Biological systems involving short-range activators and long-range inhibitors can generate complex patterns. Reaction-diffusion models postulate that differences in signaling range are caused by differential diffusivity of inhibitor and activator. Other models suggest that differential clearance underlies different signaling ranges. To test these models, we measured the biophysical properties o...

Background: The study of specific genes expressed in the testis is important to understanding testis development and function. Spermatogenesis is an attractive model for the study of gene expression during germ cell differentiation. Spermatogenesis associated-19 (Spata-19) is a recently-identified important spermatogenesis-related gene specifically expressed in testis. Its protein product is in...

The ability to create mosaic animals allows the phenotypic analysis of patches of groups of genetically different cells that develop in a wild type environment. In Drosophila, a variety of techniques have been developed over the years to generate mosaics, and in this chapter, I review the techniques that our laboratory has developed. These include the "Dominant Female Sterile" technique which a...

Brain growth occurs throughout embryogenesis and early postnatal life, but its foundation is laid in the primitive neuroepithelium. In this issue of Neuron, Sahara and O'Leary identify Fgf10 as a key regulator of the neuroepithelial to radial glial transition and subsequently of size of the rostral forebrain.

The future of prenatal diagnosis and screening lies in developing clinical approaches and laboratory technologies applicable to genetic analyses and therapeutic interventions during embryonic development.

Multistate genetic switches play a crucial role during embryonic development and tumorigenesis. An archetypical example is the three-way switch regulating epithelial-hybrid-mesenchymal transitions. We devise a special WKB-based approach to investigate white Gaussian and shot noise effects on three-way switches, and construct an effective landscape in good quantitative agreement with stochastic ...

Dehydrins are highly hydrophilic proteins that accumulate during embryogenesis and water stress responses in plants. Although dehydrins were discovered in the 1980s, their physiological functions are unknown. However, recent molecular-based studies have provided insights into the multifunctionality of dehydrins. The functional versatility of dehydrins is reviewed using recent experimental evide...

Genetic and anatomical analyses of the developing Arabidopsis embryogenic root reveal that stereotypic patterns of cell division are not required for pattern formation.