Mutation of Bdpaired induces embryo lethality in the oriental fruit fly, Bactrocera dorsalis

Abstract

BACKGROUND: Pair-rule genes were identified and named for their role in segmentation in animal embryos. Paired, a homolog of mammalian PAX3, acts as one of several pair-rule genes and is key in defining the boundaries of future parasegments and segments during insect embryogenesis. RESULTS: We cloned the paired gene from the oriental fruit fly, Bactrocera dorsalis, and then applied CRISPR/Cas9-mediated genome editing to investigate its physiological function in the embryonic stage of this pest. We identified one transcript for a paired homolog in B. dorsalis, which encodes a protein containing a Paired Box domain and a Homeobox domain. Phylogenetic analysis confirmed that the paired gene is highly conserved and the gene was highly expressed at the 12-14 h-old embryonic stage. Knock-out of Bdpaired led to lack of segment boundaries, cuticular deficiency, and embryonic lethality. Sequence analysis of the CRISPR/Cas9 mutants exhibited different insertion and deletions in the Bdpaired locus. In addition, the relative expression of Wingless (Wg) and Abdominal A (Abd-A) genes were significantly down-regulated in the Bdpaired mutant embryos. CONCLUSION: These results indicate that Bdpaired gene is critical for the embryonic development of B. dorsalis, and could be a novel molecular target for genetic-based pest management practices to combat this serious invasive pest. © 2019 Society of Chemical Industry.