INCREASED SENSITIVITY TO THE EFFECTS OF CHRONIC SOCIAL DEFEAT STRESS IN AN INNATELY ANXIOUS MOUSE STRAIN

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Genetics of coronary artery calcification among African Americans, a meta-analysis

Background: Coronary heart disease (CHD) is the major cause of death in the United States. Coronary artery calcification (CAC) scores are independent predictors of CHD. African Americans (AA) have higher rates of CHD but are less well-studied in genomic studies. We assembled the largest AA data resource currently available with measured CAC to identify associated genetic variants.Methods: We analyzed log transformed CAC quantity (ln(CAC + 1)), for association with ~2.5 million single nucleotide polymorphisms (SNPs) and performed an inverse-variance weighted meta-analysis on results for 5,823 AA from 8 studies. Heritability was calculated using family studies. The most significant SNPs among AAs were evaluated in European Ancestry (EA) CAC data; conversely, the significance of published SNPs for CAC/CHD in EA was queried within our AA meta-analysis.Results: Heritability of CAC was lower in AA (~30%) than previously reported for EA (~50%). No SNP reached genome wide significance (p < 5E-08). Of 67 SNPs with p < 1E-05 in AA there was no evidence of association in EA CAC data. Four SNPs in regions previously implicated in CAC/CHD (at 9p21 and PHACTR1) in EA reached

Caracterização citogenética em Schlumbergera truncata (Haworth) Moran e Schlumbergera &times; buckleyi (T. Moore) Tjaden (Cactaceae) Cytogenetic characterization of Schlumbergera truncata (Haworth) Moran and Schlumbergera &times; buckleyi (T. Moore) Tjaden (Cactaceae)

O número cromossômico diplóide de Schlumbergera truncata e Schlumbergera x buckleyi, de indivíduos com diferentes tipos de coloração de pétalas, foi determinado usando-se pontas de raízes. A utilização de 8-hidroxiquinoleína 0,003 M à 36 &deg;C por 3 horas possibilitou melhor separação cromossômica. Técnica de bandeamento C e de coloração Giemsa permitiram o estudo cariológico dessas espécies. O híbrido Schlumbergera &times; buckleyi (rósea) apresenta 2n = 22 cromossomos com fórmula cariotípica 16 M + 6 SM. Schlumbergera truncata, apresentando pétalas nas cores vermelha, branca e pink, possui 2n = 22 cromossomos, formulação cariotípica idêntica à de Schlumbergera &times; buckleyi, enquanto a planta com flores de coloração amarelada mostrou 2n = 34 cromossomos. A classificação cromossômica foi baseada no índice centromérico. Nas plantas que apresentam coloração vermelha, branca, pink e rósea nas pétalas, o melhor período de obtenção de metáfases corresponde ao período de florescimento. Schlumbergera truncata com flores amareladas apresenta dois picos anuais de divisão mitótica. Esses resultados dão suporte à um melhor entendimento da biologia no gênero Schlumbergera e auxiliam na classificação taxonômica nos casos onde apenas as características fenotípicas não são suficientemente confiáveis para a classificação das plantas no mesmo táxon.<br>The diploid chromosome number of Schlumbergera truncata and Schlumbergera &times; buckleyi, in individuals with different types of petal color, was determined using root tips. The use of 8-hydroxyquinolein 0.003 M at 36 ºC provided better chromosome separation. C-banding technique and Giemsa coloration allowed the karyological study of these species. Schlumbergera &times; buckleyi hybrid (light pink) species has 2n = 22 chromosomes with karyotype formula 16M + 6SM. Schlumbergera truncata with red, white, and pink petals and 2n = 22 chromosomes has karyotype formula identical to Schlumbergera &times; buckleyi, while the plant with yellowish flowers has 2n = 34 chromosomes. Chromosome classification was based on the centromeric index. In plants with white, red, pink and light pink petal color, the best time to obtain metaphases is during flowering. Schlumbergera truncata with yellowish flowers has two annual peaks of mitotic division. These results give us a better understanding of the biology of the genus Schlumbergera and aid in taxonomic classification where phenotypic characteristics alone are not reliable enough to classify plants of the same taxon