Organization of the Chorion Genes of BOMBYX MORI, a Multigene Family. II. Partial Localization of Three Gene Clusters.

Chorion genes of the inbred stock Ascoli have been localized to three linked clusters by analysis of testcross progeny. Electrophoretic variants screened by isoelectric focusing served as markers. The clusters are designated Ch 1, Ch 2, and Ch 3. The gene order is Ch 1-Ch 2-Ch 3-Y, with relative map distances of approximately 0.4 m.u. for Ch 1-2, 3.3 +/- 0.9 m.u. for Ch 2-3, and 21 m.u. for Ch 3-Y. In a separate testcross using different markers, two chorion regions were localized 2.3 m.u. and 3.1 m.u. from p. These markers could not be assigned to Ch 1, 2, or 3 because there is at present no test for allelism in this system.