Abstract The Cricetulus kamensis is endemic to China and is popular as pet. In the present study, the complete mitogenome of C. kamensis was first determined. It was 16,270 bp in length and the composition and arrangement of its genes are analogous to most other mammals. The overall base composition of heavy strand is 33.2% A, 26.8% T, 27.2% C and 12.7% G. The sequence is highly G-C poor (∼40%) and A is the most numerous nucleotide followed by T >C >G, which is similar to other mammalian mitochondrial genomes. It is notable that three extra bases “CAT” were inserted in cytb at the 3′ end position and no stop codon was found for this coding region. The mitogenome sequence of C. kamensis could contribute to a better solution of its phylogenetic position and phylogenetic relationship within Cricetinae in the future.
Two novel mitogenomes of Eozapus setchuanus (KJ648495) and Sicista concolor (KJ648496) were reported and their total lengths were 16,630 bp and 16,493 bp, respectively. Both mitogenomes which were analogous to other rodent mitogenomes, contained 13 protein-coding genes, 22 tRNAs, 2 rRNAs, and a control region. Specifically, the ND2 gene of S. concolor has three amino acids lesser than that of two other Dipodidae species (E. setchuanus and Jaculus jaculus) due to a premature termination codon in the 3' end. We detected a tandem repeat cluster of 221 bp and 274 bp in the control region of S. concolor and E. setchuanus, respectively. Along with phylogenetic relationship analysis, we speculated that the tandem repeats in control regions might be common in Dipodinae species. Our phylogenetic analysis using concatenated mitochondrial gene datasets suggested five suborder and 16 family monophyletic groups in 54 rodent taxa sampled and strongly supported a basal position of the squirrel-related clade (PP = 1; BP = 100). Dipodidae had a sister-group relationship with Muroidea, and Sicistinae was in the base of Dipodidae clade. The complete mitochondrial genomes showed high resolution in deep-level phylogenetic relationship reconstructions of Rodentia. (C) 2015 Elsevier Ltd. All rights reserved.
Of the 14 nominal species that are now or have ever been assigned to the genus Paranemertes Coe, 1901 , four have been reported to have stylets with a spirally fluted or braided appearance. Although differentiation in color patterns has been documented among species/populations, these nemerteans share similar external characters. Using the sequence datasets of mitochondrial cytochrome c oxidase subunit I (COI), 16S rRNA, and nuclear 28S rRNA genes of specimens from 14 localities of Canada, USA, Russia, Japan, and China, we analyzed the genetic differentiation and reconstructed the phylogenetic trees for these nemerteans. In conjunction with the external characters, we discuss their taxonomy and species delimitation. An analysis based on COI dataset showed high genetic variations among populations and even among worms from the same geographic area. The analyzed 111 individuals were assigned into seven networks by statistical parsimony analysis. The inter-network uncorrected p-distances ranged from 0.044 to 0.172 and the mean intra-network uncorrected p-distances varied from 0.001 to 0.005. With the exception of two networks that contain specimens from the East China Sea, all networks were well-supported by the results of Bayesian and neighbor-joining analyses on the COI data. Phylogenetic trees based on 16S rRNA and 28S rRNA datasets were basically similar to the COI trees, but specimens in some networks were merged into larger clades. Present molecular analyses support the validity of P. sanjuanensis and the synonymization of P. cylindracea with P. peregrina. Nemerteans previously recorded as P. peregrina may contain several species and sympatric speciation might have been occurred in this nemertean group.
Wood mice of the genus Apodemus are the most common small rodents in fields and broad-leaf forests in the temperate zone. In this study, we determined the complete mitochondrial genome of Apodemus latronum. It was endemic species to China, which mainly inhabited at the high land of the eastern Tibetan Plateau. The complete mitochondrial genome sequences of A. latronum was estimated to be 16,288 bases. Its organization and order were similar to that of typical vertebrate and other rodents' mitochondrial genomes, which consisting of 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and 1 control region. Most protein-coding genes used ATG as the initiation codon. However, ND1, ND2 and ND5 began with ATA, whereas ND3 initiated with ATT. The termination codon also showed some degree of variation, and three types of stop codons were observed. The mitogenome sequence of A. latronum could provide helpful data to study the phylogeny of Apodemus.
The Miyaluo captive forest musk deer population (Sichuan Province, China) is one of the largest captive breeding populations in the world. In order to evaluate the genetic quality and provide available genetic management strategy, seven polymorphism microsatellite loci were applied to assess the genetic variation of the Miyaluo forest musk deer. The results indicated that a total of 168 alleles were detected from these seven microsatellite loci in 361 individuals, and the number of the alleles per locus ranged from 12 to 41 with a mean of 24. The average observed heterozygosity, expected heterozygosity, and PIC were 0.782, 0.854, and 0.837, respectively. Considering the results of the loci Hardy–Weinberg equilibrium test, the comparison of the common allele frequency as well as the private allele between the adults and juveniles, we concluded that the heterozygosity and the genetic diversity of the Miyaluo captive breeding population are increasing due to the input of new individuals from other populations. However, the frequency of some alleles declined sharply, and some were even lost indicating that there is a risk for diversity loss. Thus, we proposed an improved management and breeding strategy for the captive breeding population of the forest musk deer.
The Chevrier's field mouse (Apodemus chevrieri) is an endemic species to China and is an important pest in agriculture and human diseases. In this study, the complete mitochondrial genome of this species was sequenced and its size was 16,298 bases (accession no.: HQ896683). The mitogenome structure was similar compared with other reported rodent mitochondrial genomes and includes 13 protein-coding genes, 2 rRNA genes (12S rRNA and 16S rRNA), 22 tRNA genes, and 1 control region. This was the first complete mitogenome sequenced in genus Apodemus. The phylogenetic analyses based on the sequences of 12 heavy-strand protein-coding genes demonstrated that A. chevrieri clustered together with genus Mus. Additionally, extremely high haplotype and nucleotide diversities (h = 0.978, pi = 2.6%) were observed based on 44 mitochondrial cytochrome b (cyt b) gene sequences. This suggests adaptive divergence of this species to a variety of living habitats and potential refuges in the eastern margin of the Hengduan Mountains during the Quaternary ice ages. No population expansions or genetic bottlenecks were observed in demographic analyses. The phylogenetic analysis of cyt b sequences and haplotypes revealed a genetic differentiation between north and south populations. The divergence between north clade and south clade occurred probably in the middle Pleistocene 1.1815 million years ago (Mya) (95% highest posterior density 2.3189-0.2737 Mya), which was congruent with the periods of the most tense uplift events in the Tibetan Plateau.
The Chinese scrub vole (Neodon irene) belongs to the subfamily Arvicolinae, which is restricted to mountain areas at high altitudes (2800-4000). In this study, we sequenced the complete mitochondrial genome of N. irene. It was determined to be 16,367 bases. The nucleotide sequence data of 12 heavy-strand protein-coding genes of N. irene and other 22 rodents were used for phylogenetic analysis. Bayesian inference (BI) and maximum likelihood (ML) were used. Both the BI and ML trees demonstrated that Microtus rossiaemeridionalis and Microtus kikuchii did not cluster together with each other. On the contrary, M. rossiaemeridionalis showed close relationship with N. irene. In the present study, only one sequence from Neodon and two sequences from Microtus were included in the phylogenetic analysis which should contribute to the unusual relationship. Therefore, in order to better understand the phylogenetic relationship within Rodentia, more rodents' complete mitochondrial genomes are required.
Fifteen new microsatellite markers were isolated in rock carp, Procypris rabaudi (Tchang), from an AC-enriched genomic library. The allele number of these loci ranged from three to 13 (average 6.87 per locus) in the tested 24 individuals. Polymorphism information content (PIC) ranged from 0.453 to 0.821 with an average of 0.719. Average observed and expected heterozygosities were 0.712 (range 0.565–0.917) and 0.772 (range 0.542–0.855), respectively. These microsatellite markers could be useful in the population genetic study of rock carp.