Brain area‐specific diurnal and photic regulation of val‐opsinA and val‐opsinB genes in the zebrafish. (17th March 2015)

• Record Type: Journal Article
• Authors: Hang, Chong Yee; Kitahashi, Takashi; Parhar, Ishwar S.
• Is Part Of: Journal of neurochemistry. Volume 133:Number 4(2015:May)
• Page Start: 501
• Page End: 510
• Publication Date: 2015-03-17
• Subjects: Neurochemistry -- Periodicals; 616.8042
• DOI: 10.1111/jnc.13084
• Languages: English
• ISSNs: 0022-3042

Abstract

<abstract abstract-type="main" id="jnc13084-abs-0001"> <title>Abstract</title> <p>Zebrafish possess two isoforms of vertebrate ancient <italic>long</italic> (VAL)‐opsin, <italic>val‐opsinA</italic> (<italic>valopa</italic>) and <italic>val‐opsinB</italic> (<italic>valopb</italic>), which probably mediate non‐visual responses to light. To understand the diurnal and light‐sensitive regulation of the <italic>valop</italic> genes in different cell groups, the current study used real‐time quantitative PCR to examine the diurnal changes of <italic>valopa</italic> and <italic>b</italic> mRNA levels in different brain areas of adult male zebrafish. Furthermore, effects of the extended exposure to light or dark condition, luminous levels and the treatment with a melatonin receptor agonist or antagonist on <italic>valop</italic> transcription were examined. In the thalamus, <italic>valop</italic> mRNA levels showed significant diurnal changes; <italic>valopa</italic> peaked in the evening, while <italic>valopb</italic> peaked in the morning. The diurnal change of <italic>valopa</italic> mRNA levels occurred independent of light conditions, whereas that of <italic>valopb</italic> mRNA levels were regulated by light. A melatonin receptor agonist or antagonist did not affect the changes of <italic>valop</italic> mRNA levels. In contrast, the midbrain and hindbrain showed arrhythmic <italic>valop</italic> mRNA levels under light and dark cycles. The differential diurnal regulation of the <italic>valopa</italic> and <italic>b</italic> genes in the thalamus and the arrhythmic expression in the midbrain and hindbrain suggest involvement of deep brain VAL‐opsin in time‐ and light‐dependent physiology. <boxed-text content-type="graphic" id="jnc13084-blkfxd-1001" position="anchor" orientation="portrait"><graphic position="anchor" mimetype="image" xlink:href="ark:/27927/pgjj8xjd3v" orientation="portrait" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /></boxed-text> We show diurnal expression changes of vertebrate ancient <italic>long</italic> (VAL) opsin genes (<italic>valopa</italic> and <italic>valopb</italic>), depending on brain area, time of day and light condition, in the adult male zebrafish. Differential regulation of the <italic>valop</italic> genes in the thalamus and arrhythmic expression in the midbrain and hindbrain suggest their involvement in time‐ and light‐dependent physiology to adjust to environmental changes.</p> </abstract>