ZFIN ID: ZDB-PUB-170811-5
Clock genes expression and locomotor activity are altered along the light-dark cycle in transgenic zebrafish overexpressing growth hormone
Cruz, B.P., Brongar, L.F., Popiolek, P., Gonçalvez, B.S.B., Figueiredo, M.A., Amaral, I.P.G., Da Rosa, V.S., Nery, L.E.M., Marins, L.F.
Date: 2017
Source: Transgenic Research   26(6): 739-752 (Journal)
Registered Authors: Figueiredo, Marcio de Azevedo, Marins, Luis Fernando
Keywords: Circadian system, Gene expression, Growth-hormone, Locomotor activity, Zebrafish
MeSH Terms:
  • ARNTL Transcription Factors/genetics
  • Animals
  • Animals, Genetically Modified*
  • DNA-Binding Proteins/genetics
  • Female
  • Gene Expression Regulation
  • Growth Hormone/genetics*
  • Locomotion/genetics
  • Male
  • Muscle, Skeletal/physiology
  • Photoperiod
  • Zebrafish/genetics*
  • Zebrafish/physiology
  • Zebrafish Proteins/genetics*
PubMed: 28795260 Full text @ Transgenic. Res.
In the present work it was demonstrated that transgenic Danio rerio overexpressing growth hormone (GH-transgenic) present either altered gene expression at a determined time point, or different expression pattern along the LD cycle, when compared with non-transgenic (NT) animals, in the positive and negative loops of the circadian system. Gene expression of clock paralogs was reduced in GH fish at the beginning of the dark phase, leading to diminished expression amplitude along the LD cycle. Furthermore, although no differences were observed between NT and GH animals for bmal1a and cry2b expression at each time point, only GH fish presented amplitude along the LD cycle. Also, the locomotor activity behavior was evaluated for both groups. GH-transgenic animals presented higher locomotor activity along the whole LD cycle when compared with NT animals. These data suggest that alterations in the gene expression patterns along the LD cycle of the positive and negative loops of the circadian system, could lead to altered locomotor activity behavior in GH-transgenic fish, and GH overexpression could be responsible for these alterations, either affecting the pathways involved in the expression of genes from the circadian system or altering the metabolism.