总体染色体结构、异染色质的有无以及单个基因座或单个多线带水平上的多重性可能产生的影响。显性致死率和可见标记点突变的诱导率之间似乎没有关系。
