340 Action of the Genetic Material 



It is this table, clearly a brain child of my description of valencies in 

 Lymantria in terms of numerical values, but said to be the result of 

 actual measuring, which has made so many people skeptical. 



Now Moewus claims to have crossing-over results which show that 

 two Fi act like one F2 and so forth. If this is true, the conclusion is 

 unavoidable that the F and M alleles must be regarded as diflferent 

 quantities of the same "gene," just as we had to conclude for the differ- 

 ent valencies of F and M in Lymantria. If we accept Moewus' claims, 

 we find a relation between gene dosage and the quantity of two defi- 

 nite stuffs (based upon almost the same precursors and only sterically 

 different). However, these stuffs are not the direct products of the 

 genie action of the F and M doses, but products of completely 

 different "genes," the amount of which has been controlled by the 

 dosages of F and M. Sonneborn (1951fo) proposes the logical explana- 

 tion that the function of M is to produce a specific inhibitor of the 

 production of the cis-isomer, in concentration and effectiveness equal 

 to that of the trans-inhibitor, controlled by Fi. Suppose the F alleles 

 control production of a substance which at some point inhibits the 

 synthesis of the dimethylester of trans-crocetin, and that the Fi allele 

 yields an amount of inhibitor capable of reducing to about one-half 

 the effective amount of the trans-isomer. If doubling, tripling, or 

 quadrupling the rate of inhibition reduces the effective amount of 

 trans-isomer by three-fourths, seven-eighths, and fifteen-sixteenths, 

 respectively, the calculated results very much resemble those in the 

 table. Thus, if Moewus' results are accepted, they provide the best 

 example of genically produced substances in proportion to genie 

 dosage. 



Sonneborn adds the assumption that the F and M alleles of 

 different and linear valency are actually duplications of the same 

 chromosome segment or pseudoalleles in Lewis' interpretation. In 

 effect this is not different from our old interpretation of the valencies 

 of the "sex genes" in Lymantria as different quantities of genie sub- 

 stance, except for the timely assumption of origin by gene duplication. 

 I refer to our former discussion of pseudoallelism and shall not dis- 

 cuss this phylogenetic assumption, as it does not make any difference 

 for the dosage problem whether it is correct or not. Altogether, I 

 should like to see a confirmation of at least the basic features of Moe- 

 wus' work, that is, location and crossing over of M and F and the 

 control of the gathe loci. 



