Platysternon megacephalum is the only living representative species of Platysternidae and only three subspecies remain: P. m. megalorcephalum, P. m. shiui, and P. m. peguense. However, previous reports implied that P. m. peguense has distinct morphological and molecular features. The characterization of the mitogenome has been accepted as an efficient means of phylogenetic and evolutionary analysis. Hence, this study first determined the complete mitogenome of P. m. peguense with the aim to identify the structure and variability of the P. m. peguense mitogenome through comparative analysis. Furthermore, the phylogenetic relationship of the three subspecies was tested. Based on different tRNA gene loss and degeneration of these three subspecies, their rearrangement pathways have been inferred. Phylogenetic analysis showed that P. m. peguense is a sister group to (P. m. megalorcephalum and P. m. shiui). Furthermore, the divergence time estimation of these three subspecies coincided with the uplift of the Tibetan Plateau. This study shows that the genetic distances between P. m. peguense and the other two subspecies are comparable to interspecific genetic distances, for example within Mauremys. In general, this study provides new and meaningful insights into the evolution of the three Platysternidae subspecies.

New developments in sequencing technology and nucleotide analysis have allowed us to make great advances in reconstructing anuran phylogeny. As a clade of representative amphibians that have radiated from aquatic to arboreal habitats, our understanding of the systematic status and molecular biology of rhacophorid tree frogs is still limited. We determined two new mitogenomes for the genus Polypedates (Rhacophoridae): P. impresus and P. mutus. We conducted comparative and phylogenetic analyses using our data and seven other rhacophorid mitogenomes. The mitogenomes of the genera Polypedates, Buergeria, and Zhangixalus were almost identical, except that the ATP8 gene in Polypedates had become a non-coding region; Buergeria maintained the legacy “LTPF” tRNA gene cluster compared to the novel “TLPF” order in the other two genera; and B. buergeri and Z. dennysi had no control region (CR) duplication. The resulting phylogenetic relationship supporting the above gene rearrangement pathway suggested parallel evolution of ATP8 gene loss of function (LoF) in Polypedates and CR duplication with concerted evolution of paralogous CRs in rhacophorids. Finally, conflicting topologies in the phylograms of 185 species reflected the advantages of phylogenetic analyses using multiple loci.

The molecular mechanisms underlying the evolution of adaptive immunity-related proteins can be deduced by a thorough examination of the major histocompatibility complex (MHC). Currently, in vertebrates, there is a relatively large amount of research on MHCs in mammals and birds. However, research related to amphibian MHC genes and knowledge about the evolutionary patterns is limited. This study aimed to isolate the MHC class I genes from Chenfu’s Treefrog (Zhangixalus chenfui) and reveal the underlying evolutionary processes. A total of 23 alleles spanning the coding region of MHC class Ia genes were identified in 13 individual samples. Multiple approaches were used to test and identify recombination from the 23 alleles. Amphibian MHC class Ia alleles, from NCBI, were used to construct the phylogenetic relationships in MEGA. Additionally, the partition strategy was adopted to construct phylogenetic relationships using MrBayes and MEGA. The sites of positive selection were identified by FEL, PAML, and MEME. In Chenfu’s Treefrog, we found that: (1) recombination usually takes place between whole exons of MHC class Ia genes; (2) there are at least 3 loci for MHC class Ia, and (3) the diversity of genes in MHC class Ia can be attributed to recombination, gene duplication, and positive selection. We characterized the evolutionary mechanisms underlying MHC class Ia genes in Chenfu’s Treefrog, and in so doing, broadened the knowledge of amphibian MHC systems.

In this study, we sequenced the complete mitochondrial genome of Argali sheep (Ovis ammon). The total length was 16,612 bp, which contained 13 protein-coding genes (PCGs), 22 tRNA genes, 2 rRNA genes, and a control region (D-loop). Eight tRNA genes with one PCG (ND6) encoded on the L-strand, others were encoded on the H-strand. The neighbor-joining analysis shows that Argali sheep has a close relationship with the same genus species of Ovis aries and Ovis orientalis. This study has provided new data for the phylogeny of Argali sheep.

The complete mitochondrial genome of Eurasian lynx (Lynx lynx) from China has been described in this study. It has a circular genome of 16,996 bp with a higher A + T content of 58.65%, and the base composition is A: 32.31%, G: 14.29%, T: 26.35%, C: 27.06%. When compared with the reported individual (KR919624) from China, there are 81 variations and 58 base deletion between the two sequences. The phylogenetic analysis indicated our sequence separated clearly from Eurasian lynx individuals in the previous publications. These results could provide more molecular information for the conservation of Eurasian lynx genetic resources.

Garrulax elliotii belonged to Passeriformes, one of the members of Timaliidae family. It was a kind of unique and resident species habitat in the evergreen broadleaf forest and alpine shrub belt. The complete mitochondrial genome of G. elliotii was constituted by 13 protein-coding genes (PCGs), 22 transfer ribonucleic acid (tRNA) genes, two Ribosomal RNA (12SrRNA and 16SrRNA) genes, and two control regions (D-loop) genes. ND6 and eight tRNA genes (tRNA^Gln, tRNA^Ala, tRNA^Asn, tRNA^Cys, tRNA^Tyr, tRNA^Ser(UCN), tRNA^Pro, and tRNA^Glu) encoded on light strand, and the other 12 protein-coding genes encoded on heavy strand. Mitochondrial genes had been widely used in studies of phylogenetic relationships, molecular diagnostics, and an important tool for genome architecture, it has a significance mean for us provided the complete mitochondrial genome of G. elliotii to the Timaliidae family construction in the future.