RT Journal Article T1 Is there direct photoentrainment in the goldfish liver? Wavelength-dependent regulation of clock genes and investigation of the Opsin 7 family A1 Saiz Aparicio, Nuria A1 Alonso Gómez, Ángel Luis A1 Bustamante-Martínez, Sergio A1 Pedro Ormeño, Nuria De A1 Delgado Saavedra, María Jesús A1 Isorna Alonso, Esther AB Widespread direct photoentrainment in zebrafish peripheral tissues is linked to diverse non-visual opsins. To explore whether this broadly distributed photosensitivity is specific to zebrafish or is a general teleost feature, we investigated hepatic photosynchronization in goldfish. First, we focused on the opsin 7 family (OPN7, a key peripheral novel opsin in zebrafish), investigating its presence in the goldfish liver. Subsequently, we studied whether light can directly entrain the goldfish liver and retina clocks. Silico analysis revealed seven OPN7 paralogs from four gene families, suggesting expansion through whole-genome and tandem duplications. The paralogs of families OPN7a, OPN7b, and OPN7d were mainly localized in neural tissues, while OPN7c paralogs were more abundant in peripheral tissues-including the liver-suggesting divergent roles. Light (independently of the wavelength employed) directly induced the per2a clock gene in the retina both in vivo and in vitro, confirming expected photoentrainment. However, in the liver, photoinduction of per1a and cry1a only occurred in vivo, not in vitro. These results suggest an indirect light-entrainment mechanism of the goldfish hepatic clock, possibly mediated by other oscillators or photosensitive organs. Our findings challenge the assumption of widespread direct photosensitivity in the peripheral tissues of teleosts. Further research is needed to understand the role of tissue-specific photoentrainment and non-visual opsins in diverse teleost species. PB Springer Nature SN 0340-7594 YR 2024 FD 2024-10-29 LK https://hdl.handle.net/20.500.14352/109807 UL https://hdl.handle.net/20.500.14352/109807 LA eng NO Saiz N, Alonso-Gómez ÁL, Bustamante-Martínez S, de Pedro N, Delgado MJ, Isorna E. Is there direct photoentrainment in the goldfish liver? Wavelength-dependent regulation of clock genes and investigation of the opsin 7 family. J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2024 Oct 28. doi: 10.1007/s00359-024-01722-5. Epub ahead of print. PMID: 39466374. NO -Online access to this article has been shared by the author(s) via Springer Nature Sharedit: https://rdcu.be/dYrsY-Datos del artículo en https://docta.ucm.es/entities/publication/c03d16ac-21ff-45bf-95b0-ad05a250d63d NO Ministerio de Ciencia e Innovación (España) NO Universidad Complutense de Madrid DS Docta Complutense RD 6 abr 2025