“Highlights” is a new feature that calls attention to exciting advances in developmental biology that have recently been reported in Developmental Dynamics. Development is a broad field encompassing many important areas. To reflect this fact, the section will spotlight significant discoveries that occur across the entire spectrum of developmental events and problems: from new experimental approaches, to novel interpretations of results, to noteworthy findings utilizing different developmental organisms.
May the (gravitational) force be with you (Dev Dyn 235:2686–2694). We are a product of the world in which we live. Nothing drives this point home better than the remarkable finding that gravity can affect gene expression. In their most recent work on the subject, Shimada and Moorman show that altered gravity changes expression of two lens-specific members of the zebrafish heat shock protein gene family, hsp70 and αA-crystallin. Environmental stresses like heat shock and oxidative stress can induce hsp70 expression in several cell types. Of interest, altered gravity only affects hsp70 and αA-crystallin expression in the lens during the period of lens development. This work suggests that, compared with other stressors, there is a specific biological response to altered gravity.
Beauty secrets (Dev Dyn 235:2710–2721). The beauty of a leaf is due in part to the delicate network of veins within it. Venation patterns are markedly diverse between species, a consequence of varied leaf shape and size. Fujita and Mochizuki have devised a mathematical model that predicts venation patterns in different leaf types. Auxin is a plant hormone that is central to vein development, and also maintains cell polarity. PIN1, which is localized to the basal side of the cell, directionally transports auxin. The predictions of venation patterns made by the authors' model, which is based on this information, are enviably accurate. Their secret is to take into account the positive feedback regulation between auxin and PIN1.
Putting it together (Dev Dyn 235:2795–2801). In the debut of the peer-reviewed section, Disease Connections, Oottamasathien et al., report on a method using tissue recombination to induce mature bladder tissue in recombination grafts. They combine mouse embryonic bladder mesenchyme with primary cultures of adult rat urothelium, the lining of the bladder, and graft them into a host mouse. Through a process that is believed to recapitulate normal bladder development, the mesenchyme induces the urothelium to differentiate as mature bladder tissue, complete with well-differentiated smooth muscle and connective tissue. When performed with genetically engineered tissue, the technique will be a powerful tool to understand the molecular mechanisms that govern bladder development and disease.