细菌基因型的命名规则

目前分子克隆中常用的大肠杆菌及其遗传标记的命名原则是由著名的美国遗传学家Milislav Demerec及其他几位遗传学泰斗于1966 年发表在《Genetics》的一篇题为“一项关于细菌基因型统一命名法的提议（A proposal for a uniform nomenclature in bacterial genetics.）”的文章中首次系统提出的。

当时提出该项提议的主要目标是：统一；每个菌株有一个唯一的命名；便于拼写、编辑、打印、记录以及信息检索；对于工作在所有生物研究领域的人都能接受、简单、清晰便于容易理解；适用于在可预见的未来的新发展。

该规则的一个背景前提是：除非另外注明，菌株的所有基因都假定处于野生型状态。Demerec在该提议中，总计提出了11项推荐命名规则。

下面对该命名原则进行简要的中英文对照译介：
1. 一种指定的野生型菌株的每一个基因座都由一个三字母、小写、斜体的符号代表。（Each locus of a given wild-type strain is designated by a three-letter, lower-case, italicized symbol。）例如：编码阿拉伯糖代谢相关酶的基因型arabinose用三字母缩写ara表示。

2. 不同的基因座，如果其中任一个基因座发生变异都可以产生相同的表型改变，应该在三字母小写斜体的基因型符号后面紧跟着一个大写的斜体字母以示区分。（Different loci, any one of which may mutate to produce the same gross phenotypic change, are distinguished from each other by adding an italicized capital letter immediately following ihe three-letter lower-case symbol.）例如：arabinose→araA、araB、araD。

3. 对于每一个突变位点，应该在基因座符号后面添加一串唯一的数字来表示（比如araB1、araA2、araC3、araA4、araC5、araB6等）。如果不知道突变具体在调控相关功能的多个基因座中哪一个发生，应该使用连字符“-”来替代表示基因座的那个大写字母（比如trp-31）。（A mutation site should be designated by placing a serial isolation number after the locus symbol. If it is not known in which of several loci governing related functions the mutation has occurred, a hyphen is used instead of the capital letter.）

4. 质粒和附加体应该使用能与基因座明确区分的符号表示（Plasmids and episomes should be designated by symbols which are clearly distinguishable from symbols used for genetic loci.）

5. 质粒和附加体上的突变基因座和突变位点应该与染色体上的基因座和位点使用相同类型的符号表示（Mutant loci and mutational sites on plasmids and episomes should be designated by symbols of the same kind as those used for loci and sites on the chromosome）

6. 在描述携带有一个附加体的菌株时，应该包含一个关于该附加体的状态和/或位置的说明。符号F-，F+，F'以及Hfr应该作为一个特例，只可被用于描述指定性因子的状态，而不能用于表述有关交配行为表型特征的信息。（The description of a strain carrying an episome should include a statement concerning the state and/or location of the episome. The symbols F-, F+, F’, and Hfr should be used only to designate the sex factor states as outlined above, and not to convey information concerning the phenotypic properties of mating activity.）

7. 对于已经发表的以及一些遵循上述推荐的命名系统的基因型符号应该保持不变。而对于不符合上述命名系统规则的基因符号应该进行相应的修正，并且在新的符号首次发布时应该将所做的改动进行标注（Genotype symbols which have already been published and which conform to the system recommended above should not be changed. Genotype symbols which do not conform to the above system should be changed accordingly, and the change should be noted when the new symbol is first published）

8. 表型特征应该用单词进行描述，或者也可以在文章中首次出现时定义一个缩写，其后用缩写进行表示。缩写应该与基因型的符号有明确区分。（Phenotypic traits should be described in words, or by the use of abbreviations which are defined the first time they appear in a given paper. The abbreviations should be clearly distinguishable from genotype symbols.）

9. 菌株应该指定为一个简单的串号。为了避免重复，不同的实验室应该使用不同的字母前缀。菌株名称应该用斜体表示。（Strains should be designated by simple serial numbers. To avoid duplications, different laboratories should use different letter prefixes. Strain designations should not be italicized.）

10. 如果菌株的命名已经被发表，并且符合第9条建议的规则，那么这个命名应该保持不变。命名规则不符合第9条建议的菌株，应该进行相应的改动，并且在新命名首次发表时将改动予以标注。（Strain designations which have already been published and which conform to Recommendation 9 should not be changed. Strain designations which do not conform to Recommendation 9 should be changed accordingly, and the change should be noted when the new designation is first published.）

11. 当一个菌株首次出现在一篇文章中时，应该对其基因型进行描述，并且提供相关的基因型信息。基因型包括所有突变基因座和/或突变位点的列表，附加体和/或质粒的列表，以及每个附加体的状态和定位的有关信息。（When a strain is first mentioned in publication its genotype should be described, and relevant phenotypic information should be given. The genotype includes a list of all mutant loci and/or mutation sites, a list of episomes and/or plasmids, and information concerning the state and location of any episome.）