Cytb Region Research Articles

Twenty-three years of PCR-based seafood authentication assay development: What have we learned?

Seafood is a prime target for fraudulent activities due to the complexity of its supply chain, high demand, and difficult discrimination among species once morphological characteristics are removed. Instances of seafood fraud are expected to increase due to growing demand. This manuscript reviews the application of DNA-based methods for commercial fish authentication and identification from 2000 to 2023. It explores (1) the most common types of commercial fish used in assay development, (2) the type of method used, (3) the gene region most often targeted, (4) provides a case study of currently published assays or primer-probe pairs used for DNA amplification, for specificity, and (5) makes recommendations for ensuring standardized assay-based reporting for future studies. A total of 313 original assays for the detection and authentication of commercial fish species from 191 primary articles published over the last 23 years were examined. The most explored DNA-based method was real-time polymerase chain reaction (qPCR), followed by DNA sequencing. The most targeted gene regions were cytb (cytochrome b) and COI (cytochrome c oxidase 1). Tuna was the most targeted commercial fish species. A case study of published tuna assays (n=19) targeting the cytb region found that most assays were not species-specific through in silico testing. This was conducted by examining the primer mismatch for each assay using multiple sequence alignment. Therefore, there is need for more standardized DNA-based assay reporting in the literature to ensure specificity, reproducibility, and reliability of results. Factors, such as cost, sensitivity, quality of the DNA, and species, should be considered when designing assays.

Population Structure Using Mitochondrial DNA for the Conservation of Liobagrus geumgangensis (Siluriformes: Amblycipitidae), an Endemic Freshwater Fish in Korea

Liobagrus geumgangensis is a novel Korean fish species endemic to the Geumgang and Mangyeonggang River basins on the Korean Peninsula. During a survey of L. geumgangensis, the discovery of Liobagrus mediadiposalis as a potential threat prompted an investigation into L. geumgangensis genetic diversity and structure. Three populations of L. geumagangensis and one population of L. mediadiposalis were investigated using a 1024-bp sequence in the cytb region of mitochondrial DNA. The Mangyeonggang River of L. geumagangensis displayed the lowest haplotype diversity (Hd) within a range of 0.000–0.337, with one to two haplotypes (h). The Jecheon region of the Geumgang River for L. geumagangensis population had the highest nucleotide diversity (π) and was within the range of 0.00000–0.00066. The h of L. mediadiposalis population was 3, the range of Hd was 0.292, and π was 0.00231. Tajima’s D (D) and Fu’s Fs (F) were negative and non-significant in the LgGJ population. The genetic structure of L. geumgangensis had no shared haplotypes among the three populations. The discovery of L. mediadiposalis in the Geumgang River suggests the necessity of non-habitat conservation and population management of fish farms to conserve L. geumgangensis.

MALDI-TOF MS Limits for the Identification of Mediterranean Sandflies of the Subgenus Larroussius, with a Special Focus on the Phlebotomus perniciosus Complex.

Leishmania infantum is the agent of visceral leishmaniasis in the Mediterranean basin. It is transmitted by sandflies of the subgenus Larroussius. Although Phlebotomus perniciosus is the most important vector in this area, an atypical Ph. perniciosus easily confused with Ph. longicuspis has been observed in North Africa. MALDI-TOF MS, an important tool for vector identification, has recently been applied for the identification of sandflies. Spectral databases presented in the literature, however, include only a limited number of Larroussius species. Our objective was to create an in-house database to identify Mediterranean sandflies and to evaluate the ability of MALDI-TOF MS to discriminate close species or atypical forms within the Larroussius subgenus. Field-caught specimens (n = 94) were identified morphologically as typical Ph. perniciosus (PN; n = 55), atypical Ph. perniciosus (PNA; n = 9), Ph. longicuspis (n = 9), Ph. ariasi (n = 9), Ph. mascittii (n = 3), Ph. neglectus (n = 5), Ph. perfiliewi (n = 1), Ph. similis (n = 9) and Ph. papatasi (n = 2). Identifications were confirmed by sequencing of the mtDNA CytB region and sixteen specimens were included in the in-house database. Blind assessment on 73 specimens (representing 1073 good quality spectra) showed a good agreement (98.5%) between MALDI-TOF MS and molecular identification. Discrepancies concerned confusions between Ph. perfiliewi and Ph. perniciosus. Hierarchical clustering did not allow classification of PN and PNA. The use of machine learning, however, allowed discernment between PN and PNA and between the lcus and lcx haplotypes of Ph. longicuspis (accuracy: 0.8938 with partial-least-square regression and random forest models). MALDI-TOF MS is a promising tool for the rapid and accurate identification of field-caught sandflies. The use of machine learning could allow to discriminate similar species.

Is vertical transmission the only pathway for Rickettsia felis?

The genus Rickettsia encompasses several species grouped into two main clusters, Typhus and the Transitional groups. The latter group contains Rickettsia felis, an endosymbiont of several arthropods with an uncertain human pathogenicity and whose most efficient transmission mechanism described thus far is transovarial. The aim of this study was to evaluate whether this pathway exists using phylogenetic analysis and partial sequences of the 17kDa and gltA genes and comparing them with host phylogeny using the cytb region. This is the first study that evaluates the vertical transmission of R. felis. In general, both phylogenies of R. felis showed no polytomies, as suspected if this pathway was the only pathway occurring. When phylogenies of the invertebrates and the gltA of R. felis were compared for strong coevolutionary insight, intricate relationships were observed, suggesting that other transmission pathways must occur, such as horizontal transmission. Further studies are needed to determine which other transmission routes occur in hematophagous arthropods.

A simple PCR-RFLP method for identification and detection of medicinal toad and its crude drug even with serious degradation of DNA

The secretions of the venom glands, dry skin and whole body of several Bufo species have been used as traditional medicines in East Asia to treat heart failure and cancer. Due to the highly similar morphological features of Bufo species and their derived commercial crude drugs, along with the high similarity of chemical composition of the secretions of venom glands, it is very challenging to identify the medicinal toads and the related crude drugs. The cyt-b sequences provide useful information to authenticate medicinal Bufo species. Based on the cyt-b sequences, a simple PCR-RFLP method was established for the identification of the medicinally used Bufo species as well as their derived crude drugs. The 23 specimens from three medicinally used Bufo species, B. bufo gargarizans (Bbg), B. melanostictus (Bm) and B. raddei (Br), were clearly divided into 3 groups according to the sequences of amplified cyt-b regions, which could be digested by specific restriction enzymes NcoI, EcoRV and BstXI, respectively. Then the specific PCR-RFLP method was further used to identify 9 samples of commercial crude drugs even with serious degradation of DNA, and all nine samples were identified as B. bufo gargarizans. The method is suitable for identification of medicinally used Bufo species and the related crude drugs.

Population genetics of Lepidoglyphus destructor inferred by the analysis of the mitochondrial cytochrome b gene and ribosomal internal transcribed spacer gene sequence

ABSTRACT The storage mite, Lepidoglyphus destructor, occurs in both rural and urban environments worldwide. It poses an allergenic threat to humans and damages stored grain. Most studies on L. destructor have focused on its allergens, but much less is known about its genetic diversity and genetic structure. This information would be helpful for comprehensive control of this species and other indoor allergenic mites. The genetic diversity and structure of four L. destructor populations were studied using the mitochondrial cytochrome b (Cytb) region and the ribosomal internal transcribed spacer (ITS) region. We obtained 30 Cytb gene sequences and 38 ITS gene sequences from four localities in China and 17 and 33 haplotypes, respectively. The length of Cytb sequences was 372 bp, and the length of ITS sequences varied from 1301 to 1320 bp. DnaSP 5.10 analysis showed that both Cytb and ITS sequences of L. destructor in the four populations had high genetic diversity. These data suggest that L. destructor has high environmental adaptability. Analysis of molecular variance (AMOVA) based on Cytb showed that the variation was mainly among populations (92.28%) with significant genetic structure, whereas the variation based on ITS was mainly within the populations (69.86%) without a significant genetic structure. Maximum likelihood (ML) tree and haplotype network diagrams based on Cytb and ITS consistently showed that the four populations of L. destructor could be divided into two clades: clade A (WH, HZ and HF) and clade B (CQ). The genetic differentiation index (FST ) showed that the CQ population was significantly differentiated from the other three populations (FST > 0.25). The long geographical separation distance and low frequency of trade activities may help explain the high level of genetic differentiation in the CQ population, while the low level of genetic differentiation among WH, HF, and HZ populations may reflect the high level of gene flow. This study improves our understanding of the population genetics of L. destructor, which would be useful for developing effective management strategies and future research of L. destructor in directions.

Documentation of the Turkestan barbel, Luciobarbus conocephalus (Kessler, 1872) in the Iranian part of Hari River basin (Teleostei: Cyprinidae: Barbinae)

The Turkestan barbel, Luciobarbus conocephalus (Kessler, 1872), is documented from the Iranian Part of Hari River basin by providing its morphometric and molecular characteristics based on the nine collected specimens in July 2016. In addition, the ichthyofauna of the Hari river basin was discussed and an up-to-date inventory was provided. Based on the results, L. conocephalus was clustered in a clade as sister group of L. capito with K2P genetic distance of 1.8% in the mtDNA cytb region. Luciobarbus conocephalus probably has entered the Hari River from the Karakum Canal in Turkmenistan (diversion from the Amu Darya River) that in recent years was connected to the channels collecting the Hari River water. Also, a misidentified specimen of L. conocephalus sequence in the GenBank sequences is discussed.

Using meta-barcoding tools to monitor primate meat consumption at dedicated establishments in Guinea-Bissau, West Africa

Guinea-Bissau (GB) is a regional stronghold for primate conservation. Ten primates occur in the country, including the Western chimpanzee (Pan troglodytes verus) and two colobus monkeys (Colobus polykomos and Piliocolobus badius temminckii). Primate meat is consumed at households and bushmeat-dedicated establishments, locally named "Abafatório". Such establishments are mentioned to be common in urban areas since the 1980s and to be specialized in serving primate meat while drinking alcoholic beverages. The meat is typically cooked in a stew and eaten with bread. However, as the trade and consumption of primate meat are illegal activities, the location of Abafatório establishments and details of the trade, namely species being consumed, are usually hidden from outsiders. Here, we characterize illicit bushmeat commerce and consumption at six Abafatórios of a small town. Our team visited the establishments every week for 15 months (2015-2017) and collected data on the type and prices of meals and gathered tissue samples taken from carcasses by establishment owners. A meta-barcoding approach (cytb and 12S mitochondrial DNA regions and Illumina MiSeq next-generation sequencing technology) was used to identify tissue samples to the species level. Two types of establishments can be distinguished – “restaurants” and “snack-bars”. Restaurants are similar to the ones found by previous works in the capital city where primate meat is sold as a dish containing few pieces of stewed meat. Snack-bars are smaller and the meat is sold inexpensively and by the piece. In the present study, 249 tissue samples were identified to be from four primates (Cercopithecus campbelli, Chlorocebus sabaeus, Papio papio, and Erythrocebus patas) and four Artiodactyla (Philantomba maxwellii, Tragelaphus scriptus, Potamochoerus porcus and Phacochoerus africanus). Primates represented approximately 92% of all species consumed across establishments, and C. campbelli was the most traded species. Our work suggests that primate meat is monetarily accessible for locals in rural areas and that the trade at Abafatórios may have extensive negative consequences to primate conservation, in particular, the reduction of primates' populations in the southern part of GB. Our work quantifies and identifies the species consumed in Abafatório establishments for the first time and highlights the need to improve regulation and law enforcement in Guinea-Bissau.

Spatial Distribution and Dietary Niche Breadth of Leopard Cats (Prionailurus bengalensis) Inhabiting Margalla Hills National Park, Pakistan.

The leopard cat (Prionailurus bengalensis) is distributed throughout the Himalayan foothills in Pakistan and occurs in moist temperate and dry coniferous forests. However, the cat species is categorized as "Data Deficient" in Pakistan. In the current study we aimed to investigate the leopard cat distribution and dietary niche in the Margalla Hills National Park, the lowest part of the Himalayan foothills in Pakistan. We recorded direct (field observations, camera trapping) and indirect signs (scats) of the species on 23 trails /tracks in the study area. The leopard cat was recorded at 13 different sampling sites in the park, with an altitudinal range between 664-1441 m asl. The diet composition of the species was investigated through scat analysis, with the species identity of the scats confirmed through the mitochondrial cytB region. The species' diet comprised both animal and plant matter. The animal-based diet (in terms of frequency of occurrence) contained wild (51.75%) as well as domestic prey (7.69%), and plant species (31.47%). Wild prey included small mammals (rodents, two mongoose species, Asian palm squirrel, and Cape hare), birds, insects and snails. The domestic prey were poultry birds, sheep, goats and dogs. Consumption of wild prey was higher in summer (n = 31 scat), whereas intake of domestic prey was higher in winter (n = 37 scats). The dietary niche breadth was wider 14.84 in summer than winter 10.67. A chi-square test showed a significant difference in seasonal dietary intake of the leopard cat. The study concludes that the leopard cat feeds mainly on wild animal prey and plant species; however, in winter consumption of domestic prey increases.

A molecular survey based on eDNA to assess the presence of a clown featherback (Chitala ornata) in a confined environment.

BackgroundThe importance of the inland fisheries sector in food security as a provider of much-needed protein and income supplier has been highlighted. This is especially the case in poor rural communities in developing countries. Inland capture fisheries in Thailand are in place nationwide in rivers, lakes, swamps and reservoirs. The clown featherback (Chitala ornata) is popularly consumed and is an economically important fish in Thailand which is often used in food products such as fish balls and fish cakes. Along with other fish species, the clown featherback is one of fish of inland fisheries at Phayao Lake. Recent fish surveys from 2016-2018 at Phayao Lake using netting and electrofishing found that the number of clown featherback have been reducing since 2016 and could not be detected at all by 2018. This is despite the fact that there are still reports of their presence in the lake from locals.MethodsWe developed an eDNA-based method for detection of the clown featherback in Phayao Lake as an alternative tool. Water samples were collected in three different sampling months (February, June and September) at six sites located in the lake. Species-specific primers and the probe were designed to amplify a 183 bp fragment of the cytB region of the clown featherback.ResultseDNA of the clown featherback can be detected in all different sampling months and sites. Concentration of the clown featherback found in Prayao Lake showed no difference over sampling month but between collecting sites. This proves that eDNA based survey is a sensitive and useful tool for monitoring and surveying the clown featherback at any time of the year.

Molecular analysis of edible bird's nest and rapid authentication of Aerodramus fuciphagus from its subspecies by PCR-RFLP based on the cytb gene.

Edible bird's nest (EBN), for its great nutritional value, is widely used around the world, especially in China and Singapore. EBNs of different origins and types may vary in price and quality. Nowadays, birds' nests are difficult to identify morphologically, except for some whole bird's nests of which origins can be roughly identified. In this study, forty-two samples were collected from different regions for sequencing analysis and phylogenetic classification to initially determine their origins. Two stable enzyme digestion sites were found in the analysis of restriction maps of the species. Then, a quick and specific PCR-RFLP method was established to identify the EBN samples' origins. The genetic identification results indicated that the forty-two samples were from five origins. With the Af/g-486bp-F/R primer and restriction enzyme Taq I, Aerodramus fuciphagus (A. fuciphagus) was efficiently differentiated from the other species. Furthermore, the cytb-592bp-F/R primer and the BamH I enzyme were found to be useful in distinguishing Aerodramus fuciphagus (A. fuciphagus) from its subspecies (Aerodramus germani, A. germani). The PCR-RFLP method provides a potential tool for the rapid discrimination of A. fuciphagus at the species and even the subspecies levels to ensure the quality of the EBN products.

Cercospora nicotianae Isolates from Flue-Cured Tobacco in North Carolina Found with G143A and F129L Mutations in Cytochrome b Gene

Frogeye leaf spot of tobacco caused by Cercospora nicotianae (Ellis & Everhart) is a widespread disease of cultivated tobacco. Recently, flue-cured tobacco producers in North Carolina reported losses due to frogeye leaf spot disease despite the use of strobilurin fungicides. Isolates (n = 4) were obtained in 2018 from affected tobacco leaves from Cumberland, Lenoir, and Nash counties. In 2019, isolates (n = 28) were collected from a field in Wilson county. After sequencing the cytb region of 32 isolates, 30 contained a single point mutation conferring a G143A or F129L amino acid change that resulted in quinone outside inhibitor (QoI) fungicide resistance. Although these resistance mutations have been found in air-cured tobacco in Kentucky, to the best of our knowledge, the present study is the first to report QoI resistance mutations in C. nicotianae populations in flue-cured tobacco and a first report in North Carolina.

Genetic Diversity of Gazelles (Gazella marica and Gazella gazella) in Southeast Turkey: A Special Emphasis on Ongoing Conservation Studies of Gazella marica in Turkey

Objective: The genetic diversity parameters for gazelle populations sampled in Turkey were estimated to assess the effects of captive breeding on the populations’ gene pools and effective population sizes. Materials and Methods: Four individuals from a recently discovered Gazella gazella population in Hatay and two captive gazelle populations were sampled (the Kizilkuyu State Farm (n=48) and the Erikce State Farm (n=25)) and analyzed using nuclear DNA, mtDNA and Y-chromosome markers. Results: The mtDNA cyt-b partial sequence analysis assigned the Erikce and Kizilkuyu samples to Gazella marica. The structure analysis differentiated significantly between them, and revealed samples originating from wild population. Both, the Y-chromosome INRA126 locus sequences of Gazella gazella and Gazella marica males and the mtDNA partial cyt-b region RFLP analysis from all the samples distinguished the two gazelle species from each other. Based on microsatellites, the estimated effective population sizes were 9.7, 8.9 and 6.4 for the Kizilkuyu, Erikce and Hatay populations, respectively. When the Kizilkuyu and Erikce populations (where severe inbreeding depressions seems to be occurring already) were pooled, the estimated Ne was 24.5. All these estimates were too small for the sustainability of either individual or pooled populations in the wild or even in captivity. Conclusion: The markers used in the study provided information on two of the gazelle species (Gazella marica, and Gazella gazella): their species identity, degree of divergences, effective population sizes and the presence of admixture within the populations. These results turned out to be invaluable in terms of their contribution to future studies for the conservation of these species.

Analysis of the mitochondrial CYTB gene sequence in human populations of northeastern Bosnia

This study offers the first report on variation sequence of the mitochondrial cytochrome b (MTCYTB) gene in populations from Bosnia (northeastern Bosnia). This study was designed on the analysis of the genetic diversity of two populations of different cultural-anthropological and genetic origin, Roma population and native/non-Roma population. The main aim of our study was to estimate the usefulness of the CYTB sequence in the analysis of genetic categorization of different populations and intergroup diversity, as well as to provide some additional information on haplogroup-associated polymorphisms within the CYTB region in defining haplogroup status. Estimation of the genetic diversity was done using intra and intergroup genetic indices. The population-specific polymorphisms have been found in both categories of the populations. The results of the analysis of genetic differentiation show significant pairwise Fst differences between the Romani and native populations. Also, registered significant genetic differentiation is illustrated on the level of genetic variation between subpopulations of the Roma and non-Roma origin. The important result in our study is the confirmation of the significance of the triad of polymorphisms T14783C-G15043A-G15301A, indicating the influence of Asian component of the maternal gene pool on the genetic structure of the studied population of the Roma. Our data show that the haplogroup polymorphisms exist in the CYTB region and can provide useful information on the haplogroups that were defined only by the control region of the mtDNA. The results of this study indicate the region of CYTB gene can be a benefit in providing some additional information in the analysis of genetic structure of human populations and can be additionally applied in population studies.

Study on mitochondrial DNA mutation in patients with primary multiple myeloma

Objective To study the mitochondrial DNA mutation in patients with primary multiple myeloma. Methods The mitochondrial DNA of 5 patients with primary multiple myeloma in the First Hospital of Qinhuangdao from February to June 2017 were amplified by polymerase chain reaction (PCR) and sequenced directly, and the results were compared with revised Cambridge Reference Sequence (rCRS) and Human Mitochondrial Gene Database (mtDB) database. Results There were 42 mutation genes, with 52.38% (22/42) mutation genes in D-loop region, 9.52% (4/42) mutation genes in ND4L region, 2.38% (1/42) mutation genes in ND5 region, 26.19% (11/42) mutation genes in Cytb region, 7.14% (3/42) mutation genes in ND1 region, and 4.76% (2/42) mutation genes in COⅡ region. Conclusion There is a high mitochondrial DNA mutation rate in patients with primary multiple myeloma. Key words: Multiple myeloma; Mitochondrial; DNA mutation

The study of Cytochrome B (CYTB): species-specific detection and phylogenetic relationship of Echinostoma revolutum, (Froelich, 1802).

Echinostoma revolutum is known as a significant intestinal trematode in various species of animals and humans. It presents complexities in terms of both the morphological and molecular biological data. This is the first study of the application of Cytochrome B gene (CYTB) as a target for studying the phylogeny and designing species-specific primer of E. revolutum. Adult trematodes were harvested from experimentally infected hamsters at 18days of post-infection. Each worm was identified based on their morphological appearance. The novel CYTB primers were designed from other Echinostoma species to initially amplify CYTB region in E. revolutum. All sequence data of E. revolutum in five provinces of Central Thailand were used as the target for designing the species-specific primer for E. revolutum. The results revealed that CYTB gene can separate E. revolutum into two sister groups by geographical distribution, comprising the eastern and western area groups. Moreover, it also separates E. revolutum from other Echinostoma species, including two sibling species; E. caproni and E. paraensei. In addition, we developed the high performance species-specific primer of E. revolutum. It can detect DNA from a single egg, as well as cercaria, metacercaria and adult stages of this trematode with no cross-reactions to other trematodes and their hosts. Therefore, this research is a positive initial step for the future study of E. revolutum CYTB. The future studies based on this gene should be continued with all species in revolutum complex to overcome the problems of systemic classification that arise in this complex group.

Phylogeography of the widespread creek chub Semotilus atromaculatus (Cypriniformes: Leuciscidae).

The extent and nature of genetic differentiation in Semotilus atromaculatus, one of the most abundant and widespread leuciscids in North America, were evaluated based on mitochondrial (mt) and nuclear DNA sequence variation. Phylogenetic relationships were first inferred based on a fragment of the cytochrome b (cytb) region and the nuclear intron s7 gene for S. atromaculatus and all other congeners as well as representative species from all other genera in the creek chub-plagopterin clade. The phylogeography of major haplogroups of S. atromaculatus was also assessed according to variation in a fragment of the mitochondrial cytb region from 567 individuals across its range. All analyses identified S. thoreauianus, S. lumbee and S. corporalis as reciprocally monophyletic groups. Analyses of nuclear sequence variation resolved S. atromaculatus as a single clade, where S. thoreauianus and S. lumbee were recovered as the sister group to S. atromaculatus, and S. corporalis was resolved as sister to all other species in the genus. Analyses of mtDNA sequence variation recovered S. atromaculatus as three well supported and differentiated monophyletic groups, with a widespread genetically homogeneous lineage extending across most of the current range of the species; a more geographically restricted and geographically structured lineage in the southern Appalachians, sister group to S. lumbee; and a geographically restricted lineage was identified from two Gulf Slope basins. Evidence of complex mito-nuclear discordance and phylogeographic differentiation within S. atromaculatus illustrates that further analysis of widespread species is warranted to understand North American freshwater fish diversity and distributions.

Single Nucleotide Polymorphisms and Haplotype Analyses in Tilapia Fish Inferred from mtDNA D-loop and Cyt-b Regions

Single Nucleotide Polymorphisms and Haplotype Analyses in Tilapia Fish Inferred from mtDNA D-loop and Cyt-b Regions

Genetic structure of the grey side-gilled sea slug (Pleurobranchaea maculata) in coastal waters of New Zealand.

Pleurobranchaea maculata is a rarely studied species of the Heterobranchia found throughout the south and western Pacific–and recently recorded in Argentina–whose population genetic structure is unknown. Interest in the species was sparked in New Zealand following a series of dog deaths caused by ingestions of slugs containing high levels of the neurotoxin tetrodotoxin. Here we describe the genetic structure and demographic history of P. maculata populations from five principle locations in New Zealand based on extensive analyses of 12 microsatellite loci and the COI and CytB regions of mitochondrial DNA (mtDNA). Microsatellite data showed significant differentiation between northern and southern populations with population structure being associated with previously described regional variations in tetrodotoxin concentrations. However, mtDNA sequence data did not support such structure, revealing a star-shaped haplotype network with estimates of expansion time suggesting a population expansion in the Pleistocene era. Inclusion of publicly available mtDNA sequence sea slugs from Argentina did not alter the star-shaped network. We interpret our data as indicative of a single founding population that fragmented following geographical changes that brought about the present day north-south divide in New Zealand waters. Lack of evidence of cryptic species supports data indicating that differences in toxicity of individuals among regions are a consequence of differences in diet.

Analysis of mitochondrial DNA mutation in leukemia

Objective To study the mitochondrial DNA mutation in leukemia. Methods Mitochondrial DNA of 16 leukemia patients in First Hospital of Qinhuangdao from February to June 2017 were amplified and sequenced by using polymerase chain reaction (PCR). The result was compared with revised Cambridge reference sequence (rCRS) and human mitochondrial genome database (mtDB), and the mutation was also analyzed. Results There were 106 mutation genes in total, including 47.17 % (50/106) in D-loop region, 2.83 % (3/106) in ND4 region, 17.92 % (19/106) in ND5 region, 22.64 % (24/106) in Cytb region, 7.55 % (8/106) in ND1 region, 1.89 % (2/106) in CoⅡregion. Conclusion There is a high mitochondrial DNA mutation rate in leukemia patients. Key words: Leukemia; Mitochondrial DNA mutation