Biological clocks play key roles in organismal development, homeostasis and function. In recent years, much work has focused on circadian clocks, but emerging studies have highlighted the existence of ultradian oscillators - those with a much shorter periodicity than 24 h. Accumulating evidence, together with recently developed optogenetic approaches, suggests that such ultradian oscillators pl...

introduction: the cell surface glycoconjugate and extracellular matrix may mediate extracellular signals which decide the fate of the cells during tissue interactions. the proper development of cornea needs cellular interaction between surface epithelium, neural crest and developing lens. materials and methods: 50 pregnant rats were chosen and the embryos from pernatal day11-to 20 and postnatal...

BACKGROUND Cell position rather than cell lineage governs most aspects of development in plants. However, the nature and the origin of positional information remains elusive. Animal epidermal patterning relies in many cases on positional information provided by cell-cell communication. The epidermal layer of the Arabidopsis root is made of alternating files of two cell types and thus presents a...