How the Fayette R. Plumb Company Gets Production

Aire Gets Company for Immune Tolerance

A specialized subset of epithelial cells in the thymus "promiscuously" transcribes thousands of peripheral genes to ensure that developing T cells can test their antigen receptors for dangerous autoreactivity. New findings by Takaba et al. indicate that the transcription factor Fezf2 acts independently of Aire in thymic epithelial cells to generate "genetic noise" for immunological tolerance.

Villification: how the gut gets its villi.

The villi of the human and chick gut are formed in similar stepwise progressions, wherein the mesenchyme and attached epithelium first fold into longitudinal ridges, then a zigzag pattern, and lastly individual villi. We find that these steps of villification depend on the sequential differentiation of the distinct smooth muscle layers of the gut, which restrict the expansion of the growing end...

How the Er Gets into Shape

How the zebrafish gets its stripes.

The study of vertebrate pigment patterns is a classic and enduring field of developmental biology. Knowledge of pigment pattern development comes from a variety of systems, including avians, mouse, and more recently, the zebrafish (Danio rerio). Recent analyses of the mechanisms underlying the development of the neural crest-derived pigment cell type common to all vertebrates, the melanocyte, h...

How the Leopard Gets Its Spots

ammals exhibit a remarkable variety of coat patterns; the variety has elicited a comparable variety of explanations—many of them at the level of cogency that prevails in Rudyard Kipling's delightful "How the Leopard Got Its Spots." Although genes control the processes involved in coat pattern formation, the actual mechanisms that create the patterns are still not known. It would be attractive f...