Rhaphidophora quadrispina Liu & Bian, 2021

Lu, Xiangyi, Liu, Jing, Huang, Xiaojuan & Bian, Xun, 2022, Contribution to the Chinese subfamily Rhaphidophorinae Walker, 1869 (Orthoptera: Rhaphidophoridae: Rhaphidophorinae) IV: Seven new species of Rhaphidophora and one new mitogenome, Zootaxa 5087 (1), pp. 129-153 : 149-151

Rhaphidophora quadrispina Liu & Bian, 2021 ZIJĒȃ

Figs. 19–20

The complete mitogenome of Rhaphidophora quadrispina was assembled into a circular-mapping form of 15892 bp in length (GenBank accession number: OL450400 ), which comprised 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and a control region (D-loop). Among these mitochondrial genes, fourteen tRNA genes and nine protein coding genes were coded with the J-strand, while other genes were encoded by the N-strand. There were 15 intergenic spacer regions and 13 overlapping regions are observed in the mitogenome ranging from 1 bp to 30 bp and 1 to 23 bp ( Table 1 ).

The overall base nucleotide composition of Rhaphidophora quadrispina mitogenome was determined to be 41.35% A, 34.18% T, 14.84% C, 9.62% G and revealed an obviously A/T (75.53%) bias ( Table 2 ). Meanwhile, the control region had the highest A+T content (81.69%), while tRNAs were the lowest (51.34%) in the mitogenome. Except control region, AT-skew values were positive from 0.02 (PCGs-1st) to 0.48 (tRNAs) and GC-skew values were negative ranging from -0.56 (tRNAs) to -0.06 (PCGs -3rd), which indicated that the content of A and C nucleotides was more abundant than G and T.

Among 13 PCGs, the longest one was ND5 gene (1735 bp), whereas the shortest was ATP8 gene (159 bp). All protein-coding genes mainly started with the standard codons ATN, except for ND5 which started with GTG. Most genes were used TAA or TAG as complete stop codons. But the termination codons of ND5 and ND4 were a single T instead of completeness. For the relative synonymous codon usage (RSCU), the first five frequently used were UUA (Leu2), AUA (Met), GUU (Val), GUA (Val) and UCA (Ser2) ( Fig. 19 ).

The lengths of tRNA genes ranging from 64 bp (trnaA and trnaH) to 72 bp (trnaV). Besides trnaS1, the other tRNA genes formed the typical cloverleaf structure ( Fig. 20 ). The lengths of rrnL and rrnS were 1313 bp and 791 bp respectively.

Figures

FIGURE 19. The relative synonymous codon usage (RSCU) of Rhaphidophora quadrispina.

FIGURE 20. The secondary structures for 22 tRNA genes of the Rhaphidophora quadrispina mitogenome.