The Ca-α1TFounder.w- allele was created using homologous recombination; the genomic region X:6144742..6147038 (based on FlyBase version FB2017_03) was deleted and an attP was inserted in that region. A GAL4 fragment (splice acceptor-GAL4 CDS-poly A) was inserted via φC31-mediated site-specific integration. The genomic region X:6130632..6135078 was deleted in the Ca-α1TΔ135 mutant.