Skin healing and scale regeneration in fed and unfed sea bream, Sparus auratus

Abstract

BackgroundFish scales are an important reservoir of calcium and phosphorus and together with the skin function as an integrated barrier against environmental changes and external aggressors. Histological studies have revealed that the skin and scales regenerate rapidly in fish when they are lost or damaged. In the present manuscript the histological and molecular changes underlying skin and scale regeneration in fed and fasted sea bream (Sparus auratus) were studied using a microarray 3 and 7 days after scale removal to provide a comprehensive molecular understanding of the early stages of these processes.ResultsHistological analysis of skin/scales revealed 3 days after scale removal re-epithelisation and formation of the scale pocket had occurred and 53 and 109 genes showed significant up or down-regulation, respectively. Genes significantly up-regulated were involved in cell cycle regulation, cell proliferation and adhesion, immune response and antioxidant activities. 7 days after scale removal a thin regenerated scale was visible and only minor changes in gene expression occurred. In animals that were fasted to deplete mineral availability the expression profiles centred on maintaining energy homeostasis. The utilisation of fasting as a treatment emphasised the competing whole animal physiological requirements with regard to barrier repair, infection control and energy homeostasis.ConclusionsThe identification of numerous genes involved in the mitotic checkpoint and cell proliferation indicate that the experimental procedure may be useful for understanding cell proliferation and control in vertebrates within the context of the whole animal physiology. In response to skin damage genes of immune surveillance were up-regulated along with others involved in tissue regeneration required to rapidly re-establish barrier function. Additionally, candidate fish genes were identified that may be involved in cytoskeletal re-modelling, mineralization and stem cells, which are of potential use in aquaculture and fish husbandry, as they may impact on the ability of the fish to produce structural proteins, such as muscle, efficiently.

Transcriptomic response to shell damage in the Antarctic clam, Laternula elliptica: Time scales and spatial localisation

“…Transcriptional responses to damage have also been studied in non-mollusc species. In a microarray experiment investigating scale regeneration (a type of biomineralisation) in sea bream, Vieira et al (2011) found 769 differentially expressed genes after 3 days but only 21 differentially expressed after 7 days. Taken together with the results of the present study, damage-repair experiments emphasise the importance of timing in biomineralisation studies.…”

An Overview of the Immunological Defenses in Fish Skin

“…Keratocytes can cover fish skin wound surfaces with a new protective layer of cells within hours after wounding by rapid migration from the surrounding wound margins [66,67]. In addition to their migratory activity, different cell types present in fish epidermis are shown to internalize particular matter such as bacteria and other particles.…”

Evolution of the angiopoietin-like gene family in teleosts and their role in skin regeneration

“…Fish skin differs in several aspects from mammalian skin and the functional divergence between skin in a terrestrial and aquatic environment is presumably underpinned by significant divergence in molecular and cellular processes. While in human skin the primary physical barrier that confers protection is the stratified epidermis that is composed of dead keratinized cells, in fish the epidermis is composed of metabolically active cells with little keratinization [5–8]. Goblet cells and club cells produce mucous rich in proteases, mucins, immunoglobulins and antimicrobial peptides (AMPs) that protect the living epidermis of the fish integument.…”