Role of annexin gene and its regulation during zebrafish caudal fin regeneration.

The molecular mechanism of epimorphic regeneration is elusive due to its complexity and limitation in mammals. Epigenetic regulatory mechanisms play a crucial role in development and regeneration. This investigation attempted to reveal the role of epigenetic regulatory mechanisms, such as histone H3 and H4 lysine acetylation and methylation during zebrafish caudal fin regeneration. It was intriguing to observe that H3K9,14 acetylation, H4K20 trimethylation, H3K4 trimethylation and H3K9 dimethylation along with their respective regulatory genes, such as GCN5, SETd8b, SETD7/9, and SUV39h1, were differentially regulated in the regenerating fin at various time points of post-amputation. Annexin genes have been associated with regeneration; this study reveals the significant up-regulation of ANXA2a and ANXA2b transcripts and their protein products during the regeneration process. Chromatin immunoprecipitation and PCR analysis of the regulatory regions of the ANXA2a and ANXA2b genes demonstrated the ability to repress two histone methylations, H3K27me3 and H4K20me3, in transcriptional regulation during regeneration. It is hypothesized that this novel insight into the diverse epigenetic mechanisms that play a critical role during the regeneration process may help to strategize the translational efforts, in addition to identifying the molecules involved in vertebrate regeneration.

Proteomic and gene expression analysis of zebrafish brain undergoing continuous light/dark stress.

Several organisms irrespective of their complexity in structure and function have an inbuilt circadian rhythm. Zebrafish could be used as an alternate model animal in sleep research as it exhibits similar sleep-wake dynamics as mammals and Drosophila. In this study, we have analysed the adult zebrafish brain for its differential proteome and gene expression during perturbed light/dark cycle. A total of 53 and 25 proteins including sncb, peroxiredoxins and TCR alpha were identified based on two-dimensional gel electrophoresis Fourier transform mass spectrometer/ion trap tandem mass spectrometer and differential in-gel electrophoresis MALDI TOF MS/MS analysis, respectively, with at least 1.5-fold changes between the control and experimental brains. Real time-polymerase chain reaction revealed that many circadian pathway-associated genes, such as per1b, bmal1b, cry1b, bmal2 and nr1d2, were differentially regulated during continuous light/dark exposures. It is hypothesized that the differential regulation of these genes might lead to the discovery of potential diagnostic markers for gaining insight into the light/dark-associated stress in humans.

Proteome profile of zebrafish Danio rerio olfactory bulb based on two-dimensional gel electrophoresis matrix-assisted laser desorption/ionization MS/MS analysis.

Zebrafish (Danio rerio), is one of the most extensively studied chordate model animal in the field of neuroscience and development biology. Understanding the proteome profile of various tissues and organs of Danio rerio has become increasingly important for inching it as an alternate translational model animal. This study aimed in understanding the proteome profile of D. rerio brain's olfactory bulb exclusively. The proteome pattern of olfactory bulb of D. rerio was determined using the two-dimensional gel electrophoresis approach involving both full range and three various narrow pH range immobilized pH gradient strips, followed by mass spectrometry and tandem mass spectrometry analysis. 221 various proteins were characterized based on matrix-assisted laser desorption/ionization mass spectrometry and tandem mass spectrometry analysis as olfactory bulb-specific proteins. The identified proteins represented various pI, mass, functions, and localization. The different proteins acknowledged in this study were found to be associated with diverse metabolic pathways, enzymatic activities, and neurological functions. Glycolysis, gluconeogenesis, and oxidative phosphorylation are the major metabolic pathways found associated with the identified proteins. The identified protein catalogue was also found to be participating in various network pathways such as GABAergic neurophysiological neurotransmission, remodeling of cytoskeleton, neurofilaments, and cell adhesion. This study provides the D. rerio olfactory bulb two-dimensional gel electrophoresis proteome map and the details of 221 olfactory bulb-specific proteins.