Molecular Characterization and Expression Analysis of Two Acetylcholinesterase Genes From the Small White Butterfly Pieris rapae (Lepidoptera: Pieridae)

Abstract

Acetylcholinesterases (AChEs) are essential for the hydrolysis of the neurotransmitter acetylcholine and play crucial roles in the termination of neurotransmission. AChEs are encoded by the ace genes. However, the ace genes from the small white butterfly, Pieris rapae (L.) (Lepidoptera: Pieridae), remained uncharacterized. In this study, two aces (Prace1 and Prace2) were identified from P. rapae. Prace1 encoded a PrAChE1 protein consisting of 694 amino acid residues, and Prace2 encoded the 638-amino-acid PrAChE2. The two identified PrAChEs both had features typical of AChEs, including the catalytic triad, choline-binding sites, an oxyanion hole, an acyl pocket, a peripheral anionic subsite, an FGESAG motif and 14 conserved aromatic amino acids. Phylogenetic analysis showed that Prace1 and Prace2 were clustered into two distinct groups: ace1 and ace2, respectively. The two Praces were distributed on different genomic scaffolds: Prace1 on scaffold 156 and Prace2 on scaffold 430. Additionally, Prace1 consisted of three exons and two introns, whereas Prace2 consisted of six exons and five introns. One amino acid mutation (Gly324Ala) in PrAChE1 and two (Ser291Gly and Ser431Phe) in PrAChE2 were consistent with mutations in other insect AChEs that are associated with insecticide insensitivity. Both Prace1 and Prace2 were highly expressed at the fifth-instar larval stage and in the larval head, and the transcriptional levels of Prace1 were significantly higher than those of Prace2 in all of the tested life stages and tissues. This is the first report characterizing two ace genes in P. rapae. The results pave the way for functional study of these genes.

Identification and Expression Profiles of 14 Odorant-Binding Protein Genes From Pieris rapae (Lepidoptera: Pieridae)

“…The P. rapae individuals used in this study were reared in our laboratory under the conditions of 26 ± 1°C, 65% relative humidity, and a 16:8 (L:D) h photoperiod, as described previously ( Jiang et al 2018 ). Two-day-old virgin adults were sampled, and different tissues were dissected, including 100 male antennae, 100 female antennae, 60 heads (without antennae; 30 from males and 30 from females, pooled together), 60 abdomens (30 from males and 30 from females, pooled together), and 200 legs (100 from males and 100 from females, pooled together).…”

A Re-Evaluation of Olive Fruit Fly Organophosphate-Resistant Ace Alleles in Iberia, and Field-Testing Population Effects after in-Practice Dimethoate Use

“…Insensitivity to these insecticides by mutations of the Ace gene, which codes for acetylcholinesterase, the target enzyme of OPs, has been demonstrated in several insects, including mosquito species, in Drosophila melanogaster (common fruit fly), Musca domestica (common housefly), Ceratitis capitata (Mediterranean fruit fly), Aphis gossypii (the aphid) and Bactrocera oleae [2,3,4,5,6]. In most insects, two types of Ace genes ( ace1 and ace2 ) have been identified [7,8]. However, in some Diptera including tephritids (such as the Bactrocera species), the ace1 gene is absent, likely due to gene loss, and only a single ace2 gene has been identified [9].…”

Understanding SARS-CoV-2 features of infectivity, aggressiveness, and transmissibility: an insect-vector theory for SARS-CoV-2 dissemination

“…In this setting, our opinion is that the virus's putative initial carrier across species could be an insect. Insects have important numbers of ACE2 receptors (evolutionarily conserved proteins, although insufficiently described) [16][17][18][19], but also of ADAM-17 enzymes, essential for the viral and ACE2 activation [20].…”