Search results for "Intron"

Promoter and exon–intron structure of the protein kinase C gene from the marine sponge Geodia cydonium: evolutionary considerations and promoter acti…

1999

Abstract We report the gene structure of a key signaling molecule from a marine sponge, Geodia cydonium. The selected gene, which codes for a classical protein kinase C (cPKC), comprises 13 exons and 12 introns; the introns are, in contrast to those found in cPKC from higher Metazoa, small in size ranging from 93 nt to 359 nt. The complete gene has a length of 4229 nt and contains exons which encode the characteristic putative regulatory and catalytic domains of metazoan cPKCs. While in the regulatory domain only one intron is in phase 0, in the catalytic domain most introns are phase 0 introns, suggesting that the latter only rarely undergo module duplication. The 5′-flanking sequence of t…

In silico characterization of an Iroquois family-related homeodomain protein.

2005

Homeobox genes have been demonstrated to play important roles during cancer differentiation and embryonic development. The subset of Iroquois-related homeobox genes (IRXs) have furthermore been. demonstrated to be involved in several embryonic developmental processes such as patterning of the anterior-posterior and dorso-ventral axis, as well as specific regions of the central nervous system, and differentiation of the otic vesicle, branchial epithelium, and limbs. We have characterized a novel homeodomain protein and corresponding gene by means of computational biology. Since the protein sequence displayed high similarity to the human IRX proteins, the newly identified homeodomain protein …

Efficient metallic spintronic emitters of ultrabroadband terahertz radiation

2016

Terahertz electromagnetic radiation is extremely useful for numerous applications such as imaging and spectroscopy. Therefore, it is highly desirable to have an efficient table-top emitter covering the 1-to-30-THz window whilst being driven by a low-cost, low-power femtosecond laser oscillator. So far, all solid-state emitters solely exploit physics related to the electron charge and deliver emission spectra with substantial gaps. Here, we take advantage of the electron spin to realize a conceptually new terahertz source which relies on tailored fundamental spintronic and photonic phenomena in magnetic metal multilayers: ultrafast photo-induced spin currents, the inverse spin-Hall effect an…

On the role of non-effective code in linear genetic programming

2019

In linear variants of Genetic Programming (GP) like linear genetic programming (LGP), structural introns can emerge, which are nodes that are not connected to the final output and do not contribute to the output of a program. There are claims that such non-effective code is beneficial for search, as it can store relevant and important evolved information that can be reactivated in later search phases. Furthermore, introns can increase diversity, which leads to higher GP performance. This paper studies the role of non-effective code by comparing the performance of LGP variants that deal differently with non-effective code for standard symbolic regression problems. As we find no decrease in p…

2004

In rats, two peroxisomal 3-ketoacyl-CoA thiolase genes (A and B) have been cloned, whereas only one thiolase gene is found in humans. The aim of this study was thus to clone the different mouse thiolase genes in order to study both their tissue expression and their associated enzymatic activity. In this study, we cloned and characterized two mouse peroxisomal 3-ketoacyl-CoA thiolase genes (termed thiolase A and B). Both thiolase A and B genes contain 12 exons and 11 introns. Using RNA extracted from mouse liver, we cloned the two corresponding cDNAs. Thiolase A and B cDNAs possess an open reading frame of 1272 nucleotides encoding a protein of 424 amino acids. In the coding sequence, the tw…

IAP et Rho : enfin connectées

2014

231 m/s n° 3, vol. 30, mars 2014 DOI : 10.1051/medsci/20143003003 5. Apcher S, Millot G, Daskalogianni C, et al. Translation of pre-spliced RNAs in the nuclear compartment generates peptides for the MHC class I pathway. Proc Natl Acad Sci USA 2013 ; 110 : 17951-6. 6. de Turris V, Nicholson P, Orozco RZ, et al. Cotranscriptional effect of a premature termination codon revealed by live-cell imaging. RNA 2011 ; 17 : 2094-107. 7. Iborra FJ, Jackson DA, Cook PR. Coupled transcription and translation within nuclei of mammalian cells. Science 2001 ; 293 : 1139-42. 8. David A, Dolan BP, Hickman HD, et al. Nuclear translation visualized by ribosome-bound nascent chain puromycylation. J Cell Biol 201…

One gene, two transcripts: isolation of an alternative transcript encoding for the autoantigen La/SS-B from a cDNA library of a patient with primary …

1994

A cDNA library was prepared from peripheral blood lymphocytes of an autoimmune patient with primary Sjögrens' syndrome. The cDNA library was screened with the patients own autoimmune serum being monospecific for the nuclear autoantigen La/SS-B. Thereby an alternative type of La mRNA was identified that differed from the known La mRNA due to an exchange of the exon 1. Sequencing of the genomic region between the exons 1 and 2 showed that the alternative 5'-end is a part of the intron. In addition, the presence of an alternative promoter site, which exists within the intron downstream of the exon 1, became evident. In consequence, the alternative La mRNA is the result of a promoter switching …

A major cysteine proteinase, EPB, in germinating barley seeds: structure of two intronless genes and regulation of expression

1996

The barley cysteine proteinase B (EPB) is the main protease responsible for the degradation of endosperm storage proteins providing nitrogenous nutrients to support the growth of young seedlings. The expression of this enzyme is induced in the germinating seeds by the phytohormone, gibberellin, and suppressed by another phytohormone, abscisic acid. In situ hybridization experiments indicate that EPB is expressed in the scutellar epithelium within 24 h of seed germination, but the aleurone tissue surrounding the starchy endosperm eventually becomes the main tissue expressing this enzyme. The EPB gene family of barley consists of two very similar genes, EPB1 and EPB2, both of which have been …

Analysis of expression of the gene encoding for the nuclear autoantigen La/SS-B using reporter gene constructs.

1998

In earlier studies mRNA isoforms encoding for the nuclear autoantigen La were identified. In an alternative La mRNA form the exon 1 was replaced with the exon 1'. Moreover, exon 1' La mRNAs were found to start at different 5'-regions. In dependence on the 5'-start the exon 1' La mRNAs encoded for up to three open reading frames upstream of the La frame, which starts in the exon 2. The exon 1' was located in the intron about 70 nts downstream of the exon 1. The exon 1' La mRNA was proposed to be the result of a promoter switch in combination with an alternative splicing mechanism. The commonly used technique to study the expression of a eucaryotic gene is to fuse a reportergene immediately d…

The evolution of splicing: transcriptome complexity and transcript distances implemented in TranD

2021

AbstractAlternative splicing contributes to organismal complexity. Comparing transcripts between and within species is an important first step toward understanding questions about how evolution of transcript structure changes between species and contributes to sub-functionalization. These questions are confounded with issues of data quality and availability. The recent explosion of affordable long read sequencing of mRNA has considerably widened the ability to study transcriptional variation in non-model species. In this work, we develop a computational framework that uses nucleotide resolution distance metrics to compare transcript models for structural phenotypes: total transcript length,…