Search results for "Intron"
showing 10 items of 420 documents
Fractional Modeling of the AC Large-Signal Frequency Response in Magnetoresistive Current Sensors
2013
Fractional calculus is considered when derivatives and integrals of non-integer order are applied over a specific function. In the electrical and electronic domain, the transfer function dependence of a fractional filter not only by the filter order n, but additionally, of the fractional order α is an example of a great number of systems where its input-output behavior could be more exactly modeled by a fractional behavior. Following this aim, the present work shows the experimental ac large-signal frequency response of a family of electrical current sensors based in different spintronic conduction mechanisms. Using an ac characterization set-up the sensor transimpedance function is obtain…
Aberrant splicing of the Drosophila melanogaster phenylalanine hydroxylase pre-mRNA caused by the insertion of a B104/roo transposable element in the…
1999
Abstract We report the insertion of the transposable element B104 in the Phenylalanine hydroxylase gene of the Drosophila mutant Henna-recessive 3 . Its presence alters the Phenylalanine hydroxylase splicing pattern, producing at least two aberrant mRNAs which contain part of the B104 sequence interrupting the coding region. This aberrant splicing is provoked by the use of a cryptic donor site encoded by the B104 3′ long terminal repeat in combination with either the gene intron 3 acceptor site or a novel acceptor site generated by the target duplication caused by transposition. One of them, referred as mRNA type 1, encodes a truncated protein that could be predictably non-functional. In mR…
Different mechanisms generating sequence variability are revealed in distinct regions of the hydroxyproline-rich glycoprotein gene from maize and rel…
1992
The sequences of the genes coding for a hydroxyproline-rich glycoprotein from two varieties of maize (Zea mays, Ac1503 and W22), a teosinte (Zea diploperennis) and sorghum (Sorghum vulgare) have been obtained and compared. Distinct patterns of variability have been observed along their sequences. The 500 bp region immediately upstream of the TATA box is highly conserved in the Zea species and contains stretches of sequences also found in the sorghum gene. Further upstream, significant rearrangements are observed, even between the two maize varieties. These observations allow definition of a 5' region, which is common to the four genes and is probably essential for their expression. The 3' e…
The Norway spruce genome sequence and conifer genome evolution
2013
Conifers have dominated forests for more than 200 million years and are of huge ecological and economic importance. Here we present the draft assembly of the 20-gigabase genome of Norway spruce (Picea abies), the first available for any gymnosperm. The number of well-supported genes (28,354) is similar to the >100 times smaller genome of Arabidopsis thaliana, and there is no evidence of a recent whole-genome duplication in the gymnosperm lineage. Instead, the large genome size seems to result from the slow and steady accumulation of a diverse set of long-terminal repeat transposable elements, possibly owing to the lack of an efficient elimination mechanism. Comparative sequencing of Pinu…
Common genomic structure for the Lepidoptera cadherin-like genes.
2005
A cadherin-like protein present in the midgut epithelial cells of Lepidoptera is associated with insect resistance to Bacillus thuringiensis Cry toxins. We describe for the first time the genes that encode the cadherin-like proteins in Ostrinia nubilalis, Helicoverpa armigera, and Bombyx mori, and analyze their organization. These genes encompass 19.6 kb, 20.0 kb, and 41.8 kb of genomic DNA, respectively, and despite the size heterogeneity, they are all composed of 35 exons that are linked by 34 introns. In contrast to the high variability noted for the sizes of the introns, the sizes of the coding exons were almost completely preserved among the three species, because the intronic sequence…
Presence of multiple group I introns closely related to bacteria and fungi in plastid 23S rRNAs of lichen-forming Trebouxia
2009
The chloroplast-encoded large subunit ribosomal RNA gene of several free-living green algae contains group I introns at Escherichia coli genic positions 1917, 1931, 1951, and 2449. Herein we report the presence of group I introns at these positions within the chloroplast-encoded large subunit ribosomal RNA gene of several lichen-forming green algae belonging to the Trebouxia genus. In contrast to the introns inserted at position 2449, all introns inserted at positions 1917, 1931, and 1951 contained LAGLIDADG homing endonuclease genes. Phylogenetic analyses show that: (i) introns inserted at positions 1917, 1931, and 1951 are closely related to introns located at homologous insertion sites i…
Suitability of chloroplast LSU rDNA and its diverse group I introns for species recognition and phylogenetic analyses of lichen-forming Trebouxia alg…
2009
To date, species identification of lichen photobionts has been performed principally on the basis of microscopic examinations and molecular data from nuclear-encoded genes. In plants, the chloroplast genome has been more readily exploited than the nuclear genome for systematic investigations. At the present time, very little information is available about the chloroplast genome of lichen-forming algae. For this reason, we have sequenced a portion of the gene encoding for the chloroplast large sub-unit rRNA (LSU rDNA) as a new molecular marker. Sequencing of the chloroplast LSU rDNAs revealed the existence of an unusual diversity of group I introns (a total of 31) within 15 analyzed Trebouxi…
SAMs Based Device Fabrication and Characterization
2015
Despite the high potentiality of SAMs for spintronics, not many results exist at the moment in the literature. This lack of results is mainly due to the difficulty to fabricate the devices. The two main technological problems consist in the ferromagnetic electrodes compatibility issues with wet chemistry and the short-circuit formation during top electrode deposition. A part of this thesis has been committed to overcome these technological problems. This chapter will explain the steps that led us to the development of SAMs-based magnetic tunnel nanojunctions.
Introduction to Self-Assembled Monolayers
2015
One of the most exciting targets of molecular spintronics field is to go towards multifunctional devices where the properties can be accurately controlled and actively changed. Spin dependent hybridization at the metal/molecule interface could thus be used in the tailoring of the resistive and magnetoresistive response of spintronic devices exploiting chemistry versatility. In this new direction, Self-Assembled Monolayers (SAMs) appear as highly promising candidates since each part and function of this system can be modulated independently (like a molecular LEGO building unit). Despite highly promising, they are still scarcely investigated in the literature probably due to the difficulties …
ADHD and DAT1: Further evidence of paternal over-transmission of risk alleles and haplotype
2010
Contains fulltext : 87259.pdf (Publisher’s version ) (Closed access) We [Hawi et al. (2005); Am J Hum Genet 77:958-965] reported paternal over-transmission of risk alleles in some ADHD-associated genes. This was particularly clear in the case of the DAT1 3'-UTR VNTR. In the current investigation, we analyzed three new sample comprising of 1,248 ADHD nuclear families to examine the allelic over-transmission of DAT1 in ADHD. The IMAGE sample, the largest of the three-replication samples, provides strong support for a parent of origin effect for allele 6 and the 10 repeat allele (intron 8 and 3'-UTR VNTR, respectively) of DAT1. In addition, a similar pattern of over-transmission of paternal ri…