Introns Early
Mostrando 1-12 de 103 artigos, teses e dissertações.
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1. Cloning and expression analysis of the chitinase gene Ifu-chit2 from Isaria fumosorosea
Entomopathogenic fungi can produce a series of chitinases, some of which function synergistically with proteases and other hydrolytic enzymes to degrade the insect cuticle. In the present study, the chitinase gene Ifu-chit2 from Isaria fumosorosea was investigated. The Ifu-chit2 gene is 1,435-bp long, interrupted by three short introns, and encodes a predict
Genet. Mol. Biol.. Publicado em: 2015-09
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2. Characterization of chitinase gene from lutzomyia longipalpis:alternative splicing description and search for promoter sequence / Caracterização de gene de quitinase de Lutzomyia longipalpis: descrição de processamento alternativo e busca por seqüência promotora
Leishmaniasis is a disease caused by Leishmania protozoa transmitted by the bite of infected sand flies. Current methods used to combat this illness have been shown to be inefficient, and better knowledge of aspects related to Leishmania-sand fly interaction are necessary for the development of new controlling methods. A cDNA codifying for a midgutspecific c
Publicado em: 2009
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3. O papel do fenômeno de "exon-shuffling" antigo e moderno na evolução de proteínas / The role of ancient and modern "exon-shuffling" phenomenon in the evolution of proteins
A partir da descoberta dos íntrons, muitas questões sobre sua origem vêm sendo discutidas como: porque eles existem em eucariotos e não são encontrados em procariotos, quando e como eles se originaram. Basicamente duas hipóteses existem para explicar a origem dos íntrons: "introns-early" e "introns-late". A primeira hipótese sugere que íntrons e éx
Publicado em: 2005
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4. Exon/intron structure of aldehyde dehydrogenase genes supports the “introns-late” theory
Whether or not nuclear introns predate the divergence of bacteria and eukaryotes is the central argument between the proponents of the “introns-early” and “introns-late” theories. In this study we compared the goodness-of-fit of each theory with a probabilistic model of exon/intron evolution and multiple nonallelic genes encoding human aldehyde
The National Academy of Sciences of the USA.
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5. De novo insertion of an intron into the mammalian sex determining gene, SRY
Two theories have been proposed to explain the evolution of introns within eukaryotic genes. The introns early theory, or “exon theory of genes,” proposes that introns are ancient and that recombination within introns provided new exon structure, and thus new genes. The introns late theory, or “insertional theory of introns,” proposes that ancient ge
The National Academy of Sciences.
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6. Toward a resolution of the introns early/late debate: Only phase zero introns are correlated with the structure of ancient proteins
We present evidence that a well defined subset of intron positions shows a non-random distribution in ancient genes. We analyze a database of ancient conserved regions drawn from GenBank 101 to retest two predictions of the theory that the first genes were constructed by exon shuffling. These predictions are that there should be an excess of symmetric exons
The National Academy of Sciences.
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7. Seven newly discovered intron positions in the triose-phosphate isomerase gene: evidence for the introns-late theory.
The gene encoding the glycolytic enzyme triose-phosphate isomerase (TPI; EC 5.3.1.1) has been central to the long-standing controversy on the origin and evolutionary significance of spliceosomal introns by virtue of its pivotal support for the introns-early view, or exon theory of genes. Putative correlations between intron positions and TPI protein structur
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8. Complex early genes
We use the pattern of intron conservation in 684 groups of orthologs from seven fully sequenced eukaryotic genomes to provide maximum likelihood estimates of the number of introns present in the same orthologs in various eukaryotic ancestors. We find: (i) intron density in the plant–animal ancestor was high, perhaps two-thirds that of humans and three time
National Academy of Sciences.
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9. Intronic U14 snoRNAs of Xenopus laevis are located in two different parent genes and can be processed from their introns during early oogenesis.
U14 is a member of the rapidly growing family of intronic small nucleolar RNAs (snoRNAs) that are involved in pre-rRNA processing and ribosome biogenesis. These snoRNA species are encoded within introns of eukaryotic protein coding genes and are synthesized via an intron processing pathway. Characterization of Xenopus laevis U14 snoRNA genes has revealed tha
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10. Analysis of nonuniformity in intron phase distribution.
The distribution of different intron groups with respect to phases has been analyzed. It has been established that group II introns and nuclear introns have a minimum frequency of phase 2 introns. Since the phase of introns is an extremely conservative measure the observed minimum reflects evolutionary processes. A sample of all known, group I introns was to
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11. Site-specific crosslinking of mammalian U11 and U6atac to the 5′ splice site of an AT–AC intron
A rare class of introns with AT–AC at their termini recently has been identified in metazoan genes. Splicing of these introns requires a different set of small nuclear ribonucleoprotein particles (snRNPs) (U11, U12, U5, and U4atac/U6atac) compared with the snRNPs (U1, U2, U5, and U4/U6) required for splicing the majority of pre-mRNA introns, but otherwise
The National Academy of Sciences of the USA.
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12. Mystery of Intron Gain
For nearly 15 years, it has been widely believed that many introns were recently acquired by the genes of multicellular organisms. However, the mechanism of acquisition has yet to be described for a single animal intron. Here, we report a large-scale computational analysis of the human, Drosophila melanogaster, Caenorhabditis elegans, and Arabidopsis thalian
Cold Spring Harbor Laboratory Press.