Abstract
Flies of a new mutant with wings transformed into halter-like or other shaped appendages were found by T. Kanehisa in the wild strain of Drosophila virilis collected at Sapporo (Hokkaido, Japan). Phenotypical changes are observed also on the thorax and the scutellum. As the mutation phenotypically resembles the “tetralteraBd” of Drosophila melanogaster reported by R. B. Goldschmidt, we named the mutation “tetraltera” (tet). Flies homozygous for tet show a penetrance of about 10 percent, whereas about 0.2 percent of flies heterozygous for the mutation show the mutant phenotype. It is determined that the tet gene is situated on the fourth chromosome, but the locus is not yet definitely determined. Another mutation which looked like tet was found in the Notch3a stock of D. virilis. This mutant strain has a low penetrance of about 0.07 percent and flies heterozygous for the gene phenotypically show the wild-type. The gene of this mutation is supposed to belong to the second linkage group, though there is some uncertainty about this because of its extremely low penetrance.
