Search results for "Embryonic Structures"
showing 10 items of 623 documents
Do laboratory exposures represent field exposures? Effects of sediments contaminated by wood industry on yolk-sac fry of rainbow trout (Oncorhynchus …
2015
Purpose. Risk assessment of contaminated sediments is routinely based on laboratory exposures. The purpose of this work was to study if sediments contaminated by the chemical wood industry cause developmental defects in fish fry and how well a laboratory exposure correlates with a field exposure. Materials and methods. Newly hatched yolk-sac fry of rainbow trout (Oncorhynchus mykiss) were exposed in the laboratory and in situ. In the laboratory, the fish were placed in contact with either clean or contaminated sediment in aquaria. In the field, half of the fish were placed in contact with the lake sediment and the other half were similarly caged 2 m above it, to discern the effects of the s…
Nanog Regulates Primordial Germ Cell Migration Through Cxcr4b
2010
Abstract Gonadal development in vertebrates depends on the early determination of primordial germ cells (PGCs) and their correct migration to the sites where the gonads develop. Several genes have been implicated in PGC specification and migration in vertebrates. Additionally, some of the genes associated with pluripotency, such as Oct4 and Nanog, are expressed in PGCs and gonads, suggesting a role for these genes in maintaining pluripotency of the germ lineage, which may be considered the only cell type that perpetually maintains stemness properties. Here, we report that medaka Nanog (Ol-Nanog) is expressed in the developing PGCs. Depletion of Ol-Nanog protein causes aberrant migration of …
Nanog Regulates Proliferation During Early Fish Development
2009
Abstract Nanog is involved in controlling pluripotency and differentiation of stem cells in vitro. However, its function in vivo has been studied only in mouse embryos and various reports suggest that Nanog may not be required for the regulation of differentiation. To better understand endogenous Nanog function, more animal models should be introduced to complement the murine model. Here, we have identified the homolog of the mammalian Nanog gene in teleost fish and describe the endogenous expression of Ol-Nanog mRNA and protein during medaka (Oryzias latipes) embryonic development and in the adult gonads. Using medaka fish as a vertebrate model to study Nanog function, we demonstrate that …
Assessment of the efficacy of Artemia sp (Crustacea) cysts chorion as barrier to chlorpyrifos (organophosphorus pesticide) exposure. Effect on hatchi…
2005
In order to reveal the efficacy of the Artemia cysts chorion as barrier to the organophosphorus pesticide chlorpyrifos, whole and decapsulated cysts have been exposed to 10 mg L(-1) chlorpyrifos in sea water during hydration and hatching phase, separately. The concentration of chlorpyrifos in capsulated and decapsulated cysts after exposure has been determined in order to elucidate the efficacy of chorion as protection to the embryo. The results obtained demonstrate the ability of the cysts chorion to obstruct the pass of chlorpyrifos molecules through this protection structure. Thus, the concentration of chlorpyrifos in exposed decapsulated cysts is higher than in exposed whole cysts. More…
CD133 Expression Is Not Synonymous to Immunoreactivity for AC133 and Fluctuates throughout the Cell Cycle in Glioma Stem-Like Cells.
2015
A transmembrane protein CD133 has been implicated as a marker of stem-like glioma cells and predictor for therapeutic response in malignant brain tumours. CD133 expression is commonly evaluated by using antibodies specific for the AC133 epitope located in one of the extracellular domains of membrane-bound CD133. There is conflicting evidence regarding the significance of the AC133 epitope as a marker for identifying stem-like glioma cells and predicting the degree of malignancy in glioma cells. The reasons for discrepant results between different studies addressing the role of CD133/AC133 in gliomas are unclear. A possible source for controversies about CD133/AC133 is the widespread assumpt…
Role of Cardiac Magnetic Resonance Imaging in the Detection of Cardiac Amyloidosis
2010
Objectives Our aim was to evaluate the role and mechanism of late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) in identifying cardiac amyloidosis (CA) and to investigate associations between LGE and clinical, morphologic, functional, and biochemical features. Background CA can be challenging to diagnose by echocardiography. Recent studies have demonstrated an emerging role for LGE-CMR. Methods LGE-CMR was performed in 120 patients with amyloidosis. Cardiac histology was available in 35 patients. The remaining 85 patients were divided into those with and without echocardiographic evidence of CA. Results Of the 35 patients with histologically verified CA, abnormal LGE was pre…
Astacins: proteases in development and tissue differentiation
2013
Capítulo en: Stöker, Walter; Brix, Klaudia (eds.). Proteases: structure and function. Wien: Springer, 2013
NT3/TrkC pathway modulates the expression of UCP-1 and adipocyte size in human and murine adipose tissue
2020
ABSTRACTNT3, through activation of its tropomyosin-related kinase receptor C (TrkC), modulates neuronal survival and neural stem cell differentiation. It is widely distributed in peripheral tissues (specially vessels and pancreas) and this ubiquitous pattern suggests a role for NT3, outside the nervous system and related to metabolic functions. The presence of the NT3/TrkC pathway in the adipose tissue (AT) has never been investigated. Present work studies in human and murine adipose tissue (AT) the presence of elements of the NT3/TrkC pathway and its role on lipolysis and adipocyte differentiation. qRT-PCR and immunoblot indicate that NT3 was present in human retroperitoneal AT and decreas…
Effect of the Bovine Oviductal Fluid onIn VitroFertilization, Development and Gene Expression ofIn Vitro-Produced Bovine Blastocysts
2012
Oviductal microenvironment generally provides better condi-tions for early embryo development than the conventionalin vitro system. In an attempt to simulate the oviductconditions or the main potentially influencing factors, theeffect was studied of a bovine oviductal fluid (bOF) treatmentapplied prior to IVF on (i) IVF parameters, (ii) cleavage rate,(iii) blastocyst yield and (iv) blastocyst quality. Embryo qualitywas assessed by morphological embryo quality and relativetranscript abundance of several developmental genes in bovineblastocysts. Furthermore, to study the effect of bOF withoutthe male effect and zona–sperm interaction, artificially acti-vated metaphase II oocytes were also treated w…
Transcriptomic Signature of Trophoblast Differentiation in a Human Embryonic Stem Cell Model1
2011
Identification of genes involved in trophoblast differentiation is of great interest in understanding cellular and molecular mechanisms involved in placental development and is relevant clinically to fetal development, fertility, and maternal health. Herein, we investigated differentiation of human embryonic stem cells (hESCs) down the trophoblast lineage by culture with bone morphogenetic protein 4 (BMP4) over a 10-day period. Within 2 days, the stemness markers POU5F1 and NANOG were markedly down-regulated, followed temporally by up-regulation of the CDX2, KRT7, HLA-G, ID2, CGA, and CGB trophoblast markers. To understand, on a global scale, changes in the transcriptome during the differen…