The Zebrafish Retina and the Evolution of the Onecut-Mediated Pathway in Cell Type Differentiation.

() genes play an important role in the proper formation of retinal cells in vertebrates, in particular horizontal, retinal ganglion and amacrine cells. However, it is not fully known how the unique and combined action of multiple gene copies leads to the induction and differentiation of specific retinal cell types. To gain new insights on how genes influence retina formation, we have examined the developmental role of , and genes during eye formation in the non-mammalian vertebrate zebrafish .

Novel Insights on Nitric Oxide Synthase and NO Signaling in Ascidian Metamorphosis.

Nitric oxide (NO) is a pivotal signaling molecule involved in a wide range of physiological and pathological processes. We investigated NOS/NO localization patterns during the different stages of larval development in the ascidia and evidenced a specific and temporally controlled pattern. NOS/NO expression starts in the most anterior sensory structures of the early larva and progressively moves towards the caudal portion as larval development and metamorphosis proceeds.

Onecut Regulates Core Components of the Molecular Machinery for Neurotransmission in Photoreceptor Differentiation.

Photoreceptor cells (PRC) are neurons highly specialized for sensing light stimuli and have considerably diversified during evolution. The genetic mechanisms that underlie photoreceptor differentiation and accompanied the progressive increase in complexity and diversification of this sensory cell type are a matter of great interest in the field. A role of the homeodomain transcription factor Onecut (Oc) in photoreceptor cell formation is proposed throughout multicellular organisms.

Functional conserved non-coding elements among tunicates and chordates.

Non-coding regions with dozens to several hundred base pairs of extreme conservation have been found in all metazoan genomes. The distribution of these conserved non-coding elements (CNE) within and across genomes has suggested that many of them may have roles as transcriptional regulatory elements. A combination of bioinformatics and experimental approaches can be used to identify CNEs with regulatory activity in phylogenetically distant species.

New insights into protamine-like component organization in Mytilus galloprovincialis' sperm chromatin.

We have analyzed Mytilus galloprovincialis' sperm chromatin, which consists of three protamine-like proteins, PL-II, PL-III, and PL-IV, in addition to a residual amount of the four core histones. We have probed the structure of this sperm chromatin through digestion with micrococcal nuclease (MNase) in combination with salt fractionation. Furthermore, we used the electrophoretic mobility shift assay to define DNA-binding mode of PL-II and PL-III and turbidimetric assays to determine their self-association ability in the presence of sodium phosphate.

Regulatory elements retained during chordate evolution: coming across tunicates.

Understanding the role of conserved noncoding elements (CNEs) throughout the genome is taking advantage of the improved efficiency of genome-sequencing techniques and bioinformatics tools. Tunicates diverged before the vertebrate whole genome duplications and, therefore, represent an optimal model system to study the evolution of complex regulatory networks. Here, we review the current knowledge on the characterization of CNEs during embryonic development, focusing on the evolutionary similarity and divergence between tunicates and other chordates.