RESUMO
Mitochondria are the intracellular organelle responsible for the production of cellular energy. They play an important role in the regulation of cellular metabolism, apoptosis and oxydative stress control. Mitochondrial DNA (mtDNA) has many special features such as a high copy number in cell, maternal inheritance, and a high mutation rate which have made it attractive to scientists from many fields. In anthropological genetics, mtDNA is useful to trace geographic distribution of genetic variation, for the investigation of expansions, migrations and other pattern of gene flow. mtDNA is widely applicated in forensic science. It is a powerful implement to identify human remains. mtDNA is characterized by the high rate of polymorphisms and mutations. Some of which are increasingly recognized as an important cause of human pathology such as oxidative phosphorylation (OXPHOS) disorders, maternally inherited diabetes and deafness (MIDD), Type 2 diabetes mellitus, neurodegenerative disorders, heart failure and cancer.
Assuntos
DNA Mitocondrial , Apoptose/fisiologia , Replicação do DNA/fisiologia , DNA Mitocondrial/química , DNA Mitocondrial/fisiologia , DNA Mitocondrial/uso terapêutico , Metabolismo Energético/fisiologia , Antropologia Forense/métodos , Medicina Legal/métodos , Genes Mitocondriais/fisiologia , Variação Genética/genética , Humanos , Doenças Mitocondriais/genética , Herança Multifatorial/fisiologia , Mutação/genética , Fosforilação Oxidativa , Estresse Oxidativo/fisiologia , Polimorfismo Genético/genética , Transcrição Gênica/fisiologiaRESUMO
The mitochondrial DNA (mtDNA) diversity of 58 individuals from Upper Egypt, more than half (34 individuals) from Gurna, whose population has an ancient cultural history, were studied by sequencing the control-region and screening diagnostic RFLP markers. This sedentary population presented similarities to the Ethiopian population by the L1 and L2 macrohaplogroup frequency (20.6%), by the West Eurasian component (defined by haplogroups H to K and T to X) and particularly by a high frequency (17.6%) of haplogroup M1. We statistically and phylogenetically analysed and compared the Gurna population with other Egyptian, Near East and sub-Saharan Africa populations; AMOVA and Minimum Spanning Network analysis showed that the Gurna population was not isolated from neighbouring populations. Our results suggest that the Gurna population has conserved the trace of an ancestral genetic structure from an ancestral East African population, characterized by a high M1 haplogroup frequency. The current structure of the Egyptian population may be the result of further influence of neighbouring populations on this ancestral population.
Assuntos
DNA Mitocondrial/genética , Genética Populacional , Egito , Exercício Físico , Haplótipos , Humanos , Polimorfismo de Fragmento de RestriçãoRESUMO
Although frequencies of mitochondrial DNA (mtDNA) haplogroups in the different European populations are rather homogenous, there are a few European populations or linguistic isolates that show different mtDNA haplogroup distributions; examples are the Saami and Ladin speakers from the eastern Italian Alps. MtDNA sequence diversity was analysed from subjects from two villages in Veneto. The first, Posina, is situated in the Venetian Alps near Vicenza. The second, Barco di Pravisdomini is a village on the plains near Venice. In spite of their common Veneto dialect, the two group populations have not preserved a genetic homogeneity; particularly, they show differences in T and J haplogroups frequencies. MtDNA diversity in these two groups seems to depend more on their geographic situation.
Assuntos
DNA Mitocondrial/genética , Idioma , População Branca/genética , Sequência de Bases , Feminino , Variação Genética , Geografia , Haplótipos , Humanos , Itália , Dados de Sequência Molecular , Polimorfismo Genético , Homologia de Sequência do Ácido NucleicoRESUMO
The first successful recovery of ancient DNA, from quagga and human mummies inspired significant enough interest to open an entire field of research. Efforts from many research groups, often in a hunt for the oldest sequences, showed that ancient DNA was a poor substrate for the enzymes used in molecular biology; it is present in tiny amounts, hard to purify, and frequently damaged. These obstacles have been partially overcome by the use of drastic laboratory precautions and by the introduction of polymerase chain reaction and phylogenetic studies. Ancient DNA analysis now finds applications in many research domains.
Assuntos
DNA/genética , Paleontologia , Animais , Arqueologia , Doenças Transmissíveis/genética , DNA/química , DNA Bacteriano/química , DNA Bacteriano/genética , DNA de Plantas/química , DNA de Plantas/genética , Doenças Genéticas Inatas/genética , Humanos , Reação em Cadeia da Polimerase , Moldes GenéticosRESUMO
Analyzing the nuclear DNA from ancient human bones is an essential step to the understanding of genetic diversity in current populations, provided that such systematic studies are experimentally feasible. This article reports the successful extraction and amplification of nuclear DNA from the beta-globin region from 5 of 10 bone specimens up to 12,000 years old. These have been typed for beta-globin frameworks by sequencing through two variable positions and for a polymorphic (AT) chi (T) gamma microsatellite 500 bp upstream of the beta-globin gene. These specimens of human remains are somewhat older than those analyzed in previous nuclear gene sequencing reports and considerably older than those used to study high-copy-number human mtDNA. These results show that the systematic study of nuclear DNA polymorphisms of ancient populations is feasible.