A Genetic Screen for regulators of CNS morphology in Drosophila

To identify genes that regulate CNS shape in Drosophila, we conducted an EMS-based, forward genetic screen of the second chromosome and uncovered 50 mutations that disrupt CNS structure. Of the 50 mutant alleles, 9 alleles were confirmed as LanB1 mutations via complementation crosses; the remaining 41 alleles underwent whole-genome sequencing. Of the 41 alleles sequenced, 40 alleles were successfully mapped to 15 genes, including viking (1), Collagen 4a1 (1), diaphanous (1), Toll-2 (3), Dark (11), brain tumor (3), lethal(2) giant larvae (1), worniu (1), tango (1), Rme-8 (3), Pvf3 (1), CG9171 (4), C1GalTA (2), infertile crescent (3), and senseless-2 (4). The genomic location of one mutant allele, jsZ4, remains unidentified after whole-genome sequencing.Notes: 1. One allele of Dark, Dark_js3, coexisted with one allele of ifc, ifc_js2. The flies carrying both above alleles are labeled as Dark_js3_ifc_js2.2. For the Toll-2_js3 allele background, due to the inability to obtain enough homozygous larvae, we crossed the Toll-2_js3 allele to the isogenic target chromosome, sib-mated the F1 progeny, and collected F2 larvae that exhibited the expected mutant CNS phenotype, which are referred to as Toll-2_js3_backcross flies.