Type I diabetes is caused by loss of insulin-secreting beta cells. To identify novel, pharmacologically-targetable histone-modifying proteins that enhance beta cell production from pancreatic progenitors, we performed a screen for histone modifications induced by signal transduction pathways at key pancreatic genes. The screen led us to investigate the temporal dynamics of ser-28 phosphorylated...

Many neural progenitors, including Drosophila mushroom body (MB) and projection neuron (PN) neuroblasts, sequentially give rise to different subtypes of neurons throughout development. We identified a novel BTB-zinc finger protein, named Chinmo (Chronologically inappropriate morphogenesis), that governs neuronal temporal identity during postembryonic development of the Drosophila brain. In both...

Cell replacement therapy could represent an attractive alternative to insulin injections for the treatment of diabetes. However, this approach requires a thorough understanding of the molecular switches controlling the specification of the different pancreatic cell-types in vivo. These are derived from an apparently identical pool of cells originating from the early gut endoderm, which are succ...

We model a moving object as a sizable physical entity equipped with GPS, wireless communication capability, and a computer. Based on a grid model, we develop a distributed system, FATES, to manage data for moving objects in a two-dimensional space. The system is used to provide time-dependent shortest paths for moving objects. The performance study shows that FATES yields shorter average trip t...

A common metaphor for describing development is a rugged "epigenetic landscape" where cell fates are represented as attracting valleys resulting from a complex regulatory network. Here, we introduce a framework for explicitly constructing epigenetic landscapes that combines genomic data with techniques from spin-glass physics. Each cell fate is a dynamic attractor, yet cells can change fate in ...

Midline signaling by Hedgehog (Hh) family members has been implicated in patterning the vertebrate embryo. We have explored the potential regulatory role of cAMP-dependent protein kinase A (PKA) in these events. Zebrafish embryos injected with RNAs encoding Sonic hedgehog (Shh), Indian hedgehog (Ihh), or a dominant-negative regulatory subunit of PKA, PKI, have equivalent phenotypes. These inclu...