Genetic similarities and phylogenetic analysis of Muntjac (Muntiacus spp. ) by comparing the nucleotide sequence of 16S rRNA and cytochrome B genome / Semelhanças genéticas e análise filogenética de muntjac (Muntiacus spp. ) comparando a sequência de nucleótidos de rRNA 16S e genoma citocromo B

This study aimed to identify the phylogenetic similarities among the muntjac (Muntiacus spp.). The phylogenetic similarities among seven major muntjac species were studied by comparing the nucleotide sequence of 16s rRNA and cytochrome b genome. Nucleotide sequences, retrieved from NCBI databases were aligned by using DNASTAR software. A phylogenetic tree was created for the selected species of muntjac by using the maximum likelihood method on MEGA7 software. The results of nucleotide sequences (16s rRNA) showed phylogenetic similarities between, the M. truongsonensis and M. rooseveltorum had the highest (99.2%) while the lowest similarities (96.8%) found between M. crinifrons and M. putaoensi. While the results of nucleotide sequences (Cty b) showed the highest similarity (100%) between M. muntjak and M. truongsonensis and the lowest s (91.5%) among M. putaoensis and M. crinifrons. The phylogenetic tree of muntjac species (16s rRNA gene) shows the main two clusters, the one including M. putaoensis, M. truongsonensis, M. rooseveltorum, and M. muntjak, and the second one including M. crinifrons and M. vuquangensis. The M. reevesi exists separately in the phylogenetic tree. The phylogenetic tree of muntjac species using cytochrome b genes shows that the M. muntjak and M. truongsonensis are clustered in the same group.

Este estudo visou identificar as semelhanças filogenéticas entre os muntjac (Muntiacus spp.). As semelhanças filogenéticas entre sete grandes espécies muntjac foram estudadas comparando a sequência de nucleótidos de 16s rRNA e genoma citocromo b. As sequências de nucleótidos, obtidas a partir de bases de dados NCBI, foram alinhadas utilizando o software DNASTAR. Foi criada uma árvore filogenética para as espécies selecionadas de muntjac utilizando o método de probabilidade máxima no software MEGA7. Os resultados das sequências de nucleótidos (16s rRNA) mostraram semelhanças filogenéticas entre o M. truongsonensis e o M. rooseveltorum tiveram o maior número (99,2%) enquanto as semelhanças mais baixas (96,8%) encontradas entre M. crinifrons e M. putaoensi. Enquanto os resultados das sequências de nucleótidos (Cty-b) apresentaram a maior semelhança (100%) entre M. muntjak e M. truongsonensis e os mais baixos (91,5%) entre M. putaoensis e M. crinifrons. A árvore filogenética das espécies muntjac (gene rRNA 16s) mostra os dois principais aglomerados, o que inclui M. putaoensis, M. truongsonensis, M. rooseveltorum e M. muntjak, e o segundo incluindo M. crinifrons e M. vuquangensis. O M. reevesi existe separadamente na árvore filogenética. A árvore filogenética das espécies muntjac usando genes citocromo b mostra que os M. muntjak e M. truongsonensis estão agrupados no mesmo grupo.

Molecular mechanisms and topological consequences of drastic chromosomal rearrangements of muntjac deer.

Muntjac deer have experienced drastic karyotype changes during their speciation, making it an ideal model for studying mechanisms and functional consequences of mammalian chromosome evolution. Here we generated chromosome-level genomes for Hydropotes inermis (2n = 70), Muntiacus reevesi (2n = 46), female and male M. crinifrons (2n = 8/9) and a contig-level genome for M. gongshanensis (2n = 8/9). These high-quality genomes combined with Hi-C data allowed us to reveal the evolution of 3D chromatin architectures during mammalian chromosome evolution. We find that the chromosome fusion events of muntjac species did not alter the A/B compartment structure and topologically associated domains near the fusion sites, but new chromatin interactions were gradually established across the fusion sites. The recently borne neo-Y chromosome of M. crinifrons, which underwent male-specific inversions, has dramatically restructured chromatin compartments, recapitulating the early evolution of canonical mammalian Y chromosomes. We also reveal that a complex structure containing unique centromeric satellite, truncated telomeric and palindrome repeats might have mediated muntjacs' recurrent chromosome fusions. These results provide insights into the recurrent chromosome tandem fusion in muntjacs, early evolution of mammalian sex chromosomes, and reveal how chromosome rearrangements can reshape the 3D chromatin regulatory conformations during species evolution.

A new viewpoint on antlers reveals the evolutionary history of deer (Cervidae, Mammalia).

Recent molecular phylogeny of deer revealed that the characters of antlers previously focused on are homoplasious, and antlers tend to be considered problematic for classification. However, we think antlers are important tools and reconsidered and analysed the characters and structures to use them for classification. This study developed a method to describe the branching structure of antlers by using antler grooves, which are formed on the antlers by growth, and then projecting the position of the branching directions of tines on the burr circumference. By making diagrams, comparing the branching structure interspecifically, homologous elements (tines, beams, and processes) of the antlers of 25 species of 16 genera were determined. Subsequently, ancestral state reconstruction was performed on the fixed molecular phylogenetic tree. It was revealed that Capreolinae and Cervini gained respective three-pointed antlers independently, and their subclades gained synapomorphous tines. We found new homologous and synapomorphous characters, as the antler of Eld's deer, which has been classified in Rucervus, is structurally close to that of Elaphurus rather than that of Rucervus, consistent with molecular phylogeny. The methods of this study will contribute to the understanding of the branching structure and phylogeny of fossil species and uncover the evolutionary history of Cervidae.

Phylogeography of red muntjacs reveals three distinct mitochondrial lineages.

BACKGROUND: The members of the genus Muntiacus are of particular interest to evolutionary biologists due to their extreme chromosomal rearrangements and the ongoing discussions about the number of living species. Red muntjacs have the largest distribution of all muntjacs and were formerly considered as one species. Karyotype differences led to the provisional split between the Southern Red Muntjac (Muntiacus muntjak) and the Northern Red Muntjac (M. vaginalis), but uncertainties remain as, so far, no phylogenetic study has been conducted. Here, we analysed whole mitochondrial genomes of 59 archival and 16 contemporaneous samples to resolve uncertainties about their taxonomy and used red muntjacs as model for understanding the evolutionary history of other species in Southeast Asia. RESULTS: We found three distinct matrilineal groups of red muntjacs: Sri Lankan red muntjacs (including the Western Ghats) diverged first from other muntjacs about 1.5 Mya; later northern red muntjacs (including North India and Indochina) and southern red muntjacs (Sundaland) split around 1.12 Mya. The diversification of red muntjacs into these three main lineages was likely promoted by two Pleistocene barriers: one through the Indian subcontinent and one separating the Indochinese and Sundaic red muntjacs. Interestingly, we found a high level of gene flow within the populations of northern and southern red muntjacs, indicating gene flow between populations in Indochina and dispersal of red muntjacs over the exposed Sunda Shelf during the Last Glacial Maximum. CONCLUSIONS: Our results provide new insights into the evolution of species in South and Southeast Asia as we found clear genetic differentiation in a widespread and generalist species, corresponding to two known biogeographical barriers: The Isthmus of Kra and the central Indian dry zone. In addition, our molecular data support either the delineation of three monotypic species or three subspecies, but more importantly these data highlight the conservation importance of the Sri Lankan/South Indian red muntjac.

Comparative gene mapping in cattle, Indian muntjac, and Chinese muntjac by fluorescence in situ hybridization.

The Indian muntjac (Muntiacus muntjak vaginalis) has a karyotype of 2n = 6 in the female and 2n = 7 in the male. The karyotypic evolution of Indian muntjac via extensive tandem fusions and several centric fusions are well documented by molecular cytogenetic studies mainly utilizing chromosome paints. To achieve higher resolution mapping, a set of 42 different genomic clones coding for 37 genes and the nucleolar organizer region were used to examine homologies between the cattle (2n = 60), human (2n = 46), Indian muntjac (2n = 6/7) and Chinese muntjac (2n = 46) karyotypes. These genomic clones were mapped by fluorescence in situ hybridization (FISH). Localization of genes on all three pairs of M. m. vaginalis chromosomes and on the acrocentric chromosomes of M. reevesi allowed not only the analysis of the evolution of syntenic regions within the muntjac genus but also allowed a broader comparison of synteny with more distantly related species, such as cattle and human, to shed more light onto the evolving genome organization.

Tandem chromosome fusions in karyotypic evolution of Muntiacus: evidence from M. feae and M. gongshanensis.

The muntjacs (Muntiacus, Cervidae) are famous for their rapid and radical karyotypic diversification via repeated tandem chromosome fusions, constituting a paradigm for the studies of karyotypic evolution. Of the five muntjac species with defined karyotypes, three species (i.e. Muntiacus reevesi, 2n = 46; M. m. vaginalis, 2n = 6/7; and M. crinifrons, 2n = 8/9) have so far been investigated by a combined approach of comparative chromosome banding, chromosome painting and BAC mapping. The results demonstrated that extensive centromere-telomere fusions and a few centric fusions are the chromosomal mechanisms underlying the karyotypic evolution of muntjacs. Here we have applied the same approach to two additional muntjac species with less well-characterized karyotypes, M. feae (2n = 14 male ) and M. gongshanensis (2n = 8 female). High-resolution G-banded karyotypes for M. feae and M. gongshanensis are provided. The integrated analysis of hybridization results led to the establishment of a high-resolution comparative map between M. reevesi, M. feae, and M. gongshanensis, proving that all tandem fusions underpinning the karyotypic evolution of these two muntjac species are also centromere-telomere fusions. Furthermore, the results have improved our understanding of the karyotypic relationships of extant muntjac species and provided compelling cytogenetic evidence that supports the view that M. crinifrons, M. feae, and M. gongshanensis should each be treated as a distinct species.

Genetic diversity of Chinese water deer (Hydropotes inermis inermis): implications for conservation.

The Chinese water deer (Hydropotes inermis inermis) is endemic to China. Historically, the species was widely distributed, but now, habitat loss and poaching have reduced its range and number drastically. In order to provide useful information for its conservation, we have investigated the genetic diversity and population structure of the Chinese water deer by analyzing the 403 bp fragment of the mitochondrial DNA (mtDNA) control region (D-loop). Eighteen different haplotypes were detected in 40 samples. Overall, Chinese water deer have a relatively high-genetic diversity compared to other rare cervid species, with a haplotype diversity of 0.923+/-0.025 and nucleotide diversity of 1.318 +/- 0.146%. No obvious phylogenetic structure among haplotypes was found for samples of different origin. An analysis of molecular variance (AMOVA) showed significant differentiation between the Zhoushan and the mainland population (F(ST)= 0.088, P < 0.001; Phi( ST ) = 0.075, P = 0.043), which suggests that exchanges of individuals between Zhoushan and the mainland should be avoided. We also recommend that a breeding center be set up for the mainland population.

[Phylogenetic relationship between tufted deer(Elaphodus cephalophus) and Muntiacus deer is revealed by the exon and intron of K+ channel gene].

In this study, partial fragments of potassium ion channel gene were amplified using the genomic DNA of muntjak, reevesi, crinifrons, and Elaphodus cephalophus. The PCR products were ligated to the plasmid of pMD18-T Vector by the method of direct T-A cloning. The positive clones were identified by colony PCR. The sequences of the recombinant clones were determined using M13-47/RV-M universal primers and aligned by the software CLUSTALW. The nucleotide divergences of exon were 0.90%-1.44% among three species of Muntiacus, 0.90%-1.26% between E. cephalophus and each of Muntiacus deer. In the nucleotide of intron there is 0%-1.22% difference among these muntjac deers, and the divergene reached about 1.83% between E. cephalophus and the three species of Muntiacus. Using the software of MEGA to analyse molecular phylogeny, Phylogenetic trees were constructed with neighbor-joining method and maximum parsimony method. The result showed Muntiacus, crinifrons is most closely related to muntjak, with reevesi as their sister species. E. cephalophus is in the other genus.

Evolution of the black muntjac (Muntiacus crinifrons) karyotype revealed by comparative chromosome painting.

The black muntjac (Muntiacus crinifrons) has an unusual karyotype of 2n = 8 in females and 2n = 9 in males. We have studied the evolution of this karyotype by hybridising chromosome-specific paints derived from flow-sorted chromosomes of the Chinese muntjac (M. reevesi, 2n = 46) to chromosomes of the black muntjac. The hybridisation pattern allowed us to infer chromosomal homologies between these two species. Tandem and centromeric fusions, reciprocal translocations, and insertions are involved in the reduction of the diploid number from 2n = 46 to 2n = 8, 9. The painting patterns further show complex chromosomal rearrangements in the male black muntjac which involve more than half the karyotype, including both sex chromosomes. Since early meiosis is reported to be normal without any visible inversion loops of the synaptonemal complex, the observed chromosomal rearrangements would lead to heterosynapsis and, therefore, leave a large fraction of the male black muntjac karyotype balanced between the two sexes.

Phylogeny of Muntiacus (Cervidae) based on mitochondrial DNA restriction maps.

Mitochondrial DNA restriction maps for 12 restriction enzymes of four species of muntjacs--Indian muntjac (M. muntjak), Gongshan muntjac (M. gongshanensis), black muntjac (M. crinifrons), and Chinese muntjac (M. reevesi)--were compared to estimate the phylogenetic relationships among them. Phylogenetic trees were constructed by both distance and parsimony methods. The two resulting trees share a similar topology, which indicates that the black muntjac and the Gongshan muntjac are closely related, followed by the Chinese muntjac; the Indian muntjac is the sister taxon to all the other muntjacs.