The complete mitochondrial genome of the Chinese Sika deer (Cervus nipponTemminck, 1838), and phylogenetic analysis among Cervidae, Moschidae and Bovidae

Molecular Evidence Reveals the Sympatric Distribution of Cervus nippon yakushimae and Cervus nippon taiouanus on Jeju Island, South Korea

Non-native species threaten native ecosystems and species, particularly on islands where rates of endemism and vulnerability to threats are high. Understanding species invasion will aid in providing insights into ecological and evolutionary processes. To identify the non-native sika deer (Cervus nippon) population in Jeju, South Korea, and their phylogenetic affinities, we collected tissue samples from roadkill and the World Natural Heritage Headquarters in Jeju. Mitochondrial DNA cytochrome B (CytB) gene sequences were analyzed to determine two distinct CytB haplotypes. Phylogenetic analysis using maximum likelihood tree revealed two haplotypes of CytB clustered into two different groups representing two subspecies: C. n. yakushimae, native to Japan, and C. n. taiouanus, native to Taiwan. The tentative divergence time between the two subspecies was estimated at 1.81 million years. Our study confirmed that the two subspecies of sika deer are sympatric in the natural ecosystem of Jeju Island. This study provides valuable information to help government and conservation agencies understand alien species and determine control policies for conserving native biodiversity in South Korea.

Comparative Genomics Reveals the Genetic Mechanisms of Musk Secretion and Adaptive Immunity in Chinese Forest Musk Deer

The Chinese forest musk deer (Moschus berezovskii; FMD) is an artiodactyl mammal and is both economically valuable and highly endangered. To investigate the genetic mechanisms of musk secretion and adaptive immunity in FMD, we compared its genome to nine other artiodactyl genomes. Comparative genomics demonstrated that eight positively selected genes (PSGs) in FMD were annotated in three KEGG pathways that were related to metabolic and synthetic activity of musk, similar to previous transcriptome studies. Functional enrichment analysis indicated that many PSGs were involved in the regulation of immune system processes, implying important reorganization of the immune system in FMD. FMD-specific missense mutations were found in two PSGs (MHC class II antigen DRA and ADA) that were classified as deleterious by PolyPhen-2, possibly contributing to immune adaptation to infectious diseases. Functional assessment showed that the FMD-specific mutation enhanced the ADA activity, which was likely to strengthen the immune defense against pathogenic invasion. Single nucleotide polymorphism-based inference showed the recent demographic trajectory for FMD. Our data and findings provide valuable genomic resources not only for studying the genetic mechanisms of musk secretion and adaptive immunity, but also for facilitating more effective management of the captive breeding programs for this endangered species.

The complete mitochondrial genome of Sika deer Cervus nippon hortulorum (Artiodactyla: Cervidae) and phylogenetic studies

Sika deer (Cervus nippon Temminck 1836) are classified in the order Artiodactyla, family Cervidae, subfamily Cervinae. At present, the phylogenetic studies of C. nippon are problematic. In this study, we first determined and described the complete mitochondrial sequence of the wild C. nippon hortulorum. The complete mitogenome sequence is 16 566 bp in length, including 13 protein-coding genes, two rRNA genes, 22 tRNA genes, a putative control region (CR) and a light-strand replication origin (OL). The overall base composition was 33.4% A, 28.6% T, 24.5% C, 13.5% G, with a 62.0% AT bias. The 13 protein-coding genes encode 3782 amino acids in total. To further validate the new determined sequences and phylogeny of Sika deer, phylogenetic trees involving 15 most closely related species available in GenBank database were constructed. These results are expected to provide useful molecular data for deer species identification and further phylogenetic studies of Artiodactyla.

Lights and shadows in the evolutionary patterns of insular bovids

Endemic bovids are intriguing elements of insular faunas. The living species include the Japanese serow (Capricornis crispus) and the Formosan serow (C. swinhoei), the tamaraw from Mindoro, Philippines, (Bubalus mindorensis) and the anoas (B. depressicornis and B. quarlesi), 2 species of dwarf buffalos endemic to Sulawesi, Indonesia. Fossil endemic bovids are only recorded in some Asian, North American and Western Mediterranean islands. Here we present a comprehensive overview of the changes in body size and evolutionary patterns exhibited by both extant and extinct insular bovids. Our appraisal indicates that each insular representative of Bovidae shows its own peculiar evolutionary model, albeit some parallel trends exist (e.g. reduction in body size, allometric changes in limb bones, alteration of the life history traits). Some changes in morphology (e.g. the simplification of horn cores, the increase in hypsodonty, the acquisition of a 'low-gear' locomotion), for instance, appear as common, albeit not general, patterns triggered by a combination of selective forces. Body size patterns support the 'generality of the island rule' and suggest that biotic interaction had/have a major role in influencing body size evolution in these species, although in different ways on different islands. All things considered, available evidence suggest that a major role in the evolution of insular bovids is played by the structure of the insular community, the nature of available niches and by the dynamics of ecological interactions.

The complete mitochondrial genome of the Alpine musk deer (Moschus chrysogaster)

Though extensive efforts have been made to investigate the phylogeny of the Cetartiodactyla, the relationships within the Cetartiodactyla, especially the position of the family Moschidae among Ruminantia families, still remain controversial. To further clarify these relationships, we sequenced the mitochondrial genome of the Alpine musk deer (Moschus chrysogaster), which is an endemic endangered species from China. Then, we conducted molecular phylogenetic analyses of the Alpine musk deer and 49 other species on the basis of Bayesian and maximum likelihood methods. The results show that the Moschidae is the sister group of the Bovidae, both of which form a clade that clusters with the Cervidae. The cetaceans are nested within the Artiodactyla as the sister group of the Hippopotamidae. Among the musk deer, M. chrysogaster and M. berezovskii are more closely related to each other than to M. moschiferus.

The complete mitochondrial genome of sika deer Cervus nippon (Cetartiodactyla: Cervinae) South Anhui population

The complete mitochondrial genome of sika deer (Cervus nippon) South Anhui population is a circular molecule of 16,429 bp in length, containing 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs and a control region. The A + T content of the overall base composition of H-strand is 62% (T: 28.7%; C: 24.6%; A: 33.3%; G: 13.4%). ND2, ND3 and ND5 genes begin with ATA as start codon, ND4L gene begins with GTG as start codon, while other nine protein-coding genes start with a typical ATG initiation codon. ND1, COI, COII, ATP8, ATP6, ND4L, ND5 and ND6 genes are terminated with TAA as stop codon, ND2 ends with TAG, COIII, ND3 and ND4 ends with T, Cyt b ends with AGA.