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Genetic structure and mtDNA diversity of Fundulus heteroclitus populations from polycyclic aromatic hydrocarbon-contaminated sites.

Genetic structure and diversity of mummichog (Fundulus heteroclitus) populations were investigated using mitochondrial DNA (mtDNA) sequences. Forty-six haplotypes were identified among 208 mummichog from the Elizabeth and York Rivers in Virginia, USA. No evidence of decreased gene or nucleotide diversity for mummichog from polycyclic aromatic hydrocarbon (PAH)-contaminated sites was observed. However, based on mtDNA data from 17 sites, a significant correlation (Mantel analysis, p = 0.035) was noted between genetic distance (F(ST)) and PAH concentration but not between genetic distance and geographic distance. Mummichog from the most heavily PAH-contaminated site, Atlantic Wood (AW), were genetically distinct from those of other Elizabeth River sites. At AW, high frequencies of several divergent haplotypes were observed that were more closely allied to the northern mummichog than to the more abundant southern form in the Chesapeake Bay. These data suggested that a locally stable population existed at the AW site. This conclusion is consistent with the observation that mummichog from the AW site display enhanced tolerance to PAH contamination relative to mummichog from noncontaminated sites. Conclusions about gene diversity and the correlation between genetic distance with site differences in PAH concentrations were also consistent with those from tandem genetic analyses based on allozymes.

Animals↗

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for mtDNA typing in hokkaido brown bear (Ursus arctos yesoensis).

To develop an easy method of typing of mitochondrial DNA (mtDNA) in Hokkaido brown bears (Ursus arctos yesoensis), the PCR-RFLP technique was improved using four restriction enzymes: Mbo 1, Cfr 13 I, TspE 1, and Fok 1. This approach identified seven groups of mtDNA haplotypes, HB1/2/5-7, HB 3, HB4, HB8/9, HB10/11, HB12 and HB13 from 102 brown bears of northern, central and eastern Hokkaido.

Animals↗

[Detection of mtDNA 11778 (G-->A) point mutation in a family with Leber's hereditary optic neuropathy by site-specific polymerase chain reaction].

OBJECTIVE: To find a simple, fast, accurate, and quantitative PCR-based method for mutation detection, so as to identify mitochondrial DNA 11778 G-->A point mutation in patients with Leber's hereditary optic neuropathy (LHON). METHOD: On the basis of sequencing of mtDNA from LHON proband, M primer for mutation and N primer for normal were designed to be coupled with reverse primer respectively. Specific PCRs were done on an amplifying condition with high stringency such as a well controlled annealing temperature, low Mg2+ concentration and less thermal cycles. The objective pedigree includes 10 individuals, were against 40 normal control persons. RESULTS: Different ratios of indicative mtDNA 11778A-->G mutation were checked out from the proband, affected maternal members and a 10 year-old boy (up to now no appearance yet), whereas not appeared on normal spouses, paternal offsprings in the family, neither did on 40 controls. CONCLUSION: This site-specific PCR method is a kind of general mutation analysis way, without the restriction of existence of endonuclease site. It can be applied for the gene diagnosis of known-mutation hereditary diseases such as LHON.

Adult↗

[A case or Leber hereditary optic neuropathy (LHON): differential diagnosis with post inflammatory atrophy of nerve II using the mtDNA analysis].

The Leber hereditary optic neuropathy (LHON) is a disease due to a mtDNA mutation. The disorder results from enzymatic perturbations in the mitochondrial respiratory chain. Clinically the LHON may present as a progressive axonal atrophy of the optic nerves with or without other neurological symptoms. The process of reaching the diagnosis of the LHON by means of the molecular analysis of mtDNA is discussed.

Adult↗

MtDNA polymorphisms among Tharus of eastern Terai (Nepal).

Tharus--a population of Terai (a region with a severe malarial morbidity in the past)--can be subdivided into three main groups: Western, Central and Southern Tharus. They have usually been considered a Mongoloid population and this has been further substantiated by mtDNA findings on Central Tharus. Studies on the distribution of malaria-related genes have shown an extremely high frequency (0.8) of the alpha-thal gene among Western and Central Tharus. This frequency, however, unexpectedly turned out to be only 0.04 in a sample of Eastern Tharus. This raised doubts on the common notion that Tharus are a single anthropological entity. In the present investigation mtDNA markers were studied in the same sample of Eastern Tharus previously examined for the alpha-thal gene. The findings were: 1. the same three features which confirmed the classification of Central Tharus as Mongoloids (i.e., the common occurrence of HpaI-1/HincII-1 and HaeII-5 morphs, and the lack of BamHI polymorphism) were also present in this sample. Since the only neighbouring population accessible to Tharus, until recently, has been Hindu (Caucasoids), this result strongly supports the notion that Tharus are indeed a single anthropological entity; 2. two statistically significant differences between Eastern and Central Tharus--namely, a much higher HaeII morph 5 frequency among Central Tharus, and the absence in the same group of the mutation at 15.487 bp (very common among Eastern Tharus)--together with the results on alpha-tal gene, suggested that Tharu subgroups underwent an effective reproductive isolation.

Blotting, Southern↗

A new mtDNA mutation in the tRNA(Lys) gene associated with myoclonic epilepsy and ragged-red fibers (MERRF).

Myoclonic epilepsy with ragged-red fibers (MERRF) has been associated with an A--G transition at mtDNA nt 8344, within a conserved region of the tRNA(Lys) gene. Although the 8344 mutation is highly prevalent in patients with MERRF, it is not observed in 10%-20% of the cases, suggesting genetic heterogeneity. We have sequenced the tRNA(Lys) gene of five MERRF patients lacking the common 8344 mutation. One of these showed a novel T-->C transition at nucleotide position 8356, disrupting a highly conserved base pair in the T psi C stem. The mutant mtDNA population was essentially homoplasmic in muscle but was heteroplasmic in blood (47%). Neither 20 patients with other mitochondrial diseases nor 25 controls carried this mutation. These findings suggest that tRNA(Lys) alterations may play a specific role in the pathogenesis of MERRF syndrome.

Adult↗

Frequent D-loop polymorphism in mtDNA enables genotyping of 1400-year-old human remains from Merowingian graves.

Improvements of DNA extraction and amplification techniques presently enable DNA analysis of ancient DNA (aDNA) from samples which range from several hundred years of age up to possibly 5000 years. Taking advantage of the abundance of mitochondrial DNA and its polymorphic D-loop sequence, ten individuals from multiple burial sites of the Merowingian culture (South Germany), estimated to be about 1400 years old, were genotyped to determine possible kinship. Moreover, gonosomal DNA markers from the X- and Y-chromosome were applied for sex determination of the remains. In all individuals investigated, deviations from the Anderson mtDNA consensus sequence were observed, all representing substitutions (7 transitions and 3 transversions). Although such mutations have been reported from recent populations, our study constitutes the first description of these mtDNA mutations from numerous aDNA samples recovered from multiple burial sites. The results obtained by molecular anthropology can aid in describing kinship relations and burial customs of ancient remains.

Journal Article↗

[Acclimatization of salmon Oncorhynchus gorbuscha (Walbaum) in the European north: data from restriction analysis of mtDNA].

Pink salmon spawners introduced into the White Sea basin (the Umba River) were compared to the spawners from the basin of the Sea of Okhotsk (the Ola River) using restriction analysis of two fragments of mitochondrial DNA (mtDNA). One of the fragments included genes ND5/ND6, the other, the cytochrome b gene and the control region. It was found that mtDNA variation and diversity at the earlier examined nuclear allozyme genes significantly decreased in the odd broodline of pink salmon 8 years after the introduction. The haplotype diversity in the even broodline was considerably lower than in the odd broodline exhibiting virtually no change two generations after the introduction. Based on the results obtained, a possible role of these changes in adaptation of White Sea pink salmon from the odd broodline to the new environment is discussed.

Adaptation, Physiological↗

Sequence analysis and phylogeny of deer (Cervidae) MtDNA control regions.

The complete control regions of three Muntiacinae species of Cervidae (M. reevesi, M. muntjak and M. crinifrons) were located after their complete mtDNA genomes were sequenced. In addition the control region sequences of nine species of other three Cervidae subfamilies were obtained from the Genbank. Base compositions, genetic distances and percent similarities among these regions were calculated and the homologous sequences were compared. Based on their control region sequences, the molecular phylogenetic tree was constructed by Neighbor-Joining method and rooted using the mtDNA control region sequence of O. aries. Furthermore, the phylogenetic relationship among the twelve species was discussed. The lengths of their control regions ranged from 909 bp to 1 049 bp and A + T content is 62.06%. The sequence alignment revealed considerable variation in 363 nucleotide sites (about 34%). According to the phylogenetic tree, we suggest: (1) As a whole, the phylogenetic taxon of the twelve Cervidae species based on their control region sequences is consistent with that made by the NCBI; (2) A. alces, a species of Alces (subfamily: Odocoileinae) is most antique one among the twelve Cervidae species; (3) M. reevesi is more antique than M. muntjak and M. crinifrons; (4) H. inermis, belonging to the subfamily Hydropotinae, is merged into the branch which includes C. capreolus and C. pygargus, two species of Capreolus (subfamily: Odocoileinae).

Animals↗

Frequencies of mtDNA haplogroups in southeastern Europe--Croatians, Bosnians and Herzegovinians, Serbians, Macedonians and Macedonian Romani.

Mitochondrial DNA polymorphisms were analyzed in of 1,610 randomly chosen adult men from 11 different regions from southeastern Europe (Croatians, Bosnians and Herzegovinians, Serbians, Macedonians and Macedonian Romani). MtDNA HVS-I region together with RFLP sites diagnostic for main Euroasian and African mtDNA haplogroups were typed to determine haplogroup frequency distribution. The most frequent haplogroup in studied populations was H with the exception of Macedonian Romani among whom the most frequent were South Asian (Indian) specific variants of haplogroup M. The multidimensional scaling plot showed two clusters of populations and two outliers (Macedonian Romani and the most distant from mainland Croatian island of Korcula). The first cluster was formed by populations from three Croatian islands (Hvar, Krk and Brac) and the second cluster was formed by Macedonians, Serbians, Croatians from mainland and coast, Herzegovinians, Bosnians, Slovenians, Poles and Russians. The present analysis does not address a precise evaluation of phylogenetic relations of studied populations although some conclusions about historical migrations could be noticed. More extended conclusions will be possible after deeper phylogenetic and statistical analyses.

Adult↗

[The sequence polymorphism of Y-chromosome DNA and mtDNA of Dong Ethnic of Congjiang, Guizhou].

To study the patrilineal and matrilineal genetic structure and the origin of Dong Ethnic of Congjiang Guizhou. Study the distribution of Y-chromosome haplotypes which consisted of 10 SNPs of Y-DNA and mtDNA haplogroups consisted of 11 SNPs by using PCR-RFLP method. The result is three haplotypes H6,H11,H14 were detected, the frequency of H11 is 92.5%. Six haplogroups were identified by mtDNA analysis, 75% of the people can be identified. The patrilineal genetic structure of Dong of Guizhou is simple, Principle component indicated that the structure is closer to Zhuang-Dong branch of Sino-Tibetan language family. The matrilineal genetic structure of Dong of Guizhou is complicated.

Asian People↗

[Sequence comparing of mtDNA D-Loop varied region in Chinese Mongolian horse and External Thoroughbred horse].

Mitochondrial DNA D-Loop varied region 400 bp sequence variations in 4 Chinese Mongolian horses and 4 External Thoroughbred horses were analyzed in this experiment. The results showed that the average nucleotide mutational rate of mtDNA D-Loop varied region in 4 Chinese Mongolian horses was 3.69%, while External Thoroughbred horses were 4.00%. Three types of mutations including transition, transversion and deletion were all found in the investigated mtDNA D-Loop regions, of which transition was the most frequent. Nucleotide mutational loci were abundant, length mutations were found and great differences were all observed among the 8 horses. It showed there existed much polymorphism in the mitochondrial DNA D-Loop varied region of Chinese Mongolian horses and External Thoroughbred horses.

Animals↗

[Rapid extraction of MtDNA from Cryptococcus neoformans and examined by electronic microscopy].

Cryptococcus neoformans may be grown to the exponential phase,are broken by a combination of NovoZym234 and mechanical means,and mitochondrial DNA was extracted from DNaseI-treated mitochondrial preparation by differential centrifugation. Three pellets, including yeast cell, protoplasts, mitochondrial, were examined by transmission electronic microscopy. The resulting mtDNA is sufficiently pure for restriction endonucleases analysis and PCR in further studying. A rapid and effective method for the preparation of the mtDNA of C.neoformans was established.

English Abstract↗

[Species identification by multiplex amplifying mtDNA-HV I, HV II and cytb regions].

OBJECTIVE: To evaluate the method for species identification by multiplex amplification of mtDNA-HV I, HV II and cytb regions. METHODS: The bloodstains or muscular tissues of human and 16 kinds of animals were collected. DNA were quantified after extraction. Three pairs of primers were mixed in the same reaction and the PCR amplification products were analyzed by PAGE and silver staining. RESULTS: The presence of three bands (278 bp, 358 bp, 425 bp) indicated the samples were from human, while only one band indicated nonhuman origin. The position of the animal's only band is different from the band (358 bp) of human. CONCLUSION: The method of species identification by multiplex amplifying mtDNA-HV I, HV II and cytb regions is simple and sensitive. It is of use for forensic identification.

Animals↗

[Studies of mtDNA of Ustilago maydis. I. Cloning and gene mapping].

This paper covers the following studies of mtDNA of Ustilago maydis. (1) By inserting the Bam HI and Pst I fragments of the mtDNA into the corresponding sites of pBR322, we cloned a unique sequence of 49.6 kb, accounting for 89.3% of the mitochondrial genome (60.7 kb). (2) With heterogenous genes from plants or fungi as probes, we identified seven genes, and mapped them onto the restriction map of the mt DNA. The genes were arranged in such an order: -UmCOB-UmOXII-S-rR NA-UmOXIII-L-rRNA-UmATPase6-UmOXI-. (3) We tried to express the three cloned genes, UmOXII, UmOXIII, and Um-ATPase 6, in E. coli maxcel expression system, but no specific protein was observed.

Chromosome Mapping↗

A tRNA(Lys) mutation in the mtDNA is the causal genetic lesion underlying myoclonic epilepsy and ragged-red fiber (MERRF) syndrome.

Skeletal muscle mtDNA of three patients with mitochondrial encephalomyopathy, characterized clinically by myoclonic epilepsy and ragged-red fiber (MERRF) syndrome, has been sequenced to determine the underlying molecular defect(s). An A-to-G substitution of nt 8344 in the tRNA(Lys) gene, a substitution suggested to be associated with MERRF encephalomyopathy, was detected in these patients. Abnormal patterns of mitochondrial translation products were observed in the skeletal muscle of patients, consistent with the expected consequential defect in protein synthesis. The genealogical studies of the three patients, as well as mtDNA from one published MERRF patient and from nine other normal and disease controls, revealed that the tRNA(Lys) mutations in the MERRF patients have arisen independently. These observations provided evidence that the base substitution is a causal mutation for MERRF.

Adult↗

Cytoplasmic transformation of Saccharomyces cerevisiae using purified mtDNA.

Transformation of cytoplasmic mutants of Saccharomyces cerevisiae proved to be successful using plasmid or intact mitochondria, but not when mtDNA was used as the transforming principle. The sphaeroplasts of two cytoplasmic mutants, respiratory deficient and erythromycin sensitive cells, were transformed using purified mtDNA from respiratory competent or erythromycin resistant donor strains.

Cytoplasm↗

mtDNA variation of aboriginal Siberians reveals distinct genetic affinities with Native Americans.

The mtDNA variation of 411 individuals from 10 aboriginal Siberian populations was analyzed in an effort to delineate the relationships between Siberian and Native American populations. All mtDNAs were characterized by PCR amplification and restriction analysis, and a subset of them was characterized by control region sequencing. The resulting data were then compiled with previous mtDNA data from Native Americans and Asians and were used for phylogenetic analyses and sequence divergence estimations. Aboriginal Siberian populations exhibited mtDNAs from three (A, C, and D) of the four haplogroups observed in Native Americans. However, none of the Siberian populations showed mtDNAs from the fourth haplogroup, group B. The presence of group B deletion haplotypes in East Asian and Native American populations but their absence in Siberians raises the possibility that haplogroup B could represent a migratory event distinct from the one(s) which brought group A, C, and D mtDNAs to the Americas. Our findings support the hypothesis that the first humans to move from Siberia to the Americas carried with them a limited number of founding mtDNAs and that the initial migration occurred between 17,000-34,000 years before present.

Americas↗