Elvira Abollo

Publications (13)26.4 Total impact

• Article: Identification of Relevant Cancer Related-Genes in the Flat Oyster Ostrea edulis Affected by Disseminated Neoplasia.

  Laura Martín-Gómez, Antonio Villalba, Maria Jesús Carballal, Elvira Abollo
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  ABSTRACT: Disseminated neoplasia (DN), an oyster disease resembling leukaemia, has been reported in a number of species of marine bivalve molluscs. The disease is characterised by a proliferation of abnormal circulating cells of unknown origin resulting in the invasion of tissues and organs, frequently with a fatal end of the affected individuals. To obtain a more comprehensive view of bivalve cancer processes, suppressive subtracted hybridisation (SSH) and quantitative RT-PCR (q-PCR) approaches were combined to investigate changes in the transcriptome of Ostrea edulis haemolymph cells associated to DN. Two SSH libraries were constructed and 587 expressed sequence tags (ESTs) were sequenced, obtaining 329 ESTs which showed expression changes in neoplastic process. Transcription expression analyses (q-PCR) were done for a total of 24 genes that could be relevant in neoplastic process, including genes with role in the regulation of cell cycle, apoptosis or chromosomal defects. Most of those genes had not been reported in association with cancer in non-vertebrate organisms. The over-expression and under-expression of some of those genes in DN-affected oysters was in agreement with observations in vertebrate cancer. The results herein reported contribute to cancer understanding in bivalve molluscs.
  Marine Biotechnology 07/2012; · 3.43 Impact Factor
• Article: Comparison of haemocytic parameters among flat oyster Ostrea edulis stocks with different susceptibility to bonamiosis and the Pacific oyster Crassostrea gigas.

  Pilar Comesaña, Sandra M Casas, Asunción Cao, Elvira Abollo, Isabelle Arzul, Benjamin Morga, Antonio Villalba
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  ABSTRACT: Farming of the flat oyster Ostrea edulis in Europe is severely constrained by the protozoan Bonamia ostreae. The introduction of the resistant species Crassostrea gigas has been a relief for the farmers, while the pilot programmes to select O. edulis strains resistant to bonamiosis performed in various countries can be seen as a promising strategy to minimise the effects of bonamiosis. However, the physiological bases of this differential susceptibility remain unknown. A search for an explanation of the intra and interspecific differences in oyster susceptibility to bonamiosis was accomplished by comparing some immune parameters among various O. edulis stocks and C. gigas. On December 2003, naïve and Bonamia-relatively resistant flat oysters from Ireland, Galician flat oysters and Pacific oysters C. gigas were deployed in a Galician area affected by bonamiosis; haemolymph samples were taken in February and May 2004. A new oyster deployment at the same place was carried out on June 2004 and haemolymph sampling was performed on April 2005. On November 2004, new sets of Irish flat oysters and C. gigas were deployed in Ireland and haemolymph sampling was performed in June 2005. Various haemocytic parameters were measured: total and differential haemocyte count, phagocytic ability, respiratory burst (superoxide anion [O(2)(-)] and hydrogen peroxide [H(2)O(2)]) and nitric oxide [NO] production. The comparison of the parameters was carried out at 3 levels: (1) between O. edulis and C. gigas, (2) among O. edulis stocks with different susceptibility to bonamiosis, and (3) between Bonamia-infected and non infected O. edulis. In addition, haemocyte-B. ostreaein vitro encounters were performed to analyse interspecific differences in the haemocytic respiratory burst, using flow cytometry. Significant differences associated with total and differential haemocyte count, and respiratory burst between O. edulis and C. gigas were detected, which could be linked to differences in susceptibility to bonamiosis between both species. Additionally, significant changes in total and differential haemocyte count, and respiratory burst of O. edulis associated with B. ostreae infection were found. However, no consistent difference in any haemocyte parameter between the O. edulis stocks involved in the study was recorded.
  Journal of Invertebrate Pathology 03/2012; 109(3):274-86. · 2.06 Impact Factor
• Article: NEW PCR-BASED SPECIES SPECIFIC PROCEDURES TO DIAGNOSE BONAMIA EXITIOSA AND BONAMIA OSTREAE, PROTOZOAN PARASITES OF OYSTERS

  Andrea Ramilo, Jose I. Navas, Antonio Villalba, Elvira Abollo
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  ABSTRACT: Times Cited: 0
  Journal of Shellfish Research 01/2012; 31:336-337. · 0.79 Impact Factor
• Article: Identification and expression of immune genes in the flat oyster Ostrea edulis in response to bonamiosis.

  Laura Martín-Gómez, Antonio Villalba, Elvira Abollo
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  ABSTRACT: The European flat Ostrea edulis is highly susceptible to infection by the protozoan Bonamia ostreae and Bonamia exitiosa, intracellular parasites able to survive and proliferate within the oyster haemocytes. The parasite, once phagocytosed by the haemocyte, the main cellular effector of the immune system, appears to have some counter mechanism that turns off the haemocyte's metabolic destructive capacity, so that the parasite survives within the cell. To further understand the molecular basis of the immune response of the flat oyster against the bonamiosis, suppression subtractive hybridization and Q-PCR approaches were combined to identify genes involved in the development of the infection both in early and advanced phases. Four subtractive cDNA libraries were constructed and sequenced, obtaining a high number of ESTs that were seen to be up or down-regulated in the infection. A group of ESTs that play a role in the immune response, such as cytokines, stress proteins, eicosanoids, proteins implicated in phagocytosis and cell junction as well as in transcription signalling were identified and their expression was analysed at different infection levels by Q-PCR. The results here reported can help to enrich our understanding about the immune response of O. edulis against bonamiosis and improve our knowledge of the immune mechanisms of oysters.
  Gene 11/2011; 492(1):81-93. · 2.34 Impact Factor
• Article: Microsatellite marker development in the protozoan parasite Perkinsus olseni.

  Belén G Pardo, Asunción Cao, Roman Vilas, Elvira Abollo, Antonio Villalba, Paulino Martínez
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  ABSTRACT: The analysis of an enriched partial genomic library and of public expressed sequence tag (EST) resources allowed the characterization of the first microsatellite loci in the protozoan parasite Perkinsus olseni. Clonal cultures from laboratory isolates derived from infected clams Ruditapes decussatus (from Spain), R. philippinarum (from Spain and Japan), and Austrovenus stutchburyi (from New Zealand) were used for the characterization of 12 microsatellites. Low variation was detected at most loci, with the number of alleles at polymorphic loci ranging from 2 to 7 (average 3.20 +/- 0.51) and gene diversity from 0.11 to 0.79 (average 0.40 +/- 0.07). Preliminary results show that (1) isolates of P. olseni are diploid cells, and (2) multiple infections can occur within a single host. Eight of the loci analyzed successfully cross-amplified in the congeneric species P. mediterraneus. These microsatellite markers will be useful to analyze in detail the population genetic structure of P. olseni, crucial for the efficient management of this parasitic disease.
  Diseases of Aquatic Organisms 04/2011; 94(2):161-5. · 2.20 Impact Factor
• Article: Differential diagnosis of Perkinsus species by polymerase chain reaction-restriction fragment length polymorphism assay.

  Elvira Abollo, Sandra M Casas, Giuseppe Ceschia, Antonio Villalba
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  ABSTRACT: Perkinsosis is an infection of marine molluscs caused by the protistan parasites of the genus Perkinsus, which has been classified by the OIE as a disease that warrants notification. In the present study, we have applied a molecular genetic approach to develop an optional method for the specific identification of Perkinsus species. A species-specific polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay of the rRNA ITS region was developed to identify and distinguish among Perkinsus species. A taxonomic key was established that allows successful identification of Perkinsus species using a single restriction enzyme (Rsa I) to discriminate P. chesapeaki and P. marinus or by a combination of two endonucleases (Rsa I plus Hinf I) to discriminate P. olseni and P. mediterraneus. In order to validate the RFLP assay, the PCR products were cloned and sequenced, and its phylogenetic affinity was determined. Phylogenetic analysis confirmed the specific identification carried out by RFLPs. Herein is the first report of P. olseni in Manila clams from the NW Adriatic Sea (Italy), which we identified by employing this method. The PCR-RFLP assay herein described may be useful to provide accurate, rapid and inexpensive identification of Perkinsus species, and may aid in ongoing epizooetiological studies and diseases control programmes.
  Molecular and Cellular Probes 01/2007; 20(6):323-9. · 2.08 Impact Factor
• Article: Molecular cloning and expression analysis of interferon regulatory factor-1 (IRF-1) of turbot and sea bream.

  M Camino Ordás, Elvira Abollo, M Mar Costa, Antonio Figueras, Beatriz Novoa
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  ABSTRACT: The interferon regulatory factor (IRF) family comprises transcription factors that regulate the expression of interferon and interferon-related cytokines. Using the RACE technique, we have determined the complete cDNA sequence of turbot (Scophthalmus maximus) and sea bream (Sparus aurata) IRFs. These sequences shared characteristics with other IRFs of fish, mammals and birds, and showed high similarity with IRF-1. Indeed, they were included in the IRF-1 cluster of the phylogenetic tree constructed with IRF-1 and IRF-2 sequences of several organisms, and presented a low number of basic amino acid residues in the carboxy-terminal end of the proteins. All of these characteristics led to the identification of turbot and sea bream IRFs as IRF-1. Two IRF-1 sequences were obtained for both turbot and sea bream, and we named them turbot/sea bream IRF-1a and IRF-1b. Turbot IRF-1a differed from turbot IRF-1b in four nucleotides. The presence of both IRF types in cDNA from 45 turbot livers was determined by RFLP, suggesting the duplication of the gene. Sea bream IRF-1b presented a deletion of 121bp in its ORF compared to sea bream IRF-1a, and since both IRF types were present in all 25 cDNAs analyzed by PCR, we hypothesized that the truncated sea bream IRF-1b was probably an alternative splicing product. Turbot and sea bream IRF-1 expression was constitutive in every analyzed organ, as reported before for other fish species. Poly I:C significantly stimulated turbot IRF-1 expression in muscle, spleen and kidney 24 h post-treatment, while viral haemorrhagic septicemia virus (VHSV) induced a differential expression of this factor in kidney 8 h after infection. These results do not agree with those previously reported for flounder and trout IRF. Other expression experiments with turbot leukocytes stimulated in vitro with poly I:C and with brain and kidney of sea bream infected with nodavirus did not bring out differential IRF expression levels in stimulated samples with respect to controls.
  Molecular Immunology 04/2006; 43(7):882-90. · 2.90 Impact Factor
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  Available from: digital.csic.es

  Article: Renal coccidiosis in the European cormorant Phalacrocorax aristotelis aristotelis from the Galician coast

  Elvira  Abollo , Santiago  Pascual 
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  ABSTRACT: A developmental stage of a species of eimeriorin Apicomplexa was found heavily infecting the kidney of the European cormorant Phalacrocorax aristotelis aristotelis beached on the coast of Galicia after the oil spill from the ‘Prestige’. The immature condition of the parasite made a precise taxonomic identification impossible. The infection caused kidney damage as a result of pressure atrophy and mechanical displacement exerted by oocysts which occupied large areas of host tissue. A cellular host reaction was always apparent in the kidney of the infected cormorants. Although the oil effect is assumed to be responsible for the death of the cormorants, the impact of the coccidiosis should be monitored in the European shag populations.
  Journal of the Marine Biological Association of the UK 07/2005; 85(04):1017 - 1019. · 1.00 Impact Factor
• Article: Whaleworms as a tag to map zones of heavy-metal pollution.

  Santiago Pascual, Elvira Abollo
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  ABSTRACT: Biological monitoring refers to the use of living organisms to evaluate environmental conditions. Of particular relevance to the health of marine ecosystems is the improvement of methodologies of biological monitoring to provide highly ecologically sensitive indices of exposure. We have shown that anisakid nematodes, a parasite group widely distributed in oceans that infects a wide range of host species, can accumulate essential and non-essential metals to levels far in excess of their host tissues. The fact that they could be used as biomarkers of trace-metal contamination in studies of environmental impact suggests a potential use as a monitor species in a marine ecosystem under anthropogenic stress because they might produce a warning or alert signal of high ecological relevance.
  Trends in Parasitology 06/2005; 21(5):204-6. · 5.14 Impact Factor
• Article: SSU rDNA analysis of Kudoa rosenbuschi (Myxosporea) from the Argentinean hake Merluccius hubbsi.

  Elvira Abollo, Beatriz Novoa, Antonio Figueras
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  ABSTRACT: The cloning and sequencing of the small subunit (SSU) ribosomal DNA gene from Kudoa rosenbuschi (myxosporean species associated with post-mortem myoliquefaction process in the Argentinean hake Merluccius hubbsi) is reported. The SSU rDNA was found to contain 1740 bp with a single polymorphic site with either a C or T at position 221. The sequence data obtained in this study and those known sequences of Kudoa species deposited in the GenBank were all analyzed to construct a phylogenetic tree. Nucleotide sequences showed the highest degree of identity with K. funduli, followed by K. miniauriculata, K. clupeidae and K. dianae. Phylogenetic analysis placed K. rosenbuschi in the same branch of K. clupeidae and K. funduli, and showed it to be closely related to K. dianae, K. paniformis and K. miniauriculata.
  Diseases of Aquatic Organisms 05/2005; 64(2):135-9. · 2.20 Impact Factor
• Article: Accumulation of heavy metals in the whaleworm Anisakis simplex s.l. (Nematoda: Anisakidae)

  Santiago  Pascual , Elvira  Abollo 
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  ABSTRACT: Third-stage larval and adult infrapopulations of the whaleworm Anisakis simplex sensu lato (s.l.) (Nematoda: Anisakidae) from their respective fish, cephalopod and cetacean hosts caught or stranded in the Galician coast (north-west Spain), were analysed for heavy metals by atomic absorption spectrometry. Results suggest that the whaleworm may accumulate lead and copper to levels far in excess of their host tissues.
  Journal of the Marine Biological Association of the UK 09/2003; 83(05):905 - 906. · 1.00 Impact Factor
• Article: An SEM study of Phocascaris cystophorae Berland, 1964 (Nematoda: Anisakidae), a parasite of the hooded seal Cystophora cristata.

  Elvira Abollo, Santiago Pascual
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  ABSTRACT: Scanning electron microscopy was used to study the surface morphological characteristics (excretory pore, interlabia knobs, lips and adjacent structures, caudal papillae and papilla-like structures) of the nematode Phocascaris cystophorae, a parasite from the stomach of the hooded seal Cystophora cristata. A comparative morphological analysis was made between species of Phocascaris and Contracaecum osculatum (sensu lato), which are all parasitic in phocid seals.
  Systematic Parasitology 03/2002; 51(2):155-8. · 1.25 Impact Factor
• Article: What makes a cephalopod a suitable host for parasite? The case of Galician waters

  Angel F González, Santiago Pascual, Camino Gestal, Elvira Abollo, Angel Guerra
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  ABSTRACT: We analyse the cephalopod–parasite systems taking into account the abiotic and biotic factors that may affect the host risk of infection (contact) with parasites. On the basis of 2000 individuals comprising 10 cephalopod species collected at a microgeographic area (Galician waters, NW Spain), an attempt is made to find associations between parasite relative species diversity (RSD) and cephalopod life cycle characteristics. Additionally, an index of similarity and the ratios of adult/immature (A/I) and specialist/generalist (S/G) regarding the parasite condition were used to define cephalopod ecological groupings at those species with similar risk of becoming infected with a given parasite fauna. Results show the existence of three ecological groupings (coastal, intermediate, and nerito-oceanic), which suggest that the ecological niche of a cephalopod species is more important in determining its risk of parasitic infection than is phylogeny.
  Fisheries Research.