The Drosophila blastoderm and the vertebrate neural tube are archetypal examples of
morphogen-patterned tissues that create precise spatial patterns of different cell types. In …

Morphogens are long-range signaling molecules that pattern developing tissues in a
concentration-dependent manner. The graded activity of morphogens within tissues …

Gap genes are involved in segment determination during the early development of the fruit
fly Drosophila melanogaster as well as in other insects. This review attempts to synthesize …

Developing embryos exhibit a robust capability to reduce phenotypic variations that occur
naturally or as a result of experimental manipulation. This reduction in variation occurs by an …

Morphogen gradients provide embryonic tissues with positional information by inducing
target genes at different concentration thresholds and thus at different positions. The Bicoid …

Shadow enhancers, groups of seemingly redundant enhancers, are found in a wide range of
organisms and are critical for robust developmental patterning. However, their mechanism of …

Activation of the gap gene hunchback (hb) by the maternal Bicoid gradient is one of the most
intensively studied gene regulatory interactions in animal development. Most efforts to …

Several fundamental concepts of developmental biology have emerged from studies on the
early development of the Drosophila melanogaster embryo. In the late 1980s, studies on …

The spatial organization of cell fates during development involves the interpretation of
morphogen gradients by cellular signaling cascades and transcriptional networks. Recent …

In order to contribute to the appropriate tissues during development, cells need to know their
position within the embryo. This positional information is conveyed by gradients of signaling …