Displaying publications 1 - 20 of 170 in total

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  1. Phylogenetic Relationships of Sun Bear (Helarctos malayanus) Based on Mitochondrial DNA from Sumatra and Other Southeast Asian Regions
    Roesma DI, Tjong DH, Syaifullah, Aidil DR, Maulana MR, Salis VM
    Pak J Biol Sci, 2023 Nov;26(12):615-627.
    PMID: 38334154 DOI: 10.3923/pjbs.2023.615.627
    <b>Background and Objective:</b> The <i>Helarctos malayanus</i> is the sole bear species-living in Indonesia (Sumatra and Borneo). The available biological data for sun bears (<i>H. malayanus</i>) in Sumatra is limited, especially for morphological and genetic data. A morphological approach is difficult to do. Therefore, a molecular approach is the most likely choice. Phylogenetic analysis was carried out on <i>H. malayanus</i> in Central Sumatra (Dharmasraya, South Solok and Riau) using the Cytochrome B gene. <b>Materials and Methods:</b> Blood samples from three individuals of <i>H. malayanus</i> were obtained at the Sumatran Tiger Rehabilitation Center, Dharmasraya. Three <i>H. malayanus</i> Central Sumatra sequences and 62 GenBank sequences were used in the analysis. The DNA sequences were analyzed using the DNA Star, AliView, Bioedit, DNA SP, haplotype network, IQ Tree and MEGA software. <b>Results:</b> Forty-one haplotypes were identified in 65 sequences, with 17 haplotypes belonging to <i>H. malayanus</i>. Haplotype network analysis divides <i>H. malayanus</i> into Haplogroup I (Sundaland) and Haplogroup II (Mainland). All individuals of <i>H. malayanus</i> in Central Sumatra have the same haplotype as Peninsular Malaysia sequence. The sun bear (<i>H. malayanus</i>) has a monophyletic relationship with other bear species. The <i>H. malayanus</i> has a higher genetic distance between the two lineages (1.0-2.3%) than the genetic distance within the subpopulations of each lineage. <b>Conclusion:</b> The study results supported sun bear (<i>H. malayanus</i>) divided into two different lineages: Mainland (subcluster 1) and Sundaland (subcluster 2 and 3). The geographic isolation causes the absence of gene flow, which results in high genetic distance between sun bears (<i>H. malayanus</i>) in Sundaland and Mainland lineages.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  2. Fulltext Mitochondrial Cardiomyopathy: Molecular Epidemiology, Diagnosis, Models, and Therapeutic Management
    Yang J, Chen S, Duan F, Wang X, Zhang X, Lian B, et al.
    Cells, 2022 Nov 06;11(21).
    PMID: 36359908 DOI: 10.3390/cells11213511
    Mitochondrial cardiomyopathy (MCM) is characterized by abnormal heart-muscle structure and function, caused by mutations in the nuclear genome or mitochondrial DNA. The heterogeneity of gene mutations and various clinical presentations in patients with cardiomyopathy make its diagnosis, molecular mechanism, and therapeutics great challenges. This review describes the molecular epidemiology of MCM and its clinical features, reviews the promising diagnostic tests applied for mitochondrial diseases and cardiomyopathies, and details the animal and cellular models used for modeling cardiomyopathy and to investigate disease pathogenesis in a controlled in vitro environment. It also discusses the emerging therapeutics tested in pre-clinical and clinical studies of cardiac regeneration.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  3. Fulltext Changes in Mitochondrial Epigenome in Type 2 Diabetes Mellitus
    Low HC, Chilian WM, Ratnam W, Karupaiah T, Md Noh MF, Mansor F, et al.
    Br J Biomed Sci, 2023;80:10884.
    PMID: 36866104 DOI: 10.3389/bjbs.2023.10884
    Type 2 Diabetes Mellitus is a major chronic metabolic disorder in public health. Due to mitochondria's indispensable role in the body, its dysfunction has been implicated in the development and progression of multiple diseases, including Type 2 Diabetes mellitus. Thus, factors that can regulate mitochondrial function, like mtDNA methylation, are of significant interest in managing T2DM. In this paper, the overview of epigenetics and the mechanism of nuclear and mitochondrial DNA methylation were briefly discussed, followed by other mitochondrial epigenetics. Subsequently, the association between mtDNA methylation with T2DM and the challenges of mtDNA methylation studies were also reviewed. This review will aid in understanding the impact of mtDNA methylation on T2DM and future advancements in T2DM treatment.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  4. Fulltext Whole mitochondrial genome sequencing of Malaysian patients with cardiomyopathy
    Kuan SW, Chua KH, Tan EW, Tan LK, Loch A, Kee BP
    PeerJ, 2022;10:e13265.
    PMID: 35441061 DOI: 10.7717/peerj.13265
    Cardiomyopathy (CMP) constitutes a diverse group of myocardium diseases affecting the pumping ability of the heart. Genetic predisposition is among the major factors affecting the development of CMP. Globally, there are over 100 genes in autosomal and mitochondrial DNA (mtDNA) that have been reported to be associated with the pathogenesis of CMP. However, most of the genetic studies have been conducted in Western countries, with limited data being available for the Asian population. Therefore, this study aims to investigate the mutation spectrum in the mitochondrial genome of 145 CMP patients in Malaysia. Long-range PCR was employed to amplify the entire mtDNA, and whole mitochondrial genome sequencing was conducted on the MiSeq platform. Raw data was quality checked, mapped, and aligned to the revised Cambridge Reference Sequence (rCRS). Variants were named, annotated, and filtered. The sequencing revealed 1,077 variants, including 18 novel and 17 CMP and/or mitochondrial disease-associated variants after filtering. In-silico predictions suggested that three of the novel variants (m.8573G>C, m.11916T>A and m.11918T>G) in this study are potentially pathogenic. Two confirmed pathogenic variants (m.1555A>G and m.11778G>A) were also found in the CMP patients. The findings of this study shed light on the distribution of mitochondrial mutations in Malaysian CMP patients. Further functional studies are required to elucidate the role of these variants in the development of CMP.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  5. Fulltext Insights into subspecies classification and conservation priorities of Central Asian lynx populations revealed by morphometric and genetic analyses
    Bizhanova N, Nanova O, Fadakar D, Grachev A, Hong Z, Mohd Sah SA, et al.
    Sci Rep, 2024 Mar 02;14(1):5186.
    PMID: 38431728 DOI: 10.1038/s41598-024-55807-x
    The Eurasian lynx (Lynx lynx) exhibits geographic variability and phylogenetic intraspecific relationships. Previous morphological studies have suggested the existence of multiple lynx subspecies, but recent genetic research has questioned this classification, particularly in Central Asia. In this study, we aimed to analyse the geographic and genetic variation in Central Asian lynx populations, particularly the Turkestan lynx and Altai lynx populations, using morphometric data and mtDNA sequences to contribute to their taxonomic classification. The comparative analysis of morphometric data revealed limited clinal variability between lynx samples from the Altai and Tien Shan regions. By examining mtDNA fragments (control region and cytochrome b) obtained from Kazakhstani lynx populations, two subspecies were identified: L. l. isabellinus (represented by a unique haplotype of the South clade, H46) and L. l. wrangeli (represented by haplotypes H36, H45, and H47 of the East clade). L. l. isabellinus was recognized only in Tien Shan Mountain, while Altai lynx was likely identical to L. l. wrangeli and found in northern Kazakhstan, Altai Mountain, Saur and Tarbagatai Mountains, and Tien Shan Mountain. The morphological and mtDNA evidence presented in this study, although limited in sample size and number of genetic markers, renders the differentiation of the two subspecies challenging. Further sampling and compilation of whole-genome sequencing data are necessary to confirm whether the proposed subspecies warrant taxonomic standing.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  6. [Invasion of Drosophila albomicans into Shanghai and areas nearby and a study on its mitochondrial DNA polymorphism]
    Chen W, Zhang J, Geng Z, Zhu D
    Yi Chuan Xue Bao, 1994;21(3):179-87.
    PMID: 7917431
    We report the fact that D. albomicans invaded into Shanghai suddenly in the autumn of 1991. Using 9 restriction enzymes, we analyse the RFLPs of mitochondrial DNA of 29 isofemale lines belonging to 4 populations of Shanghai, Jiading, Qinpu and Nanhui. We find that all 29 haplotypes are different from each other. Comparing with the populations of Canton, Kunming, Sanhutan (Taiwan), Sumoto (Japan), and Kuala Lumper (Malaysia), we come to the conclusion that D. albomicans caught in Shanghai and areas nearby is from a few of places in the south of China-mainland. This conclusion agrees with the viewpoint that this species is on the speciation stage of migration towards north. We also discuss the mtDNA polymorphism within the species.
    Matched MeSH terms: DNA, Mitochondrial/genetics*
  7. Somatic mitochondrial DNA mutations in different grades of glioma
    Soon BH, Abu N, Abdul Murad NA, Then SM, Abu Bakar A, Fadzil F, et al.
    Per Med, 2022 01;19(1):25-39.
    PMID: 34873928 DOI: 10.2217/pme-2021-0033
    Aim: Mitochondrial DNA (mtDNA) alterations play an important role in the multistep processes of cancer development. Gliomas are among the most diagnosed brain cancer. The relationship between mtDNA alterations and different grades of gliomas are still elusive. This study aimed to elucidate the profile of somatic mtDNA mutations in different grades of gliomas and correlate it with clinical phenotype. Materials & methods: Forty histopathologically confirmed glioma tissue samples and their matched blood were collected and subjected for mtDNA sequencing. Results & conclusion: About 75% of the gliomas harbored at least one somatic mutation in the mtDNA gene, and 45% of these mutations were pathogenic. Mutations were scattered across the mtDNA genome, and the commonest nonsynonymous mutations were located at complex I and IV of the mitochondrial respiratory chain. These findings may have implication for future research to determine the mitochondrial energetics and its downstream metabolomics on gliomas.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  8. Lions and brown bears colonized North America in multiple synchronous waves of dispersal across the Bering Land Bridge
    Salis AT, Bray SCE, Lee MSY, Heiniger H, Barnett R, Burns JA, et al.
    Mol Ecol, 2022 Dec;31(24):6407-6421.
    PMID: 34748674 DOI: 10.1111/mec.16267
    The Bering Land Bridge connecting North America and Eurasia was periodically exposed and inundated by oscillating sea levels during the Pleistocene glacial cycles. This land connection allowed the intermittent dispersal of animals, including humans, between Western Beringia (far northeast Asia) and Eastern Beringia (northwest North America), changing the faunal community composition of both continents. The Pleistocene glacial cycles also had profound impacts on temperature, precipitation and vegetation, impacting faunal community structure and demography. While these palaeoenvironmental impacts have been studied in many large herbivores from Beringia (e.g., bison, mammoths, horses), the Pleistocene population dynamics of the diverse guild of carnivorans present in the region are less well understood, due to their lower abundances. In this study, we analyse mitochondrial genome data from ancient brown bears (Ursus arctos; n = 103) and lions (Panthera spp.; n = 39), two megafaunal carnivorans that dispersed into North America during the Pleistocene. Our results reveal striking synchronicity in the population dynamics of Beringian lions and brown bears, with multiple waves of dispersal across the Bering Land Bridge coinciding with glacial periods of low sea levels, as well as synchronous local extinctions in Eastern Beringia during Marine Isotope Stage 3. The evolutionary histories of these two taxa underline the crucial biogeographical role of the Bering Land Bridge in the distribution, turnover and maintenance of megafaunal populations in North America.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  9. Fulltext Remarkably low genetic variation but high population differentiation in the climbing perch, Anabas testudineus (Anabantidae), based on the mtDNA control region
    Jamsari AF, Muchlisin ZA, Musri M, Siti Azizah MN
    Genet. Mol. Res., 2010;9(3):1836-43.
    PMID: 20845309 DOI: 10.4238/vol9-3gmr933
    Anabas testudineus (Anabantidae) is an important food fish in Southeast Asia. We analyzed the mitochondrial DNA control region sequence data to evaluate the genetic variability and population structure of this species. Sixty specimens were collected from four populations in Sumatra and two populations in Peninsular Malaysia. We found a very low level of genetic variability, with five of the six populations exhibiting total absence of genetic variation. Based on analysis of molecular variance, 84.72% of the total variation was among populations and 15.28% within populations. A geographical division based on FST values indicated highly significant genetic differentiation among populations from the four drainage systems: Aceh, Sumatra Utara, Pulau Pinang, and Terengganu (FST ranging from 0.633 to 1.000). No phylogeographic relationships among populations were detected, despite the generation of four distinct clades in a neighbor-joining phylogenetic tree.
    Matched MeSH terms: DNA, Mitochondrial/genetics*
  10. Mitochondrial genomics identifies major haplogroups in Aboriginal Australians
    van Holst Pellekaan SM, Ingman M, Roberts-Thomson J, Harding RM
    Am J Phys Anthropol, 2006 Oct;131(2):282-94.
    PMID: 16596590
    We classified diversity in eight new complete mitochondrial genome sequences and 41 partial sequences from living Aboriginal Australians into five haplogroups. Haplogroup AuB belongs to global lineage M, and AuA, AuC, AuD, and AuE to N. Within N, we recognize subdivisions, assigning AuA to haplogroup S, AuD to haplogroup O, AuC to P4, and AuE to P8. On available evidence, (S)AuA and (M)AuB are widespread in Australia. (P4)AuC is found in the Riverine region of western New South Wales, and was identified by others in northern Australia. (O)AuD and (P8)AuE were clearly identified only from central Australia. Our eight Australian full mt genome sequences, combined with 20 others (Ingman and Gyllensten 2003 Genome Res. 13:1600-1606) and compared with full mt genome sequences from regions to the north that include Papua New Guinea, Malaya, and Andaman and Nicobar Islands, show that ancestral connections between regions are deep and limited to clustering at the level of the N and M macrohaplogroups. The Australian-specific distribution of the five haplogroups identified indicates genetic isolation over a long period. Ancestral connections within Australia are deeper than those reflected by known linguistic or culturally based affinities. Applying a coalescence analysis to a gene tree for the coding regions of the eight genomic sequences, we made estimates of time depth that support a continuity of presence for the descendants of a founding population already established by 40,000 years ago.
    Matched MeSH terms: DNA, Mitochondrial/genetics*
  11. Contrasting genetic and morphological differentiation among geographical lineages of a stenotopic miniature rasborine, Boraras maculatus, in Peninsular Malaysia
    Fam YQ, Jamaluddin JAF, Muhammad-Rasul AH, Ilham-Norhakim ML, Rosely NFN, Lavoué S
    J Fish Biol, 2024 Jan;104(1):171-183.
    PMID: 37775959 DOI: 10.1111/jfb.15572
    The variability in the stenotopic miniature rasborine Boraras maculatus (Cypriniformes: Danionidae: Rasborinae) across acidic-water habitats of Peninsular Malaysia (PM) was investigated using two molecular markers (the mitochondrial cytochrome c oxidase subunit I [COI] gene and the nuclear rhodopsin gene), as well as morphological evidence. Molecular phylogenetic analyses revealed differentiation among populations of B. maculatus in PM with the distinction of four allopatric lineages. Each of them was recognized as a putative species by automatic species delimitation methods. These lineages diverged from each other between 7.4 and 1.9 million years ago. A principal component analysis (PCA) was conducted to examine the multivariate variation in 11 morphometric measurements among three of these lineages. PCA results showed a significant overlap in morphological characteristics among these lineages. Additionally, a photograph-based machine learning approach failed to fully differentiate these lineages, suggesting limited morphological differentiation. B. maculatus represents a case of morphological stasis in a stenotopic miniature species. Strong habitat preference, coupled with long-term habitat fragmentation, may explain why each lineage of B. maculatus has a restricted distribution and did not disperse to other regions within and outside of PM, despite ample possibilities when the Sunda shelf was emerged and drained by large paleodrainages for most of the past 7 million years. The conservation status of B. maculatus and its peat swamp habitats are discussed, and it is concluded that peat swamps comprise several evolutionary units. Each of these units is considered a conservation unit and deserves appropriate protection.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  12. Ancient DNA analysis of elite nomadic warrior from Chinge-Tey I funerary commemorative complex in the "Valley of the Kings", Tuva
    Nedoluzhko A, Vergasova E, Sharko F, Agapitova N, Kharitonov D, Sukhanova X, et al.
    BMC Genomics, 2025 Mar 05;26(1):220.
    PMID: 40045199 DOI: 10.1186/s12864-025-11361-y
    BACKGROUND: In the Ist millennium BC bearers of the Scythian-type nomadic cultures inhabited the steppes of Eurasia, from Northern China to the Carpathians. According to archaeological data, the origin of nomadic life style and economy can be traced to the eastern part of this steppe "corridor", primarily to the territory of the present-day Republic of Tuva in Russia. Here, in the Turan-Uyuk Basin, also known as the "Valley of the Kings", some of the earliest known Scythian-type archaeological sites called Arzhan-1, Arzhan-2, Chinge-Tey I, Tunnug 1 were studied. Each of them is a large-scale funerary commemorative complex with burials of tribal nomadic leaders, surrounded by graves of supposed members of their families or associates. All these people belonged to the societies which are associated with the earliest nomadic cultures in Asia. Representatives of similar cultures will later be known and described as the Scythians/the Saka in Assyrian, Achaemenid, and Greek sources. Arzhan 2 and Chinge-Tey I elite level sites as well as ordinary pastoralist burials of the early-Scythian period in Tuva are attributed to the Aldy-Bel archaeological culture of the Early Iron Age (8th- 6th century BC). Taking the first step to shed light on the genetic origin of Aldy-Bel elites, we carried out a comparative genome-wide analysis of an elite level person buried in grave 9 at Chinge-Tey I (7th- 6th centuries BC) and two published earlier genomes of individuals, whose burials (graves 14 and 22) accompanied the 'royal couple' (grave 5) at Arzhan-2. This study aims also at checking a hypothesis of genetic kinship between human individuals buried in the large-scale burial complexes of the "Valley of the Kings" and brings up the issue of possible dynastic connections of local elites, buried under different kurgans of the valley.

    RESULTS: First, ancient DNA analysis of an elite nomadic warrior from Chinge-Tey I has been carried out, thus a third wide-genome dataset for Aldy-Bel culture- one of the earliest nomadic cultures in Asia, is presented in this study. Second, we undertook a comparative analysis of genome-wide data of three mentioned Aldy-Bel culture representatives and individuals of the other Bronze and Early Iron Age population groups of Asia to estimate their possible genetic connections. Then, kinship analysis was undertaken for these three Aldy-Bel culture individuals. Finally, mitochondrial and Y-chromosome haplogroups of Chinge-Tey princely person were compared to those of other Aldy-Bel culture representatives and to individuals of subsequent Scythian-type Uyuk-Sagly culture in Tuva.

    CONCLUSION: (1) Generating the third wide-genome of the enabled us to undertake its comparison with two other genomes of Aldy-Bel culture representatives (Arzhan-2, graves 14 and 22) and with other Bronze and Early Iron Age population groups in Asia to trace the origin and genetic connection of Aldy-Bel population, representing one of the earliest Scythian-type nomadic group. (2) The results obtained show that the princely individual from Chinge-Tey I and two 'king's associates' from Arzhan-2 were genetically close to nomads of simultaneous Tasmola culture in Eastern and Central Kazakhstan and pastoralists buried in the Early Iron Age cemeteries of present-day Xinjiang (first of all, Abusanteer archaeological site). Aldy-Bel culture representatives appeared also close to individuals of the Middle Bronze Age Okunevo culture in the Minusinsk Basin. Besides, Aldy-Bel pastoralists turned out genetically close to nomads of the subsequent Uyuk-Sagly culture in Mongolia (5th - 3rd centuries BC). (3) Ancient DNA kinship analyses, undertaken for three Aldy-Bel culture individuals pointed out to the absence of their tribe kinship. (4) On the other hand, Chinge-Tey warrior's mitochondrial haplogroup G was previously described in two (graves 14 and 5) individuals from Arzhan-2, including a female individual from the "royal" tomb 5. This result provided a possibility of maternal kinship among this so called 'queen' from Arzhan-2 and the princely person from Chinge-Tey I. This possibility supported a hypothesis of their family ties suggested on archaeological materials. Y-chromosome haplogroup Q1b1, revealed for the princely person, was widely distributed among local people of Aldy-Bel and subsequent Uyuk-Sagly cultures.

    Matched MeSH terms: DNA, Mitochondrial/genetics
  13. Mitochondrial Replacement Therapy: An Islamic Perspective
    Ibrahim AH, Rahman NNA, Saifuddeen SM
    J Bioeth Inq, 2023 Sep;20(3):485-495.
    PMID: 37440155 DOI: 10.1007/s11673-023-10279-y
    Mitochondrial replacement technology (MRT) is an emerging and complex bioethical issue. This treatment aims to eliminate maternal inherited mitochondrial DNA (mtDNA) disorders. For Muslims, its introduction affects every aspect of human life, especially the five essential interests of human beings-namely, religion, life, lineage, intellect, and property. Thus, this technology must be assessed using a comprehensive and holistic approach addressing these human essential interests. Consequently, this article analyses and assesses tri-parent baby technology from the perspective of Maqasidic bioethics-that is, Islamic bioethics based on the framework of Maqasid al-Shariah. Using this analysis, this article suggests that tri-parent baby technology should not be permitted for Muslims due to the existence of third-party cell gametes which lead to lineage mixing and due to the uncertain safety of the therapy itself and because the major aim of the technology is to fulfil the affected couples interest to conceive their own genetically healthy child, not to treat and cure mtDNA disorders sufferers.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  14. Tracking the southern river terrapin (Batagur affinis) through environmental DNA: prospects and challenges
    Wilson JJ, Sing KW, Chen PN, Zieritz A
    Mitochondrial DNA A DNA Mapp Seq Anal, 2018 08;29(6):862-866.
    PMID: 28885060 DOI: 10.1080/24701394.2017.1373109
    Environmental DNA detection has emerged as a powerful tool to monitor aquatic species without the need for capture or visual identification and is particularly useful for rare or elusive species. Our objective was to develop an eDNA approach for detecting the southern river terrapin (Batagur affinis) in Malaysia. We designed species-specific primers for a fragment of B. affinis mtDNA and evaluated their effectiveness in silico, in vitro and in situ. The primers amplified 110 bp of the cytochrome b mtDNA sequence of B. affinis from aquarium water samples housing nine juvenile B. affinis. We also successfully detected B. affinis eDNA from river samples taken from a site where turtles were known to be in the vicinity. Prospects and challenges of using an eDNA approach to help determine the distribution of B. affinis, essential information for an effective conservation plan, are discussed.
    Matched MeSH terms: DNA, Mitochondrial/genetics*
  15. Fulltext Phylogeography of the termite Macrotermes gilvus and insight into ancient dispersal corridors in Pleistocene Southeast Asia
    Veera Singham G, Othman AS, Lee CY
    PLoS One, 2017;12(11):e0186690.
    PMID: 29186140 DOI: 10.1371/journal.pone.0186690
    Dispersal of soil-dwelling organisms via the repeatedly exposed Sunda shelf through much of the Pleistocene in Southeast Asia has not been studied extensively, especially for invertebrates. Here we investigated the phylogeography of an endemic termite species, Macrotermes gilvus (Hagen), to elucidate the spatiotemporal dynamics of dispersal routes of terrestrial fauna in Pleistocene Southeast Asia. We sampled 213 termite colonies from 66 localities throughout the region. Independently inherited microsatellites and mtDNA markers were used to infer the phylogeographic framework of M. gilvus. Discrete phylogeographic analysis and molecular dating based on fossil calibration were used to infer the dynamics of M. gilvus dispersal in time and space across Southeast Asia. We found that the termite dispersal events were consistently dated within the Pleistocene time frame. The dispersal pattern was multidirectional, radiating eastwards and southwards out of Indochina, which was identified as the origin for dispersal events. We found no direct dispersal events between Sumatra and Borneo despite the presence of a terrestrial connection between them during the Pleistocene. Instead, central Java served as an important link allowing termite colonies to be established in Borneo and Sumatra. Our findings support the hypothesis of a north-south dispersal corridor in Southeast Asia and suggest the presence of alternative dispersal routes across Sundaland during the Pleistocene. For the first time, we also propose that a west-east dispersal through over-water rafting likely occurred across the Pleistocene South China Sea. We found at least two independent entry routes for terrestrial species to infiltrate Sumatra and Borneo at different times.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  16. Sequencing and characterisation of complete mitogenome DNA for Rasbora sarawakensis (Cypriniformes: Cyprinidae: Rasbora) with phylogenetic consideration
    Lim LWK, Kamar CKA, Roja JS, Chung HH, Liao Y, Lam TT, et al.
    Comput Biol Chem, 2020 Dec;89:107403.
    PMID: 33120127 DOI: 10.1016/j.compbiolchem.2020.107403
    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.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  17. Causes and consequences of sperm mitochondrial dysfunction
    Durairajanayagam D, Singh D, Agarwal A, Henkel R
    Andrologia, 2021 Feb;53(1):e13666.
    PMID: 32510691 DOI: 10.1111/and.13666
    Mitochondria have multiple functions, including synthesis of adenine triphosphate, production of reactive oxygen species, calcium signalling, thermogenesis and apoptosis. Mitochondria have a significant contribution in regulating the various physiological aspects of reproductive function, from spermatogenesis up to fertilisation. Mitochondrial functionality and intact mitochondrial membrane potential are a pre-requisite for sperm motility, hyperactivation, capacitation, acrosin activity, acrosome reaction and DNA integrity. Optimal mitochondrial activity is therefore crucial for human sperm function and semen quality. However, the precise role of mitochondria in spermatozoa remains to be fully explored. Defects in sperm mitochondrial function severely impair the maintenance of energy production required for sperm motility and may be an underlying cause of asthenozoospermia. Sperm mtDNA is susceptible to oxidative damage and mutations that could compromise sperm function leading to infertility. Males with abnormal semen parameters have increased mtDNA copy number and reduced mtDNA integrity. This review discusses the role of mitochondria in sperm function, along with the causes and impact of its dysfunction on male fertility. Greater understanding of sperm mitochondrial function and its correlation with sperm quality could provide further insights into their contribution in the assessment of the infertile male.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  18. Gene flow creates a mirage of cryptic species in a Southeast Asian spotted stream frog complex
    Chan KO, Hutter CR, Wood PL, Grismer LL, Das I, Brown RM
    Mol Ecol, 2020 10;29(20):3970-3987.
    PMID: 32808335 DOI: 10.1111/mec.15603
    Most new cryptic species are described using conventional tree- and distance-based species delimitation methods (SDMs), which rely on phylogenetic arrangements and measures of genetic divergence. However, although numerous factors such as population structure and gene flow are known to confound phylogenetic inference and species delimitation, the influence of these processes is not frequently evaluated. Using large numbers of exons, introns, and ultraconserved elements obtained using the FrogCap sequence-capture protocol, we compared conventional SDMs with more robust genomic analyses that assess population structure and gene flow to characterize species boundaries in a Southeast Asian frog complex (Pulchrana picturata). Our results showed that gene flow and introgression can produce phylogenetic patterns and levels of divergence that resemble distinct species (up to 10% divergence in mitochondrial DNA). Hybrid populations were inferred as independent (singleton) clades that were highly divergent from adjacent populations (7%-10%) and unusually similar (<3%) to allopatric populations. Such anomalous patterns are not uncommon in Southeast Asian amphibians, which brings into question whether the high levels of cryptic diversity observed in other amphibian groups reflect distinct cryptic species-or, instead, highly admixed and structured metapopulation lineages. Our results also provide an alternative explanation to the conundrum of divergent (sometimes nonsister) sympatric lineages-a pattern that has been celebrated as indicative of true cryptic speciation. Based on these findings, we recommend that species delimitation of continuously distributed "cryptic" groups should not rely solely on conventional SDMs, but should necessarily examine population structure and gene flow to avoid taxonomic inflation.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  19. Phylogeographic analysis of pigtail macaque populations (Macaca nemestrina) inferred from mitochondrial DNA
    Rosenblum LL, Supriatna J, Melnick DJ
    Am J Phys Anthropol, 1997 Sep;104(1):35-45.
    PMID: 9331452
    Mitochondrial DNA variation was surveyed in nine populations of the pigtail macaque (Macaca nemestrina), covering all three recognized subspecies in Southeast Asia. To do this, a 2,300 base pair fragment spanning the mitochondrial NAD 3 and NAD 4 genes and flanking tRNA subunits leucine and glycine was targeted for amplification and digested with a battery of 16 restriction endonucleases. Out of a total of 107 individuals, 32 unique haplotypes could be distinguished. Parsimony and neighbor-joining analyses grouped the haplotypes into five strongly supported assemblages representing China/Thailand, Malaysia, Sumatra, Borneo, and Siberut. These results indicate that the mainland and island mtDNA haplotypes are strictly and uniquely limited to the geographic ranges of the recognized morphological subspecies. Cladistic and neighbor-joining analyses indicate that inferred phylogenies of mtDNA haplotypes are congruent with subspecies designations. Furthermore, in support of morphological studies, results indicate that the Mentawai macaque is most likely not a distinct species but a subspecies of M. nemestrina.
    Matched MeSH terms: DNA, Mitochondrial/genetics*
  20. Genetic Polymorphism of Aedes albopictus Population Inferred From ND5 Gene Variabilities In Subang Jaya, Malaysia
    Adilah-Amrannudin N, Hamsidi M, Ismail NA, Ismail R, Dom NC, Ahmad AH, et al.
    J Am Mosq Control Assoc, 2016 Dec;32(4):265-272.
    PMID: 28206858 DOI: 10.2987/16-6579.1
    This study was performed to establish the genetic variability of Aedes albopictus within Subang Jaya, Selangor, Malaysia, by using the nicotinamide adenine dinucleotide dehydrogenase 5 subunit (ND5) mitochondrial DNA (mtDNA) marker. A total of 90 samples were collected from 9 localities within an area of the Subang Jaya Municipality. Genetic variability was determined through the amplification and sequencing of a fragment of the ND5 gene. Eight distinct mtDNA haplotypes were identified. The evolutionary relationship of the local haplotypes alongside 28 reference strains was used to construct a phylogram, the analysis of which revealed low genetic differentiation in terms of both nucleotide and haplotype diversity. Bayesian method was used to infer the phylogenetic tree, revealing a unique relationship between local isolates. The study corroborates the reliability of ND5 to identify distinct lineages for polymorphism-based studies and supplements the existing body of knowledge regarding its genetic diversity. This in turn could potentially aid existing vector control strategies to help mitigate the risk and spread of the dengue virus.
    Matched MeSH terms: DNA, Mitochondrial/genetics*
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