Search results for "Romer"
showing 10 items of 86 documents
Proliferation of aneuploid cells induced by CENP-E depletion is counteracted by the p14ARF tumor suppressor
2018
The spindle assembly checkpoint (SAC) is a cellular surveillance mechanism that ensures the fidelity of chromosomes segregation. Reduced expression of some of its components weakens the SAC and induces chromosome instability and aneuploidy, which are both well-known hallmarks of cancer cells. Centromere protein-E (CENP-E) is a crucial component of the SAC and its function is to facilitate kinetochore microtubule attachment required to achieve and maintain chromosome alignment. The present study investigates the possible role of p14ARF as a controller of aneuploid cells proliferation. We used RNA interference to induce aneuploidy by partial depletion of CENP-E in human primary fibroblasts (I…
Micromeria rodriguezii (Lamiaceae) en la flora peninsular ibérica
2020
Micromeria rodriguezii es una especie endémica de las Islas Baleares (Mediterráneo occidental). Una población de esta especie se ha encontrado en la provincia de Castellón (España), en el margen de un camino forestal. Se proporciona un estudio de la morfología de las plantas de esta población, así como su estado de conservación en la Comunidad Valenciana. Debido a que esta es la única población ibérica conocida hasta el momento, se debe elaborar un plan de manejo y conservación para garantizar su conservación.
Patterns of morphological variation in two sexually dimorphic bird species with different tail shapes
2007
Many studies have focused on tail ornamentation in birds, but not all tail shapes have been studied in depth. Graduated and pin tails have received less attention than forked tails, despite being more likely, in terms of aerodynamic theory, to be honest signals. We report morphological variation in live specimens of two sexually dimorphic passerines from the same site with different tail shapes: graduated (Cape sugarbird Promerops cafer ) and pin (orangebreasted sunbird Antobaphes violacea ). Coefficients of variation (CVs) were calculated for all morphological traits, both non-ornamental (range 1.91–5.72) and ornamental (range 5.83–21.71). Males and females did not differ in CV for any non…
New and interesting Orthoptera from the Arabian Peninsula and Socotra.
2017
Abstract This paper reports on some interesting taxa recently found in the Arabian Peninsula and the island of Socotra. Among them is a new species of brachypterous grasshopper Sphodromerus carapezzanus sp. n. (Acrididae: Calliptaminae), described from an isolated area in Dhofar (Oman). A female Heteracris hemiptera (Uvarov, 1935) (Acrididae: Eyprepocnemidinae) is reported, with morphological characters which do not fully comply with those of any known subspecies. Two species, hitherto rarely documented, are also reported, Phaneroptila insularis Uvarov, 1957 (Tettigoniidae: Phaneropterinae) from Socotra and Cataloipus thomasi Uvarov, 1933 (Acrididae: Eyprepocnemidinae) from Oman. Pycnodicty…
Phosphorylation of CENP-A on serine 7 does not control centromere function.
2019
CENP-A is the histone H3 variant necessary to specify the location of all eukaryotic centromeres via its CENP-A targeting domain and either one of its terminal regions. In humans, several post-translational modifications occur on CENP-A, but their role in centromere function remains controversial. One of these modifications of CENP-A, phosphorylation on serine 7, has been proposed to control centromere assembly and function. Here, using gene targeting at both endogenous CENP-A alleles and gene replacement in human cells, we demonstrate that a CENP-A variant that cannot be phosphorylated at serine 7 maintains correct CENP-C recruitment, faithful chromosome segregation and long-term cell viab…
Progressive derivation of serially homologous neuroblast lineages in the gnathal CNS of Drosophila
2018
Along the anterior-posterior axis the central nervous system is subdivided into segmental units (neuromeres) the composition of which is adapted to their region-specific functional requirements. In Drosophila melanogaster each neuromere is formed by a specific set of identified neural stem cells (neuroblasts, NBs). In the thoracic and anterior abdominal region of the embryonic ventral nerve cord segmental sets of NBs resemble the ground state (2nd thoracic segment, which does not require input of homeotic genes), and serial (segmental) homologs generate similar types of lineages. The three gnathal head segments form a transitional zone between the brain and the ventral nerve cord. It has be…
Gene expression profiles uncover individual identities of gnathal neuroblasts and serial homologies in the embryonic CNS of Drosophila.
2015
The numbers and types of progeny cells generated by neural stem cells in the developing CNS are adapted to its region-specific functional requirements. In Drosophila, segmental units of the CNS develop from well-defined patterns of neuroblasts. Here we constructed comprehensive neuroblast maps for the three gnathal head segments. Based on the spatiotemporal pattern of neuroblast formation and the expression profiles of 46 marker genes (41 transcription factors), each neuroblast can be uniquely identified. Compared with the thoracic ground state, neuroblast numbers are progressively reduced in labial, maxillary and mandibular segments due to smaller sizes of neuroectodermal anlagen and, part…
CENP-A Is Dispensable for Mitotic Centromere Function after Initial Centromere/Kinetochore Assembly
2016
SummaryHuman centromeres are defined by chromatin containing the histone H3 variant CENP-A assembled onto repetitive alphoid DNA sequences. By inducing rapid, complete degradation of endogenous CENP-A, we now demonstrate that once the first steps of centromere assembly have been completed in G1/S, continued CENP-A binding is not required for maintaining kinetochore attachment to centromeres or for centromere function in the next mitosis. Degradation of CENP-A prior to kinetochore assembly is found to block deposition of CENP-C and CENP-N, but not CENP-T, thereby producing defective kinetochores and failure of chromosome segregation. Without the continuing presence of CENP-A, CENP-B binding …
The dark side of centromeres: types, causes and consequences of structural abnormalities implicating centromeric DNA
2018
Centromeres are the chromosomal domains required to ensure faithful transmission of the genome during cell division. They have a central role in preventing aneuploidy, by orchestrating the assembly of several components required for chromosome separation. However, centromeres also adopt a complex structure that makes them susceptible to being sites of chromosome rearrangements. Therefore, preservation of centromere integrity is a difficult, but important task for the cell. In this review, we discuss how centromeres could potentially be a source of genome instability and how centromere aberrations and rearrangements are linked with human diseases such as cancer.
Longitudinal study of DNA methylation during the first 5 years of life
2016
[Background]: Early life epigenetic programming influences adult health outcomes. Moreover, DNA methylation levels have been found to change more rapidly during the first years of life. Our aim was the identification and characterization of the CpG sites that are modified with time during the first years of life. We hypothesize that these DNA methylation changes would lead to the detection of genes that might be epigenetically modulated by environmental factors during early childhood and which, if disturbed, might contribute to susceptibility to diseases later in life. [Methods]: The study of the DNA methylation pattern of 485577 CpG sites was performed on 30 blood samples from 15 subjects,…