GENETIC-STUDIES OF A BEHAVIORAL MUTANT, GLUCOSE AVERSION, IN THE GERMAN-COCKROACH (DICTYOPTERA, BLATTELLIDAE)

Glucose aversion (Glu) is a naturally occurring behavioral mutant of t he German cockroach, Blattella germanica. Earlier work suggested that Glu is a seri-dominant autosomal trait. Further study was undertaken t o place the mutant gene in the linkage map of the species and expand t he information on its genetic basis. Linkage was investigated in rest crosses with morphologic markers for 7 of the 11 autosomal linkage gro ups. Assays for amounts of glucose ingested per individual confirmed t he expected low consumption of Glu heterozygotes (Glu/+) and that cont inuous selection pressure on the parental strain had resulted in near- and probably complete homozygosity for Glu. Glu genotypes were identi fied by means of a discriminating ingestion that separated heterozygot es from wild type (Glu+). Variations in expression indicate that genet ic factors influence food consumption in B. germanica. Positive result s were obtained in linkage tests of Glu with ruby eye (ru), indicating that the Glu locus lies in linkage group VIII (chromosome 9), a group notable for mutants that apparently result in the expression of laten t, highly primitive development pathways.