th day 3 and 7 of regeneration may indicate that, in teleosts, this transcript and its protein product may be regulating the process of skin scale regeneration by the induction of cell proliferation. There is also an element of cytoskeletal remodelling via the up regulation of structural proteins and protein degradation. Similarly, as was noted with the fasted group, there are a couple of genes up regulated in sea bream, that in humans produce structural problems when defective. Mutations in Dynamin 2 produce abnormally large nuclei in skeletal muscle cells, resulting in muscle weakness, whilst serpin H1 is an essential chaperone in col lagen synthesis, with deficiencies in humans resulting in the premature rupture of placental membranes. As with the 3 days fasted vs.
fasted without scales compari sons, at day 7 there are up regulated transcripts poten tially linked with mineralization. Such as, caldecrin precursor that exerts a hypocalcaemic activity, decreasing serum calcium, and may indicate that the fish is now actively mobilising calcium for scale mineralization. Real time RT PCR To corroborate Brefeldin_A the microarray data gene specific qPCRs were performed. In general, the direction of change in expression was concordant between qPCR and the microarray probes and a positive Pearson correlation was obtained between qPCR and probe 1 and between qPCR and probe 2. Despite the good correlation observed between the gene expression ana lyzed by qPCR and the microarray data, a few excep tions were observed, the qPCR fold change for SPP1 transcript in group 3ST, for ColVA2 transcript in group 3WS, for Col1A1 transcript for group 3ST and for p22phox transcript in group 3STWS vs.
starved group was not correlated with the microarray fold change. The latter is explained by the high variability found for this gene in different individuals in the experimental groups. The best concordance between qPCR and microarray data is achieved when the observed microarray fold change is between 2 and 7, and in the present experiments the genes analyzed by qPCR which had fold changes closest to the lower limit had lower correlations with the microarray data. Conclusions Fish skin is a very metabolically active organ which has crucial physiological functions, in osmotic regulation and is also an important immune barrier.
Loss of scales and superficial wounds occur in both wild and captive teleosts and the vital importance of integument integrity means damage must be repaired as soon as possible. Although several studies exist which characterise tissue and cellular changes underlying skin regeneration in tel eosts, molecular studies have largely been centred on scale formation and calcification, with the latter process not taking place until 14 28 days after scale removal. The study described here, concentrates on the initial stages of scale removal and re epithelialization. Our results show that this is a dramatic process, mainly occurring within the first three days after scal