Search

Background: Ribosomal DNA (rDNA) is the most abundant and important housekeeping gene in the cell. It usually acted as DNA damage sensor in DNA damage reaction. Gastric cancer (GC) as a tumor with high morbidity and mortality, it is hard to diagnosis in an early stage. Methods: In this study, we collected and test the copy number of rDNA in blood sample of 42 GC patients and 56 healthy controls (HC) to explore the relationship between rDNA and GC. Besides, we make a correlation between the copy number of rDNA and ten biomarkers (CYFR21-1, CA15-3, CA72-4, NSE, CEA, CA125, ProGRP, AFP, SCC, CA19-9). Results: The copy number of 18 S, 5.8 S, 28 S rDNA in GC is less than HC and 5 S is more than HC in their blood sample. And the expression of H-cox-1 and ND1 in GC is higher than HC in blood sample. it shows the expression of CA15-3 is related to ND1 and H-cox-1. Conclusion: We found for the first time the changes of rDNA and mtDNA expression in the blood of patients with gastric cancer. All these finding suggests rDNA may have potential in diagnosing GC. [ABSTRACT FROM AUTHOR]

Background: Mizoram has the highest incidence of cancer in India. Among women, breast cancer is most prevalent and the state occupies fifth position globally. The reason for high rate of cancer in this region is still not known but it may be related to ethnic/racial variations or lifestyle factors. Methods: The present study aims to identify the candidate mitochondrial DNA (mtDNA) biomarkers-ND1and ATPase for early breast cancer diagnosis in Mizo population. Genomic DNA was extracted from blood samples of 30 unrelated breast cancer and ten healthy women. The mtNDI and mtATP coding regions were amplified by step-down PCR and were subjected to restriction enzyme digestion and direct sequencing by Sanger method. Subsequently, the results of the DNA sequence analysis were compared with that of the revised Cambridge Reference Sequence (rCRS) using Mutation Surveyor and MITOMAP. Results: Most of the mutations were reported and new mutations that are not reported in relationship with breast cancer were also found. The mutations are mostly base substitutions. The effect of non-synonymous substitutions on the amino acid sequence was determined using the PolyPhen-2 software. Statistical analysis was performed for both cases and controls. Odds ratios (ORs) and 95 % confidence intervals (CIs) were estimated from logistic regression. High intake of animal fat and age at menarche was found to be associated with a higher risk of breast cancer in Mizo population. Conclusion: Our results also showed that ATPase6 as compared to ATPase8 gene is far more predisposed to variations in Mizo population with breast cancer and this finding may play an important role in breast cancer prognosis. [ABSTRACT FROM AUTHOR]

Mitochondrial single nucleotide polymorphisms (SNPs) are significantly correlated with the development of diabetes mellitus . However, these polymorphisms are emerging to be considerably diverse among different population and regions. Sivaganga district is recently being given importance for genetic studies due to its rigid family structure. Hence, the present study is planned to investigate the correlation between mitochondrial SNP of ND1 gene with type II diabetes (T2D) of Karaikudi population of Sivaganga district. For this study, 206 samples including 105 T2D and 101 healthy volunteers were collected and screened for ND1 gene mutation. Genotyping for the ND1 gene was characterized by polymerase chain reaction, Restriction fragment length polymorphism (RFLP) followed by sequencing. In addition, clinical and biochemical variables were analyzed. RFLP and sequencing results showed G>A transition at 3316 position of ND1 gene in both T2D (6.67 %) and in control subjects (1.9 %). Since the frequency of the mutation was found high in T2D patients, we screened for the mutation in their family members and identified its maternal mode of inheritance. The result warrants for the detailed study to identify population based mitochondrial mutation association with disease development. [ABSTRACT FROM AUTHOR]

The 'East Pacific Barrier' has been recognized as the World's largest marine biogeographic barrier. Munida gregaria is the only species of its family with transpacific populations; however, it still remains to be elucidated whether these two distantly located populations belong to the same species. In this study, we investigated the genetic cohesion of M. gregaria across the East Pacific Barrier by analyzing mitochondrial markers. Cytochrome oxidase subunit I and NADH dehydrogenase subunit 1 genes were sequenced for individuals from different areas, i.e., the southeast Pacific, the southern tip of South America, the southwest Atlantic, and the southwest Pacific. A median-joining network, pairwise Fs, genetic diversity statistics, and neutrality tests were computed. Our results, i.e., the absence of different haplogroups on both sides of the East Pacific Barrier and existence of shared haplotypes, showed that populations on both sides of this barrier belong to the same species. At a population genetic level, our results suggest that individuals from both regions have been connected, since although some differentiation was found between the southern tip of South America and the southwest Pacific, the southeast Pacific and southwest Atlantic showed no signs of differentiation from the southwest Pacific. In addition, our results provided evidence of a population expansion in southern South America during the Pleistocene. The role of Pleistocene glaciations and the Antarctic Circumpolar Current in shaping the distribution of sub-Antarctic marine invertebrates is discussed. [ABSTRACT FROM AUTHOR]

The complete nucleotide sequence of the mitochondrial genome of long-finned squid Loligo edulis forma kensaki ( L. edulis f. kensaki, Teuthida: Myopsida) was determined. It contains 13 protein-coding genes, 12SrRNA, 16SrRNA, and the 22 tRNA genes, and three long noncoding regions. We also determined the mitochondrial genome nucleotide sequence of seasonal brood samples of L. edulis f. budo collected from the western part of the Sea of Japan in the autumn to winter seasons, which showed morphologic discrepancies with L. edulis f. kensaki. Comparison of the two complete sets of mitochondrial DNA data showed that the similarity of the two sequences was as high as 99.9 %, with only eight nucleotide substitutions in coding regions. The complete mitochondrial genome of Loligo edulis f. kensaki from Nagasaki Pref. is 17360 bp and L. edulis f. budo from the Shimane Pref. is 17351 bp. The nucleotide sequences and haplotype patterns in ND1 suggest that L. edulis f . kensaki and L. edulis f . budo share a single genetic background. [ABSTRACT FROM AUTHOR]

We have studied levels and distribution of genetic variation in nine isolated populations of Brown trout in NW Spain. In the present study, we have tried to test the importance of preservation of genetic variability for the survival of a set of isolated Brown trout (Salmo trutta) populations from the same river drainage. We screened genetic variation in three different markers, mitochondrial, microsatellites and Major Histocompatibility Complex (MHC), presumed to be under different selective pressures. Overall, genetic diversity varied considerably across populations and the distribution of genetic variation was similar at MHC and microsatellites; highly polymorphic populations at the microsatellite loci were also highly polymorphic at the MHC. We also observed high levels of differentiation among populations. Although we found evidence suggesting that balancing selection has influenced the long term evolution of the MHC, genetic drift seems to have eroded the effect of selection, becoming the predominant evolutionary force shaping genetic variation in some of the smaller populations. Despite current lack of variation at the MHC, these small populations seem to have remained viable for a long time. [ABSTRACT FROM AUTHOR]

Mitochondrial DNA (mtDNA) mutations can cause rare forms of dystonia, but the role of mtDNA mutations in other types of dystonia is not well understood. We now report identification by sequencing, restriction endonuclease analyses, and clonal analyses of a heteroplasmic missense A to G base pair substitution at nucleotide position 3796 (A3796G) in the gene encoding the ND1 subunit of mitochondrial complex I in a patient with adult-onset dystonia, spasticity, and core-type myopathy. The mutation converts a highly conserved threonine to an alanine. The same mutation subsequently was identified in 2 of 74 additional unrelated adult-onset dystonia patients. A muscle biopsy was obtained from 1 of these 2 subjects and this revealed abnormalities of electron transport chain (ETC) activities. The mutation was absent in 64 subjects with early onset dystonia, 82 normal controls, and 65 subjects with Parkinson's disease or multiple system atrophy. The A3796G mutation previously has been reported in 3 of 226 subjects from mitochondrial haplogroup H. Each of the 3 subjects in our study harboring the A3796G mutation was also from haplogroup H. However, a subgroup analysis of haplogroup H subjects from our study indicates that the A3796G mutation is significantly overrepresented among haplogroup H adult-onset dystonia subjects compared with haplogroup H controls ( P<0.01). This difference remains significant even after excluding the index patient ( P=0.04). These data suggest that, among haplogroup H subjects, the presence of the A3796G mutation increases the risk of developing adult-onset dystonia. [ABSTRACT FROM AUTHOR]

Comparison of meristic characters (pored lateral line scales, vertebrae, and fin rays), and PCR-RFLP analysis in the D-loop and ND1 regions of mitochondrial DNA were performed to estimate the genetic diversity in local populations of the Japanese rosy bitterling, Rhodeus ocellatus kurumeus. In terms of meristic characters, the Fukuoka population was the largest in both range and variance of the number of pored lateral line scales and vertebrae (abdominal and caudal), and Osaka was the second, whereas the Kagawa population showed the smallest range and variance in these characters. In PCR-RFLP analysis, 11 haplotypes (3 in Fukuoka, 2 in Okayama, 2 in Kagawa, and 4 in Osaka) were observed, and nucleotide sequence divergence (NSD) was approximately two times larger in ND1 (mean, 0.61%) than in D-loop (mean, 0.31%). In the neighbor-joining (NJ) tree, based upon the NSD value in ND1, haplotypes were arranged into four clades, which corresponded to the locality of each haplotype. The Fukuoka population was conspicuously apart from the other populations (mean, 0.90% in NSD), but the remaining three showed a similar genetic distance with each other (mean, 0.48%–0.52% in NSD). In haplotype diversity of mtDNA, half the stations in Osaka and all in Kagawa were monomorphic. Especially, two haplotypes endemic to Kagawa were randomly distributed, irrespective of drainages. Rhodeus o. kurumeus in Fukuoka inhabits small rivers and creeks (open water systems), while that in Kagawa and Osaka lives in small ponds (closed water systems). Taking the information of morphology, mtDNA, and habitat into consideration, the low genetic diversity in Kagawa and Osaka populations of R. o. kurumeus is thought to be mainly the result of the isolation of their habitat. [ABSTRACT FROM AUTHOR]