Search results for "Exon"

Accelerated Evolution of Fetuin-A (FETUA, also AHSG) is Driven by Positive Darwinian Selection, not GC-Biased Gene Conversion

2009

article i nfo Human Fetuin-A (FETUA, also termed AHSG) is a serum protein composed of two cystatin-like domains D1 and D2 of together 235 amino acids (aa) and an unrelated domain D3 of 114 aa. Though the protein plays a role in diverse physiological and pathological processes, comparably little is known about sequence evolution of FETUA. We therefore analyzed its molecular evolution on the basis of coding sequences of 16 primate species. Ratios of non-synonymous to synonymous substitution rates (dn/ds= ω) suggest that a previously reported acceleration of sequence evolution of exon 7, which encodes domain D3, is driven by positive selection instead of neutral evolution. Irrespective of the …

A variable intron distribution in globin genes of Chironomus: evidence for recent intron gain

1998

The intron positions found in globin genes of plants, protozoa and invertebrates have been interpreted as evidence for a three-intron-four-exon structure of the ancestral globin gene. In particular, the so-called 'central' introns, which are not found in vertebrate globin genes but are present in a variety of invertebrate and plant species, have been used as an argument for an ancestral gene structure featuring three introns. We have analyzed the presence or absence of central introns in the Gb genes 2beta, 9 and 7A of various European and Australasian species of the insect Chironomus. We find unrelated central introns at different positions in some of the species investigated, while other …

Characterization of a Cu/Zn Superoxide dismutase-encoding gene region in Drosophila willistoni

1994

A Cu/Zn superoxide dismutase-encoding gene (Sod) from Drosophila willistoni was cloned and sequenced. The gene shows a typical structure for a fruit-fly Sod gene, with a coding region of 462 bp in two exons separated by a 417-bp intron. Comparison of the Sod sequences from D. willistoni and D. melanogaster suggests that these species are only remotely related. Downstream from the Sod gene, there is an ORF on the opposite strand that putatively encodes the last exon of an unidentified gene. The polyadenylation signals of the two genes are separated by only 61 bp in D. willistoni, conforming to the common picture of compact dipteran genomes.

A novel nonsense mutation in exon 2 of the factor IX gene resulting in severe haemophilia B

2006

Intragenic anaplastic lymphoma kinase (ALK) rearrangements: Translocations as a novel mechanism ofALKactivation in neuroblastoma tumors

2014

Anaplastic lymphoma kinase (ALK) has been demonstrated to be deregulated in sporadic as well as in familiar cases of neuroblastoma (NB). Whereas ALK-fusion proteins are common in lymphoma and lung cancer, there are few reports of ALK rearrangements in NB indicating that ALK mainly exerts its oncogenic capacity via activating mutations and/or overexpression in this tumor type. In this study, 332 NB tumors and 13 cell lines were screened by high resolution single nucleotide polymorphism microarray. Gain of 2p was detected in 23% (60/332) of primary tumors and 46% (6/13) of cell lines, while breakpoints at the ALK locus were detected in four primary tumors and two cell lines. These were furthe…

Alterations of pre-mRNA splicing in cancer

2005

Recent genomewide analyses of alternative splicing (AS) indicate that up to 70% of human genes may have alternative splice forms, suggesting that AS together with various posttranslational modifications plays a major role in the production of proteome complexity. Splice-site selection under normal physiological conditions is regulated in the developmental stage in a tissue type-specific manner by changing the concentrations and the activity of splicing regulatory proteins. Whereas spliceosomal errors resulting in the production of aberrant transcripts rarely occur in normal cells, they seem to be an intrinsic property of cancer cells. Changes in splice-site selection have been observed in v…

Genetic polymorphism in dopamine receptor D4 is associated with early body condition in a large population of greater flamingos,Phoenicopterus roseus

2012

Body condition is an important determinant of fitness in many natural populations. However, as for many fitness traits, the underlying genes that regulate body condition remain elusive. The dopamine receptor D4 gene (DRD4) is a promising candidate as dopamine is known to play an important role in the regulation of food intake and the metabolism of both glucose and lipids in vertebrates. In this study, we take advantage of a large data set of greater flamingos, Phoenicopterus roseus, to test whether DRD4 polymorphism predicts early body condition (EBC) while controlling for whole-genome effects of inbreeding and outbreeding using microsatellite multilocus heterozygosity (MLH). We typed 670 o…

Coat colours in the Massese sheep breed are associated with mutations in the agouti signalling protein (ASIP) and melanocortin 1 receptor (MC1R) genes

2012

Massese is an Italian dairy sheep breed characterized by animals with black skin and horns and black or apparent grey hairs. Owing to the presence of these two coat colour types, this breed can be considered an interesting model to evaluate the effects of coat colour gene polymorphisms on this phenotypic trait. Two main loci have been already shown to affect coat colour in sheep: Agouti and Extension coding for the agouti signalling protein (ASIP) and melanocortin 1 receptor (MC1R) genes, respectively. The Agouti locus is affected by a large duplication including the ASIP gene that may determine the Agouti white and tan allele (A(Wt)). Other disrupting or partially inactivating mutations ha…

Intronic L1 insertion and F268S, novel mutations in RPS6KA3 (RSK2) causing Coffin-Lowry syndrome

2003

Two novel mutations of the ribosomal S6 kinase 2 gene (also known as RSK2) have been identified in two unrelated patients with Coffin–Lowry syndrome. The first mutation consists of a de novo insertion of a 5′-truncated LINE-1 element at position −8 of intron 3, which leads to a skipping of exon 4, leading to a shift of the reading frame and a premature stop codon. The L1 fragment (2800 bp) showed a rearrangement with a small deletion, a partial inversion of the ORF 2, flanked by short direct repeats which duplicate the acceptor splice site. However, cDNA analysis of the patient shows that both sites are apparently not functional. The second family showed the nucleotide change 803T>C in exon…

Molecular analysis of METTL1, a novel human methyltransferase-like gene with a high degree of phylogenetic conservation.

1999

A novel human gene, METTL1, has been identified by its sequence similarity to the yeast ORF YDL201w. The human cDNA and the genomic structure of METTL1 have been analyzed. The transcript contains 1292 nucleotides and codes for a protein of 276 amino acids. The gene consists of seven exons and extends over 3.5 kb. The six introns vary in length between 93 and 1137 nucleotides. The gene is transcribed in a large variety of organs and tissues and shows differential splicing of two exons, giving rise to at least three different transcripts. The METTL1 gene was assigned to chromosome 12q13 by radiation hybrid mapping. The METTL1 gene product shows high sequence similarities to putative proteins …