Genetic variation within and among species of five sections of the genus Arachis L. (Leguminosae) using RAPDs

Some Arachis species are widely used as commercial plants, e.g. the groundnut A. hypogaea, an important source of good quality protein and oil, and A. pintoi and A. glabrata, that are utilized as forage species. Germplasm of most Arachis species is available in germplasm banks. However, little it is known about the genetic attributes of this germplasm, and mainly about its genetic variability, which is very important for its maintenance. In the present study RAPDs were used to assay the genetic variation within and among 48 accessions of five sections of the genus Arachis and to establish the genetic relationships among these accessions. Ten of 34 primers tested were selected for DNA amplification reactions since they yielded the largest numbers of polymorphic loci. A dendrogram was constructed based on data from the 10 primers selected. Eighty RAPD polymorphic bands were analyzed among the accessions studied. The relationships among species based on RAPDs were similar to those previously reported based on morphological, cytological and crossability data; demonstrating that RAPDs can be used to determine the genetic relationships among species of the different sections of the genus Arachis. In general, wide variation was found among accessions and low variation was found within the accessions that had two or more plants analyzed. However, higher polymorphism was found in the section Trierectoides and in one accession of A. major, indicating that generalizations should be avoided and each species should be analyzed in order to establish collection and maintenance strategies.

RAPD optimization for genetic studies with Citrulus lanatus and Sesamum indicum genotypes

The Random Amplified Polymorphic DNA (RAPD) technique is powerful for DNA polymorphism determinations and is widely used in research involving different organisms, but it is known that RAPD can be affected by many factors that may result in false positive bands and non-reproducible assays. In this study, we analyzed the effect of several factors such as DNA template, primer and Taq DNA polymerase concentrations to optimize and standardize the RAPD technique for further genetic studies with Citrulus lanattus and Sesamum indicum L. The best combination of DNA, Taq DNA polymerase enzyme and primer concentrations in RAPD amplification procedures for sesame and watermelon genotypes was established.

Genetic diversity of microsatellite loci in Leopardus pardalis, Leopardus wiedii and Leopardus tigrinus

The microsatellite loci FCA045, FCA077, FCA008, and FCA096 are highly variable molecular markers which were used to determine the genetic diversity in 148 captive Leopardus sp. The PCR-amplified products of microsatellite loci were characterized in ABI Prism 310 Genetic Analyzer. Allele numbers, heterozygosity, polymorphism information content, exclusive allele number, and shared alleles were calculated. Sixty-five alleles were found and their sizes ranged from 116 to 216 bp in four microsatellite loci. The heterozygosity ranged from 0.36 to 0.81 in Leopardus pardalis, 0.57 to 0.67 in L. tigrinus and 0.80 to 0.92 in L. wiedii. The polymorphism information content was from 0.80 to 0.88 in L. pardalis, 0.76 to 0.88 in L. tigrinus and 0.77 to 0.90 in L. wiedii. The margay (L. wiedii) showed the highest index of polymorphism among the three species in this study. These results imply that microsatellite DNA markers can help in the study of the genetic diversity of Leopardus specimens. ©FUNPEC-RP.

β-casein gene polymorphism permits identification of bovine milk mixed with bubaline milk in mozzarella cheese

Mozzarella cheese is traditionally prepared from bubaline (Bubalus bubalis) milk, but product adulteration occurs mainly by addition of or full substitution by bovine milk. The aim of this study was to show the usefulnes of molecular markers to identify the admixture of bovine milk to bubaline milk during the manufacturing process of mozzarella cheese. Samples of mozzarella cheese were produced by adding seven different concentrations of bovine milk: 0%, 1%, 2%, 5%, 8%, 12% and 100%. DNA extracted from somatic cells found in cheese were submitted to PCR-RFLP analysis of casein genes: α-s1-CN - CSN1S1 that encompasses 954 bp from exon VII to intron IX (AluI and HinfI), β-CN - CSN2 including 495 bp of exon VII (Hae III and HinfI), and κ-CN - CSN3, encompassing 373 bp of exon IV (AluI and HindIII). Our results indicate that Hae III-RFLP of CSN2exon VII can be used as a molecular marker to detect the presence of bovine milk in mozzarella cheese. Copyright © 2008, Sociedade Brasileira de Genética.

Assessing genetic variability in bat species of Emballonuridae, Phyllostomidae, Vespertilionidae and Molossidae families (Chiroptera) by RFLP-PCR

A PCR-RFLP analysis of the restriction pattern in nuclear (RAG2) and mitochondrial (12S/16S) gene sequences of bat species from the Molossidae, Phyllostomidae, Vespertilionidae, and Emballonuridae families produced a large number of fragments: 107 for RAG2 and 155 for 12S/16S combined in 139 and 402 haplotypes, respectively. The values detected for gene variation were low for both sequences (0.13 for RAG2 and 0.15 for 12S/16S) and reflected their conservative feature, reinforced by high values of inter- and intraspecies genetic identity (70-100%). The species with a high gene divergence were variable in the analyses of RAG2 (Eumops perotis, Artibeus lituratus, and Carollia perspicillata) and of 12S/16S (Nyctinomops laticaudatus, C. perspicillata, and Cynomops abrasus), and furthermore, one of them, C. perspicillata, also showed the highest intraspecific variation. The species that exhibited the lowest variation for both genes was Molossus rufus. In the families, the highest variation was observed in the Molossidae and this can be attributed to variation exhibited by Eumops and Nyctinomops species. The variations observed were interpreted as a natural variability within the species and genus that exhibited a conserved pattern in the two gene sequences in different species and family analyzed. Our data reinforce the idea that the analyses of mitochondrial and nuclear genes contribute to our knowledge of the diversity of New World bats. The genetic variability found in different taxa suggests that an additional diversity, unnoticed by other methods, can be revealed with the use of different molecular strategies. ©FUNPEC-RP.

Color polymorphism in Leptodactylus fuscus (Anura, Leptodactylidae): A defensive strategy against predators?

Color patterns are strongly related to defensive strategies in anurans. Some anurans present more than one morphotype. Leptodactylus fuscus, for example, present two morphotypes (with and without vertebral white line). The proportion of each pattern in nature is different, whereby there are always more individuals without stripes. Therefore, we speculated if this difference in the observed color pattern is due to unequal predation pressures (i.e. stronger over the striped morphotype), and/or if there is a genetic component related to autossomic heritage. To test the selective predation over the morphotypes, we prepared plasticine models of L. fuscus with both phenotypes and placed them in the field. We did not find evidence of predation selection and as we found significant relationships between the proportions of the phenotypes and Mendelian proportions, we suggest that the phenotypes observed in this species are genetically determined (involving dominant and recessive alleles) and may not have a defensive function.

Head and neck carcinogenesis: Impact of MTHFD1 G1958A polymorphism

Objective: To investigate the MTHFD1 G1958A polymorphism involved in the folate metabolism as a risk for head and neck cancer, and to find the association of the polymorphism with the risk factors and clinical and histopathological characteristics. Methods: Retrospective study investigating MTHFD1 G1958A polymorphism in 694 subjects (240 patients in the Case Group and 454 in the Control Group) by Restriction Fragment Length Polymorphism (RFLP) Analysis. Multiple logistic regression and chi-square tests were used in the statistical analysis. Results: Multivariable analysis showed that smoking and age over 42 years were disease predictors (p < 0.05). MTHFD1 1958GA or AA genotypes were associated with smoking (p = 0.04) and alcoholism (p = 0.03) and were more ofen found in more advanced stage tumors (p = 0.04) and in patients with a shorter survival (p = 0.03). Conclusion: Te presence of MTHFD1 G1948A polymorphism associated with smoking and alcoholism raises the head and neck cancer risk.

Effect of exercise training on the cardiovascular and biochemical parameters in women with eNOS gene polymorphism

Context: Presence of endothelial nitric oxide synthase (eNOS) gene polymorphism has been associated with cardiovascular disease (CVD) whereas exercise training (EX) promotes beneficial effects on CVD which is related to increased nitric oxide levels (NO). Objective: To evaluate if women with eNOS gene polymorphism at position-G894T would be less responsive to EX than those who did not carry T allele. Methods: Women were trained 3 days/week, 40 minutes session during 6 months. Cardio-biochemical parameters and genetic analysis were performed in a double-blind fashion. Results: Plasma NOx - levels were similar in both groups at baseline (GG genotype: 18.44±3.28 μM) and (GT + TT genotype: 17.19±2.43 μM) and after EX (GG: 29.20±4.33 and GT+TT: 27.38±3.12 μM). A decrease in blood pressure was also observed in both groups. Discussion and conclusion: The presence of eNOS polymorphism does not affect the beneficial effects of EX in women. © 2011 Informa UK, Ltd.

Genetic Diversity in the Modern Horse Illustrated from Genome-Wide SNP Data

Horses were domesticated from the Eurasian steppes 5,000-6,000 years ago. Since then, the use of horses for transportation, warfare, and agriculture, as well as selection for desired traits and fitness, has resulted in diverse populations distributed across the world, many of which have become or are in the process of becoming formally organized into closed, breeding populations (breeds). This report describes the use of a genome-wide set of autosomal SNPs and 814 horses from 36 breeds to provide the first detailed description of equine breed diversity. FST calculations, parsimony, and distance analysis demonstrated relationships among the breeds that largely reflect geographic origins and known breed histories. Low levels of population divergence were observed between breeds that are relatively early on in the process of breed development, and between those with high levels of within-breed diversity, whether due to large population size, ongoing outcrossing, or large within-breed phenotypic diversity. Populations with low within-breed diversity included those which have experienced population bottlenecks, have been under intense selective pressure, or are closed populations with long breed histories. These results provide new insights into the relationships among and the diversity within breeds of horses. In addition these results will facilitate future genome-wide association studies and investigations into genomic targets of selection. © 2013 Petersen et al.

Effects of a single nucleotide polymorphism in the leptin gene on the productive traits of dairy buffaloes (Bubalus bubalis)

The gene responsible for coding the leptin hormone has been associated with productive and reproductive traits in cattle. In dairy cattle, different polymorphisms found in the leptin gene have been associated with several traits of economic interest, such as energy balance, milk yield and composition, live weight, fertility and dry matter consumption. The aim of this study was to detect genetic variability in the leptin gene of buffaloes and to test possible associations with milk yield, fat and protein percentages, age at first calving and first calving interval. Three genotypes (AA, AG and GG) were identified by polymerase chain reaction-restriction fragment length polymorphism, which presented genotypic frequencies of 0.30, 0.54 and 0.16, respectively. The allele frequencies were 0.57 for the A allele and 0.43 for the G allele. No significant effects were found in the present study, but there is an indicative that leptin gene affects lipid metabolism. © 2013 Springer Science+Business Media Dordrecht.

Revisiting AFLP fingerprinting for an unbiased assessment of genetic structure and differentiation of taurine and zebu cattle

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Worldwide genetic variation at the 3 ' untranslated region of the HLA-G gene: balancing selection influencing genetic diversity

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Type-2 diabetes mellitus and the frequency of the G22A polymorphism of the adenosine deaminase gene in a mixed population in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Mannose-binding lectin gene polymorphism and risk factors for cardiovascular disease in postmenopausal women

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genetic variability of inflammatory genes in the brazilian population

Inflammatory gene variants have been associated with several diseases, including cancer, diabetes, vascular diseases, neurodegenerative diseases, arthritis, and others. Therefore, determining the population genetic composition of inflammation-related genes can be useful for the determination of general risk, prognostic and therapeutic strategies to prevent or cure specific diseases. We have aimed to identify polymorphism genotype frequencies in genes related to the inflammatory response in the Brazilian population, namely, IjBL - 62AT, IjBL - 262CT, tumor necrosis factors alpha (TNFa) - 238GA, TNFa - 308GA, lymphotoxin-alpha (LTa) + 80AC, LTa + 252AG, FAS - 670AG, and FASL - 844TC, considering the white, black, and Pardo ethnicities of the Sa˜o Paulo State. Our results suggest that the Brazilian population is under a miscegenation process at the current time, since some genotypes are not in the Hardy–Weinberg equilibrium. In addition, we conclude that the Pardo ethnicity is derived from a complex mixture of ethnicities, including the native Indian population.