The complete mitochondrial genome sequence of the Gracile shrew mole,Uropsilus gracilis(Soricomorpha: Talpidae)

Comparison and Phylogenetic Analysis of Mitochondrial Genomes of Talpidae Animals

Talpidae is a model group for evolutionary studies due to their highly specialized morphologies and diverse lifestyles. Mitochondrial genomes are molecular markers commonly used in species evolution and phylogenetic studies. In this study, the complete mitochondrial genome sequence of Scaptochirus moschatus was obtained by Illumina NovaSeq sequencing. The complete mitochondrial genomes of 14 Talpidae species (including Scaptochirus moschatus obtained in the present study) and the cytochrome b (Cyt b) gene sequences of 48 Talpidae species were downloaded from the NCBI database for comparison and phylogenetic studies to analyze the phylogenetic relationships and to find the possible reasons of the niche differentiation and ecotype specialization of Talpidae animals. The results showed that the mitochondrial genome sequences of 14 species belonging to the family Talpidae were 16,528 to 16,962 bp, all containing 13 protein-coding genes, 22 tRNA, two rRNA, and a non-coding region (control region). The difference in the number of repetitive repeats in the control region is responsible for the difference in the length of Talpidae mitochondrial genome sequences. Combining the divergence time of Talpidae animals with the geological history, it is found that the niche differentiation and ecotype divergence of Talpidae is closely related to historically global climate changes. Semi-aquatic groups diverged in the early Oligocene (about 31.22 MYA), probably in response to the global climate transition from warm to cool. During the early Miocene (about 19.54 MYA), some species of Talpidae moved to underground habitats and formed fossorial groups that were adept at digging due to the effects of the glaciation. In the middle Miocene (about 16.23 MYA), some Talpidae animals returned to the ground and formed semi-fossorial shrew moles as global climate warming again.

The complete mitochondrial genome of Talpa martinorum (Mammalia: Talpidae), a mole species endemic to Thrace: genome content and phylogenetic considerations

The complete mitogenome sequence of Talpa martinorum, a recently described Balkan endemic mole, was assembled from next generation sequence data. The mitogenome is similar to that of the three other Talpa species sequenced to date, being 16,835 bp in length, and containing 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, an origin of L-strand replication, and a control region or D-loop. Compared to other Talpa mitogenomes sequenced to date, that of T. martinorum differs in the length of D-loop and stop codon usage. TAG and T-- are the stop codons for the ND1 and ATP8 genes, respectively, in T. martinorum, whilst TAA acts as a stop codon for both ND1 and ATP8 in the other three Talpa species sequenced. Phylogeny reconstructions based on Maximum Likelihood and Bayesian inference analyses yielded phylogenies with similar topologies, demonstrating that T. martinorum nests within the western lineage of the genus, being closely related to T. aquitania and T. occidentalis.

Complete mitochondrial genome of the Iberian Mole Talpa occidentalis (Talpidae, Insectivora) and comparison with Talpa europaea

The complete mitogenome of Talpa occidentalis, the Iberian mole, was sequenced using a combination of the Illumina and Sanger methods. The 16,962 bp genome obtained contains 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and a control region. Thirty-seven identical repetitions of a 10-nucleotide (CACACGTACG) repeat element were identified in the non-coding control region (D-loop). The number, order, and orientation of the mitochondrial genes are the same as in T. europaea, the only mitogenome published so far for this genus. These two mitogenomes differ only at the repeat element included in the control region. The phylogeny obtained for the Talpidae species using the protein-coding genes of these mitogenomes agrees with the current classification of this family.

Complete mitogenome of Intermediate Egret Ardea intermedia (Ciconiiformes: Ardeidae)

The Intermediate Egret Ardea intermedia belongs to family Ardeidae, and it is widely distributed over east Africa across the Indian subcontinent to Southeast Asia and Australia. In the present study, the total mitochondrial genome of A. intermedia was determined. The genome is 18,578 bases in length and contains 13 protein-coding genes (PCGs), 22 transfer RNA genes, 2 ribosomal RNA genes and 2 non-coding regions (CR and CRR), with a base composition of A 30.8%, G 14.0%, T 24.3% and C 30.9%. The dn/ds values of ten PCGs (ND1, ND2, ATP8, ATP6, Cox3, ND3, ND4L, ND4, ND5 and ND6) are below 1. Bayesian inference (BI) and maximum likelihood (ML) methods generated similar topologies. Phylogenies showed that Ardea novaehollandiae and A. intermedia should be assign to Egretta and Ardea, respectively. The mitogenomic data of A. intermedia will be useful in the conservation genetics and phylogeny of the species.

Mitogenome of a cryptic species within Uropsilus and divergence time estimation

Uropsilus sp. 4 is a new cryptic species, collected in Changyang county, Hubei province, China. In this study, the whole mitochondrial genome of Uropsilus sp. 4 was first determined and characterized. The genome is 16,542 bp in length, containing 13 protein coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and a putative control region. Base on NJ, ML, and BI methods, we obtained the same topologies. U. sp. 4 clustered with U. gracilis and the divergence time was 1.78 Ma (95% CI 1.24-2.32 Ma), in concordance with the third period of last orogenic push of the Qinghai-Tibetan Plateau, might contribute to the speciation of U. sp. 4.

Complete mitochondrial genome sequence of Arboreal Brown-toothed Shrew,Episoriculus macrurus

The Arboreal Brown-toothed Shrew (Episoriculus macrurus) belongs to the family Soricidae, and distributes in China, Nepal, India, Myanma, and Vietnam. In this study, the complete mitochondrial genome sequence of E. macrurus was determined. The mitogenome is 16,943 bp in length. Phylogenetic trees were constructed by the methods of Bayesian inference and maximum likelihood. The results showed that in the family of Soricidae, Crocidurinae differentiated earlier than Soricinae. Episoriculus was more close to Nectogale or Neomys rather than Sorex, and Blarinella was close to Sorex. This study contributes to illuminating the taxonomic status of E. macrurus.

Description of the mitogenome of Gansu mole (Scapanulus oweni)

The Gansu mole Scapanulus oweni belongs to family Talpidae, and is distributed in the Central and Southwest China. In this study, the total mitochondrial genome of S. oweni was firstly determined. The genome is 16,826 bases in length and contains 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and a displacement loop region, with a base composition of A 34.0%, G 13.5%, T 28.7% and C 23.9%. All of the protein-coding genes initiate with the orthodox ATG start codon execpt for Nd2 and Nd3 begin with ATT, Nd4 and Nd5, start with GTG and ATA, respectively. Four types of stop codons are used by the coding genes, including TAA for Nd1, Cox1, Cox2, Atp8, Atp6, Nd4L, Nd5, Nd6, TAG for Nd2, AGA for Cytb, and an incomplete stop codon T for Cox3, Nd3 and Nd4. The mito-genomic data of Gansu mole, S. oweni will be useful in determining its taxonomic status within Talpidae.

The complete mitogenome of Chinese Mole Shrew, Anourosorex squamipes (Soricidae)

The Chinese Mole Shrew, Anourosorex squamipes belongs to the family Soricidae, and widely distributes in central and southern China, northern and south Burma, east India, northern Vietnam and Thailand. In this study, the complete mitochondrial genome sequence of Anourosorex squamipes was determined. The mitogenome is 17,121 base pairs in length and contains 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and 1 control region, with base composition of 34.0% A, 31.3% T, 22.0% C, and 12.7% G. The genome organization, nucleotide composition and codon usage did not differ significantly from those of other shrews. The study contributes to illuminating taxonomic status of Chinese Mole Shrew Anourosorex squamipes.

Complete mitochondrial genome sequence of Nectogale elegans

The elegant water shrew (Nectogale elegans) belongs to the family Soricidae, and distributes in northern South Asia, central and southern China and northern Southeast Asia. In this study, the complete mitochondrial genome of N. elegans was sequenced. It was determined to be 17,460 bases, and included 13 protein-coding genes (PCGs), 22 tRNA genes, 2 ribosomal RNA genes and one non-coding region, which is similar to other mammalian mitochondrial genomes. Bayesian inference and maximum likelihood methods were used to construct phylogenetic trees based on 12 heavy-strand concatenated PCGs. Phylogenetic analyses further confirmed that Crocidurinae diverged prior to Soricinae, and Sorex unguiculatus differentiated earlier than N. elegans.