Recent paper published in Pigment Cell Melanoma Res. (Dec 2014) doi: 10.1111/pcmr.12335.
Pigment patterns in adult fish result from superimposition of two largely independent pigmentation mechanisms
Ceinos RM, Guillot R, Kelsh RN, Cerdá-Reverter JM, Rotllant J
Dorso-ventral pigment pattern differences are the most widespread pigmentary adaptations in vertebrates. In mammals, this pattern is controlled by regulating melanin chemistry in melanocytes using a protein, agouti-signalling peptide (ASIP). In fish, studies of pigment patterning have focused on stripe formation, identifying a core striping mechanism dependent upon interactions between different pigment cell types. In contrast, mechanisms driving the dorso-ventral countershading pattern have been overlooked. Here, we demonstrate that, in fact, zebrafish utilize two distinct adult pigment patterning mechanisms - an ancient dorso-ventral patterning mechanism, and a more recent striping mechanism based on cell-cell interactions; remarkably, the dorso-ventral patterning mechanism also utilizes ASIP. These two mechanisms function largely independently, with resultant patterns superimposed to give the full pattern.
Recent paper published in Archives of Biochemistry and Biophysics (Jan 2015) doi: 10.1016/j.abb.2014.12.023.
Molecular characterization of cbfb gene and identification of new transcription variants: Implications for function
B. Simões, N. Conceição, A.C. Matias, J. Bragança, R.N. Kelsh, M.L. Cancela
The CBFβ gene encodes a transcription factor that, in combination with CBFα (also called Runx, runt-related transcription factor) regulates expression of several target genes. CBFβ interacts with all Runx family members, such as RUNX2, a master-regulator of bone-related gene transcription that contains a conserved DNA-binding domain (Runt domain). CBFβ stimulates DNA binding of the Runt domain, and is essential for most of the known functions of RUNX2.
A comparative analysis of the zebrafish cbfβ gene and protein, and of its orthologous identified homologous proteins in different species indicates a highly conserved function. We cloned eleven transcripts of the zebrafish cbfβ gene, one resulting in the known Cbfβ protein (with 187 amino-acids (aa)), and three additional variants resulting from skipping exon 5a (resulting in a protein with 174 aa) or exon 5b resulting in a protein with 201 aa), both observed for the first time in zebrafish, and a completely novel isoform containing both exon 5a and 5b (and resulting in a protein with 188 aa). Functional analysis of these isoforms provides insight into their role in regulating gene transcription. From the other seven variants two correspond to premature early termination of Cbfβ forms, while the others show in-frame exon-skipping causing changes in the Cbfβ domain that may affect its function.