Functional Molecular Biodiversity: Assessing the Immune Status of Two Sponge Populations (Suberites domuncula) on the Molecular Level

• Published in: Marine ecology (Berlin, West) West), 2004-07, Vol.25 (2), p.93-108
• Main Authors: Schröder, Heinz C., Grebenjuk, Vladislav A., Binder, Michael, Skorokhod, Alexander, Batel, Renato, Hassanein, Hamdy, Müller, Werner E. G.
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; immune status; Marine; Mediterranean Sea; Molecular biodiversity; Porifera; Sea water ecosystems; sponge populations; sponges; Suberites domuncula; Synecology
• ISSN: 0173-9565; 1439-0485
• DOI: 10.1111/j.1439-0485.2004.00017.x

.  Porifera (sponges) are sessile filter feeders living primarily in the marine environment. In this study the population diversity of one species, the demosponge Suberites domuncula, has been investigated in an isolated area, the Limski Canal (LC) near Rovinj (Croatia; Mediterranean Sea), in comparison to that in the open sea (OS), only 10–20 km apart from the LC. The immune competence of the S. domuncula specimens was studied in response to exposure to the bacterial endotoxin LPS. The level of phosphorylation of the p38 kinase from specimens collected in LC is significantly lower than that of OS animals. To confirm the biochemical data on the molecular level, the technique of identification of the differentially expressed transcripts in specimens from OS versus LC was applied. Most of the differently expressed transcripts coded for the allograft inflammatory factor‐1 (AIF‐1), a molecule involved in self‐self/self‐non‐self recognition also in S. domuncula. The level of gene expression of the AIF‐1 gene, determined by Northern blotting and quantitative ‘real‐time Q‐PCR’ revealed much higher values in the OS animals. Moreover, the degree of polymorphism in the AIF‐1 and in the adjacent tubulin locus was high in animals from both locations. Populations of S. domuncula therefore comprise a high genetic diversity even in closely located areas. This finding has prompted long‐term research activities in the Limski Canal, a defined marine protected area.