... gonadal activation are modified when food is scarce or temperatures are low by changing hypothalamic Tshβ, Kiss1 and Rfrp expression to adaptively adjust the timing of reproductive organ development. Seasonal reproduction Photoperiodism Ambient temperature Food scarcity Hypothalamic gene...

... show hypothalamic gene expression characteristic for seasonal reproduction when transferred from DD (grey shading) into LL (white; D). This process has been proposed to consist of a circadian rhythm of photo-inducibility and coinciding light. (A) Despite absent rhythm in activity, a light sensitivity...

... breeding seasons at lower latitudes than at higher latitudes, leading to nearly year-round reproduction in the most southern stream populations. A review of recent progress in our understanding of the physiological mechanisms underlying seasonal reproduction in the three-spined stickleback indicates...

..., with effects at both the brain and gonadal level. Luteinizing hormone Gonadal development Gonadotropin-releasing hormone Hypothalamic–pituitary–gonadal axis Seasonal reproduction Testosterone For many animals, the decision of when to breed is a critical one because timing reproduction...

.... * Author for correspondence (e-mail: [email protected] ) 8 4 2009 2009 energy expenditure respirometry gonadal cycles timing of reproduction seasonal reproduction phenology supplemental factors environmental cues captive experiments predictability day length In most...