Season-Related Differences in the Biosynthetic Activity of the Neonatal Chicken Pineal Gland
Aneta Piesiewicz*, Podobas Ewa, Kędzierska Urszula, Joachimiak Ewa, Markowska Magdalena, Majewski Pawel, Skwarlo-Sonta Krystyna
Identifiers and Pagination:Year: 2010
First Page: 134
Last Page: 140
Publisher Id: TOOENIJ-3-134
Article History:Received Date: 03/03/2010
Revision Received Date: 09/06/2010
Acceptance Date: 20/06/2010
Electronic publication date: 13/10/2010
Collection year: 2010
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: (https://creativecommons.org/licenses/by/4.0/legalcode). This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Influence of the season of hatch on the functional characteristics of the pineal gland was examined in neonatal Hi-Line male chickens. The pineal glands from 2-day-old birds hatched in summer and winter, and kept from the day of hatch in artificial lighting conditions (12L:12D), were isolated under dim red light in the middle of the day or night. The pineal glands were analyzed to characterize their melatonin biosynthetic activity: (1) expression of the Arylalkylamine– N–acetyltransferase and Hydroxyindole-O-methyltransferase genes, encoding the final two enzymes of the melatonin biosynthesis pathway; (2) the activity of AA-NAT and HIOMT; and (3) the content of the main substrates of this pathway, tryptophan (TRY) and serotonin (5-HT). Daily changes in pineal AA-NAT activity were observed in chickens hatched in both seasons, with a more pronounced nocturnal increase in summer. In contrast, the level of Aa-nat gene expression, although exhibited the same nocturnal/diurnal pattern in both seasons, was much lower in the summer. The activity of HIOMT was season- and daytime-independent. In “winter” chickens the pineal content of 5-HT was low and stable, while in “summer” birds it was correlated with levels of AA-NAT activity and Aa-nat gene expression. TRY content was very high and exhibited neither daily nor seasonal changes. The pineal gland of newly hatched chickens kept in controlled 12L:12D conditions exhibits daily variations in melatonin biosynthetic activity influenced by the season. This suggests a maternal effect on the perinatal/postnatal development of the circadian clock residing in the chicken pineal gland.