185 research outputs found
Progress in Understanding and Sequencing the Genome of Brassica rapa
Brassica rapa, which is closely related to
Arabidopsis thaliana, is an important crop and a
model plant for studying genome evolution via
polyploidization. We report the current understanding of the
genome structure of B. rapa and efforts for the
whole-genome sequencing of the species. The tribe
Brassicaceae, which comprises ca. 240 species,
descended from a common hexaploid ancestor with a basic genome
similar to that of Arabidopsis. Chromosome
rearrangements, including fusions and/or fissions, resulted in
the present-day âdiploidâ Brassica
species with variation in chromosome number and phenotype.
Triplicated genomic segments of B. rapa are
collinear to those of A. thaliana with InDels.
The genome triplication has led to an approximately 1.7-fold
increase in the B. rapa gene number compared to
that of A. thaliana. Repetitive DNA of B.
rapa has also been extensively amplified and has
diverged from that of A. thaliana. For its
whole-genome sequencing, the Brassica rapa Genome
Sequencing Project (BrGSP) consortium has developed suitable
genomic resources and constructed genetic and physical maps.
Ten chromosomes of B. rapa are being allocated to
BrGSP consortium participants, and each chromosome will be
sequenced by a BAC-by-BAC approach. Genome sequencing of
B. rapa will offer a new perspective for plant
biology and evolution in the context of polyploidization
Complete Binocular Blindness as the First Manifestation of HIV-Related Cryptococcal Meningitis
Ocular complications of HIV-related cryptococcal meningitis are reasonably common, but complete binocular blindness as the first manifestation of HIV is extremely rare. A 58-year-old man presented with binocular blindness. He experienced blurred vision for 3 days before the blindness. Mild pleocytosis was present in the cerebrospinal fluid, from which Cryptococcus neoformans was cultured. Serology revealed positivity for HIV antibody. He was treated with antifungal and antiretroviral therapy. This case indicates that HIV-related cryptococcal meningitis should be taken into consideration when determining the cause of unexpected sudden binocular blindness
The first generation of a BAC-based physical map of Brassica rapa
<p>Abstract</p> <p>Background</p> <p>The genus <it>Brassica </it>includes the most extensively cultivated vegetable crops worldwide. Investigation of the <it>Brassica </it>genome presents excellent challenges to study plant genome evolution and divergence of gene function associated with polyploidy and genome hybridization. A physical map of the <it>B. rapa </it>genome is a fundamental tool for analysis of <it>Brassica </it>"A" genome structure. Integration of a physical map with an existing genetic map by linking genetic markers and BAC clones in the sequencing pipeline provides a crucial resource for the ongoing genome sequencing effort and assembly of whole genome sequences.</p> <p>Results</p> <p>A genome-wide physical map of the <it>B. rapa </it>genome was constructed by the capillary electrophoresis-based fingerprinting of 67,468 Bacterial Artificial Chromosome (BAC) clones using the five restriction enzyme SNaPshot technique. The clones were assembled into contigs by means of FPC v8.5.3. After contig validation and manual editing, the resulting contig assembly consists of 1,428 contigs and is estimated to span 717 Mb in physical length. This map provides 242 anchored contigs on 10 linkage groups to be served as seed points from which to continue bidirectional chromosome extension for genome sequencing.</p> <p>Conclusion</p> <p>The map reported here is the first physical map for <it>Brassica </it>"A" genome based on the High Information Content Fingerprinting (HICF) technique. This physical map will serve as a fundamental genomic resource for accelerating genome sequencing, assembly of BAC sequences, and comparative genomics between <it>Brassica </it>genomes. The current build of the <it>B. rapa </it>physical map is available at the <it>B. rapa </it>Genome Project website for the user community.</p
Ectopic Expression of OsDREB1G, a Member of the OsDREB1 Subfamily, Confers Cold Stress Tolerance in Rice
Plants adapt to adverse environmental conditions through physiological responses, such as induction of the abscisic acid signaling pathway, stomatal regulation, and root elongation. Altered gene expression is a major molecular response to adverse environmental conditions in plants. Several transcription factors function as master switches to induce the expression of stress-tolerance genes. To find out a master regulator for the cold stress tolerance in rice, we focused on functionally identifying DREB subfamily which plays important roles in cold stress tolerance of plants. Here, we characterized OsDREB1G (LOC_Os02g45450), a functionally unidentified member of the DREB1 subgroup. OsDREB1G is specifically induced under cold stress conditions among several abiotic stresses examined. This gene is dominantly expressed in leaf sheath, blade, node, and root. Transgenic rice overexpressing this gene exhibited strong cold tolerance and growth retardation, like transgenic rice overexpressing other OsDREB1 genes. However, unlike these rice lines, transgenic rice overexpressing OsDREB1G did not exhibit significant increases in drought or salt tolerance. Cold-responsive genes were highly induced in transgenic rice overexpressing DREB1G compared to wild type. In addition, OsDREB1G overexpression directly induced the expression of a reporter gene fused to the promoters of cold-induced genes in rice protoplasts. Therefore, OsDREB1G is a typical CBF/DREB1 transcription factor that specifically functions in the cold stress response. Therefore, OsDREB1G could be useful for developing transgenic rice with enhanced cold-stress tolerance
Genome-wide comparative analysis of the Brassica rapa gene space reveals genome shrinkage and differential loss of duplicated genes after whole genome triplication
Euchromatic regions of the Brassica rapa genome were sequenced and mapped onto the corresponding regions in the Arabidopsis thaliana genome
Rapidly Progressive Cardiac Manifestation of Behçet's Disease Involving Conduction System and Aortic Valve
Cardiac conduction system impairment is a rare clinical manifestation of Behçet's disease. We report a patient who showed 1st degree atrioventricular block at first presentation, and showed aggravated finding of 3rd degree atrioventricular block on five months later. His cardiac manifestation finally developed to acute severe aortic regurgitation on six months later from his first cardiac manifestation. We observed this rapid progression during 6 months and successfully improved symptom and disease severity of the patient with treatment targeting Behçet's disease
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