As harlequins grow old

Preparing for Your Future as You Grow

Commissural axons cross the nervous system midline and connect to targets in the contralateral hemisphere. In this issue of Neuron, Michalski et al. (2013) demonstrate that synapses formed by ipsilaterally misrouted commissural axons exhibit defects in synapse maturation. Thus, midline crossing primes axons for subsequent synaptogenesis.

Public health workers needed: educational programs grow as shortage looms.

Cloned interstitial stem cells grow as contiguous patches in hydra.

The migration of interstitial cells was analyzed during the growth of stem cell clones in vivo. The spatial distribution of cloned cells was analyzed at a time by which extensive migration of interstitial cells could have occurred. All interstitial cell clones were found to form large contiguous patches of cells. The results indicate that there is little migration of large interstitial cells in...

To grow old: regulatory role of ethylene and jasmonic acid in senescence

Senescence, the final stage in the development of an organ or whole plant, is a genetically programmed process controlled by developmental and environmental signals. Age-related signals underlie the onset of senescence in specific organs (leaf, flower, and fruit) as well as the whole plant (monocarpic senescence). Rudimentary to most senescence processes is the plant hormone ethylene, a small g...

Evidence of old carbon used to grow new fine roots in a tropical forest.

In this study, we explore how a hurricane disturbance influenced carbon allocation for the production of new fine roots. Before and after a hurricane, we measured the age of carbon (time since fixation from the atmosphere) in fine root structural tissues using natural abundance radiocarbon (14C) measured by accelerator mass spectrometry. Roots were sampled from five seasonally dry tropical fore...