Characterization of the Complete Mitochondrial Genome of a Whipworm Trichuris skrjabini (Nematoda: Trichuridae)

Abstract

The complete mitochondrial (mt) genome of Trichuris skrjabini has been determined in the current study and subsequently compared with closely related species by phylogenetic analysis based on concatenated datasets of mt amino acid sequences. The whole mt genome of T. skrjabini is circular and 14,011 bp in length. It consists of a total of 37 genes including 13 protein coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNAs) genes, and two non-coding regions. The gene arrangement and contents were consistent with other members of the Trichuridae family including Trichuris suis, Trichuris trichiura, Trichuris ovis, and Trichuris discolor. Phylogenetic analysis based on concatenated datasets of amino acids of the 12 PCGs predicted the distinctiveness of Trichuris skrjabini as compared to other members of the Trichuridae family. Overall, our study supports the hypothesis that T. skrjabini is a distinct species. The provision of molecular data of whole mt genome of T. skrjabini delivers novel genetic markers for future studies of diagnostics, systematics, population genetics, and molecular epidemiology of T. skrjabini.

Complete Mitochondrial Genome of Trichuristrichiura from Macaca sylvanus and Papio papio

“…In the present study, we resolved the complete mt genome sequences of two haplotypes of Trichuris isolated from M. sylvanus and one complete mt genome of Trichuris from P. papio . The size of the complete mt genomes were within the range reported for the Trichuridae family (ranging from 13,904 bp ( T. discolor ) to 14,521 bp ( T. suis )) [ 3 , 16 , 17 , 19 , 22 ]. The complete mtDNA is a circular molecule and encodes 37 genes—13 PCGs ( atp 6, atp 8, cox 1–3, co b, nad 1–6 and nad 4L), two rRNAs ( rrn S and rrn L), and 22 for tRNAs.…”

“…The initiation codons (ATG, ATA and ATT) agreed with those reported in the pig-derived and human-derived Trichuris . [ 16 , 18 , 20 ], while T. ovis and T. discolor also employed TTG [ 3 , 16 , 19 ], and T. skrjabini sequence used only two start codons (ATG and ATA) [ 22 ]. Two termination codons (TAA and TAG) were used as stop codons in all the four species of Trichuridae family ( T. suis , T. trichiura , T. ovis and T. discolor ) except T. skrjabini, which possesses another stop codon, TGA [ 3 , 16 , 17 , 19 , 22 ].…”

“…[ 16 , 18 , 20 ], while T. ovis and T. discolor also employed TTG [ 3 , 16 , 19 ], and T. skrjabini sequence used only two start codons (ATG and ATA) [ 22 ]. Two termination codons (TAA and TAG) were used as stop codons in all the four species of Trichuridae family ( T. suis , T. trichiura , T. ovis and T. discolor ) except T. skrjabini, which possesses another stop codon, TGA [ 3 , 16 , 17 , 19 , 22 ]. The sequences of this study were in accordance with the most related species (primates derived Trichuris ) [ 3 , 19 ].…”

“…Currently, the complete mt genome of several species of whipworms has been sequenced— Trichuris trichiura from humans and baboons [ 3 , 19 ]; Trichuris sp. from the Endangered François’ Leaf-Monkey [ 17 ]; Trichuris rhinopiptheroxella from the endangered golden snub-nosed monkey [ 20 ]; Trichuris suis from pig [ 3 , 19 ]; Trichuris ovis from antelope [ 16 ]; Trichuris discolor from wild yak [ 16 ]; Trichuris skrjabini from sheep [ 22 ]; and Trichuris muris (LC050561, unpublished). This fact, and considering the hypothesis that Trichuris infecting primates represent a complex of cryptic species with some species capable of infecting both humans and non-human primates (NHPs), reflects the need to delve into the mt genomes of Trichuris spp.…”

The metazoan landscape of mitochondrial DNA gene order and content is shaped by selection and affects mitochondrial transcription

“…Therefore, we cannot rule out the possibility that the sequence of ATP8 was heavily mutated and therefore erroneously reported as missing from organisms within the mentioned phyla 35 . Indeed, ATP8 was putatively identified in the mtDNA of select Nematoda and Platyhelminth species 36 , 37 and confirmed in several whipworm species 38 , 39 . Within Bivalvia orders, ATP8 deletion appears to be limited to a few taxa, namely Mytiloida (61%, N = 8), Ostreoida (94%, N = 17), and Veneroida (39%, N = 11).…”