Analysis of complete mitochondrial genome of <I>Cristaria plicata</I>

Abstract

The complete mitochondrial genome of Cristaria plicata was obtained using long amplification polymerase chain reaction (LA-PCR). Analysis showed that the total length of sequence was 15 712 bp, including 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and 26 non-coding regions ranged from 2 bp to 328 bp in size. The nucleotide composition of A, T, C, G were 36.54% 27.22% 23.22% and 13.02%, respectively. Most genes were encoded on the L strand, While ND3-ND5, ND4L, COI-COIII, ATP6, ATP8, tRNAAsp, and tRNAHis were encoded on the H strand. The arrangement of genes in C. plicata was identical to that of Lampsilis ornata, but was different from that of Hyriopsis cum-ingii between COII and 12S rRNA in the same family. Thirteen protein genes contained 3 initiation codons, i.e., I (AUU, AUC), V (GUG), and M (AUA, AUG), all of which had complete stop codons (UAA or UAG), except for the stop codon in ND2 that had an incomplete T. Fifteen tRNAs had typical cloverleaf structure, except for tRNAThr, tRNALys, tRNASer(UCN), tRNAAsp, tRNAArg, tRNATyr, and tRNAMet. Like other freshwater bivalvia, C. plicata contained ATP8 gene, which might be related to the balance of osmotic pressure in the cytoplasm.