Parádi E, Vogel E W, Szilágyi E
Mutat Res. 1983 Oct;111(2):145-59. doi: 10.1016/0027-5107(83)90059-3.
The effect of storage on MMS-induced recessive lethals in the zeste-white (3A1-3C2) and the maroon-like (18F4-20F) regions was studied by complementation analysis. (1) Without any exception, all 52 mutants (from unstored spermatozoa) mapped in the zeste-white region were restricted to single complementation units. Furthermore, none of an additional 15 lethals, sampled from sperm that had been stored in females for 9-12 days, was associated with a deletion. (2) Of 34 mutations induced by 8.5 X 10(-2) mM MMS in the maroon-like (mal) region, 4 spanned 2 or more complementation units, and thus are considered to be deletions. A high dose of 2.5 mM MMS provided 55 lethals for analysis of which 4 were deletions. There was no evidence for any difference in the frequency of deletions as the MMS concentration was enhanced from 8.5 X 10(-2) mM to 2.5 mM. However, with storage, 47.1% lethals (16 of 34 mutants induced by 2.5 mM MMS) mapped in the mal region were found to involve large structural changes. (3) A high proportion of double mutants in both the zeste-white (z w) and the maroon-like regions was found among the chromosomes analyzed. These double mutants have one lethal positioned within the region studied and the other outside it. Clearly, the proportion of double mutants increased with dose, from 6.3 to 41.7% in z w and from 14.7 to 61.8% in the mal section. Apurinic sites in DNA reacted with MMS are considered as the likely primary lesions responsible for the storage effect on MMS-induced recessive lethals in the mal region. Thus, the ability of MMS to produce delayed deletion lethals seems to correlate with preference for alkylation of base nitrogens. An interesting aspect for further analysis is the apparent infrequency in the zeste-white region of alkylation-induced chromosomal breakage, as observed by various investigators for MMS, EMS and MNNG.
通过互补分析研究了储存对MMS诱导的位于小体-白色（3A1 - 3C2）和栗色样（18F4 - 20F）区域隐性致死突变的影响。（1）毫无例外，所有52个（来自未储存精子的）定位在小体-白色区域的突变体都局限于单个互补单位。此外，从在雌性体内储存9 - 12天的精子中抽取的另外15个致死突变体，没有一个与缺失相关。（2）在栗色样（mal）区域由8.5×10⁻² mM MMS诱导的34个突变中，4个跨越2个或更多互补单位，因此被认为是缺失。高剂量的2.5 mM MMS产生了55个致死突变体用于分析，其中4个是缺失。没有证据表明随着MMS浓度从8.5×10⁻² mM提高到2.5 mM，缺失频率有任何差异。然而，经过储存后，发现定位在mal区域的47.1%致死突变体（2.5 mM MMS诱导的34个突变体中的16个）涉及大的结构变化。（3）在所分析的染色体中，在小体-白色（zw）和栗色样区域都发现了高比例的双突变体。这些双突变体有一个致死突变位于所研究的区域内，另一个在区域外。显然，双突变体的比例随剂量增加，在zw区域从6.3%增加到41.7%，在mal区域从14.7%增加到61.8%。与MMS反应的DNA中的脱嘌呤位点被认为是对mal区域中MMS诱导的隐性致死突变产生储存效应的可能主要损伤。因此，MMS产生延迟缺失致死突变的能力似乎与碱基氮烷基化的偏好相关。一个值得进一步分析的有趣方面是，正如不同研究者对MMS、EMS和MNNG所观察到的，在小体-白色区域烷基化诱导的染色体断裂明显罕见。
