Termination-associated Sequence Research Articles

The mitochondrial genomes of big-eared bats, Macrotus waterhousii and Macrotus californicus (Chiroptera: Phyllostomidae: Macrotinae)

In the species-rich family Phyllostomidae, the genus Macrotus (‘big eared’ bats) contains only two species; Macrotus waterhousii, distributed in western, central, and southern Mexico, Guatemala and some Caribbean Islands, and Macrotus californicus, distributed in the southwestern USA, and in the Baja California peninsula and the state of Sonora in Mexico. In this study, we sequenced and assembled the mitochondrial genome of Macrotus waterhousii and characterized in detail this genome and that of the congeneric M. californicus. Then, we examined the phylogenetic position of Macrotus in the family Phyllostomidae based on protein coding genes (PCGs). The AT-rich mitochondrial genomes of M. waterhousii and M. californicus are 16,792 and 16,691 bp long, respectively, and each encode 13 PCGs, 22 tRNA genes, 2 rRNA genes, and a putative non-coding control region 1,336 and 1,232 bp long, respectively. Mitochondrial synteny in Macrotus is identical to that reported before for all other cofamilial species. In the two studied species, all tRNAs exhibit a ‘typical’ cloverleaf secondary structure with the exception of trnS1, which lacks the D arm. A selective pressure analysis demonstrated that all PCGs are under purifying selection. The CR of the two species feature three domains previously reported in other mammals, including bats: extended terminal associated sequences (ETAS), central (CD), and conserved sequence block (CSB). A phylogenetic analysis based on the 13 mitochondrial PCGs demonstrated that Macrotus is monophyletic and the subfamily Macrotinae is a sister group of all remaining phyllostomids in our analysis, except Micronycterinae. The assembly and detailed analysis of these mitochondrial genomes represents a step further to continue improving the understanding of phylogenetic relationships within the species-rich family Phyllostomidae.

Mitophylogeny of Pangasiid Catfishes and its Taxonomic Implications for Pangasiidae and the Suborder Siluroidei.

Pangasiidae (catfish order: Siluriformes) comprises 30 valid catfish species in four genera: Pangasius, Pangasianodon, Helicophagus, and Pseudolais. Their systematics are frequently revised due to the addition of newly described species. Although Pangasiidae is known to be a monophyletic family, the generic and phylogenetic relationships among the taxa are poorly resolved. This study characterized three newly obtained complete mitogenomes of Mekong River catfishes from Vietnam (Pangasius mekongensis, Pangasius krempfi, and Pangasianodon hypophthalmus), as well as the inter-and intrafamilial relationships of the Pangasiidae and catfish families in Siluroidei. The genomic features of their mitogenomes were similar to those of previously reported pangasiids, including all regulatory elements, extended terminal associated sequences (ETAS), and conserved sequence blocks (CSBs) (CSB-1, CSB-2, CSB-3, and CSBs, A to F) in the control region. A comprehensive phylogeny constructed from datasets of multiple 13 PCG sequences from 117 complete mitogenomes of 32 recognized siluriform families established Pangasiidae as monophyletic and a sister group of Austroglanididae. The [Pangasiidae + Austroglanididae] + (Ictaluridae + Cranoglanididae) + Ariidae] clade is a sister to the "Big Africa" major clade of Siluriformes. Furthermore, both phylogenies constructed from the single barcodes (83 partial cox1 and 80 partial cytB, respectively) clearly indicate genus relationships within Pangasiidae. Pangasianodon was monophyletic and a sister to the (Pangasius + Helicophagus + Pseudolais) group. Within the genus Pangasius, P. mekongensis was placed as a sister taxon to P. pangasius. Pangasius sanitwongsei was found to be related to and grouped with Pangasianodon, but in single-gene phylogenies, it was assigned to the Pangasius + Helicophagus + Pseudolais group. The datasets in this study are useful for studying pangasiid systematics, taxonomy and evolution.

The complete mitochondrial genome of Schizothorax eurystomus Kessler, 1872 (Cypriniformes, Cyprinidae)

Schizothorax eurystomus, Kessler 1872 is a unique economic fish in Xinjiang, China that is rarely seen in the market. Next-generation sequencing (NGS) was used to determine the complete mitochondrial genome of S. eurystomus collected from the Yarkand River in Xinjiang. The results showed that the mitochondrial genome is a circular, 16,488-bp-long nucleotide with the typical vertebrate genome structure of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and a control region. The termination-associated sequence (TAS), central conserved sequence block (CSB), and conserved sequence block were detected in the control region. Phylogenetic analysis placed S. eurystomus in a fully supported clade with S. biddulphi, and that clade was sister to S. yunnanensis. To our knowledge, this is the first study on the complete mitochondrial genome of S. eurystomus from the Yarkand River in Xinjiang, and it provides baseline genetic information for future studies.

The complete mitochondrial genome of the roosterfish Nematistius pectoralis Gill 1862: Purifying selection in protein coding genes, organization of the control region, and insights into family-level phylogenomic relationships in the recently erected order Carangiformes

The roosterfish Nematistius pectoralis is considered as one of the most magnificent sportfishes worldwide. This study developed the first genomic resource for this trophy-fish that is heavily targeted by the fly-fishing industry. The complete mitochondrial genome of N. pectoralis was assembled using short read sequences and analyzed in detail. The mitochondrial genome of N. pectoralis is 16,537 bp in length and comprises 13 protein-coding genes (PCGs), 2 ribosomal RNA genes (12S and 16S), and 22 transfer RNA genes. A long intergenic space 770 bp in length was assumed to be the d-loop or Control Region (CR). Most of the PCGs and tRNA genes are encoded in the l-strand. All PCGs are under purifying selection and atp8 and nad6 experienced the least selective pressure. All tRNAs exhibit a cloverleaf secondary structure except tRNA-Serine 1 that lacked the d-arm loop. The d-loop of N. pectoralis exhibits three domains commonly described in other fishes; extended terminal associated sequences (ETAS), central, and conserved sequence block (CSB). A ML phylogenetic reconstruction of the newly recognized order Carangiformes based on all 13 mitochondrial PCGs did not support the monophyly of this clade but recognized several families as monophyletic, including Bothidae, Carangidae, Istiophoridae, Latidae, Paralichthyidae, Polynemidae, and Rhombosoleidae. Nematistius pectoralis was sister to a clade composed of Toxotes chatareus (fam. Toxotidae) + Lactarius lactarius (fam. Lactariidae). This genomic resource developed for N. pectoralis will aid in improving our understanding of the population genomics of and strengthen conservation and management strategies in this remarkable trophy-fish.

Complete Mitochondrial Genomes of Five Racerunners (Lacertidae: Eremias) and Comparison with Other Lacertids: Insights into the Structure and Evolution of the Control Region.

Comparative studies on mitochondrial genomes (mitogenomes) as well as the structure and evolution of the mitochondrial control region are few in the Lacertidae family. Here, the complete mitogenomes of five individuals of Eremias scripta (2 individuals), Eremias nikolskii, Eremias szczerbaki, and Eremias yarkandensis were determined using next-generation sequencing and were compared with other lacertids available in GenBank. The circular mitogenomes comprised the standard set of 13 protein-coding genes (PCGs), 22 transfer RNA genes, 2 ribosomal RNA genes and a long non-coding control region (CR). The extent of purifying selection was less pronounced for the COIII and ND2 genes in comparison with the rest of the PCGs. The codons encoding Leucine (CUN), Threonine, and Isolecucine were the three most frequently present. The secondary structure of rRNA of Lacertidae (herein, E. scripta KZL15 as an example) comprised four domains and 28 helices for 12S rRNA, with six domains and 50 helices for 16S rRNA. Five types and twenty-one subtypes of CR in Lacertidae were described by following the criteria of the presence and position of tandem repeats (TR), termination-associated sequence 1 (TAS1), termination-associated sequence 2 (TAS2), conserved sequence block 1 (CBS1), conserved sequence block 2 (CSB2), and conserved sequence block 3 (CSB3). The compositions of conserved structural elements in four genera, Acanthodactylus, Darevskia, Eremias, and Takydromus, were further explored in detail. The base composition of TAS2 – TATACATTAT in Lacertidae was updated. In addition, the motif “TAGCGGCTTTTTTG” of tandem repeats in Eremias and the motif ”GCGGCTT” in Takydromus were presented. Nucleotide lengths between CSB2 and CSB3 remained 35 bp in Eremias and Darevskia. The phylogenetic analyses of Lacertidae recovered the higher-level relationships among the three subfamilies and corroborated a hard polytomy in the Lacertinae phylogeny. The phylogenetic position of E. nikolskii challenged the monophyly of the subgenus Pareremias within Eremias. Some mismatches between the types of CR and their phylogeny demonstrated the complicated evolutionary signals of CR such as convergent evolution. These findings will promote research on the structure and evolution of the CR and highlight the need for more mitogenomes in Lacertidae.

The complete mitochondrial genome of the Honduran white bat Ectophylla alba (Allen 1982) (Chiroptera: Phyllostomidae).

The Honduran white bat, Ectophylla alba (Allen 1982), is one of eight species belonging to the family Phyllostomidae that exclusively roosts in tents. Due to its restricted distribution, habitat specificity, and diet requirements, E. alba has been strongly affected by habitat loss and fragmentation during the last decade. In this study, we developed the first genomic resource for this species; we assembled and analyzed in detail the complete mitochondrial genome of E. alba. The mitogenome of E. alba is 16,664bp in length and is comprised of 13 protein coding genes (PCGs), 2 ribosomal RNA genes, 22 transfer RNA genes (tRNAs), and a putative Control Region (CR) 1,232bp in length. Gene arrangement in the mitochondrial chromosome of E. alba is identical to that reported before in other species of co-familiar bats. All PCGs are under purifying selection, with atp8 experiencing the least selective pressure. In all PCGs, codons ending with adenine are preferred over others ending in thymine and cytosine. Except tRNA-Serine 1, all tRNAs exhibit a cloverleaf secondary structure. The CR of E. alba exhibits three domains commonly described in other mammals, including bats; extended terminal associated sequences (ETAS), central, and conserved sequence block (CSB). A ML phylogenetic reconstruction of the family Phyllostomidae based on all 13 mitochondrial PCGs confirms the monophyletic status of the subfamily Sternodermatinae and indicates the close relationship between E. alba and the genus Artibeus. This is the first genomic resource developed for E. alba and represents the first step to improving our understanding of the genomic underpinnings involved in the evolution of specialization as well as acclimatization and adaptation to local and global change of specialist bats.

The complete mitochondrial genome of the half-fin anchovy, Setipinna tenuifilis (Valenciennes, 1848)

The complete mitochondrial genome of the half-fin anchovy, Setipinna tenuifilis collected from Yellow and Bohai Seas was determined by next-generation sequencing. The mitogenome is a circular molecule 16,668 bp in length, including the typical structure of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and a control region. The termination-associated sequence (TAS), central conserved sequence block (CSB) and CSB are detected in the control region. The gene contents of the mitogenome are identical to those observed in most bony fishes.

The complete mitochondrial genome of Platycephalus sp.1 (Teleostei, Platycephalidae) obtained by whole genome sequencing

In this study, we used next-generation sequencing to obtain the complete mitochondrial genome of Platycephalus sp.1. This mitochondrial genome, consisting of 16,552 base pairs (bp), contains 13 protein-coding genes, two ribosomal RNAs, 22 transfer RNAs, and two non-coding control regions (control region and origin of light-strand replication) as those found in other vertebrates. Control region, of 877 bp in length, is located between tRNAPro and tRNAPhe. Within the control region, typical conserved domains, such as the termination-associated sequence, central and conserved sequence blocks domains were identified. The overall base composition shows 25.83% of T, 29.98% of C, 27.01% of A, and 17.18% of G, with a slight A + T rich feature (52.84%). The complete mitogenome data provides useful genetic markers for the studies on the molecular identification, population genetics, phylogenetic analysis and conservation genetics.

The complete mitochondrial genome of the spiny red gurnard Chelidonichthys spinosus McClelland, 1844 (Scorpaeniformes: Triglidae)

The spiny red gurnard, Chelidonichthys spinosus is a common marine economic fish species along the coast of China. In the present study, the complete mitochondrial genome of spiny red gurnard collected from the Yangtze Estuary was determined by next-generation sequencing (NGS). The mitogenome is a circular nucleotide 16,466 bp in length and has the typical vertebrate genome structure of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and two control regions (Origin of Heavy chain and Origin of Light chain). The termination associated sequence (TAS), the central conserved sequence block (central CSB), and the conserved sequence block (CSB) were detected in the control region. Phylogenetic analysis of C. spinosus places in a fully supported clade with C. kumu in a sister position to Eutrigla gurnardus. The complete mitochondrial genome sequence of the spiny red gurnard provides baseline genetic information for future studies on the molecular systematics and phylogeny of bony fishes in the Triglidae.

Complete mitochondrial genome sequence of Lepus yarkandensis Günther, 1875 (Lagomorpha, Leporidae): characterization and phylogenetic analysis.

Lepus yarkandensis is a national second-class protected animal endemic to China and distributed only in the hot and arid Tarim Basin in Xinjiang. We sequenced and described the complete mitogenome of L. yarkandensis to analyze its characteristics and phylogeny. The species’ DNA is a 17,047 bp circular molecule that includes 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes, and one control region. The overall base composition was as follows: A, 31.50%; T, 29.40%; G, 13.30% and C, 25.80%, with a high A+T bias of 60.9%. In the PCGs, ND6 had deviation ranges for AT skew (–0.303) and GC skew (0.636). The Ka/Ks values of ND1 (1.067) and ND6 (1.352) genes were >1, indicating positive selection, which might play an important role in the adaptation of L. yarkandensis to arid and hot environments. The conserved sequence block, the central conserved domain, and the extended termination-associated sequences of the control region and their features were identified and described. The phylogenetic tree based on the complete mitogenome showed that L. yarkandensis was closely related to the sympatric Lepus tibetanus pamirensis. These novel datasets of L. yarkandensis can supply basic data for phylogenetic studies of Lepus spp., apart from providing essential and important resource for further genetic research and the protection of this species.

Complete Mitochondrial Genome of Three Species of the Genus Microtus (Arvicolinae, Rodentia).

Simple SummaryThe knowledge and analysis of mitochondrial genomes can be useful to answer some interesting questions about the biology of some species. This is the case of vole species that are characterized by unusual genetic features related to sex chromosomes and variation of their karyotypes. In this work, we describe the mitochondrial genomes of three emblematic vole species, demonstrating that they are highly conserved in the organization of their protein coding, transfer RNA and ribosomal RNA genes. In addition, we performed a detailed analysis of their control regions identifying several domains and conserved boxes related to mitochondrial DNA regulation. Finally, a phylogenetic analysis with the mitochondrial DNA confirmed the established phylogeny of the analyzed voles.The 65 species of the genus Microtus have unusual sex-related genetic features and a high rate of karyotype variation. However, only nine complete mitogenomes for these species are currently available. We describe the complete mitogenome sequences of three Microtus, which vary in length from 16,295 bp to 16,331 bp, contain 13 protein-coding genes (PCGs), two ribosomal RNA genes, 22 transfer RNA genes and a control region. The length of the 13 PCGs and the coded proteins is the same in all three species, and the start and stop codons are conserved. The non-coding regions include the L-strand origin of replication, with the same sequence of 35 bp, and the control region, which varies between 896 bp and 930 bp in length. The control region includes three domains (Domains I, II and III) with extended termination-associated sequences (ETAS-1 and ETAS-2) in Domain I. Domain II and Domain III include five (CSB-B, C, D, E and F) and three (CSB-1, CSB-2, and CSB-3) conserved sequence blocks, respectively. Phylogenetic reconstructions using the mitochondrial genomes of all the available Microtus species and one representative species from another genus of the Arvicolinae subfamily reproduced the established phylogenetic relationships for all the Arvicolinae genera that were analyzed.

Sequencing and characterisation of complete mitogenome DNA for Rasbora sarawakensis (Cypriniformes: Cyprinidae: Rasbora) with phylogenetic consideration

The Blueline Rasbora (Rasbora sarawakensis) is a small ray-finned fish categorized under the genus Rasbora in the Cyprinidae family. In this study, the complete mitogenome sequence of R. sarawakensis was sequenced using four primers targeting overlapping regions. The mitogenome is 16,709 bp in size, accommodating 22 transfer RNA genes, 13 protein-coding genes, two ribosomal RNA genes and a putative control region. Identical gene organisation was detected between this species and other genus counterparts. The heavy strand houses 28 genes while the light strand stores the other nine genes. Most protein-coding genes employ ATG as start codon, excluding COI gene, which utilizes GTG instead. The central conserved sequence blocks (CSB-F, CSB-E and CSB-D), variable sequence blocks (CSB-3, CSB-2 and CSB-1) as well as the terminal associated sequence (TAS) are conserved in the control region. The maximum likelihood phylogenetic tree revealed the divergence of R. sarawakensis from the basal region of the Rasbora clade, where its evolutionary relationships with R. maculatus and R. pauciperforata are poorly resolved as indicated by the low bootstrap values. This work acts as steppingstone towards further molecular evolution and population genetics studies of Rasbora genus in future.

Characterization of the Complete Mitochondrial Genome of Arius dispar (Siluriformes: Ariidae) and Phylogenetic Analysis Among Sea Catfishes

The mitochondrial genome (mitogenome) was 16792 bp in length, containing 13 protein coding genes (PCGs), two rRNA genes (12S rRNA and 16S rRNA), 22 tRNA genes, and two main non-coding regions. Among these 37 genes, 28 genes were encoded on the heavy strand, while 9 genes were transcribed on the light strand. The non-coding regions of A. dispar included a control region, a light strand replication and another 11 intergenic spacers. The CR of A. dispar contained 8 conserved sequence blocks (CSBs), a termination-associated sequence (TAS) and a pyrimidine tract. Phylogenetic analysis based on 12 PCGs revealed that A. dispar was genetically closest to Arius arius. The families Schilbeidae, Claroteidae, Mochokidae, and Ariidae formed a closely evolved clade. Molecular information from this research introduces mitogenomice data of A. dispar and suggests the phylogenetic relationships among Siluriformes.

Sequencing and characterization of complete mitogenome DNA of Rasbora tornieri (Cypriniformes: Cyprinidae: Rasbora) and its evolutionary significance

The yellowtail rasbora (Rasbora tornieri) is a miniature ray-finned fish categorized under the genus Rasbora in the family of Cyprinidae. In this study, a complete mitogenome sequence of R. tornieri was sequenced using four primers targeting two halves of the mitogenome with overlapping flanking regions. The size of mitogenome was 16,573 bp, housing 22 transfer RNA genes, 13 protein-coding genes, two ribosomal RNA genes and a putative control region. Identical gene organization was detected between this species and other members of Rasbora genus. The heavy strand encompassed 28 genes while the light strand accommodated the other nine genes. Most protein-coding genes execute ATG as start codon, excluding COI and ND3 genes, which utilized GTG instead. The central conserved sequence blocks (CSB-E, CSB-F and CSB-D), variable sequence blocks (CSB-1, CSB-3 and CSB-2) as well as the terminal associated sequence (TAS) were conserved within the control region. The maximum likelihood phylogenetic family tree revealed the divergence of R. tornieri from the basal region of the Rasbora clade, where its evolutionary relationships with other Rasbora members are poorly resolved as indicated by the low bootstrap values. This work acts as window for further population genetics and molecular evolution studies of Rasbora genus in future.

Complete mitochondrial DNA genome of banded cichlid Heros severus Heckel, 1840 (Perciformes: Cichlidae)

In this study, we sequenced the complete mitochondrial genome of Heros severus Heckel, 1840 (Perciformes, Cichlidae). This mitochondrial genome, consisting of 16,577 base pairs (bp), contains 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and 2 noncoding control regions (control region and origin of light-strand replication) as those found in other vertebrates. Control region, of 917 bp in length, is located between tRNAPro and tRNAPhe. Within the control region, typical conserved domains, such as the termination-associated sequence (TAS), central, and conserved sequence blocks domains were identified. The overall base composition of the heavy strand shows 27.6% of T, 26.3% of C, 29.3% of A, and 16.8% of G, with a slight A + T rich feature (56.9%). The complete mitogenome data provide useful genetic markers for the studies on the molecular identification, population genetics, phylogenetic analysis, and conservation genetics.

The complete mitochondrial genome of Jaydia lineata (Perciformes, Apogonidae) obtained by next-generation sequencing

In this study, we used next-generation sequencing to obtain the complete mitochondrial genome of Jaydia lineata. This mitochondrial genome, consisting of 16,510 base pairs (bp), contains 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs and 2 noncoding control regions (control region and origin of light-strand replication) as those found in other vertebrates. Control region, of 848 bp in length, is located between tRNAPro and tRNAPhe. Within the control region, typical conserved domains, such as the termination-associated sequence, central and conserved sequence blocks domains were identified. The overall base composition shows 26.71% of T, 28.46% of C, 27.24% of A and 17.58% of G, with a slight A + T rich feature (53.95%). The complete mitogenome data provides useful genetic markers for the studies on the molecular identification, population genetics, phylogenetic analysis and conservation genetics.

Sequencing and Characterisation of Complete Mitochondrial DNA Genome for Trigonopoma pauciperforatum (Cypriniformes: Cyprinidae: Danioninae) with Phylogenetic Consideration.

The Trigonopoma pauciperforatum or the redstripe rasbora is a cyprinid commonly found in marshes and swampy areas with slight acidic tannin-stained water in the tropics. In this study, the complete mitogenome sequence of T. pauciperforatum was first amplified in two parts using two pairs of overlapping primers and then sequenced. The size of the mitogenome is 16,707 bp, encompassing 22 transfer RNA genes, 13 protein-coding genes, two ribosomal RNA genes and a putative control region. Identical gene organisation was detected between this species and other family members. The heavy strand accommodates 28 genes while the light strand houses the remaining nine genes. Most protein-coding genes utilise ATG as start codon except for COI gene which uses GTG instead. The terminal associated sequence (TAS), central conserved sequence block (CSB-F, CSB-D and CSB-E) as well as variable sequence block (CSB-1, CSB-2 and CSB-3) are conserved in the control region. The maximum likelihood phylogenetic tree revealed the divergence of T. pauciperforatum from the basal region of the major clade, where its evolutionary relationships with Boraras maculatus, Rasbora cephalotaenia and R. daniconius are poorly resolved as suggested by the low bootstrap values. This work contributes towards the genetic resource enrichment for peat swamp conservation and comprehensive in-depth comparisons across other phylogenetic researches done on the Rasbora-related genus.

The complete mitochondrial genome of Talpa aquitania (Talpidae; Insectivora), a mole species endemic to northern Spain and southern France.

The complete mitogenome sequence of Talpa aquitania, a recently described Talpa species, was assembled using whole-genome sequencing data. It varies in length from 16,776 to 16,846 bp, contains 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, one origin of L-strand replication, and a control region. In the control region, which varied from 1320 to 1390 bp, we identified the extended termination-associated sequence (ETAS-1 and ETAS-2) and the conserved sequence blocks (CSB-1, 2, 3, B, C, D, E, F). In addition, this region includes a 10 bp tandem repeat DNA sequence, with a variable number of repeats that suggest the existence of heteroplasmy. Phylogeny reconstructions based on Maximum Likelihood, Neighbor-joining and Bayesian inference analyses yielded phylogenies with similar topologies demonstrating that T. aquitania and T. occidentalis are sister species.

Sequencing and Characterisation of Complete Mitogenome DNA for Rasbora hobelmani (Cyprinidae) with Phylogenetic Consideration

The Kottelat rasbora Rasbora hobelmani is a small ray-finned fish categorized under the genus Rasbora in the Cyprinidae family. In this study, the complete mitogenome sequence of R. hobelmani was sequenced using two pairs of primers covering overlapping regions. The mitogenome is 16 541 bp in length, housing 22 transfer RNA genes, 13 protein-coding genes, two ribosomal RNA genes and one putative control region. Identical gene organisation was spotted between this species and other Rasbora genus members. The heavy strand contains 28 genes while the light strand contains the remaining nine genes. Most protein-coding genes employ ATG as start codon, except for the COI gene, which exploits GTG instead. The central conserved sequence blocks (CSB-F, CSB-E and CSB-D), variable sequence blocks (CSB-3, CSB-2 and CSB-1) as well as the terminal associated sequence (TAS) are conserved in the control region. The maximum likelihood phylogenetic tree revealed the close phylogeny of R. hobelmani with R. sumatrana, R. aprotaenia, R. lateristriata and R. steineri with bootstrap value of at least 99%. This work acts as milestone towards future evolution and population genetics studies of this species as well as the Rasbora genus.

Sequencing and characterization of complete mitogenome DNA for Rasbora myersi (Cypriniformes: Cyprinidae: Rasbora) and its evolutionary significance

The Seluang fish (Rasbora myersi) is a small ray-finned fish categorized under the genus Rasbora in the Cyprinidae family. In this study, the complete mitogenome sequence of R. myersi was sequenced using two primer pairs targeting overlapping regions. The mitogenome is 16,581 bp in length, encompassing 22 transfer RNA genes, 13 protein-coding genes, two ribosomal RNA genes and a putative control region. Identical gene organisation was observed between this species and other genus counterparts. The heavy strand accommodates 28 genes while the light strand houses the other nine genes. Most protein-coding genes utilize ATG as start codon, excluding COI gene, which employs GTG instead. The central conserved sequence blocks (CSB-F, CSB-E and CSB-D), variable sequence blocks (CSB-3, CSB-2 and CSB-1) as well as the terminal associated sequence (TAS) are conserved within the control region. The R. myersi formed a trio with R. borapetensis and R. argyrotaenia in a moderately strong clade with bootstrap value of 86. This work acts as essential gateway towards further molecular evolution and population genetics studies of the Rasbora genus in future.