Project description:DNA binding profiles of three maternal factors (Tcf7, Gata.a and Zic-r.a) in chordate 16-cell stage embryo. 16-cell stage ciona intestinalis embryos were collected from multiple batches and the extracted chromatin was immunoprecipitated by the antibodies which specifically recognize ciona Gata.a, Tcf7 and Zic-r.a, respectively.
Project description:We recently showed HMX is expressed in bipolar tail neurons (BTN) in early embryos of Ciona intestinalis. In order to assess the function of the homeobox transcription factor in this cell fate, we used an overexpression strategy. ciHMX was overexpressed in the epidermis, followed by RNAseq of experimental and control embryos. We then looked for differential expression of BTN fate markers, testing if HMX is able to regulate BTN fate determination.
Project description:A genomic overview of in vivo binding of a transcription factor ZicL in the ascidian gastrula embryo. ZicL is a key regulator of the early ascidian development, and so called 'master-regulatory genes' for mesodermal and neural tissues are under the control of ZicL. Keywords: ChIP-chip
Project description:The primitive chordate Ciona intestinalis has emerged as a significant model system for the study of heart development. The Ciona embryo employs a conserved heart gene network in the context of extremely low cell numbers and reduced genetic redundancy. Here, I review recent studies on the molecular genetics of Ciona cardiogenesis as well as classic work on heart anatomy and physiology. I also discuss the potential of employing Ciona to decipher a comprehensive chordate gene network and to determine how this network controls heart morphogenesis.
Project description:Gene number can be considered a pragmatic measure of biological complexity, but reliable data is scarce. Estimates for vertebrates are 50-100,000 genes per haploid genome, whereas invertebrate estimates fall below 25,000. We wished to test the hypothesis that the origin of vertebrates coincided with extensive gene creation. A prediction is that gene number will differ sharply between invertebrate and vertebrate members of the chordate phylum. A gene number estimation method requiring limited sequence sampling of genomic DNA was developed and validated by using data for Caenorhabditis elegans. Using the method, we estimated that the invertebrate chordate Ciona intestinalis has 15,500 protein-coding genes (+/-3,700). This number is significantly lower than gene numbers of vertebrate chordates, but similar to those of invertebrates in distantly related phyla. The data indicate that evolution of vertebrates was accompanied by a dramatic increase in protein-coding capacity of the genome.