Search results for "genètica"
showing 10 items of 159 documents
The molecular characterization of new types of Saccharomyces cerevisiae × S. kudriavzevii hybrid yeasts unveils a high genetic diversity.
2012
11 pages, 2 tables, 4 figures. --Article first published online: 6 JAN 2012. --This is the pre-peer reviewed version of the following article: Peris, D., Belloch, C., Lopandić, K., Álvarez-Pérez, J. M., Querol, A. and Barrio, E. (2012), The molecular characterization of new types of Saccharomyces cerevisiae × S. kudriavzevii hybrid yeasts unveils a high genetic diversity. Yeast, 29: 81–91. which has been published in final form at http://dx.doi.org/10.1002/yea.2891
Gene expression is circular: factors for mRNA degradation also foster mRNA synthesis.
2013
SummaryMaintaining proper mRNA levels is a key aspect in the regulation of gene expression. The balance between mRNA synthesis and decay determines these levels. We demonstrate that most yeast mRNAs are degraded by the cytoplasmic 5′-to-3′ pathway (the “decaysome”), as proposed previously. Unexpectedly, the level of these mRNAs is highly robust to perturbations in this major pathway because defects in various decaysome components lead to transcription downregulation. Moreover, these components shuttle between the cytoplasm and the nucleus, in a manner dependent on proper mRNA degradation. In the nucleus, they associate with chromatin—preferentially ∼30 bp upstream of transcription start-sit…
Cyclin-dependent kinase inhibitor p21 controls adult neural stem cell expansion by regulating Sox2 gene expression.
2012
Summary In the adult brain, continual neurogenesis of olfactory neurons is sustained by the existence of neural stem cells (NSCs) in the subependymal niche. Elimination of the cyclin-dependent kinase inhibitor 1A (p21) leads to premature exhaustion of the subependymal NSC pool, suggesting a relationship between cell cycle control and long-term self-renewal, but the molecular mechanisms underlying NSC maintenance by p21 remain unexplored. Here we identify a function of p21 in the direct regulation of the expression of pluripotency factor Sox2, a key regulator of the specification and maintenance of neural progenitors. We observe that p21 directly binds a Sox2 enhancer and negatively regulate…
Domain organization and evolution of multifunctional autoprocessing repeats-in-toxin (MARTX) toxin in Vibrio vulnificus.
2011
ABSTRACT The objective of this study was to analyze multifunctional autoprocessing repeats-in-toxin (MARTX) toxin domain organization within the aquatic species Vibrio vulnificus as well as to study the evolution of the rtxA1 gene. The species is subdivided into three biotypes that differ in host range and geographical distribution. We have found three different types (I, II, and III) of V. vulnificus MARTX (MARTX Vv ) toxins with common domains (an autocatalytic cysteine protease domain [CPD], an α / β-hydrolase domain, and a domain resembling that of the LifA protein of Escherichia coli O127:H6 E2348/69 [Efa/LifA]) and specific domains (a Rho-GTPase inactivation domain [RID], a domain of …
UVPAR: fast detection of functional shifts in duplicate genes.
2006
Abstract Background The imprint of natural selection on gene sequences is often difficult to detect. A plethora of methods have been devised to detect genetic changes due to selective processes. However, many of those methods depend heavily on underlying assumptions regarding the mode of change of DNA sequences and often require sophisticated mathematical treatments that made them computationally slow. The development of fast and effective methods to detect modifications in the selective constraints of genes is therefore of great interest. Results We describe UVPAR, a program designed to quickly test for changes in the functional constraints of duplicate genes. Starting with alignments of t…
On the complexity of the Saccharomyces bayanus taxon: Hybridization and potential hybrid speciation
2014
Although the genus Saccharomyces has been thoroughly studied, some species in the genus has not yet been accurately resolved; an example is S. bayanus, a taxon that includes genetically diverse lineages of pure and hybrid strains. This diversity makes the assignation and classification of strains belonging to this species unclear and controversial. They have been subdivided by some authors into two varieties (bayanus and uvarum), which have been raised to the species level by others. In this work, we evaluate the complexity of 46 different strains included in the S. bayanus taxon by means of PCR-RFLP analysis and by sequencing of 34 gene regions and one mitochondrial gene. Using the sequenc…
The Lsm1-7/Pat1 complex binds to stress-activated mRNAs and modulates the response to hyperosmotic shock
2018
RNA-binding proteins (RBPs) establish the cellular fate of a transcript, but an understanding of these processes has been limited by a lack of identified specific interactions between RNA and protein molecules. Using MS2 RNA tagging, we have purified proteins associated with individual mRNA species induced by osmotic stress, STL1 and GPD1. We found members of the Lsm1-7/Pat1 RBP complex to preferentially bind these mRNAs, relative to the non-stress induced mRNAs, HYP2 and ASH1. To assess the functional importance, we mutated components of the Lsm1-7/Pat1 RBP complex and analyzed the impact on expression of osmostress gene products. We observed a defect in global translation inhibition under…
Evolución del virus de la hepatitis C en muestras hospitalarias de la Comunidad Valenciana
2004
Aproximadamente 170 millones de personas en el mundo se encuentran infectadas por el virus de la hepatitis C (VHC). La gran heterogeneidad del mismo, permite distinguir hasta 6 genotipos y más de 50 subtipos, los cuales presentan diferencias en cuanto a su prevalencia, distribución geográfica y rutas de transmisión. Sin ir más lejos, en la Comunidad Valenciana, el VHC está presente en casi el 3% de la población. Los genotipos mayoritarios presentes, corresponden al 1b y 1a, siendo el 1b mucho más prevalente que el segundo. Así pues se plantea el principal objetivo de esta tesis: ¿Qué hace al genotipo 1b ser más prevalente en la Comunidad Valenciana que el 1a? Dos regiones del genoma del vir…
Gen FOXP2: Esquizofrenia, alucinaciones auditivas y lenguaje.
2009
La presente tesis se ha centrado en la evaluación a través de diferentes aproximaciones de la implicación del gen FOXP2, gen sometido a selección positiva en el linaje humano y relacionado directamente con una alteración de uno de los rasgos más característicos de la especie humana, el lenguaje, en la vulnerabilidad a la esquizofrenia. El estudio de asociación caso-control no ha permitido establecer una implicación consistente entre las variantes estructurales analizadas (SNPs y posibles expansiones de trinucleótidos) con las alucinaciones auditivas como fenotipo alternativo a la esquizofrenia. No obstante, la participación del gen FOXP2 en la vulnerabilidad a las alucinaciones auditivas, c…
Bases genéticas de la esquizofrenia: aspectos emocionales, cognitivos y neuroanatómicos.
2009
La esquizofrenia es un desorden mental severo, con una incidencia del 1% y una elevada heredabilidad (alrededor del 80%). Por ello, hay un enorme interés en conocer los factores genéticos implicados en la vulnerabilidad a padecer esquizofrenia. Sin embargo, esta enfermedad presenta una herencia poligénica y además un importante número de factores ambientales parecen influir en su aparición. Asimismo, la heterogeneidad clínica también es elevada y esto dificulta el tener un fenotipo bien definido para el estudio genético. Por ello, el estudio de fenotipos más recortados y mejor definidos puede ser de gran utilidad. En el presente trabajo, se han seleccionado nueve genes de interés. Nuestra h…