GENETIC AND BIOCHEMICAL-STUDIES ON OMMOCHROME GENESIS IN AN ALBINO STRAIN A TERRESTRIAL ISOPOD, ARMADILLIDIUM-VULGARE

Genetic studies and quantitative determination of levels of 3-hydroxyk ynurenine and kynurenine were performed in an albino strain of a terre strial isopod Armadillidium vulgare. From the results of matings betwe en the albino and the albino, the red, the dark red, or the wild type individuals, the albino A. vulgare seems to be regulated by an autosom al gene(s) recessive to its wild allele. Litter mating of Fl progenies obtained by crossing the albino and the red mutant or the albino and the dark red mutant yielded progenies at a ratio of 3:6:3:4 for the re d, the dark red, the wild, and the albino phenotypes, respectively The albino gene(s) seems not to be allelic but to be epistatic to the red gene(s) with respect to ommochrome biosynthesis. Quantitative determi nation of 3-hydroxykynurenine carried out by high-performance liquid c hromatography with electrochemical detection revealed that the 3-hydro xykynurenine content in the albino was significantly lower than that i n the wild or the red type. The whole content of 3-hydroxykynurenine a fter enzymatic conversion of kynurenine to 3-hydroxykynurenine was sti ll considerably lower than that found in the wild type, even though it increased after the conversion. The albino gene(s) seems to be associ ated with a blockage at distinct level(s) of ommochrome biosynthesis.