SNPs rs471462296, rs456245081 and rs438495570 in the 5'UTR region of DGAT1 gene in Nelore / SNPs rs471462296, rs456245081 e rs438495570 na região 5'UTR do gene DGAT1 em Nelore

O objetivo desta pesquisa foi avaliar os SNPs rs471462296, rs456245081 e rs438495570 do gene DGAT1 em bovinos Nelore. Foram analisados 109 bovinos. A extração do DNA genômico foi realizada do sangue dos animais, usando-se o kit Ilustra Blood Genomic Prep Mini Spin® (GE Healthcare, UK). A concentração e o grau de pureza do DNA foram determinados por meio de espectrofotômetro (Nanodrop - Thermo Fisher Scientifc, USA). A genotipagem dos SNPs ocorreu mediante o emprego do ensaio Taqman® (Applied Biosystems, USA). Na análise genômica, não foram encontradas alterações nas frequências alélicas e genotípicas (P≥0,05) para os SNPs testados. Dessa forma, a região 5'UTR analisada apresentou-se monomórfica e a variação de SNPs não foi observada, o que limita seu uso como marcadores moleculares para o gene DGAT1 em Nelore.(AU)

Assessment of BCL2/J(H) translocation in healthy individuals exposed to low-level radiation of 137CsCl in Goiânia, Goiás, Brazil.

Healthy radio-exposed individuals who received low levels of Cesium-137 radiation during the accident that occurred in Goiânia in 1987, their families and controls were tested for the detection of t(14;18)-rearranged B cells in peripheral blood by using a highly sensitive, real-time quantitative PCR method. The chromosomal translocation t(14;18)(q32;q21) is characteristic of follicular lymphoma and is a frequent abnormality observed in other types of non-Hodgkin's lymphoma. This translocation leads to constitutive activation of the BCL2 oncogene by the enhancers of the immunoglobulin heavy-chain locus. In healthy individuals, the same translocation may also be found in a small fraction of peripheral blood lymphocytes, and positive cells might serve as an indicator for environmental exposure to carcinogens and possibly correlate with the cumulative risk of developing t(14;18)- positive non-Hodgkin's lymphoma. Twenty healthy radio-exposed individuals, 10 relatives and 10 non-exposed healthy individuals were tested for the detection of this translocation. Only 1 non-exposed individual was positive for the chromosomal translocation, and healthy radio-exposed individuals presented lower levels of cells bearing the BCL2/J(H) rearrangement when compared to the levels of the patients with follicular lymphoma before treatment. However, evaluation of more cells would be required to confirm the total absence of circulating cells bearing BCL2/J(H) rearrangement.

Cattle fetal sex determination by polymerase chain reaction using DNA isolated from maternal plasma.

The objective of this study was to evaluate the use of polymerase chain reaction analysis (PCR) of fetal cells/DNA in the maternal plasma of pregnant cows to determine the sex of the fetus. Plasma was harvested from 35 cows of mixed genotype at different stages of pregnancy ranging from 5 to 35 weeks. A male calf and a heifer calf provided the control samples. Fetal sex was determined by amplification of Y-specific sequences. For the 35 cows, the fetal sex predicted by this technique was in accordance with the sex of the calf at birth in 88.6% of cases. The agreement between predicted and observed fetal sex was less for cows with a gestational length of 35-48 days (63.6%). Regression analysis showed that there was a strong relationship between the probability of correctly predicting fetal sex and the stage of gestation. It was estimated that the test performed at 43.8 days post fertilization would have 95% accuracy, increasing to 99% accuracy for testing at 48.4 days and 99.9% accuracy for tests at 55.0 days or later. It was concluded that PCR analysis of fetal cells in maternal plasma can be used to predict successfully the sex of the fetus in cattle.

Cytogenetic damage in the buccal epithelium of Brazilian aviators occupationally exposed to agrochemicals.

The frequency of micronuclei in both buccal cells and peripheral blood lymphocytes is extensively used as a biomarker of chromosomal damage and genome stability in human populations. We examined whether prolonged exposure to complex mixtures of pesticides leads to an increase in cytogenetic damage. The exposed group comprised 50 agricultural aviators, mainly from Central and Southeast regions of Brazil, who had inhaled agrochemicals for more than 10 years without personal protection equipment; the control group consisted of 17 men from the same regions, without indication of exposure to pesticides, There were three times higher frequencies of micronuclei (P < 0.05) and 2.5 times higher frequencies of binucleated cells in the aviators when compared to controls. However, cytotoxic alterations such as broken eggs and karyorrhexis did not present statistically significant differences between the exposed and control groups. Therefore, diverse agrochemicals used to combat pests in agriculture possess genotoxic effects in the oral mucosa of the agricultural pilots, as showed in this study.

Sensibilidade da PCR na amplificação do DNA bovino em diluição seriada e mistura de amostra macho e fêmea / Sensitivity of PCR to amplify sex-specific bovine DNA in diluted samples

A mixture of bovine DNA from a male and a female Jersey (Bos taurus taurus) bred in different proportions was used to determine the sensitivity of PCR to amplify and discriminate the bovine DNA samples. Samples were obtained from the peripheral blood of a bull and a heifer and DNA was isolated using a commercial kit for extraction and purification of nucleic acids. Two primers sets were designed to flank genomic regions: one autosomal and one Y-specific. DNA samples were diluted in water to a final concentration of 4x10-14 ng. The results showed positive amplification of the samples diluted to a concentration of 4x10-10ng and 4x10-4ng for the autosomal and Y-specific regions, respectively. PCR was able to discriminate the male DNA in a mixture of 99:1 (DNA ♀: DNA ♂) heifer to bull ratio. Therefore, the PCR was successful in amplifying the bovine genome in samples containing low concentrations of DNA. Thus, PCR can be used as a sensitive and efficient tool to determine the sex of the fetus in pregnant cows, helping to promote correct and efficient animal management, sex selection, and breeding in commercial herds.

Association between male infertility and androgen receptor mutations in Brazilian patients.

The androgen receptor is encoded by a single-copy gene located in the long arm of the X chromosome (Xq11-12); it consists of eight exons and encodes an intracellular transcription factor that belongs to the steroid/nuclear receptor superfamily. Disturbances in the function of the androgen receptor can lead to several forms of male pseudohermaphroditism, such as androgen insensitivity syndrome, which can lead to infertility. Infertility affects around 20% of couples, and in half of the cases it is a male problem. Seventy male patients with idiopathic infertility were selected; data were obtained on age, drinking and smoking habits, occupation, and family history. The mean age of the patients was 37 years old (standard deviation = 12.3); 44% were azoospermic, 33% were oligozoospermic and 24% did not have alterations in the spermogram. Our objective was to evaluate a possible association between male infertility and mutations in the androgen receptor gene based on the presence or absence of exons 1 and 4 of this gene. These two exons were tested by PCR, and their products were separated on 1.5% agarose gels. We found that azoospermic patients had higher mutation rates on exons 1 and 4 of the androgen receptor gene, when compared to other alterations that also lead to infertility, such as oligozoospermia and teratozoospermia. So, we conclude that patients who do not produce sperm have a higher number of mutations in the androgen receptor gene when compared to those who only have impaired sperm production. Based on molecular analysis, we found that there was no correlation between alterations in the spermogram and mutations on exons 1 and 4 of the androgen receptor gene and no association between alterations in the spermogram and alcohol drinking or smoking.