Search results for "differentiation"
showing 10 items of 1605 documents
Biochemical taxonomic differentiation between Mullus barbatus and mullus surmuletus (Pisces, mullidae)
1991
Abstract 1. 1. The electrophoretic data from seven enzymatic systems, codifying for 20 loci, and the patterns of general proteins from some tissues of Mullus barbatus and Mullus surmuletus were examined. 2. 2. The value of the genetic distance index as per Nei is 0.068, this criterium showing a high similarity between the two species. 3. 3. Species-specific patterns were found for the SOD enzyme and general proteins of the muscle.
Honest mistake or perhaps not: The role of descriptive and injunctive norms on the magnitude of dishonesty
2021
Trivial acts of dishonesty are very prevalent in everyday life and have severe economic and societal consequences. The present study aims to examine the role of descriptive and injunctive norms in minor and major dishonesty under ambiguity. We devised a novel experimental design in which rule violations can be the result of honest mistakes or various dishonest processes. In this ambiguous context, we observed a high prevalence of minor rule violations at baseline. In two experiments, exposure to increased peer cheating (i.e., negative descriptive norms) promoted major rule violations, whereas the presence of explicit or subtle rule reminders (i.e., injunctive norms) marginally reduced minor…
Prediction model for aneuploidy in early human embryo development revealed by single-cell analysis.
2014
Aneuploidies are prevalent in the human embryo and impair proper development, leading to cell cycle arrest. Recent advances in imaging and molecular and genetic analyses are postulated as promising strategies to unveil the mechanisms involved in aneuploidy generation. Here we combine time-lapse, complete chromosomal assessment and single-cell RT–qPCR to simultaneously obtain information from all cells that compose a human embryo until the approximately eight-cell stage (n=85). Our data indicate that the chromosomal status of aneuploid embryos (n=26), including those that are mosaic (n=3), correlates with significant differences in the duration of the first mitotic phase when compared with e…
Clustering transmembrane-agrin induces filopodia-like processes on axons and dendrites
2005
The transmembrane form of agrin (TM-agrin) is primarily expressed in the CNS, particularly on neurites. To analyze its function, we clustered TM-agrin on neurons using anti-agrin antibodies. On axons from the chick CNS and PNS as well as on axons and dendrites from mouse hippocampal neurons anti-agrin antibodies induced the dose- and time-dependent formation of numerous filopodia-like processes. The processes appeared within minutes after antibody addition and contained a complex cytoskeleton. Formation of processes required calcium, could be inhibited by cytochalasine D, but was not influenced by staurosporine, heparin or pervanadate. Time-lapse video microscopy revealed that the processes…
Development of the wing discs of Zophobas atratus under natural and experimental conditions: occurrence of a gradual larval-pupal commitment in the e…
1999
Using light and electron microscopy, we studied the development of the wing discs in the large beetle Zophobas atratus, under natural and experimental conditions. A reversible differentiation of the wing discs is usually observed during supernumerary instars of crowded larvae. Juvenile hormone analog (JHA) application during the wandering period or compelled experimental crowding during the larval-pupal switchover – or commitment – inhibits the onset of metamorphosis. Isolation, followed by recrowding, also induces the disc cells to secrete unusual cuticular material. Recrowding is able to trigger the reversal of metamorphosis during the 4-day period when larval-pupal commitment is taking p…
Sonic hedgehog promotes the migration and proliferation of optic nerve oligodendrocyte precursors.
2007
Optic nerve (ON) oligodendrocyte precursors (OPCs) are generated under the influence of the Sonic hedgehog (Shh) in the preoptic area from where they migrate to colonise the entire nerve. The molecular events that control this migration are still poorly understood. Recent studies suggested that Shh is often used by the same cell population to control different processes, including cell proliferation and migration, raising the possibility that Shh could contribute to these aspects of OPC development. In support of this idea, we show here that Shh induces the proliferation of OPCs derived from embryonic mouse ON explants and acts as a chemoattractant for their migration. In ovo injections of …
Activation of TRK Genes in Ewingʼs Sarcoma Trk A Receptor Expression Linked to Neural Differentiation
1997
Trk receptors have been identified by immunohistochemical methods in primitive neuroectodermal tumor (PNET)/Ewing's sarcoma (ES). However, the presence of different members of the Trk family of receptors in PNET/ES has not been specified. We have examined whether Trk A, B, and C receptors are specifically expressed in ES both with and without features of neural differentiation. Ten ES tumors (five primary tumors of bone and five extraosseous tumors transplanted into nude mice) were investigated for expression of Trk receptors by immunohistochemistry and reverse transcription-polymerase chain reaction. One primary ES and the five grafted ES tumors exhibited signs of neural differentiation; t…
Molecular mechanisms in developmental biology.
1996
Some general molecular mechanisms underlying development are described. Namely: those involved in the differentiation of the R7 receptor in Drosophila embryonic retina; those involved in the determination of embryonic axes and in polar cell differentiation, in Drosophila; those involved in the determination of the AB and P cell lineage and in vulva differentiation in Caenorhabditis embryos.
Abnormal peripubertal development of the rat mammary gland following exposure in utero and during lactation to a mixture of genistein and the food co…
2012
The impact of early exposure to endocrine disruptor mixtures on mammary gland development is poorly known. Here, we identify the effects of a conception to weaning exposure of rats to the phytoestrogen genistein (G) and/or the antiandrogen vinclozolin (V) at 1 mg/kg-d, alone or in association. Using several approaches, we found that G- and GV-exposed rats displayed significantly greater epithelial branching and proliferation, wider terminal end buds than controls at PND35, as well as ductal hyperplasia and periductal fibrosis. Focal branching defects were present in V-exposed rats. An increased ER and AR expression was observed in G- and CV- as compared to V-exposed rats at PND35. Surprisin…
Role of GATA-1 and HSP70 in the Dyserythropoiesis of Early Myelodysplastic Syndromes.
2009
Abstract Abstract 3823 Poster Board III-759 Myelodysplastic syndromes (MDS) are heterogeneous hematopoietic stem cell disorders characterized by a hypercellular dysplastic bone marrow (BM) with peripheral blood cytopenias, mainly anemia. Early MDS with less than 10% BM blasts which belong in most cases to low and intermediate-1 (int-1) risk groups according to the International Prognostic Scoring System (IPSS), usually demonstrate dyserythropoiesis. The growth of erythroid progenitors is altered, with increased caspase activation leading to excessive cell death, and cellular dysplasia characterized, in liquid culture of CD34+-derived erythroid progenitors, by a delayed expression of the gly…