Rodents rely on Merkel cells for texture discrimination tasks.

The cutaneous somatosensory system contains multiple types of mechanoreceptors that detect different mechanical stimuli (Johnson, 2001). These stimuli, either alone or in combination, are ultimately interpreted by the brain as different aspects of the sense of touch. Psychophysical and electrophysiological experiments in humans and other mammals implicate one of these mechanoreceptors, the Merkel cell/neurite complex, in two-point discrimination and the detection of curvature, shape, and texture (Johnson and Lamb, 1981; Johnson et al.

Loci controlling nitrate reductase activity in maize: ultraviolet-B signaling in aerial tissues increases nitrate reductase activity in leaf and root when responsive alleles are present.

Environmental factors, such as ultraviolet-B (UV-B) irradiation, have the ability to affect pathways such as nitrogen metabolism. As fixed nitrogen is the keystone mineral nutrient that controls grain crop yield, any alteration in this cycle can be detrimental to plant productivity. Nitrate reductase enzyme activity is responsible for the reduction of nitrate to nitrite, and nitrate is the major form of nitrogen assimilated in plants.

Mammalian Merkel cells are descended from the epidermal lineage.

Merkel cells are specialized cells in the skin that are important for proper neural encoding of light touch stimuli. Conflicting evidence suggests that these cells are lineally descended from either the skin or the neural crest. To address this question, we used epidermal (Krt14(Cre)) and neural crest (Wnt1(Cre)) Cre-driver lines to conditionally delete Atoh1 specifically from the skin or neural crest lineages, respectively, of mice.