کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2196447 1098821 2012 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Circadian clocks and the measurement of daylength in seasonal reproduction
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
Circadian clocks and the measurement of daylength in seasonal reproduction
چکیده انگلیسی

Temperate zone organisms measure changes in daylength to adapt to seasonal changes in their environment. Recent studies have revealed that the long day (LD)-induced thyrotropin (TSH) in the pars tuberalis (PT) of the pituitary gland act as a master factor regulating seasonal reproduction on the the ependymal cells (ECs) within the mediobasal hypothalamus (MBH) to induce expression of type 2 deiodinase (Dio2), a thyroid hormone (TH)-activating enzyme in both LD and short day (SD) breeders. Locally activated TH in the MBH is believed to trigger GnRH secretion from the hypothalamus in LD breeders, while it terminates reproductive activity in SD breeders. Circadian clock is involved in seasonal time measurement and clock genes are expressed in the PT and ECs. Although circadian and melatonin-dependent control of TSH appears to link the circadian clock and the photoperiodic response in mammals, how this circadian clock measure daylength remains to be clarified.


► Many organisms measure daylength to adapt to seasonal environmental changes.
► Changes in daylength are measured by the circadian clock.
► Pars tuberalis TSH induces hypothalamic Dio2 in both long/short day breeders.
► Dio2 activates hypothalamic thyroid hormone and regulates seasonal reproduction.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Molecular and Cellular Endocrinology - Volume 349, Issue 1, 5 February 2012, Pages 76–81
نویسندگان
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