Pseudoacanthocephalus sichuanensis, Zhao & Yang & Ru & Chen & Li & Li, 2024

Zhao, Cui-Hong, Yang, Rui-Jia, Ru, Si-Si, Chen, Hui-Xia, Li, Dai-Xuan & Li, Liang, 2024, Integrative taxonomy of the genus PSeUDoaCanthoCephaLUS (Acanthocephala: Echinorhynchida) in China, with the description of two new species and the characterization of the mitochondrial genomes of PSeUDoaCanthoCephaLUS SIChUanenSIS sp. n. and PSeUDoaCanthoCephaLUS nGUYenthILeae, Parasites & Vectors (541) 17 (1), pp. 1-20 : 14-16

Mitogenomes of Pseudoacanthocephalus sichuanensis and P. nguyenthileae

Te complete mitogenomes of P. sichuanensis and P. nguyenthileae have 15812 bp and 13701 bp, respectively, both of which include 36 genes, containing 12 PCGs (cox1–3, cytb, nad1–6, nad4L and atp6, missing atp8), 22 transfer RNA (tRNA) genes and two rRNA genes (rrnL and rrnS) ( Fig. 11 ; Additional file 7: Table S4; Additional file 8: Table S5). Two non-coding regions (NCRs) are present in the mitogenomes of P. sichuanensis and P. nguyenthileae (NCR1 is 2282 bp in P. sichuanensis vs only 202 bp in P. nguyenthileae , both between tRNA-Trp and tRNA-Val; NCR2 is 650 bp in P. sichuanensis vs 618 bp in P. nguyenthileae , both between tRNA-Ile and tRNA-Met) ( Fig. 11 ; Additional file 7: Table S4; Additional file 8: Table S5). All genes are transcribed from the same strand. Te overall A + T content in the mitogenomes of P. sichuanensis and P. nguyenthileae is 56.8% and 56.3%, respectively, with both displaying a strong nucleotide compositional bias toward A+ T. Te nucleotide content of P. sichuanensis and P. nguyenthileae mitogenomes are provided in Additional file 9: Table S6.

Taken together, the 12 PCGs of the mitogenomes of P. sichuanensis and P. nguyenthileae are 10,179 bp and 10,206 bp in length (excluding termination codons), with each gene ranging in size from 240 bp (nad4L) to 1627 bp (nad5), which encoded 3391 and 3401 amino acids, respectively (Additional file 7: Table S4; Additional file 8: Table S5). Among the 12 PCGs of P. sichuanensis and P. nguyenthileae , six genes (cox1, cox3, nad4L, nad1, nad2 and nad5) used GTG as the start codon, whereas two genes (cox2 and atp6) in P. sichuanensis and four genes (cox2, nad3, nad6 and atp6) in P. nguyenthileae used ATG as the start codon. TTG was used by the nad4 and cytb genes in both species. TTG was used by the nad6 gene and ATA was used by the nad3 as the start codon in P. sichuanensis . TAA was the most commonly used termination codon in both species (4 genes [cox3, nad2, nad3, nad4L] in P. sichuanensis vs 3 genes [cox3, nad2, nad3] in P. nguyenthileae ); two genes (cox1 and cytb) in P. sichuanensis and three genes (cox1, nad4L and cytb) in P. nguyenthileae used TAG as termination codon. Te incomplete termination codon T was inferred for the cox2, nad1, nad4, nad5, nad6 and atp6 genes in both species. Data on the component and usages of codons in the mitogenomes of P. sichuanensis and P. nguyenthileae are provided in Additional file 1: Figure S1 ; Additional file 7: Table S4; Additional file 8: Table S5.

Tere are 22 tRNAs and two rRNAs (rrnL located between tRNA-Tyr and tRNA-Leu1; rrnS located between tRNA-Met and tRNA-Phe) in the mitogenomes of P. sichuanensis and P. nguyenthileae ( Fig. 11 ; Additional file 7: Table S4; Additional file 8: Table S5). Te length of the 22 tRNAs and their anticodon secondary structures of P. sichuanensis and P. nguyenthileae are provided in Additional file 2: Figure S2 ; Additional file 3: Figure S3 ; Additional file 7: Table S4; Additional file 8: Table S5.

Te gene arrangement of the 36 genes in the mitogenomes of P. sichuanensis and P. nguyenthileae are identical, both in the following order: cox1, tRNA-Gly, tRNA-Gln, tRNA- Tyr, rrnL, tRNA-Leu1, nad6, tRNA- Asp, atp6, nad3, tRNA-Trp, tRNA-Val, tRNA-Lys, tRNA- Glu, tRNA-Tr, tRNA-Ser2, nad4L, nad4, tRNA-His, nad5, tRNA-Leu2, tRNA-Pro, cyt b, nad1, tRNA-Ile, tRNA-Met, rrnS, tRNA-Phe, cox2, tRNA-Cys, cox3, tRNA- Ala, tRNA-Arg, tRNA-Asn, tRNA-Ser1, nad2 ( Fig. 11 ).

Figures

Fig. 11 Gene map of the mitochondrial genome of Pseudoacanthocephalus sichuanensis sp. n. and Pseudoacanthocephalus nguyenthileae. NCR, Non-coding region; PCG, protein-coding gene; rRNA, ribosomal RNA; tRNA,transfer RNA

Fig. 1 Pseudoacanthocephalus sichuanensis sp. n. collected from Bufo gargarizans in China.a Mature female, b mature male, c proboscis of male, d egg, e testes and cement glands, f copulatory bursa, g posterior end of female, h proboscis hooks of female

Fig. 2 Photomicrographs of Pseudoacanthocephalus sichuanensis sp. n. collected from Bufo gargarizans in China.a Proboscis of male, b anterior part of male, c testes,d cement glands (arrowed),e copulatory bursa,f posterior end of female, g egg,h, i mature female

Fig. 3 Scanning electron micrographs of Pseudoacanthocephalus sichuanensis sp. n. collected from Bufo gargarizans in China.a Proboscis of male, lateral view, b proboscis of male, apical view,c neck of male, d sensory pit in neck, e magnified image of middle proboscis hooks of female,f magnified image of posterior proboscis hooks of female,g copulatory bursa (2 auriform protrusions indicated by arrows), h magnified image of sensory papillae on copulatory bursa, i magnified image of genital pore, j egg