The reference sequence for each human chromosome provides the framework for understanding genome function, variation and evolution. Here we report the finished sequence and biological annotation of ...human chromosome 1. Chromosome 1 is gene-dense, with 3,141 genes and 991 pseudogenes, and many coding sequences overlap. Rearrangements and mutations of chromosome 1 are prevalent in cancer and many other diseases. Patterns of sequence variation reveal signals of recent selection in specific genes that may contribute to human fitness, and also in regions where no function is evident. Fine-scale recombination occurs in hotspots of varying intensity along the sequence, and is enriched near genes. These and other studies of human biology and disease encoded within chromosome 1 are made possible with the highly accurate annotated sequence, as part of the completed set of chromosome sequences that comprise the reference human genome.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To develop an efficient and reliable method that accurately differentiates bovine lymphocytes from monocytes in leukograms.
Blood samples from 30 healthy cows and 1 calf with bovine leukocyte ...adhesion deficiency.
Flow cytometric analysis of intracellular complexity and CD45 expression on bovine leukocytes was compared with results for conventional light microscopy methods. Verification of leukocyte subpopulations determined by intracellular complexity and CD45 expression was conducted, using 2-color phenotypic analysis with selected monoclonal antibodies.
The CD45 and side-scatter properties of bovine leukocytes clearly differentiated cell types, including neutrophils, eosinophils, monocytes, and lymphocytes.
This is a rapid assay that is simple to use. More importantly, it is more accurate than the conventional method that involves the use of blood slides and light microscopy, because of the ability of the assay to readily distinguish bovine monocytes and lymphocytes. Rapid preparation of samples and short analysis times allow for efficient and reliable examination of a large number of samples, and the task of viewing slides by light microscopy is eliminated. The labor-savings benefit of this procedure is most apparent in research environments that require frequent processing of batches of blood samples.
Chromosome 9 is highly structurally polymorphic. It contains the largest autosomal block of heterochromatin, which is heteromorphic in 6-8% of humans, whereas pericentric inversions occur in more ...than 1% of the population. The finished euchromatic sequence of chromosome 9 comprises 109,044,351 base pairs and represents >99.6% of the region. Analysis of the sequence reveals many intra- and interchromosomal duplications, including segmental duplications adjacent to both the centromere and the large heterochromatic block. We have annotated 1,149 genes, including genes implicated in male-to-female sex reversal, cancer and neurodegenerative disease, and 426 pseudogenes. The chromosome contains the largest interferon gene cluster in the human genome. There is also a region of exceptionally high gene and G + C content including genes paralogous to those in the major histocompatibility complex. We have also detected recently duplicated genes that exhibit different rates of sequence divergence, presumably reflecting natural selection.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Chromosome deletions in the mouse have proven invaluable in the dissection of gene function. The brown deletion complex comprises >28 independent genome rearrangements, which have been used to ...identify several functional loci on chromosome 4 required for normal embryonic and postnatal development. We have constructed a 172-bacterial artificial chromosome contig that spans this 22-megabase (Mb) interval and have produced a contiguous, finished, and manually annotated sequence from these clones. The deletion complex is strikingly gene-poor, containing only 52 protein-coding genes (of which only 39 are supported by human homologues) and has several further notable genomic features, including several segments of <1 Mb, apparently devoid of a coding sequence. We have used sequence polymorphisms to finely map the deletion breakpoints and identify strong candidate genes for the known phenotypes that map to this region, including three lethal loci (I4Rnl, I4Rn2, and I4Rn3) and the fitness mutant brown-associated fitness (baf). We have also characterized misexpression of the basonuclin homologue, Bnc2, associated with the inversion-mediated coat color mutant white-based brown ($B^{w}$). This study provides a molecular insight into the basis of several characterized mouse mutants, which will allow further dissection of this region by targeted or chemical mutagenesis.
Chromosome 13 is the largest acrocentric human chromosome. It carries genes involved in cancer including the breast cancer type 2 (BRCA2) and retinoblastoma (RB1) genes, is frequently rearranged in ...B-cell chronic lymphocytic leukaemia, and contains the DAOA locus associated with bipolar disorder and schizophrenia. We describe completion and analysis of 95.5 megabases (Mb) of sequence from chromosome 13, which contains 633 genes and 296 pseudogenes. We estimate that more than 95.4% of the protein-coding genes of this chromosome have been identified, on the basis of comparison with other vertebrate genome sequences. Additionally, 105 putative non-coding RNA genes were found. Chromosome 13 has one of the lowest gene densities (6.5 genes per Mb) among human chromosomes, and contains a central region of 38 Mb where the gene density drops to only 3.1 genes per Mb.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To determine whether numbers of coliform bacteria in feces of dairy cattle changed during the periparturient period and whether fluctuations were associated with changes in dry-matter intake.
12 ...healthy Holstein cows.
Fecal samples were collected on a semi-regular basis (i.e., 3 to 7 times/wk) beginning 4 to 6 weeks before the anticipated parturition date and continuing through the third day (5 cows) or second week (7 cows) after parturition, and total numbers of fecal coliform bacteria were determined. Daily feed intake of 7 cows was monitored.
For 11 cows, fecal coliform bacterial counts between 34 and 25 days prior to parturition were low and relatively constant (< 102 change in number of bacteria). Coliform bacteria were not detected in 4 to 8% of fecal samples from 10 cows. All cows had a 10(4) to 10(7) increase in number of colony forming units/g of feces near the time of parturition. Number of fecal coliform bacteria peaked within 7 days of parturition in 9 cows and within 12 days of parturition in 3. Number of fecal coliform bacteria was not correlated with feed intake.
Cows may have large increases in fecal coliform bacteria count during the periparturient period; however, periparturient cows do not continually shed high numbers of coliform bacteria, and coliform bacteria may not always be detectable by conventional culture methods. Changes in fecal coliform bacteria count did not correlate with changes in dry-matter intake.
Despite the considerable advances of molecular-thermodynamic theory of micelle growth, agreement between theory and experiment has been achieved only in isolated cases. A general theory that can ...provide self-consistent quantitative description of the growth of wormlike micelles in mixed surfactant solutions, including the experimentally observed high peaks in viscosity and aggregation number, is still missing. As a step toward the creation of such theory, here we consider the simplest system – nonionic wormlike surfactant micelles from polyoxyethylene alkyl ethers, CiEj. Our goal is to construct a molecular-thermodynamic model that is in agreement with the available experimental data. For this goal, we systematized data for the micelle mean mass aggregation number, from which the micelle growth parameter was determined at various temperatures. None of the available models can give a quantitative description of these data. We constructed a new model, which is based on theoretical expressions for the interfacial-tension, headgroup-steric and chain-conformation components of micelle free energy, along with appropriate expressions for the parameters of the model, including their temperature and curvature dependencies. Special attention was paid to the surfactant chain-conformation free energy, for which a new more general formula was derived. As a result, relatively simple theoretical expressions are obtained. All parameters that enter these expressions are known, which facilitates the theoretical modeling of micelle growth for various nonionic surfactants in excellent agreement with the experiment. The constructed model can serve as a basis that can be further upgraded to obtain quantitative description of micelle growth in more complicated systems, including binary and ternary mixtures of nonionic, ionic and zwitterionic surfactants, which determines the viscosity and stability of various formulations in personal-care and house-hold detergency.
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•Preceding works on growth of wormlike micelles in surfactant solutions are reviewed.•Data for micelle aggregation number vs. surfactant concentration are systematized.•Quantitative model of growth of nonionic wormlike surfactant micelles is proposed.•Formula for the free energy of chain conformations inside the micelle is derived.•The concentration and temperature dependencies of aggregation number are described.
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