Daily rhythms of expression in reproductive genes along the brain-pituitary-gonad axis and liver of zebrafish
| Autor: | Mairi Cowan, Francisco Javier Sánchez-Vázquez, José Fernando López-Olmeda, José Antonio Muñoz-Cueto, Juan Fernando Paredes |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Male medicine.medical_specialty Gonad Physiology media_common.quotation_subject GNRHR2 030209 endocrinology & metabolism Biology Biochemistry 03 medical and health sciences 0302 clinical medicine Internal medicine medicine Zeitgeber Endocrine system Rhythmic process Animals Gonads Molecular Biology Zebrafish media_common Reproductive success Reproduction Brain biology.organism_classification Circadian Rhythm 030104 developmental biology medicine.anatomical_structure Endocrinology Liver Pituitary Gland Female |
| Zdroj: | Comparative biochemistry and physiology. Part A, Molecularintegrative physiology. 231 |
| ISSN: | 1531-4332 |
| Popis: | The brain-pituitary-gonadal (BPG) axis regulates the activation of the endocrine machinery that triggers reproduction, which is a typical rhythmic process. In this research we focused on investigating the daily expression rhythms of the key reproductive genes involved in the BPG axis and the liver of zebrafish. To this end, male and female zebrafish were subjected to a stimulating photoperiod with a 14 h light:10 h dark cycle. Brain, pituitary and gonads, as well as female liver samples, were taken every 4 h during a 24 h cycle. The results revealed that most genes exhibited statistically significant daily rhythms. Most of the brain reproductive genes (gnrh2, gnrh3, kiss1, kiss2 and gnrhr3) displayed a daily rhythm of expression with a nocturnal acrophase (between Zeitgeber Time [ZT] 14:34 h and ZT18:34 h, lights off at ZT = 14 h). The male kiss2 gene presented neither significant rhythms nor daily variations, while the male gnrh3 and female kiss2 genes exhibited diurnal peaks of expression at ZT06:34 h and ZT04:34 h, respectively. In contrast, the pituitary genes (fshβ, lhβ, gnrhr2) showed daily rhythms of expression with an acrophase during the light phase (between ZT02:10 h and ZT10:35 h). The female gnrhr3 gene exhibited neither significant rhythms nor daily variations. The male gnrhr3 gene presented a nocturnal acrophase (ZT14:32 h). The gonad genes (star, cyp17a1, 20βhsd, lhr, fshr, cyp19a1a, foxl2, amh, dmrt1 and 11βhsd) revealed statistically significant daily rhythms with nocturnal acrophases, except for female cyp17a1a (ZT06:21 h) and 20βhsd (ZT05:19 h). Lastly, the female liver genes presented daily rhythms with a maximum peak of expression around the transition phase from darkness to light (ZT01:00 h for erα and at ZT23:09 h for vtg2). These findings are consistent with the daily reproduction rhythms displayed by zebrafish, which are timed by the reproductive axis. Considering that reproductive success is critical for survival of the species, the knowledge of the rhythms of the endocrine BPG machinery provides useful information to understand the reproduction process and to establish optimal protocols and conditions for reproductive treatments. |
| Databáze: | OpenAIRE |
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