Genome-wide identification and expression profiling of ATP-binding cassette (ABC) transporters in Pomacea canaliculata: Candidates associated with toxin response and embryonic development.

ATP-binding cassette (ABC) transporters constitute one of the largest transmembrane protein families and play essential roles in development and xenobiotic detoxification. The invasive freshwater snail Pomacea canaliculata exhibits rapid development, strong environmental adaptability, and high tolerance to various chemicals. However, the gene features and functional differentiation of its ABC transporters mediating these biological traits are largely unclear. This study conducted a genome-wide identification and characterization of ABC transporters in P. canaliculata, and integrated transcriptomic data to analyze their expression profiles. A total of 79 ABC transporters were identified and classified into eight subfamilies (ABCA-ABCH) based on phylogenetic tree, with a notable expansion in the ABCC subfamily. Collinearity analysis revealed that tandem duplication events were the primary driver of this subfamily-specific expansion. Transcriptome analysis revealed that PcABC genes exhibited distinct spatiotemporal and toxin-responsive expression patterns. PcABCF1 was highly expressed on day 1 post-oviposition, whereas PcABCA3, PcABCG5, and PcABCG8 were significantly upregulated during organ formation and on day 1 post-hatching. Exposure to the ethanol extract of Alternanthera philoxeroides leaves, PcABCB1.2, PcABCC5.1, PcABCG1.5, and PcABCG2 exhibited significant transcriptional responses. This study systematically characterizes the ABC transporter gene family in P. canaliculata and extends knowledge on the functional divergence of its members in embryonic development and toxic stress.