Patterns of p53, p73 and mortalin gene expression associated with haemocyte polyploidy in the soft-shell clam, Mya arenaria

• Published in: Journal of invertebrate pathology Vol. 98; no. 2; pp. 148 - 152
• Main Authors: Siah, A., Delaporte, M., Pariseau, J., McKenna, P., Berthe, F.C.J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.06.2008; Elsevier
• Subjects: Animal aquaculture; Animal productions; animal proteins; Animals; Biological and medical sciences; biosynthesis; Cell Transformation, Neoplastic; Cell Transformation, Neoplastic - genetics; clams; DNA-Binding Proteins; DNA-Binding Proteins - biosynthesis; DNA-Binding Proteins - genetics; Flow Cytometry; Fundamental and applied biological sciences. Psychology; Gene Expression; Genes, p53; Genes, p53 - genetics; genetics; Haemocytes; heat shock proteins; Hematologic Neoplasms; Hematologic Neoplasms - genetics; Hematologic Neoplasms - veterinary; hemic neoplasia; hemocytes; Hemocytes - physiology; HSP70 Heat-Shock Proteins; HSP70 Heat-Shock Proteins - biosynthesis; HSP70 Heat-Shock Proteins - genetics; Invertebrate aquaculture; Invertebrates; Mollusca; Mortalin; Mya; Mya - genetics; Mya arenaria; Nuclear Proteins; Nuclear Proteins - biosynthesis; Nuclear Proteins - genetics; p53; p73; Pathology; physiology; Polyploidy; Reverse Transcriptase Polymerase Chain Reaction; shellfish diseases; Tetraploidy; transcription factors; Tumor Protein p73; Tumor Suppressor Proteins; Tumor Suppressor Proteins - biosynthesis; Tumor Suppressor Proteins - genetics; veterinary; Canada; North America; Atlantic Ocean; Northwest Atlantic; America; Tetraploidy; Mya arenaria; Mortalin; p73; Haemocytes; p53; Edible mollusc; Disease; Gene expression; Marine environment; Hemocyte; Bivalvia; Mya arenaria;Haemocytes;p53;p73;Mortalin;Tetraploidy; Shellfish breeding; Invertebrata; Mollusca; Tumor suppressor gene
• ISSN: 0022-2011; 1096-0805; 1096-0805
• DOI: 10.1016/j.jip.2008.03.002

The molecular mechanisms by which haemocytes of clams are transformed in the course of haemic neoplasia remain by far unknown. The aim of this study was to quantify the expression of p53/p73 and mortalin genes, in relation with the ploidy status of clam haemocytes and to correlate the p53 expression with mortalin expression. For this purpose, soft-shell clams, Mya arenaria, were collected from an endemic zone for neoplasia. The ploidy of haemocytes was assessed for each individual clam by flow cytometry using a propidium iodide protocol, while p53/p73 and mortalin gene expressions were quantified by real-time RT-PCR. Results show that haemocytes of some clams with a moderate percentage (15–50%) of tetraploid cells have a significantly high level of p53 and p73 in comparison with clams belonging to categories with low (<15%) or high levels (>50%) of tetraploid cells, where low levels of expression of these genes were observed. Furthermore, mortalin gene expression is strongly correlated ( r 2 = 0.68, p < 0.01) with p53 gene expression level. This reinforces the hypothesis of a cytoplasmic p53 sequestration mechanism in clam haemic neoplasia. Further studies are needed to confirm these preliminary results and further unravel the molecular pathways involved in this process. Our results are believed to provide phenotypic foundation for such studies to be undertaken.