Cariograma e conteúdo de DNA cromossômico do alotriploide híbrido de Timor: Uma comparação com seus progenitores

O Híbrido de Timor (HT) ‘CIFC 4106’ é um anortoploide (alotriploide, 3x=33, 2C=2,10 pg), semi-estéril, oriundo do cruzamento natural entre Coffea arabica (4x=44, 2C=2,62 pg) e Coffea canephora (2x=22, 2C=1,41 pg). Acredita-se que o ‘CIFC 4106’ é primeira planta de HT encontrada em 1927, numa plantação de C. arabica ‘Typica’ situada no Timor Leste. Estudos citogenéticos em Coffea têm possibilitado entender a história evolutiva e inferir as contribuições dos genomas parentais na formação de alopoliploides, como C. arabica. Nesse sentido, o conteúdo de DNA cromossômico; mensurado pela combinação da citogenética, citometria de fluxo e de imagem; gerou dados relevantes acerca da origem de C. arabica, um alotetraploide verdadeiro. O presente trabalho objetivou quantificar o conteúdo de DNA nuclear, caracterizar o cariótipo e mensurar o conteúdo de DNA cromossômico do HT e dos seus ancestrais: C. canephora, C. eugenioides e C. arabica. O valor 2C médio nuclear e o número cromossômico variou entre os quatro Coffea: C. canephora (2x=22, 2C=1,41 pg), C. eugenioides (2x=22, 2C=1,38 pg), HT (3x=33, 2C=2,10 pg) e C. arabica (4x=44, 2C=2,62 pg). Portanto, uma série euploide foi confirmada, destacando o conteúdo de DNA do HT equivalente a soma dos valores 1C dos seus progenitores. A caracterização do cariograma mostrou a predominância de cromossomos metacêntricos e submetacêntricos, com exceção apenas de um par acrocêntrico (22) em C. arabica. Distribuindo os valores médios 2C nuclear pelos valores médios de densidade óptica integrada; obtidos por meio da citometria de imagem; o conteúdo de DNA de cada cromossomo dos quatro Coffea foi mensurado. O valor 1C cromossômico de C. canephora oscilou de 0,090 (cromossomo 1) a 0,050 pg (11), C. eugenioides de 0,095 (cromossomo 1) a 0,044 pg (11), C. arabica de 0,090 (cromossomo 1) a 0,030 pg (22), e HT de 0,104 (cromossomo 1) a 0,026 pg (33). Os dados qualitativos (classes cromossômicas) e quantitativos (valor 1C) dos Coffea foram comparados, evidenciando a contribuição das três espécies de Coffea na origem do alotriploide HT.

The genome of Anopheles darlingi, the main neotropical malaria vector

Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ∼100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vector–human and vector–parasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles-darlingi.

Body mass index and waist circumference: association with cardiovascular risk factors

OBJECTIVE

To evaluate the association between cardiovascular risk factors and the anthropometric values--body mass index (BMI) and waist circumference (WC).

METHODS

It was studied 231 employees of Federal University of Viçosa, Brazil, 54.1% of them were men (21-76 years old). Glycemia, total cholesterol, LDL, HDL, triglycerides, blood pressure, BMI, WC, waist-to-hip ratio and body fatness were measured. It was also investigated smoking, alcohol consumption and physical activity.

RESULTS

The prevalence of overweight/obesity in this population was high mainly in women. The abdominal obesity was observed in 74% of the women and 46.1% of the men. The average of BMI, body fatness, total cholesterol, HDL and triglycerides were significantly higher in men than in women. (p < 0,05). The sedentary lifestyle was a risk factor for obesity. Smoking and alcohol consumption were more common among men and normal weight volunteers. Most of the correlations between anthropometric indices and risk factors for cardiovascular diseases were significant, but weak and the WC was the index that had the strongest correlation and that associated with the largest number of variables. It was observed that with an increase of the BMI and the abdominal fat, there was also an increase of the glycemia, triglycerides and blood pressure and a decrease of HDL. The metabolic syndrome was more common among men and overweight and obese volunteers.

CONCLUSION

In this study, the frequency of cardiovascular risk factors increased along with BMI and WC.