title: Acute downregulation of Type II and Type III iodothyronine deiodinases by photoperiod in peripubertal male and female Siberian hamsters.
abstract: Availability of the thyroid hormone triiodothyronine (T3) in the mediobasal hypothalamus plays a central role in seasonal reproductive responses to photoperiod. Across many vertebrates, Type 2 iodothyronine deiodinase (DIO2) is elevated under reproductively stimulatory long days (LD) and synthesizes the conversion of thyroxine to T3; Type 3 iodothyronine deiodinase (DIO3) reduces T3 production and signaling, and is upregulated under reproductively-inhibitory short days (SD). In Siberian hamsters, regulation of hypothalamic T3 is dominated by dio3 expression, whereas dio2 expression is less-consistently affected by photoperiod. In adult hamsters, changes in deiodinase mRNA expression typically require several weeks to manifest, but it is not known whether or how quickly these mechanisms are engaged during the rapid responses to photoperiod observed in young, peri-pubertal hamsters. This experiment tested the hypotheses that (1) deiodinase responses to photoperiod are accelerated in juvenile hamsters and (2) photoperiodic downregulation of deiodinase expression occurs more rapidly than upregulation. Hypothalamic dio2 and dio3 mRNA expression was quantified in male and female Siberian hamsters that were weaned on postnatal day 18 (PND 18) into SD or remained in their natal LD, and on PND 31 were exposed to a single long or short day. In SD males and females, a single long day inhibited dio3 mRNA expression, but did not increase dio2 mRNA. In LD males, a single short day rapidly inhibited dio2 mRNA expression, but did not stimulate expression of dio3 mRNA. Downregulation of dio2 and dio3 mRNAs precedes gonadotrophin responses to day length. Rapid photoperiodic inhibition of deiodinase mRNAs may initiate changes in thyroid hormone signaling in advance of longer-term, melatonin-dependent, responses.
authors.affiliation: Department of Psychology, University of Chicago, Chicago, IL 60637, USA. Electronic address: august@uchicago.edu.
authors.forename: August
authors.initials: A
authors.lastname: Kampf-Lassin
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Prendergast
mesh_terms: D000818:Animals; D006224:Cricetinae; D005260:Female; D007453:Iodide Peroxidase / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008550:Melatonin / Q000378:metabolism; D017111:Phodopus; D017440:Photoperiod
chemical_list: D007453:Iodide Peroxidase; D008550:Melatonin
keywords: Reproduction; Seasonality; Thyroid; dio2; dio3
references.citation: Endocrinology. 2013 Feb;154(2):831-41
references.pmid: 23295738
references.citation: Endocrinology. 1980 Jan;106(1):231-6
references.pmid: 7349955
references.citation: J Neuroendocrinol. 2009 Dec;21(12):1007-14
references.pmid: 19840238
references.citation: Science. 1965 Jun 18;148(3677):1609-11
references.pmid: 14287606
references.citation: Am J Physiol Regul Integr Comp Physiol. 2013 Apr 15;304(8):R628-35
references.pmid: 23408031
references.citation: J Comp Physiol A. 1994 Apr;174(4):469-84
references.pmid: 8182563
references.citation: Am J Physiol Regul Integr Comp Physiol. 2007 Jan;292(1):R568-72
references.pmid: 17197645
references.citation: Biol Reprod. 1985 Feb;32(1):1-26
references.pmid: 3882162
references.citation: Neuroendocrinology. 1986;43(3):317-21
references.pmid: 3736780
references.citation: J Neuroendocrinol. 2012 Jul;24(7):991-8
references.pmid: 22487258
references.citation: J Biol Rhythms. 2001 Aug;16(4):283-301
references.pmid: 11506375
references.citation: Endocrinology. 1984 Feb;114(2):664-70
references.pmid: 6418534
references.citation: Physiol Behav. 1992 Aug;52(2):267-70
references.pmid: 1523252
references.citation: Endocrinology. 2005 Jun;146(6):2551-4
references.pmid: 15746251
references.citation: Nature. 2003 Nov 13;426(6963):178-81
references.pmid: 14614506
references.citation: Neurosci Lett. 1995 Sep 22;198(1):65-7
references.pmid: 8570099
references.citation: Endocrinology. 2013 May;154(5):1813-9
references.pmid: 23525217
references.citation: Endocrinology. 1982 Aug;111(2):488-92
references.pmid: 7094883
references.citation: Brain Res. 1984 Mar 5;294(2):333-9
references.pmid: 6704731
references.citation: Experientia. 1985 May 15;41(5):651-2
references.pmid: 3996540
references.citation: J Biol Rhythms. 1997 Apr;12(2):122-35
references.pmid: 9090566
references.citation: Endocrinology. 2004 Apr;145(4):1546-9
references.pmid: 14726436
references.citation: Endocrinology. 2007 Sep;148(9):4385-92
references.pmid: 17540726
references.citation: Am J Physiol. 1996 Oct;271(4 Pt 2):R1041-6
references.pmid: 8897998
references.citation: Am J Physiol. 1982 Jan;242(1):R44-50
references.pmid: 7058930
references.citation: Endocrinology. 1980 Nov;107(5):1525-9
references.pmid: 7428680
references.citation: Am J Physiol Regul Integr Comp Physiol. 2007 Jun;292(6):R2368-72
references.pmid: 17272662
references.citation: Thyroid. 2005 Aug;15(8):883-97
references.pmid: 16131331
references.citation: Neuroendocrinology. 1984 Mar;38(3):226-31
references.pmid: 6538940
references.citation: Endocrinology. 2007 Aug;148(8):3608-17
references.pmid: 17478556
references.citation: J Neuroendocrinol. 2010 Jan;22(1):43-50
references.pmid: 19912473
references.citation: Biol Reprod. 1993 Sep;49(3):555-60
references.pmid: 8399850
references.citation: J Biol Rhythms. 1994 Spring;9(1):71-81
references.pmid: 7949308
references.citation: Endocrinology. 1984 Jun;114(6):2074-83
references.pmid: 6426935
references.citation: Biol Reprod. 1986 Sep;35(2):327-35
references.pmid: 3094595
references.citation: Am J Physiol. 1988 Nov;255(5 Pt 2):R812-22
references.pmid: 3189592
references.citation: Proc Natl Acad Sci U S A. 2002 Dec 10;99(25):16291-6
references.pmid: 12456888
references.citation: Endocrinology. 1980 Oct;107(4):1061-4
references.pmid: 7408759