Insect Photoperiodism

Shedding light on photoperiodism.

I n mammals, photoreception is restricted to the eye. By contrast, nonmammalian vertebrates possess photoreceptors in a wide array of extraocular tissues, including the pineal complex and brain (1). The identity of the deep brain photoreceptors has remained elusive. They continue to be the least studied of all nonvisual photoreceptor classes, although their existence in the vertebrates has been...

Photoperiodism in Pigs

Andersson, H. 2000. Photoperiodism in pigs. Studies on timing of male puberty and melatonin. Doctoral thesis ISSN 1401-6257, ISBN 91-576-5901-X. The routine castration of male piglets, which is performed in many countries to avoid boar taint in meat, is a cause for great concern in terms of animal welfare. Castrates also have reduced feed efficiency and more fat than do entire males. More of th...

Seasonality and photoperiodism in fungi.

This review gives a retrospective of what is known about photoperiodism in fungi, which is largely based on reports about seasonal spore concentrations. Relatively few species have been investigated under laboratory conditions, so that our knowledge whether seasonal reproduction in fungi is mainly a direct response to environmental conditions or whether it involves a photoperiodic machinery wit...

Photoperiodism: The Coincidental Perception of the Season

Many plants use the seasonal change in daylength as a signal for flowering. Daylength sensing in Arabidopsis has now been shown to occur by an external coincidence mechanism, which operates by the circadian and light regulation of CONSTANS.

Photoperiodism in Mammals: Regulation of Nonreproductive Traits