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Novel Variation (novel + variation)
Selected AbstractsNovel variations in the signal peptide region of transforming growth factor ,1 gene in patients with hepatitis: a brief report from IndiaINTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 2 2005V. Gupta Summary Genotypic status of the signal peptide region of transforming growth factor ,1 (TGF-,1) showed a significant difference in C/C-genotype frequency at +29 position (codon 10) between a range of viral hepatitis patients and controls (P = 0.009, OR = 3.15, CI = 1.29,7.678), contributed by those who were infected with hepatitis B virus (HBV) alone or HBV + hepatitis delta virus (HDV) (P = 0.003, OR = 5.0, CI = 1.78,13.97). [source] Rapid denaturing high-performance liquid chromatography (DHPLC) for mutation scanning of the transforming growth factor ,3 gene using a novel proof-reading polymeraseINTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 5 2003A. Bayat Summary We have utilized a novel variation on the conventional denaturing high-performance liquid chromatography (DHPLC) technology, which we term rapid DHPLC, combining changes in instrumentation, cartridge technology and analysis conditions to enable significant increases in throughput to be achieved. In addition, the use of a novel proof-reading polymerase for sample amplification with a low misincorporation rate enables simplification of the DHPLC patterns and hence enhanced mutation detection recognition. This scheme for increasing DHPLC throughput has been tested by scanning the transforming growth factor (TGF) ,3 gene for the presence of mutations for which there is limited published or on-line data available regarding the presence of gene polymorphisms. TGF, isoforms have multiple roles in cell division, growth, proliferation, transformation and differentiation. TGF,3 is a TGF, cytokine isoform, and has an important role in embryogenesis, cell differentiation and wound healing. The TGF,3 gene consists of seven exons and six introns spanning 43 000 bp of the human genome on chromosome 14q23,24. The rapid DHPLC approach enabled scanning of all seven exons and part of the promoter region (1000 bp upstream from exon 1 in the 5,-flanking regions) of the TGF,3 gene in 95 Caucasian individuals in only 8 days, in comparison to the 17 days it would have previously taken. Mutations were clearly identified in the promoter region of the TGF,3 gene but were absent from the exonic regions. Understanding the genetic variations affecting the TGF,3 gene is important as this molecule has multiple regulatory functions on a variety of cell types. [source] Homoeologous recombination in allopolyploids: the polyploid ratchetNEW PHYTOLOGIST, Issue 1 2010Robert T. Gaeta Summary Polyploidization and recombination are two important processes driving evolution through the building and reshaping of genomes. Allopolyploids arise from hybridization and chromosome doubling among distinct, yet related species. Polyploids may display novel variation relative to their progenitors, and the sources of this variation lie not only in the acquisition of extra gene dosages, but also in the genomic changes that occur after divergent genomes unite. Genomic changes (deletions, duplications, and translocations) have been detected in both recently formed natural polyploids and resynthesized polyploids. In resynthesized Brassica napus allopolyploids, there is evidence that many genetic changes are the consequence of homoeologous recombination. Homoeologous recombination can generate novel gene combinations and phenotypes, but may also destabilize the karyotype and lead to aberrant meiotic behavior and reduced fertility. Thus, natural selection plays a role in the establishment and maintenance of fertile natural allopolyploids that have stabilized chromosome inheritance and a few advantageous chromosomal rearrangements. We discuss the evidence for genome rearrangements that result from homoeologous recombination in resynthesized B. napus and how these observations may inform phenomena such as chromosome replacement, aneuploidy, non-reciprocal translocations and gene conversion seen in other polyploids. [source] Great cardiac vein variationsCLINICAL ANATOMY, Issue 5 2004Gerald S. Bales Abstract A novel variation in the relationship of the great cardiac vein to the circumflex artery was observed in an otherwise normal cadaver heart. Vessels originated and terminated normally, but in their midcourse they were twisted around each other such that each made one complete loop around the other. This variation did not seem to be involved in any pathologies. Variations in the course of the great cardiac vein have been little studied until recently, but their simplicity emphasizes the uniqueness of our intertwined case. Commonly, the great cardiac vein varies with respect to presence, location, and the superficial or deep relationship of single crossings of the anterior interventricular and circumflex arteries. Although rare, the intertwined variation described in the present case may have important basic science implications for understanding mechanisms of vasculo-angiogenesis, and clinical implications for catheter-based procedures and surgeries in the region of the coronary sulcus. Also, a review of great cardiac vein variations is presented herein. Clin. Anat. 17:436,443, 2004. © 2004 Wiley-Liss, Inc. [source] HTR2A variation and sudden infant death syndrome: a case,control analysisACTA PAEDIATRICA, Issue 1 2009Casey M Rand Abstract Aim: The serotonergic (5-HT) system functions in central autonomic regulation with homeostatic roles in cardiorespiratory control, thermoregulation, arousal and sleep-wake cycling. Altered function and development of this system in cases of sudden infant death syndrome (SIDS) have been established, but the aetiology of these disturbances remains unclear. The serotonin receptor, HTR2A, functions within this system with roles in the homeostatic response to hypoxia including excitatory effects on respiration, gasping and rhythm generation, all functions potentially compromised in SIDS. The objective of this study was to examine the relationship between SIDS risk and HTR2A variation. Methods: All coding regions, intron,exon boundaries and the promoter region of HTR2A were PCR amplified and analysed by standard sequencing in 96 SIDS cases and 96 matched controls. Results: Twenty-one HTR2A variations were identified in this case,control cohort, including four novel variations (c.C-1185A, c.T-923C, c.T-17C and c.C50T). None of the variations identified showed a significant association with SIDS. Conclusion: This report provides evidence that despite known alterations of the 5-HT system in SIDS, and the logical role for the HTR2A receptor, genetic variation of HTR2A as studied in our cohort is not responsible for these alterations. These results represent a further step in the investigation of the aetiology of the altered serotonin system in SIDS cases. [source] |