Apolar growth of Neurospora crassa leads to increased secretion of extracellular proteins.

Protein secretion in filamentous fungi has been shown to be restricted to actively growing hyphal tips. To determine whether an increase in the amount f growing surface area of a fungus can lead to an increase in the amount of protein secretion, we examined secretion in a temperature-sensitive Neurospora crassa mcb mutant that shows a loss of growth polarity when incubated at restrictive temperature. Incubation of the mcb mutant at restrictive temperature results in a three- to fivefold increase in the level of extracellular protein and a 20-fold increase in carboxymethyl cellulase activity relative to a wild-type strain.

Circadian rhythm of brain-derived neurotrophic factor in the rat suprachiasmatic nucleus.

This study was conducted to determine whether the rat suprachiasmatic nucleus (SCN) is characterized by circadian expression of brain-derived neurotrophic factor (BDNF). In constant darkness, SCN content of both BDNF mRNA and protein oscillated in a circadian fashion. BDNF mRNA and protein levels in the SCN reached peak values during the early subjective day and during the subjective night, respectively.