Gloria MorcilloNational Distance Education University | UNED · Faculty of Science
Gloria Morcillo
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Publications (80)
Bisphenol A (BPA), a known endocrine disrupting chemical (EDC) that can mimic the action of oestrogens by interacting with hormone receptors, is potentially able to influence reproductive functions in vertebrates and invertebrates. The freshwater pulmonate Physa acuta is a sensitive organism to xenobiotics appropriate for aquatic toxicity testing i...
Triclosan (TCS) is an antibacterial agent widely used in personal care and consumer products and commonly detected in aquatic ecosystems. In the present study, the effects of TCS on endocrine-related genes of Chironomus riparius aquatic larvae, a reference organism in aquatic toxicology, were evaluated. Twenty-four-hour in vivo exposures at 10µg/L,...
Graphical abstract of the presented work.
Acute exposures (24 to 96h) to a wide range of DEHP concentrations (1 ng/L to 0.1 g/L) caused no mortality in C. riparius larvae but led to a loss of mobility and coloring, and to a general decrease in the transcriptional activity of the studied genes.
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Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental pollutant used worldwide as a plasticizer and solvent in many formulations. Based on available toxicological data, it has been classified as toxic for reproduction and as an endocrine disruptor. Despite this, ecotoxicological studies in aquatic wildlife organisms are still scarce. In t...
The freshwater snail Physa acuta is a sensitive organism to xenobiotics that is appropriate for toxicity testing. Cadmium (Cd) is a heavy metal with known toxic effects on several organisms, which include endocrine disruption and activation of the cellular stress responses. There is scarce genomic information on P. acuta; hence, in this work, we id...
Several organic UV filters have hormonal activity in vertebrates, as demonstrated in fishes, rodents and human cells. Despite the accumulation of filter contaminants in aquatic systems, research on their effects on the endocrine systems of freshwaters invertebrates is scarce. In this work, the effects of five frequently used UV filters were investi...
Organic ultraviolet (UV) filters are used in a wide variety of products, including cosmetics, to prevent damage from UV light in tissues and industrial materials. Their extensive use has raised concerns about potential adverse effects in human health and aquatic ecosystems that accumulate these pollutants. To increase sun radiation protection, UV f...
Organic ultraviolet (UV) filters are emerging contaminants that are ubiquitous in fresh and marine aquatic systems due to their extensive use in cosmetics, plastics, paints, textiles, and many other industrial products. The estrogenic effects of organic UV filters have been long demonstrated in vertebrates, and other hormonal activities may be alte...
Butyl benzyl phthalate (BBP) has been extensively used worldwide as a plasticizer in the polyvinyl chloride (PVC) industry and the manufacturing of many other products, and its presence in the aquatic environment is expected for decades. BBP is included in the list of Substances of Very High Concern (SVHC) by the European Chemicals Agency (ECHA), a...
Chironomids, sentinel organisms for the evaluation of water quality, are considered an outstanding model in Ecotoxicology for studying the effects of environmental pollutants. In contrast to its widespread use in studies with laboratory cultures, the use of natural populations (chronically exposed to complex mixtures of pollutants in their environm...
Small Heat Shock Proteins (sHSPs) comprise the most numerous, structurally diverse, and functionally uncharacterized family of heat shock proteins. Several Hsp genes (Hsp 90, 70, 40, and 27) from the insect Chironomus riparius are widely used in aquatic toxicology as biomarkers for environmental toxins. Here, we conducted a comparative study and ch...
Biomarkers are an important tool in laboratory assays that link exposure or effect of specific toxicants to key molecular and cellular events, but they have not been widely used in invertebrate populations exposed to complex mixtures of environmental contaminants in their natural habitats. The present study focused on a battery of biomarkers and th...
Chironomids, a genus of non-biting midges, are considered sentinel organisms for the evaluation of water quality and an outstanding model in Ecotoxicology for studying the effects of environmental pollutants. In contrast to its widespread use in studies with laboratory cultures, the use of natural populations (chronically exposed to complex mixture...
Although there are alternative telomere structures, most telomeres contain DNA arrays of short repeats (6-26 bp) maintained by telomerase. Like other diptera, Chironomus riparius has noncanonical telomeres and three subfamilies, TsA, TsB and TsC, of longer sequences (176 bp) are found at their chromosomal ends. Reverse transcription PCR was used to...
Small heat shock proteins constitute the most diverse and least conserved group within the large family of heat shock proteins, which play a crucial role in cell response to environmental insults. Chironomus riparius larvae are widely used in environmental research for testing pollutant toxicity in sediments and freshwater environments. Different g...
A pesar de que los biomarcadores constituyen una herramienta importante en los ensayos de laboratorio, permitiendo vincular la exposición o el efecto de sustancias tóxicas con eventos clave moleculares y celulares, todavía no se ha hecho extensivo su empleo en poblaciones naturales de invertebrados expuestos a mezclas complejas de contaminantes amb...
Los ftalatos son compuestos plastificantes de amplio uso industrial y presencia ubicua en el medio ambiente. El di(2- etilhexil) ftalato (DEHP) y el butil bencil ftalato (BBP) son dos de los cinco ftalatos evaluados por la Agencia Europea de Sustancias Químicas y ambos están incluidos en su lista de sustancias candidatas que suscitan especial preoc...
A pesar de que los biomarcadores constituyen una herramienta importante en los ensayos de laboratorio, permitiendo vincular la exposición o el efecto de sustancias tóxicas con eventos clave moleculares y celulares, todavía no se ha hecho extensivo su empleo en poblaciones naturales de invertebrados expuestos a mezclas complejas de contaminantes amb...
Los ftalatos son compuestos plastificantes de amplio uso industrial y presencia ubicua en el medio ambiente. El di(2-etilhexil) ftalato (DEHP) y el butil bencil ftalato (BBP) son dos de los cinco ftalatos evaluados por la Agencia Europea de Sustancias Químicas y ambos están incluidos en su lista de sustancias candidatas que suscitan especial preocu...
A pesar de que los biomarcadores constituyen una herramienta importante en los ensayos de laboratorio, permitiendo vincular la exposición o el efecto de sustancias tóxicas con eventos clave moleculares y celulares, todavía no se ha hecho extensivo su empleo en poblaciones naturales de invertebrados expuestos a mezclas complejas de contaminantes amb...
There is increasing evidence indicating that several UV filters might have endocrine disruptive effects. Numerous studies have evaluated hormonal effects in vertebrates, mainly reporting estrogenic and androgenic activities in mammals and fishes. There is only limited knowledge about potential endocrine activity in invertebrate hormonal systems. In...
Non-coding RNAs (ncRNAs) represent an important transcriptional output of eukaryotic genomes. In addition to their functional relevance as housekeeping and regulatory elements, recent studies have suggested their involvement in rather unexpected cellular functions. The aim of this work was to analyse the transcriptional behaviour of non-coding RNAs...
In this work, the effects of butyl benzyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP), two of the most extensively used phthalates, were studied in Chironomus riparius under acute short-term treatments, to compare their relative toxicities and identify genes sensitive to exposure. The ecotoxicity of these phthalates was assessed by analys...
We characterized the Hsp70 cDNA in Chironomus riparius and evaluated its expression profile under different environmental stressors. It is highly conserved, at both DNA and protein levels, displaying many of the hallmarks of Hsps and sharing 80-96% of overall amino acid identities with homologous sequences from other diptera. The changes are mainly...
Cadmium is a widespread and highly toxic pollutant of particular ecotoxicological relevance for aquatic ecosystems where it accumulates. To identify biomarkers for ecotoxicity monitoring, the effect of cadmium on the expression of different genes related to the stress response as well as to the ecdysone hormone-signalling pathway was studied in the...
In contrast to their traditional role, telomeres seem to behave as transcriptionally active regions. RNAs complementary to the short DNA repeats characteristic of telomerase-maintained telomeres have recently been identified in various mammalian cell lines, representing a new and unexpected element in telomere architecture. Here, we report the exis...
Bisphenol A (BPA) is an endocrine disruptor that can mimic the action of estrogens by interacting with hormone receptors and is, therefore, potentially able to influence reproductive functions in vertebrates. Although information about the interaction with the endocrine systems in invertebrates is limited, it has also been shown its effect on repro...
The Chironomus riparius gene sequences encoding ribosomal proteins L11 and L13 were characterized and their expression analysed during development, and under different types of cellular stress. A comparative and phylogenetic study among different orders of insects was carried out by analysis of sequence databases. L11 is highly conserved, both at t...
Cadmium is a widespread environmental pollutant that causes severe impacts in organisms. Although the effects of cadmium on aquatic insects have been studied in terms of their toxicity and changes in developmental parameters, little is known about its molecular and genetic effects. We have investigated the alterations in the pattern of gene express...
A growing number of cellular processes originally thought not to involve the nucleolus now seem to be associated with this organelle. In recent years, a variety of RNAs and proteins with no apparent function in ribosome genesis have been discovered in this nuclear compartment. This paper reports the presence in the nucleolus of a reverse transcript...
As in other Diptera, the telomeres of Chironomus thummi lack canonical short telomerase-specified repeats and instead contain complex sequences. They react to heat shock and other stress treatments by forming giant puffs at some chromosome termini, which are visible in polytene cells. All telomeres, except the telocentric end of chromosome four (4L...
Members of the genus Chironomus, as well as other Diptera, lack the highly conserved structure of most telomeres, characterized by short repeats generated by telomerase, and have long repeats at their chromosome ends. Among Chironomus species with characterized telomeres Chironomus thummi is of particular interest because one of the telomeres, 3R,...
A method is reported for obtaining silver colloids with a large particle size. It is based on the growth of seed colloidal particles obtained by chemical reduction of silver nitrate with citrate. These colloids were characterized by means of UV−visible spectroscopy and transmission electron microscopy. The nucleation mechanism is discussed on the b...
Ag-coated Au and Au-coated Ag colloidal particles were prepared by deposition of Ag or Au through chemical reduction on Au or Ag colloids, respectively. Different amounts of the depositing metal were employed in order to obtain different compositions of the Au100-xAgx and Ag100-yAuy resulting particles. The obtained colloids were characterized by U...
The localization of a reverse transcriptase-related protein in salivary gland polytene chromosomes was investigated by immunohistochemistry in two species of Chironomus. The antibodies used were raised against a recombinant protein containing phylogenetically conserved motifs of reverse transcriptases and derived from an abundant non-LTR element pr...
Hsp70, the most abundant and conserved heat shock protein, has been described as strongly concentrating in the nucleolus during heat shock. The important metabolic processes that take place in the nucleolus, rDNA transcription, processing, and assembling with ribosomal proteins, and the nucleolar architecture itself are very sensitive to temperatur...
We summarize the most remarkable features of the heat shock inducible large telomeric puffs (T-BRs)in polytene chromosomes of
Chironomus thummi.Kinetic aspects of formation of
T-BRs
as well as their transcriptional behaviour clearly support the view that
T-BRs
are components of the heat shock response in
Chironomus.Available molecular data indicate...
The activating effect of chloride, perchlorate, and nitrate anions on different silver colloids used in surface-enhanced Raman spectroscopy is studied. This study is done from a morphological point of view by using transmission electron microscopy and UV-VIS absorption spectroscopy and by relating the morphological changes induced by these anions t...
FT-Raman spectroscopy is becoming a more and more applied technique owing to its success in the study of fluorescence samples. Nevertheless, the poor Raman signal obtained in NIR region makes necessary to employ very concentrated aqueous solutions of the molecule. On the other hand, SERS spectroscopy has been successfully applied in the NIR region...
The heat shock transcription factor (HSF) has been found by immunocytochemistry using the Drosophila HSF antibody at T-BRIII, a telomeric heat shock-induced puff in polytene chromosomes of Chironomus thummi salivary glands. Other heat shock-activated loci were also positively stained by the antibody. Neither the telomeres nor other heat shock loci...
The heat shock protein HSP90, which is mainly cytoplasmic, has recently been reported to be present in the nucleus. We have found a specific chromosomal localization of HSP90 in different species of Drosophila and Chironomus using immunocytochemical techniques with different mono- and polyclonal antibodies for this hsp. HSP90 was found associated w...
Transcription of telomeric-associated sequences has been detected in the salivary gland cells of the larvae Chironomus thummi. In this species, a heat shock induces puffing at some telomeres, especially at one of the telomeres of chromosome III. We found that this process was concomitant with an increase in the overall telomeric transcript levels....
The induction of puff III-A3b, a major heat-shock puff in Chironomus thummi salivary cells, was insensitive to the transcription inhibitor 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB), whereas no transcriptional activity could be detected at the other heat-shock puffs in the presence of this drug. In these conditions, a polypeptide with t...
The effects of a set of stress treatments on gene expression of Chironomus thummi salivary gland cells have been analyzed. Among the treatments assayed, only during recovery from carbon dioxide have we observed a response similar to that previously described after heat-shock treatment: induction of the heat-shock puffs and synthesis of the heat-sho...
The patterns of puffing, transcription and protein synthesis under heat shock were analysed in polytene nuclei of Chironomus thummi piger, in comparison with those obtained in the closely related subspecies C. th. thummi. Most chromosomal heat shock puffs, as well as heat shock induced polypeptides, in C. th. piger paralleled those previously repor...
In Chironomus thummi thummi a Balbiani ring-like structure is induced at the right end of chromosome III by heat shock. Telomere-specific clones were obtained by microcloning this chromosome region. One of the recombinant clones, CthS, which had an insert of 176 base pairs (bp), hybridized in situ to all the chromosome ends of C. th. thummi except...
A Balbiani ring-like structure (T-BR III) is induced at the right telomere on chromosome III by a 35 degrees C heat-shock. The location of T-BR III was identified in 3 micron-semithin sections that were afterwards resectioned to obtain ultrathin sections. These were stained either by uranyl acetate-lead citrate or PTA. The puff appeared composed of...
We have studied the effect of RNA synthesis inhibitors, such as Actinomycin D, -Amanitin, or DRB, on the heat-inducible puffs of Chironomus thummi. While the appearance of most of the T-puffs is blocked by the inhibitory treatments, the induction of a heat-shock Balbiani Ring (T-BR-III) takes place in the presence of these drugs. No transcriptional...
Replication, transcription and translation rates have been analysed in root meristems of Allium cepa L. growing under two different steady conditions (10 and 25 degrees C). Cell size and the relative duration of cycle compartments are similar for both steady states, while cycle time is four times longer at the lower temperature. Though replication...
The formation of a new telomeric Balbiani ring in the right arm of chromosome III (T-BR III) has been induced in Chironomus thummi larvae by applying a wide range of temperature treatments (33 degrees - 39 degrees C). In this paper we present some kinetic and functional characteristics of this structure. T-BR III incorporates tritiated uridine, and...
We have studied the behaviour of Balbiani rings (BRs) in chromosome IV of C. thummi salivary gland cells during their recovery from heat shock (5 min at 39°C). The results show that such treatment induces a characteristic initial puff regression followed by the re-expansion of BR1 and BR2, reaching an even larger size than in controls. After the as...
Inhibition of RNA synthesis prevents the fusion of prenucleolar bodies in the NOR region during nucleologenesis. However, their physical coalescence between themselves is increased, as shown in Allium cepa L. meristems.
Inhibition of RNA synthesis prevents the fusion of prenucleolar bodies in the NOR region during nucleologenesis. However, their physical coalescence between themselves is increased, as shown inAllium cepa L. meristems.
Inhibition of protein synthesis accelerates chromosome decondensation in late mitosis/early interphase, as shown by chromatin pattern analysis in cells ofAllium cepa L. root meristems. Protein synthesis inhibition also activates nucleologenesis, a function linked to postmitotic reinitiation of transcription.The kinetics of nucleologenesis under dif...
Ethanol/acetone permeabilised meristems of Allium cepa L. roots retained endogenous RNA polymerase activity, as was shown by radioactivity incorporation into an acid-insoluble, RNAase-sensitive product after incubation in [3H]UTP. The reaction required the presence of all 4 ribonucleoside triphosphates in the incubation mixture, and was rapidly com...
Growth temperature modifies the cycle time in Allium cepa L. root meristems, affecting neither the cell size nor the relative duration of the cycle phases. It was to be expected that a similar nucleolus would be found whose activity was merely modified by temperature as any other enzymatic reaction. However, stereology of nucleoli growing at two ph...
Allium cepa L. root meristems, after a brief fixing in cold methanol, retain endogenous RNA polymerase activity. This is shown by autoradiography of meristems squashed after being incubated with the four ribonucleotides, UTP being 3H-labelled. The pattern of labelling after this assay is similar to that shown after in vivo incorporation of [3H]cyti...
In recent years the combination of Raman scattering and microscopy has opened a new frontier in the biological application of Raman spectroscopy. Micro-Raman has taken advantage from the impressive technical improving of laser and detection devices which nowadays allows the study of materials with reduced dimensions and small objects such as cells...
Contenido: 1) Biotecnología; 2) Alimentos y biotecnología; 3) DNA, genes y genomas; 4) Del gen a la proteína; 5) Ingeniería genética; 6) Microorganismos y alimentos fermentados; 7) Microorganismos genéticamente modificados. Su aplicación en los alimentos y sus potenciales efectos sobre la salud y nutrición del hombre; 8) La biotecnología en la agri...
Projects
Projects (3)
Project CTM2009-07189. Ministry of Science and Innovation (Spain).
The aim of this project is to select accurate genetic biomarkers for the assessment of the toxicity of environmental pollutants, using the model species Chironomus riparius.
Project CTM2015-64913-R. Ministry of Science and Competitiveness (Spain).
Nowadays two of the major environmental challenges that we face are climate change and the increase of toxic compounds in the environment, both qualitatively and quantitatively. The toxicity of a compound is not only strongly influenced by environmental conditions (pH, temperature, salinity, etc.), but also by the ability of an organism to respond to their presence. Thus, climate change and contamination interact with a magnification effect, the first one reducing the organisms’ ability to respond to toxic compounds, and the second one affecting their adaptation capacity to environmental changes. This combination could eventually lead to a decrease of their their chances to survive. Invertebrates are the most diverse animals and play an important role in the ecosystems. However, the mechanisms by which they respond to the interaction of toxic substances and climate change are largely unexplored, even though this combination will particularly affect poikilotherms. Their great diversity, which results in a broad spectrum of sensitivity to toxic compounds and climate change, makes them a useful tool as bioindicators to assess the status of our environment.
Therefore, the aim of this project is to investigate the response of three invertebrate species to several contaminants at different temperatures, in order to simulate alterations that climate change will produce regarding this physical factor. An integrated analysis of the effects will be conducted through the study of molecular, cellular, and ecologically relevant parameters, which will facilitate a better understanding of these phenomena and their interconnection. The selected species are model organisms in ecotoxicology: a Dipteran (Chironomus riparius), a mollusk (Physa acuta) and an annelid (Eisenia fetida). A standardized protocol will be designed with the aim to first study ecologically important parameters (survival, development, reproduction, etc.) and to subsequently analyze the alterations caused by toxic compounds at toxicogenomic and epigenetic level.
The specific methodology, routinely used by the group in previous projects, will be further optimized, focusing mainly on standardization of all processes and with the aim to evaluate the effects on the endocrine system, the cellular stress response, and the detoxification mechanisms, three basic pillars for homeostasis maintenance during environmental challenges.
With this project we aim to provide information about the toxicity of environmental pollutants in invertebrates, shed light on the influence of climate change in the response to toxic compounds in the organisms and incorporate a new methodology to the toxicogenomic bioassays usually employed in toxicity testing. An additional benefit of this project would be that the obtained data will help to improve the decision-making in risk assessment processes and bioremediation.
Project CTM2012-37547. Ministry of Science and Competitiveness (Spain).
The main aims of environmental monitoring and evaluation of ecological risk are to detect the impact at the organism level and to predict the adverse effects of environmental toxicants on populations, communities and ecosystems. In this project, we intend to characterize the mechanism of interaction of a wide spectrum of compounds, listed as Endocrine Disrupting Chemicals (EDCs), with the endocrine system of invertebrates at the organism level. We will focus on analysis of the changes in the expression of the genome and on the induced epigenetic alterations, looking for common signalling pathways, action targets and potential biomarkers, with the goal of providing new elements for evaluation of this type of contaminant in natural populations of invertebrates of aquatic ecosystems.
The organisms selected for this study are two aquatic invertebrate models that differ in their ecology as well as in their feeding and reproductive strategies: an arthropod (Cl. Insecta), Chironomus riparius, a reference species in aquatic ecotoxicology, with sexual dimorphism in adults; and a mollusc (Cl. Gasteropoda), Physa acuta, an hermaphrodite with cross-fertilization. The compounds selected are included on the priority list of EDCs drawn up by the EU1 are diverse in terms of their chemical structure, and cover a wide range of applications (plasticisers, UV filters, pesticides, fungicides, etc.).
The specific aims of the research proposed are:
1) To analyse the toxicogenomic effects by focusing on the changes induced in gene regulation that are directly or indirectly related to endocrine pathways, reproduction and development, to be able to understand the mechanisms of action of these compounds, to characterize the physiological processes involved and to identify biomarkers for their evaluation.
2) To characterize the epigenetic effects through alterations in the level and patterns of methylation of DNA and histones, to be able to interpret possible long-term and transgenerational effects of considerable relevance at the population level.
3) To validate molecular biomarkers in natural ecosystems by the study of field populations exposed to mixtures of contaminants, to be able to design ecotoxicological monitoring protocols, which would be extremely useful when evaluating the environmental impact of these compounds.