Peripheral blood gene expression signatures which reflect smoking and aspirin exposure are associated with cardiovascular events.

Background: Cardiovascular disease and its sequelae are major causes of global mortality, and better methods are needed to identify patients at risk for future cardiovascular events. Gene expression analysis can inform on the molecular underpinnings of risk factors for cardiovascular events. Smoking and aspirin have known opposing effects on platelet reactivity and MACE, however their effects on each other and on MACE are not well described.

A whole blood gene expression-based signature for smoking status.

Background: Smoking is the leading cause of preventable death worldwide and has been shown to increase the risk of multiple diseases including coronary artery disease (CAD). We sought to identify genes whose levels of expression in whole blood correlate with self-reported smoking status.

Methods: Microarrays were used to identify gene expression changes in whole blood which correlated with self-reported smoking status; a set of significant genes from the microarray analysis were validated by qRT-PCR in an independent set of subjects.

Improved detection of global copy number variation using high density, non-polymorphic oligonucleotide probes.

Background: DNA sequence diversity within the human genome may be more greatly affected by copy number variations (CNVs) than single nucleotide polymorphisms (SNPs). Although the importance of CNVs in genome wide association studies (GWAS) is becoming widely accepted, the optimal methods for identifying these variants are still under evaluation. We have previously reported a comprehensive view of CNVs in the HapMap DNA collection using high density 500 K EA (Early Access) SNP genotyping arrays which revealed greater than 1,000 CNVs ranging in size from 1 kb to over 3 Mb.

Melanocyte-lineage expression of Cre recombinase using Mitf regulatory elements.

Manipulation of gene expression in melanocytes is an important tool for studying pigment cell biology. We constructed transgenic mice in which Cre recombinase was placed under the control of regulatory elements from the Microphthalmia-associated transcriptional factor (Mitf) gene using bacterial artificial chromosome (BAC). Bacterial artificial chromosome that contained either 50 or 108 kb DNA 5' to the melanocyte-specific (1M) transcriptional start site gave rise to transgenic lines in which Cre is expressed specifically in cells of the melanocyte lineage, as judged by activation of the Gt(Rosa)26(tm1Sor)(R26R) reporter locus.

Global variation in copy number in the human genome.

Copy number variation (CNV) of DNA sequences is functionally significant but has yet to be fully ascertained. We have constructed a first-generation CNV map of the human genome through the study of 270 individuals from four populations with ancestry in Europe, Africa or Asia (the HapMap collection). DNA from these individuals was screened for CNV using two complementary technologies: single-nucleotide polymorphism (SNP) genotyping arrays, and clone-based comparative genomic hybridization.

Genome-wide detection of human copy number variations using high-density DNA oligonucleotide arrays.

Recent reports indicate that copy number variations (CNVs) within the human genome contribute to nucleotide diversity to a larger extent than single nucleotide polymorphisms (SNPs). In addition, the contribution of CNVs to human disease susceptibility may be greater than previously expected, although a complete understanding of the phenotypic consequences of CNVs is incomplete. We have recently reported a comprehensive view of CNVs among 270 HapMap samples using high-density SNP genotyping arrays and BAC array CGH.

Sperm plasma membrane breakdown during Drosophila fertilization requires sneaky, an acrosomal membrane protein.

Fertilization typically involves membrane fusion between sperm and eggs. In Drosophila, however, sperm enter eggs with membranes intact. Consequently, sperm plasma membrane breakdown (PMBD) and subsequent events of sperm activation occur in the egg cytoplasm.

Effects of G-protein mutations on skin color.

A new class of dominant dark skin (Dsk) mutations discovered in a screen of approximately 30,000 mice is caused by increased dermal melanin. We identified three of four such mutations as hypermorphic alleles of Gnaq and Gna11, which encode widely expressed Galphaq subunits, act in an additive and quantitative manner, and require Ednrb. Interactions between Gq and Kit receptor tyrosine kinase signaling can mediate coordinate or independent control of skin and hair color.

Genetics of dark skin in mice.

Chemical mutagenesis in the mouse is a powerful approach for phenotype-driven genetics, but questions remain about the efficiency with which new mutations ascertained by their phenotype can be localized and identified, and that knowledge applied to a specific biological problem. During a global screen for dominant phenotypes in about 30,000 animals, a novel class of pigmentation mutants were identified by dark skin (Dsk). We determined the genetic map location, homozygous phenotype, and histology of 10 new Dsk and 2 new dark coat (Dcc) mutations, and identified mutations in Agouti (Met1Leu, Dcc4), Sox18 (Leu220ter, Dcc1), Keratin 2e (Thr500Pro, Dsk2), and Egfr (Leu863Gln, Dsk5).