Genetic variation in the odorant receptors family 13 and the mhc loci influence mate selection in a multiple sclerosis dataset

<p>Abstract</p> <p>Background</p> <p>When selecting mates, many vertebrate species seek partners with major histocompatibility complex (MHC) genes different from their own, presumably in response to selective pressure against inbreeding and towards MHC diversity. Attempts at replication of these genetic results in human studies, however, have reached conflicting conclusions.</p> <p>Results</p> <p>Using a multi-analytical strategy, we report validated genome-wide relationships between genetic identity and human mate choice in 930 couples of European ancestry. We found significant similarity between spouses in the MHC at class I region in chromosome 6p21, and at the odorant receptor family 13 locus in chromosome 9. Conversely, there was significant dissimilarity in the MHC class II region, near the <it>HLA-DQA1 </it>and -<it>DQB1 </it>genes. We also found that genomic regions with significant similarity between spouses show excessive homozygosity in the general population (assessed in the HapMap CEU dataset). Conversely, loci that were significantly dissimilar among spouses were more likely to show excessive heterozygosity in the general population.</p> <p>Conclusions</p> <p>This study highlights complex patterns of genomic identity among partners in unrelated couples, consistent with a multi-faceted role for genetic factors in mate choice behavior in human populations.</p

Detection of Protein-Synthesizing Microorganisms in the Environment via Bioorthogonal Noncanonical Amino Acid Tagging (BONCAT)

Bioorthogonal noncanonical amino acid tagging (BONCAT) is a recently developed method for studying microbial in situ activity. This technique is based on the in vivo incorporation of artificial amino acids that carry modifiable chemical tags into newly synthesized proteins. BONCAT has been demonstrated to be effective in labeling the proteomes of a wide range of taxonomically and physiologically distinct Archaea and bacteria without resulting in preferential synthesis or degradation of proteins. After chemical fixation of cells, surrogate-containing proteins can be detected by whole-cell fluorescence staining using azide-alkyne click chemistry. When used in conjunction with rRNA-targeted fluorescence in situ hybridization (FISH), BONCAT allows the simultaneous taxonomic identification of a microbial cell and its translational activity. Rather than studying the bulk proteome, BONCAT is able to specifically target proteins that have been expressed in reaction to an experimental condition. BONCAT-FISH thus provides researchers with a selective, sensitive, fast, and inexpensive fluorescence microscopy technique for studying microbial in situ activity on an individual cell level. This protocol provides a detailed description of how to design and perform BONCAT experiments using two different bioorthogonal amino acids, l-azidohomoalanine (AHA) and l-homopropargylglycine (HPG), which are both surrogates of l-methionine. It illustrates how incorporation of these noncanonical amino acids into new proteins can be detected via copper-catalyzed or strain-promoted azide-alkyne click chemistry and outlines how the visualization of translational activity can be combined with the taxonomic identification of cells via FISH. Last, the protocol discusses potential problems that might be encountered during BONCAT studies and how they can be overcome