Mitochondrial DNA D-loop Region Research Articles

Identification of sequence nucleotide polymorphisms in the D-loop region of mitochondrial DNA as a risk factor for epithelial ovarian cancer

Objective: Single nucleotide polymorphisms (SNPs) and mutations in the D-Loop region of mitochondrial DNA have been long proposed to drive the pathogenesis and progression of human malignancies. We investigated the links between SNPs of D-Loop and epithelial ovarian cancer risk. Method: Mitochondrial DNA (mtDNA) of peripheral blood from 93 epithelial ovarian cancer patients and controls were examined for single nucleotide polymorphisms (SNPs) and mutations in the D-Loop region. Results: The 73A/G, 207G/A and 523C/del (p < 0.05), which indicated that the patients who carry these alleles were susceptible to epithelial ovarian cancer. Additional SNPs 254T/G, 259A/G, 275G/A, 366G/A, 411C/G, 414T/G, 418C/G, 441C/A, 476C/A, 524C/del, 530C/T were significantly associated with the tendency toward the increased risk for epithelial ovarian cancer. In contrast, the alleles 249A/del and 263A/G were correlated with the reduced risk of epithelial ovarian cancer. Conclusion: In conclusion, SNPs in the mtDNA D-loop were found to be risk markers for epithelial ovarian cancer.

Geographic variation within a tandemly repeated mitochondrial DNA D-loop region of a North American freshwater fish, Pylodictis olivaris

The present study reports the distribution of a 35-bp mitochondrial DNA (mtDNA) D-loop tandemly repeated sequence in the populations of a North American freshwater catfish, Pylodictis olivaris, and the important role of a past geological event in the phylogeographic pattern of this species. A total of 330 individuals of flathead catfish, representing 34 drainages throughout the species' native range in the United States, were collected. While more than 70% of individuals sampled from the Southeastern Gulf Coast drainages were characterized by the presence of a 35-bp mtDNA D-loop tandem repeat proximal to the 5′ end, more than 95% of samples from the Mississippi River and its tributaries, as well as from the drainages of the Southwest Gulf Coast region, lack this tandem repeat. Concomitantly, phylogenetic analyses revealed the existence of two distinct matrilineal lineages (lineage I and II) of P. olivaris, which were estimated to have diverged from a common ancestor sometime between 0.70 and 2.05myr ago. While one lineage is comprised of samples from the Mississippi River and its tributaries and rivers draining to the Southwest Gulf Coast, the other lineage is comprised of samples from the Southeastern Gulf Coast drainages. Each lineage also has two sub-lineages, which also showed geographic specificity.

When and how did Bos indicus introgress into Mongolian cattle?

The Mongolian cattle are one of the most widespread breeds with strictly Bos taurus morphological features in northern China. In our current study, we presented a diversity of mitochondrial DNA (mtDNA) D-loop region and Y chromosome SNP markers in 25 male and 8 female samples of Mongolian cattle from the Xinjiang Uygur autonomous region in Western China, and detected 21 B. taurus and four Bos indicus (zebu) mtDNA haplotypes. Among four B. indicus mtDNA haplotypes, two haplotypes belonged to I1 haplogroup and the remaining two haplotypes belonged to I2 haplogroup. In contrast, all 25 male Mongolian cattle samples revealed B. taurus Y chromosome haplotype and no B. indicus haplotypes were found. Historical and archeological records indicate that B. taurus was introduced to Xinjiang during the second millennium BC and B. indicus appeared in this region by the second century AD. The two types of cattle coexisted for many centuries in Xinjiang, as depicted in clay and wooden figurines unearthed in the Astana cemetery in Turfan (3rd–8th century AD). Multiple lines of evidence suggest that the earliest B. indicus introgression in the Mongolian cattle may have occurred during the 2nd–7th centuries AD through the Silk Road around the Xinjiang region. This conclusion differs from the previous hypothesis that zebu introgression to Mongolian cattle happened during the Mongol Empire era in the 13th century.

Single nucleotide polymorphisms in the D-loop region of mitochondrial DNA are associated with epithelial ovarian cancer prognosis

Objective: The single nucleotide polymorphisms (SNPs) in the displacement loop (D-loop) of mitochondrial DNA (mtDNA) is found in many types of cancers. A lot of reports show the SNPs of D-loop may be related to cancers prognosis. This study investigated whether the SNPs were associated with the outcome of epithelial ovarian cancer (EOC). Method: The D-loop region of mtDNA samples from blood were obtained from 89 patients with primary EOC, who received surgery. The 3 year survival curves were calculated by Kaplan–Meier method and compared by the log-rank test. Multivariate analysis was performed with Cox proportional hazards model. Result: The SNP sites of nucleotides 309 C/T, 324 C/G and 446 C/A were identified for prediction of post-operational survival. In an overall multivariate analysis, the alleles 309 and 324 were identified as independent predictors of EOC outcome. Conclusion: The results indicated that the SNPs in D-loop are associated with the clinical outcome of patients with EOC. The analysis of SNPs in D-loop region may help identify the patient genotype to predict prognosis of the EOC patients.

陕西省林麝mtDNA D-loop区序列结构和种群遗传多样性分析

PDF HTML阅读 XML下载 导出引用 引用提醒 陕西省林麝mtDNA D-loop区序列结构和种群遗传多样性 DOI: 10.5846/stxb201305221148 作者: 作者单位: 陕西省动物研究所;陕西师范大学，西安,陕西师范大学,陕西省动物研究所 西安,陕西省动物研究所 西安,陕西省动物研究所 西安 作者简介: 通讯作者: 中图分类号: 基金项目: 陕西省重大科技专项（2010ZDKG-54）；陕西省科学技术研究发展计划项目（2012KW-21）；陕西省科学院青年人才培养项目（2012K-027）；陕西省科学院科技专项（2009K-02） Structure of the mitochondrial DNA D-Loop region and genetic diversity of Moschus berezovskii in Shaanxi Province Author: Affiliation: Shaanxi Institute of Zoology;Shaanxi Normal University，Xi’an,,Shaanxi Institute of Zoology,Xi’an,Shaanxi Institute of Zoology,Xi’an,Shaanxi Institute of Zoology,Xi’an Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:林麝（Moschus berezovskii）曾广泛分布于中国，由于盗猎和栖息地缩小，秦岭地区野生种群数量迅速下降，圈养繁殖种群已成立了几十年，但大多数圈养种群的遗传背景不清，种群规模增长非常缓慢。为了给这一物种的保护和管理提供有用的信息，调查了陕西省林麝1 个圈养种群3 个野生种群线粒体DNA（mtDNA）D-Loop 632 bp片段的遗传多样性和种群结构。在69个个体中其碱基组成为A+T的平均含量63.2%高于G + C含量36.8%，共检测到变异位点171个（约占总位点数的27.05%）。核苷酸多样性（Pi）为 0.04424，平均核苷酸差异数（K）为19.908。69个个体分属32个单倍型，单倍型间的平均遗传距离（P）为0.070。32个单倍型构建的NJ系统树聚为3个分支，4个林麝群体中的单倍型是随机分布的。4个群体的平均遗传距离为0.043（标准误SE为0.005），凤县养殖场群体与留坝和陇县群体的亲缘关系较远。单倍型间的平均遗传距离为0.043，可见其遗传分化尚未达到种群分化的水平。结果表明，陕西省林麝群体mtDNA D-loop区序列存在着较丰富的变异和遗传多样性，凤县野生群体和凤县养殖场群体的核苷酸多样性和单倍型多样较高，养殖场种群没有出现近亲繁殖及遗传多样性下降的情况。凤县野生群体和凤县养殖场群体两者遗传分化较小，存在着较高的基因流水平。 Abstract:Forest musk deer (Moschus berezovskii) were once distributed widely in China. However, wild populations in the Qinling Mountains have declined dramatically because of poaching and habitat loss. Captive breeding populations have been established for several decades, but the genetic background of most captive populations has been unclear and the populations have increased very slowly. In order to gather useful information for the conservation and management of this species, we investigated the genetic diversity and population structure of forest musk deer by analyzing a 632-bp fragment of the mitochondrial DNA (mtDNA) D-loop region in one captive breeding population and three wild populations in Shaanxi Province, China. The captive breeding population was from the Fengxian musk deer plant; the three wild populations were from Fengxian, Liuba and Longxian Counties. The mtDNA was extracted from two samples: hair and muscle. The average contents of A+T (63.2%) were higher than those of G+C (36.8%) in the mtDNA D-loop region. A total of 171 variable sites (about 27.05% of the total nucleotides in the sequence) were detected in 69 individuals. The nucleotide diversity (Pi) of the 69 individuals was 0.04424, and the average number of nucleotide differences (K) between them was 19.908. The 69 individuals belonged to 32 haplotypes, according to the determined sequences. The average genetic distance (P) among the haplotypes of the species was 0.070. Analysis of the phylogenetic tree using the neighbour-joining method showed that the 32 haplotypes were clustered into three groups. The 32 haplotypes were randomly distributed between the four forest musk deer populations. By means of the median-joining method, we found that haplotype 3 was located in the center of the star graph, and that the other haplotypes were associated with haplotype 3 by 1-38 steps. The average genetic distance of the four groups was 0.0434 (standard error 0.005). The genetic relationship between the Fengxian musk deer plant and Liuba populations was distant. The average genetic distance among the haplotypes was 0.043, so the genetic differentiation had not yet reached the level of population differentiation. Our data indicated that the variation and genetic diversity were high in the four populations of Moschus berezovskii. The captive breeding population and the wild population in Fengxian both had a higher nucleotide diversity and haplotype diversity. There was no inbreeding or genetic diversity reduction in the captive breeding population. The analysis of molecular variance demonstrated that most variation occurred within samples and that there was significant differentiation between the four populations. The genetic differentiation between the farm populations and the wild populations in Fengxian was small, with a high degree of gene flow. Estimates of the gene flow indicated that there were few genetic exchanges among the four populations. Building pedigree records and increasing the gene flow between populations will help to conserve these populations and this species. 参考文献 相似文献 引证文献

Continental monophyly and molecular divergence of Peninsular Malaysia's Macaca fascicularis fascicularis.

The phylogenetic relationships of long-tailed macaque (Macaca fascicularis fascicularis) populations distributed in Peninsular Malaysia in relation to other regions remain unknown. The aim of this study was to reveal the phylogeography and population genetics of Peninsular Malaysia's M. f. fascicularis based on the D-loop region of mitochondrial DNA. Sixty-five haplotypes were detected in all populations, with only Vietnam and Cambodia sharing four haplotypes. The minimum-spanning network projected a distant relationship between Peninsular Malaysian and insular populations. Genetic differentiation (F ST, Nst) results suggested that the gene flow among Peninsular Malaysian and the other populations is very low. Phylogenetic tree reconstructions indicated a monophyletic clade of Malaysia's population with continental populations (NJ = 97%, MP = 76%, and Bayesian = 1.00 posterior probabilities). The results demonstrate that Peninsular Malaysia's M. f. fascicularis belonged to Indochinese populations as opposed to the previously claimed Sundaic populations. M. f. fascicularis groups are estimated to have colonized Peninsular Malaysia ~0.47 million years ago (MYA) directly from Indochina through seaways, by means of natural sea rafting, or through terrestrial radiation during continental shelf emersion. Here, the Isthmus of Kra played a central part as biogeographical barriers that then separated it from the remaining continental populations.

Genetic diversity of maternal lineage in the endangered Kiso horse based on polymorphism of the mitochondrial DNA D-loop region.

ABSTRACTTo determine genetic characteristics of the maternal lineage of the Kiso horse based on polymorphisms of the mitochondrial DNA D-loop region, we collected blood samples from 136 Kiso horses, 91% of the entire population, and sequenced 411 bp from 15,437 to 15,847 in the region. First of all, we estimated the demographic history; by searching homology between the obtained and known sequences using Basic Local Alignment Search Tool, by mismatch analysis to evaluate the mutation processes using Arlequin, and by building a phylogenetic tree showing the relationship of the mtDNA haplotypes for 24 horse breeds around the world using Molecular Evolutionary Genetics Analysis softwear. The results suggested that various horses that came to Japan stayed at Kiso region and became ancestors of Kiso horse and also genetically supported the theory that the Kiso horse was historically improved by other Japanese native horse breeds. Next, we analyzed the diversity of current maternal lineage by classifying the resulting sequences, and by calculating the haplotype diversity and nucleotide diversity using Arlequin. Then, we visualized the relationship among haplotypes by a median-joining network using NETWORK 4.6.0.0. The results suggested the diversity of maternal lineage in the Kiso horse was reasonably maintained. Lastly, we predicted future change of the diversity of maternal lineage in Kiso horse by assessing the regional distribution of the acquired haplotypes. The distribution suggested that diversity of maternal lineage would possibly be reducing.

Identification of sequence polymorphisms in the D-loop region of mitochondrial DNA as risk biomarkers for malignant fibrous histiocytoma

Single nucleotide polymorphisms (SNPs) in the mitochondrial DNA Displacement-loop (D-loop) region particularly in a highly polymorphic homopolymeric C stretch named D310 have been reported to be associated with cancer risk in several types of cancer. In order to evaluate the frequency of D-loop SNPs in a large series of malignant fibrous histiocytoma (MFH) and establish correlations with cancer risk, we sequenced the D-loop of 92 MFH patients and analyzed their use as predictive biomarkers for MFH risk. The minor alleles of nucleotides 73G, 151T were associated with an increased risk for MFH patients, whereas the alleles of nucleotides 16,298C, 152C, and insertion of C at the site 315 (located within the D310) were associated with a decreased risk for MFH patients. These results suggest that SNPs in the mitochondrial D-loop should be considered as a biomarker which may be useful for the early detection of MFH in individuals at risk of this cancer.

Mitochondrial D-loop sequence variation among Hucul horse

Genetic variation in the Czech Hucul horse population was analyzed using a sequence analysis of the D-loop region of mitochondrial DNA. One hundred and sixty-five Hucul horses were tested. Sequencing of the 700-base pairs fragment of the mitochondrial DNA D-loop region revealed 38 mutation sites representing 14 haplotypes, which were clustered into six haplogroups. The genetic information obtained from the mitochondrial DNA typing is of utmost importance for the future breed-conservation strategies. &amp;nbsp;

Molecular phylogeny of Indian horse breeds with special reference to Manipuri pony based on mitochondrial D-loop

Manipuri pony is the geographically distant breed of horse from the five recognized horse breeds found in the Indian subcontinent. The phylogenetic relationship of Manipuri pony with the other breeds is unknown. The diversity in the mitochondrial (mt) DNA D-loop region is employed as an important tool to understand the origin and genetic diversification of domestic horses and to examine genetic relationships among breeds around the world. This study was carried out to understand the maternal lineages of Manipuri pony using the 247 bp region of the mtDNA D-loop. The dataset comprised of eleven numbers of self developed sequences of Manipuri pony, 59 and 35 number of retrieved sequences of Indian horse breeds and other worldwide breeds respectively. A total of 35 haplotypes was identified with a high level of genetic diversity in the Indian breeds. A total of seven major mtDNA haplogroups (A-G) was identified in the Indian horse breeds that indicated the abundance of mtDNA diversity and multiple origins of maternal lineages in them. The majority of the studied sequences of Indian breeds (33.3 %) were grouped into haplogroup D and least (3.9 %) in haplogroup E. The Manipuri breed showed the least FST distance (0.03866) with the most diverged Indian breeds and with Thoroughbred horse among the worldwide. This study indicated a close association between Manipuri pony and Thoroughbred.

Sequence polymorphisms in the D-loop region of mitochondrial DNA and outcome of non-Hodgkin lymphoma

Accumulation of single nucleotide polymorphisms (SNPs) in the displacement loop (D-loop) of mitochondrial DNA (mtDNA) might be associated with cancer risk and disease outcome. We have identified 140 SNPs including 26 SNPs with frequency distribution of minor allele greater than 5% in a case–control study for non-Hodgkin lymphoma patients previously. In this study, we assessed the predictive power of D-loop SNPs in NHL patients. Five SNP sites were identified by log-rank test for statistically significant prediction of NHL survival in a univariate analysis. In an overall multivariate analysis, allele 16304 was identified as an independent predictor of NHL outcome. The survival time of NHL patients with 16304C was significantly shorter than that of patients with 16304T (relative risk, 0.513; 95% CI, 0.266–0.989; p = 0.046). The analysis of genetic polymorphisms in the mitochondrial D-loop can help identify subgroups of patients who are at a high risk of a poor disease outcome.

Single nucleotide polymorphisms in the D-loop region of mitochondrial DNA is associated with renal cell carcinoma outcome

Accumulation of single nucleotide polymorphisms (SNPs) in the displacement loop (D-loop) of mitochondrial DNA (mtDNA) has been described in various types of cancers and might be associated with cancer risk and disease outcome. We identified 14 SNPs with a frequency higher than 5% and 5 SNPs associated with the risk of renal cell carcinoma (RCC) in a case–control study previously. In the present study, we assessed the relationship of these SNPs and the outcome of RCC patients, a SNP of 262C/T was identified by the log-rank test for statistically significant prediction of RCC survival. In an overall multivariate analysis, allele 262 was identified as an independent predictor of RCC outcome. The length of survival of patients with 262T was significantly shorter than that of patients with allele 262C (relative risk, 2.136, 95%CI, 1.863–2.449; p = 0.000). The analysis of genetic polymorphisms in the mitochondrial D-loop can help identify patients subgroup at high risk of a poor disease outcome.

Clinal variation in a brown lemur (Eulemur spp.) hybrid zone: Combining morphological, genetic and climatic data to examine stability

Studies of hybrid zones can inform our understanding of reproductive isolation and speciation. Two species of brown lemur (Eulemur rufifrons and E. cinereiceps) form an apparently stable hybrid zone in the Andringitra region of southeastern Madagascar. The aim of this study was to identify factors that contribute to this stability. We sampled animals at 11 sites along a 90-km transect through the hybrid zone and examined variation in 26 microsatellites, the D-loop region of mitochondrial DNA, six pelage and nine morphological traits; we also included samples collected in more distant allopatric sites. Clines in these traits were noncoincident, and there was no increase in either inbreeding coefficients or linkage disequilibrium at the centre of the zone. These results could suggest that the hybrid zone is maintained by weak selection against hybrids, conforming to either the tension zone or geographical selection-gradient model. However, a closer examination of clines in pelage and microsatellites indicates that these clines are not sigmoid or stepped in shape but instead plateau at their centre. Sites within the hybrid zone also occur in a distinct habitat, characterized by greater seasonality in precipitation and lower seasonality in temperature. Together, these findings suggest that the hybrid zone may follow the bounded superiority model, with exogenous selection favouring hybrids within the transitional zone. These findings are noteworthy, as examples supporting the bounded superiority model are rare and may indicate a process of ecologically driven speciation without geographical isolation.

Introgression and isolation contributed to the development of Hungarian Mangalica pigs from a particular European ancient bloodline

BackgroundMangalica breeds are indigenous to Hungary and their breeding history dates back to about 200–250 years ago. They are fat-type pigs and have a rare curly hair phenotype. The aim of our study was to establish the relationships between these unique breeds and other European breeds.ResultsBased on a core sequence of 382 bp present in 2713 mitochondrial D-loop sequences from pigs belonging to 38 local breeds from nine countries, five cosmopolitan breeds and wild boars from 14 countries, we identified 164 haplotypes. More than half of the 2713 sequences belonged to either four haplotypes characteristic of continental European breeds or two haplotypes characteristic of British/cosmopolitan breeds; each haplotype is present in more than 100 individuals. Most Mangalica individuals belonged either to one of these common continental European haplotypes or to two Mangalica-specific haplotypes that were absent in all other breeds. In addition, we identified the ancestral mitochondrial D-loop signature present in these 2713 sequences and found that ~ 80% carried the European ancient signatures, ANC-Aside and ANC-Cside or their closely related signatures, while most of the remaining sequences carried a modern Asian signature, ANC-Easia. Mangalica individuals carried the ANC-Aside signature, but not the ANC-Cside or ANC-Easia signatures.ConclusionsIn all the Mangalica individuals, a unique ancient European signature was found in the mitochondrial DNA D-loop region, but they belonged almost exclusively to either certain very abundant European or two Mangalica-specific D-loop haplotypes. This indicates that the present-day Mangalica population in Hungary evolved either by introgression of other European breeds and wild boars or via total isolation after the divergence of European ancient porcine bloodlines.

Identification of sequence polymorphisms in the D-loop region of mitochondrial DNA as a risk factor for non-Hodgkin lymphoma

Accumulation of single nucleotide polymorphisms (SNPs) in the displacement loop (D-loop) of mitochondrial DNA (mtDNA) may be associated with an increased cancer risk. We investigated the non-Hodgkin lymphoma (NHL) risk profile of D-loop SNPs in a case–control study. The minor alleles of nucleotides 73A/G, 263A/G, 315C/C insert were associated with a decreased risk for NHL. The minor alleles of the nucleotides 200G/A were specifically associated with the risk of diffuse large B-cell lymphoma, whereas the minor allele of nucleotides 16362C/T and 249Del/A was specifically associated with the decreased risk of T-cell lymphoma. In conclusion, SNPs in mtDNA are potential modifiers of NHL risk. The analysis of genetic polymorphisms in the mitochondrial D-loop can help identify subgroups of patients who are at a high risk of developing NHL.

Mitochondrial DNA A10398G Mutation is not Associated with Breast Cancer Risk in a Sample of Iraqi Women

The aim of this study was to investigate if there is a relationship between mtDNA polymorphism (A10398G) and breast cancer in a sample of 59 Iraqi women. Breast cancer is the second most common diagnosed cause of cancer death in the developed countries and accounts for 23% of the total cancers. Different studies reported that breast cancer accounts for 14% of all cancer deaths in females. It is well documented that the different factors such as genetics and environment factors are involved in tumorigenesis. Mutations in the mitochondrial DNA D-loop region and somatic mutations are emerging as early genetic markers of cancer. Identification of such markers for breast cancer would prevent late detection and increase the chance of recovery and survival rate. In breast cancer different mtDNA alterations were reported. The A10398G mutation in NADH Dehyrogenase (ND3) a subunit of complex I of the Oxidative Phosphorylation process (OXPHOS) is perhaps one of the most studied mutations with conflicting reports of its association with breast cancer. Genomic DNA was extracted from 21 unrelated women with malignant tumors, 22 women with benign tumors and 16 healthy women blood donors. Subsequently, PCR amplification was performed using specific primers, PCR products were subjected to a suitable restriction enzyme. No genetic variants were identified in mtDNA among malignant tumoral group and controls while 9% of benign tumor cases exhibited the variant. Our finding indicated that A10398G polymorphism cannot be used as a biomarker for breast cancer detection in Iraqi women.

Screening of the gene mutation in D-loop region of mitochondrial DNA in oral squamous cell carcinoma

To investigate the gene mutation in D-loop region of mitochondrial DNA (mtDNA) in oral squamous cell carcinoma (OSCC) tissue and to explore the role of the gene mutation in D-loop region in the OSCC tumorigenesis. mtDNA was obtained from cancer, paracancerous and normal mucosa tissues of thirty patients with OSCC. The D-loop regions of mtDNA were amplified with PCR, sequencing and then analyzed by Chromas software and BLAST to identify the mutation site. Mutation in the D-loop region was found in eight cases, with the mutation rate of 27%. There were nine mutations totally, including one point mutation, two base deletions, three insertion mutations, three heterozygous mutations. In these mutations, base deletions were different from each other and heterozygous mutations had no same mutation form, while the three insertion mutations were same, the insertion of base C. One case had T/A heterozygous mutation and base C insertion at the same time. There were mutations in mtDNA D-loop in OSCC, but the relationship between occurrence of OSCC and mutation of mtDNA needs further study.

Mutation detection of mitochondrial DNA D-loop region in bone marrow cells of acute leukemia

This study was aimed to detect the mutations and microsatellite instability (mtMSI) in mitochondrial DNA (mtDNA) D-loop region in bone marrow cells of acute leukemia (AL) patients, and to analyze their relationship with the pathogenesis of AL. 19 cases of newly diagnosed AL were enrolled in this study. Through extracting mtDNA, the D-loop region was amplified by polymerase chain reaction (PCR), the sequences of PCR products were detected by the pros- and cons-direct sequencing methods. The sequencing results were compared with the revised Cambridge reference sequence (rCRS) and the relevant database (MITOMAP database, GenBank database, mtDB database). The results showed that the mutation rate of mtDNA D-loop region in AL was 79% (15/19). 215 variations (35 mutations, 180 SNP) and a kind of mtMSI in the D-loop region were detected. A new type of mutation nt150 C-CT was found. Also, there was no significant difference in the number of mutations between patients with different ages and different types of AL (AML, B-ALL). It is concluded that there is high frequency of mutations in the mtDNA D-loop, and the mutations may be associated with the pathogenesis of AL.

Clinicopathologic Characteristics and Prognoses for Multicentric Occurrence and Intrahepatic Metastasis in Synchronous Multinodular Hepatocellular Carcinoma Patients

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and the outcomes for patients are still poor. It is important to determine the original type of synchronous multinodular HCC for preoperative assessment and the choice of treatment therapy as well as for the prediction of prognosis after treatment. To analyze clinicopathologic characteristics and prognoses in patients with multicentric occurrence (MO) and intrahepatic metastasis (IM) of synchronous multinodular hepatocellular carcinoma (HCC). The study group comprised 42 multinodular HCC patients with a total of 112 nodules. The control group comprised 20 HCC patients with 16 single nodular HCC cases and 4 HCC cases with a portal vein tumor emboli. The mitochondrial DNA (mtDNA) D-loop region was sequenced, and the patients of the study group were categorized as MO or IM based on the sequence variations. Univariate and multivariate analyses were used to determine the important clinicopathologic characteristics in the two groups. In the study group, 20 cases were categorized as MO, and 22 as IM, whereas all 20 cases in the control group were characterized as IM. Several factors significantly differed between the IM and MO patients, including hepatitis B e antigen (HBeAg), cumulative tumor size, tumor nodule location, cirrhosis, portal vein and/or microvascular tumor embolus and the histological grade of the primary nodule. Multivariate analysis further demonstrated that cirrhosis and portal vein and/or microvascular tumor thrombus were independent factors differentiating between IM and MO patients. The tumor-free survival time of the MO subjects was significantly longer than that of the IM subjects (25.7 ∓ 4.8 months vs. 8.9 ∓ 3.1 months, p=0.017). Similarly, the overall survival time of the MO subjects was longer (31.6 ∓ 5.3 months vs. 15.4 ∓ 3.4 months, p=0.024). The multivariate analysis further demonstrated that the original type (p=0.035) and Child-Pugh grade (p<0.001) were independent predictors of tumor-free survival time. Cirrhosis (p=0.011), original type (p=0.034) and Child-Pugh grade (p<0.001) were independent predictors of overall survival time. HBeAg, cumulative tumor size, tumor nodule location, cirrhosis, portal vein and/or microvascular tumor embolus and histological grade of the primary nodule are important factors for differentiating IM and MO. MO HCC patients might have a favorable outcome compared with IM patients.

Genetic diversity of &lt;I&gt;Pseudosciaena polyactis&lt;/I&gt; in Zhoushan based on mitochondrial DNA D-loop region sequences

Pseudosciaena polyactis is an economically important species of marine fish in China that is currently declining due to overexploitation, environmental pollution and related factors. Research in to the genetic structure of Pseudosciaena polyactis populations plays a key role in protecting and promoting sustainable utilization. We collected 53 individuals of Pseudosciaena polyactis from Zhoushan, Zhejiang and sequenced and amplified the mitochondrial DNA (mtDNA) D-loop region using Polymerase Chain Reactions (PCR). The sequence length of the 53 individuals ranged from 795 to 801 bp. The sequences were analyzed by Clustal X1.83, MEGA3.1 and DnaSP4.0. The results showed that the average base content of T, C, A, G was 30.3%, 23.1%, 32.3% and 14.3%, respectively and there were 93 transition or transversion sites, including 53 single nucleotide mutation sites and 40 parsimony informative sites, which accounted for 11.6% of the length of the analyzed sequences. In total, we identified 52 haplotypes and found haplotype diversity (hd) of 0.9993, average number of nucleotide differences were 9.73875 (k), and nucleotide diversity (&pi;) of 0.01233. The average genetic distance of haplotypes was 0.012, and the average transition/transversion was 4.305. Based on mitochondrial DNA D-loop region sequences, these results indicate that the genetic diversity of the Pseudosciaena polyactis population in Zhoushan is currently at a medium level.