BGN 2: Remarks to the proposals and comments on genetic symbolization, etc. in BGN, Vol. 1 BARLEY GENETICS NEWSLETTER, VOL. 2, I. SPECIAL NOTICES
Scholz, pp. 5-8

I.10. Remarks to the proposals and comments on genetic symbolization, etc. in BGN, Vol. 1.

The following remarks are in the order of your Proposals:

(1) No comment.

(2) 1. I agree with Hagberg and von Wettsetin to consider English and Latin (inclusive Latinized Greek) as languages of high internationality. It would be highly unreasonable to change, e.g., albina, agropyroides, chlorina, deficiens, eceriferum, erectoides, virescens, xantha. The use of Latin should be possible also in the future. Also your suggestion to symbolize genes for disease resistance by the Latin genus and species names of the parasite supports this opinion.

    2. Symbols should primarily be as short as possible. Therefore, triple letters for new symbols should not be obligatory but may be used if appropriate and wanted by the author.

    3. I can not find the case cited by H. & W. to be a weighty argument against your proposal. With pleiotropic effects, the most striking character should be considered for the decision on dominance or recessivity, e.g. the dense spike in erectoides mutants; in some cases this decision must necessarily be rather arbitrary, of course.

The changing use of capital resp. small letters, just as the special case of segregation may be, should not be admitted. Each allele should be given a definitive symbol.

I plead for your suggestion that the capital letter symbol should be used to designate the phenotype of the original variety, if genes exhibit clearly incomplete dominance. This is, however, practicable with mutants only; in other cases, where no original variety or the like can be fixed, the decision may be rather arbitrary.

    4. All letters and numbers should be written on one line. Superscripts and subscripts should not be used, since they are troublesome not only in programming some types of computers, but also in good old typewriting and printing.

    5. Before designating wild type alleles one has to know what the wild type is. It is easy, of course, with mutants. But what to do with V/Vt/Vd/v!, Ddt/ddt, Bt/bt, Ea/ea, S/s, Sh/sh, and the many resistant/susceptibility genes. Therefore, we need as a prerequisite the agreement on a definitive wild type, which perhaps would be desirable though not easy.

    6. The proposal of H. & W. to accept both systems should, in my opinion, be followed. Of course, your proposal for the purpose of standardization is indeed absolutely evident, especially since the former Ml-a etc. symbols are now being changed (first to Pml etc., now obviously to Egl etc.). However, I comprehend when the Swedish group defends against the resymbolization of their truly numerous mutants, especially as their system also conforms to the general international rules. Therefore, one should make the special concession to them to retain their system. This seems to be the only practicable compromise.

However, in order to make the two systems as similar as possible I would like to suggest to use neither superscripts nor subscripts on the one side and to use a hyphen between the basic symbol and the special locus number or letter, resp., on the other side, e.g.:

Ms2, Eg-ld etc.  or ert-r52 etc.

(ms-2 and Egld is a discussible alternative, but not ertr52.) The willingness for these little changes may be expected of all colleagues, I believe.

    7. No definite opinion. I doubt whether the objection by H. & W. is heavy, because the use of a slash (/) between the symbols i, su or en, resp., and the basic character symbol would hardly give rise to confusion with a fraction in a genic formula.

    8. through 13. No comments.

    14. It seems to me to be a little odd to designate extra-chromosomal factors by Ec/ (or Ec-), in the same way like some chromosomal genes, e.g. En/ (or En-). From this reason mainly, and less because of formal objections as to Rule 11, brackets should be retained.

(3) No comment.

(4) 1c., 1e., and 3. (first sentence of p. 7): I plead completely for H. & W.'s suggestions.

(5), (6), (7) No comments.

(8) I would like to ask you the question whether it is truly suitable to give the centromeres the map position 0. Certainly there are advantages, but also disadvantages, inclusive the difficulties to locate the centromeres exactly enough and within a reasonable space of time in the future. Why are barley maps to be handled otherwise than the chromosome maps of such well-studied organisms like Drosophila, maize, and tomato?

(9) No comment.

(Additional suggestions, pp. 8-10):

    1. The suggestion by H. & W. should be followed. From my person, however, there is no objection against your proposal.

    2. No comment.

    3. At the end of their comments, Hagberg and von Wettstein touch upon an important problem, viz. the necessity to establish the identity of loci between the mapped "classical" genes and the newly identified mutant genes. This is relevant, however, not only to chlorophyll deficiency genes but also to others.

As is well known, for a number of the Swedish mutant groups new symbols have been introduced. These symbols indeed conform to the general international rules just as the "classical" ones and are also well descriptive. However, they were established unfortunately without any reference to the long ago established symbols for the same characters, e.g.:

ert - l; cer - ge, gl, gs; mat - ea; alb - a, xan - x

Now this situation is a matter of fact, especially since the Swedish mutant material has been and is being studied so extensively. So far the identity of mutant and previously known loci has been tested in only few cases, so that at present both system still can exist side by side without major mutual trouble. But what to do in the future, when allelism tests will have increased? Which symbol for a special locus is then to be deleted, the new one or the old one? Should then be applied the principle of priority, or of the size of material? Or should rather already now be decided whether only one, the old or the new basic symbol for a group of polymeric genes is to be valid? I feel, this problem must be solved now, and it can be solved only by a reasonable compromise to be settled primarily between your American and the Swedish group. Only then one can expect that a revised system will be followed everywhere and for a long future.

F. Scholz

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