Novel simple sequence repeats (SSRs) detected by ND-FISH in heterochromatin of Drosophila melanogaster

<p>Abstract</p> <p>Background</p> <p>In recent years, substantial progress has been made in understanding the organization of sequences in heterochromatin regions containing single-copy genes and transposable elements. However, the sequence and organization of tandem repeat DNA sequences, which are by far the majority fraction of <it>D. melanogaster </it>heterochromatin, are little understood.</p> <p>Results</p> <p>This paper reports that the heterochromatin, as well as containing long tandem arrays of pentanucleotide satellites (AAGAG, AAGAC, AATAT, AATAC and AACAC), is also enriched in other simple sequence repeats (SSRs) such as A, AC, AG, AAG, ACT, GATA and GACA. Non-denaturing FISH (ND-FISH) showed these SSRs to localize to the chromocentre of polytene chromosomes, and was used to map them on mitotic chromosomes. Different distributions were detected ranging from single heterochromatic clusters to complex combinations on different chromosomes. ND-FISH performed on extended DNA fibres, along with Southern blotting, showed the complex organization of these heterochromatin sequences in long tracts, and revealed subclusters of SSRs (several kilobase in length) flanked by other DNA sequences. The chromosomal characterization of C, AAC, AGG, AAT, CCG, ACG, AGC, ATC and ACC provided further detailed information on the SSR content of <it>D. melanogaster </it>at the whole genome level.</p> <p>Conclusion</p> <p>These data clearly show the variation in the abundance of different SSR motifs and reveal their non-random distribution within and between chromosomes. The greater representation of certain SSRs in <it>D. melanogaster </it>heterochromatin suggests that its complexity may be greater than previously thought.</p

Proyecto, investigación e innovación en urbanismo, arquitectura y diseño industrial

Actas de congresoLas VII Jornadas de Investigación “Encuentro y Reflexión” y I Jornadas de Investigación de becarios y doctorandos. Proyecto, investigación e innovación en Urbanismo, Arquitectura y Diseño Industrial se centraron en cuatro ejes: el proyecto; la dimensión tecnológica y la gestión; la dimensión social y cultural y la enseñanza en Arquitectura, Urbanismo y Diseño Industrial, sustentados en las líneas prioritarias de investigación definidas epistemológicamente en el Consejo Asesor de Ciencia y Tecnología de esta Universidad Nacional de Córdoba. Con el objetivo de afianzar continuidad, formación y transferencia de métodos, metodología y recursos se incorporó becarios y doctorandos de los Institutos de investigación. La Comisión Honoraria la integraron las tres Secretarias de Investigación de la Facultad, arquitectas Marta Polo, quien fundó y María del Carmen Franchello y Nora Gutiérrez Crespo quienes continuaron la tradición de la buena práctica del debate en la cotidianeidad de la propia Facultad. Los textos que conforman las VII Jornadas son los avances y resultados de las investigaciones realizadas en el bienio 2016-2018.Fil: Novello, María Alejandra. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Repiso, Luciana. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Mir, Guillermo. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Brizuela, Natalia. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Herrera, Fernanda. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Períes, Lucas. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Romo, Claudia. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Gordillo, Natalia. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; ArgentinaFil: Andrade, Elena Beatriz. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; Argentin

Chromosomal markers in the genus karenia: Towards an understanding of the evolution of chromosomes, life cycle patterns and phylogenetic relationships in dinoflagellates

Dinofagellates are a group of protists whose genome is unique among eukaryotes in terms of base composition, chromosomal structure and gene expression. Even after decades of research, the structure and behavior of their amazing chromosomes—which without nucleosomes exist in a liquid crystalline state—are still poorly understood. We used fow cytometry and fuorescence in situ hybridization (FISH) to analyze the genome size of three species of the toxic dinofagellate genus Karenia as well the organization and behavior of the chromosomes in diferent cell-cycle stages. FISH was also used to study the distribution patterns of ribosomal DNA (45S rDNA), telomeric and microsatellites repeats in order to develop chromosomal markers. The results revealed several novel and important features regarding dinofagellate chromosomes during mitosis, including their telocentric behavior and radial arrangement along the nuclear envelope. Additionally, using the (AG)10 probe we identifed an unusual chromosome in K. selliformis and especially in K. mikimotoi that is characterized by AG repeats along its entire length. This feature was employed to easily diferentiate morphologically indistinguishable life-cycle stages. The evolutionary relationship between Karenia species is discussed with respect to diferences in both DNA content and the chromosomal distribution patterns of the DNA sequences analyzed.Dinofagellates are a group of protists whose genome is unique among eukaryotes in terms of base composition, chromosomal structure and gene expression. Even after decades of research, the structure and behavior of their amazing chromosomes—which without nucleosomes exist in a liquid crystalline state—are still poorly understood. We used fow cytometry and fuorescence in situ hybridization (FISH) to analyze the genome size of three species of the toxic dinofagellate genus Karenia as well the organization and behavior of the chromosomes in diferent cell-cycle stages. FISH was also used to study the distribution patterns of ribosomal DNA (45S rDNA), telomeric and microsatellites repeats in order to develop chromosomal markers. The results revealed several novel and important features regarding dinofagellate chromosomes during mitosis, including their telocentric behavior and radial arrangement along the nuclear envelope. Additionally, using the (AG)10 probe we identifed an unusual chromosome in K. selliformis and especially in K. mikimotoi that is characterized by AG repeats along its entire length. This feature was employed to easily diferentiate morphologically indistinguishable life-cycle stages. The evolutionary relationship between Karenia species is discussed with respect to diferences in both DNA content and the chromosomal distribution patterns of the DNA sequences analyzed

A novel FISH technique for labeling the chromosomes of dinoflagellates in suspension

Dinoflagellates possess some of the largest known genomes. However, the study of their chromosomes is complicated by their similar size and their inability to be distinguished by traditional banding techniques. Dinoflagellate chromosomes lack nucleosomes and are present in a liquid crystalline state. In addition, approaches such as fluorescent in situ hybridization (FISH) are problematic because chromosomes are difficult to isolate from the nuclear membrane, which in dinoflagellates remains intact, also during mitosis. Here we describe a novel, reliable and effective technique to study dinoflagellate chromosomes by physical mapping of repetitive DNA sequences in chromosomes in suspension (FISH-IS), rather than on a microscope slide. A suspension of non-fixed chromosomes was achieved by lysing the cells and destabilizing the nuclear envelope. This treatment resulted in the release of the permanently condensed chromosomes in a high-quality chromosomal suspension. Nevertheless, slide preparations of the chromosomes were not suitable for conventional FISH because the nuclear integrity and chromosomal morphology was destroyed. Our newly developed, simple and efficient FISH-IS technique employs fluorescently labeled, synthetic short sequence repeats that are hybridized with suspended, acetic-acid-pretreated chromosomes for 1 h at room temperature. The method can be successfully used to discriminate single chromosomes or specific chromosomal regions, depending on the specificity of the repeat sequences used as probes. The combination of FISH-IS and flow sorting will improve genomic studies of dinoflagellates, overcoming the difficulties posed by their huge genomes, including long stretches of non-coding sequences in multiple copies and the presence of high-copy-number tandem gene array

Protein tyrosine phosphatase 1B modulates GSK3b/Nrf2 and IGFIR signaling pathways in acetaminophen-induced hepatotoxicity

Acute hepatic failure secondary to acetaminophen (APAP) poisoning is associated with high mortality. Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of tyrosine kinase growth factor signaling. In the liver, this pathway confers protection against injury. However, the involvement of PTP1B in the intracellular networks activated by APAP is unknown. We have assessed PTP1B expression in APAP-induced liver failure in humans and its role in the molecular mechanisms that regulate the balance between cell death and survival in human and mouse hepatocytes, as well as in a mouse model of APAPinduced hepatotoxicity. PTP1B expression was increased in human liver tissue removed during liver transplant from patients for APAP overdose. PTP1B was upregulated by APAP in primary human and mouse hepatocytes together with the activation of c-jun (NH2) terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38 MAPK), resulting in cell death. Conversely, Akt phosphorylation and the antiapoptotic Bcl2 family members BclxL and Mcl1 were decreased. PTP1B deficiency in mouse protects hepatocytes against APAP-induced cell death, preventing glutathione depletion, reactive oxygen species (ROS) generation and activation of JNK and p38 MAPK. APAP-treated PTP1B-/- hepatocytes showed enhanced antioxidant defense through the glycogen synthase kinase 3 (GSK3)b/Src kinase family (SKF) axis, delaying tyrosine phosphorylation of the transcription factor nuclear factor-erythroid 2-related factor (Nrf2) and its nuclear exclusion, ubiquitination and degradation. Insulin-like growth factor-I receptor-mediated signaling decreased in APAP-treated wild-type hepatocytes, but was maintained in PTP1B-/- cells or in wild-type hepatocytes with reduced PTP1B levels by RNA interference. Likewise, both signaling cascades were modulated in mice, resulting in less severe APAP hepatotoxicity in PTP1B-/- mice. Our results demonstrated that PTP1B is a central player of the mechanisms triggered by APAP in hepatotoxicity, suggesting a novel therapeutic target against APAPinduced liver failure. © 2013 Macmillan Publishers Limited. All rights reserved.We acknowledge the following grant support: SAF2012-33283 (MINECO, Spain), Comunidad de Madrid S2010/BMD-2423, EFSD and Amylin Paul Langerhans Grant and Centro de Investigaciones Biomédicasen Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM, ISCIII, Spain) (to AMV); SAF2012-38048 (MINECO, Spain) (to JM-P); PI09/0185 and Centro de Investigacion Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD, ISCIII, Spain) (to JM); AGL2010-17579 (MINECO, Spain) (to LG); and SAF2010-17822 (MINECO, Spain) (to AC).Peer Reviewe

Pandemia COVID-19: Estudio de la Anatomía y actitud hacia la donación del propio cuerpo en estudiantes de Medicina (2020-2021)

The COVID-19 pandemic affected all activities. In the university environment, the areas where practical activity is essential were very difficult to compensate for the training deficit. Within the basic subjects of Health Sciences, Anatomy students suffered from the impossibility of accessing cadaveric material, but also many other resources. The objective of this study was to assess the opinion of the students regarding the changes imposed by the pandemic and their attitude towards donating their own bodies. Material and Method: A voluntary survey was carried out to the students who attended in 2020 and 2021, with different levels of restrictions and information regarding donation. The questions referred to demographic data, importance that is assigned to the bodies for the learning of Anatomy, if they were student assistants in that period, if the pandemic affected their training, if they know that the body can be donated and that the Faculty has a program, if they would like to obtain more information, collaborate and / or donate their own body. The results showed great similarity, except that Group 2 had less knowledge of the possibility of donating and the existence of a program, without affecting the will to donate. Also the reasons for not donating were a bit more ambiguous in that group. In addition, some results were compared with similar groups from 2018, showing that the study groups valued cadaveric material less but had a more positive attitude towards donation.La pandemia COVID-19 afectó todas las actividades. En el ámbito universitario, las áreas donde la actividad práctica es esencial se vieron muy complicadas para compensar el déficit formativo. Dentro de las asignaturas básicas de las Ciencias de la Salud, los estudiantes de Anatomía padecieron la imposibilidad de acceder al material cadavérico, aunque también a muchos otros recursos. El objetivo de este estudio fue valorar la opinión de los estudiantes respecto a los cambios impuestos por la pandemia y &nbsp;de actitud hacia la donación del propio cuerpo. Material y Método: Se realizó una encuesta voluntaria a los alumnos que cursaron en 2020 y 2021, con diferentes niveles de restricciones y de información referida a la donación. Las preguntas se refirieron a datos demográficos, importancia que se asigna a los cuerpos para el aprendizaje de la Anatomía, si fueron ayudantes alumnos en ese período, si la pandemia afectó su formación, si saben que se puede donar el cuerpo y que la Facultad tiene un programa, si le gustaría obtener más información, colaborar y/o donar el propio cuerpo. Los resultados evidenciaron gran similitud, excepto que el Grupo 2 tenía menos conocimiento de la posibilidad de donar y de la existencia de un programa, sin que ello incidiera en la voluntad de donar. También las razones para no donar fueron un poco más ambiguas en ese grupo. Además, se compararon algunos resultados con grupos similares del 2018, mostrando que los grupos en estudio valoraron menos el material cadavérico pero tuvieron una actitud más positiva hacia la donación

100 años investigando el mar. El IEO en su centenario (1914-2014).

Se trata de un libro que pretende divulgar a la sociedad las principales investigaciones multidisciplinares llevadas a cabo por el Instituto Español de Oceanografía durante su primer siglo de vida, y dar a conocer la historia del organismo, de su Sede Central y de los nueve centros oceanográficos repartidos por los litorales mediterráneo y atlántico, en la península y archipiélagos.Kongsberg 200Postprin