Increased food intake stimulates GnRH-I, glycoprotein hormone alpha-subunit and follistatin mRNAs, and ovarian follicular numbers in laying broiler breeder hens.
The aim of this study, in 36 week-old laying broiler breeder hens, was to establish the effects on reproductive neuroendocrine gene expression of reinstating ad libitum food intake after moderate food restriction from 2 weeks of age. Seven days of ad libitum feeding increased the number of large pre-ovulatory ovarian follicles and gonadotropin releasing hormone-I (GnRH-I), glycoprotein hormone alpha-subunit and follistatin mRNAs. Plasma luteinizing hormone (LH) was also increased while plasma follicle-stimulating hormone (FSH) was reduced. There were no associated changes in gonadotropin inhibitory hormone (GnIH), LHbeta or FSHbeta mRNAs. The mechanism underlying the increased expression of alpha-subunit and follistatin mRNAs was investigated in vitro by incubating pituitary fragments with pulses of GnRH-I. This treatment increased alpha-subunit and follistatin mRNAs but did not affect gonadotropin beta-subunit mRNAs. It is concluded that lifting food restriction in laying hens increases GnRH-I gene transcription or mRNA stability which may be a consequence, or cause of increased GnRH-I release. This, in turn, increases glycoprotein hormone alpha-subunit and follistatin mRNAs, resulting in increased plasma LH and decreased plasma FSH, respectively.
Ciccone
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NA
Division of Genetics and Genomics, Roslin Institute, Roslin, Midlothian EH25 9PS, United Kingdom.
Dunn
I C
IC
Sharp
P J
PJ
D000818:Animals; D002645:Chickens / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004435:Eating / Q000502:physiology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D038681:Follistatin / Q000096:biosynthesis* / Q000235:genetics; D015292:Glycoprotein Hormones, alpha Subunit / Q000096:biosynthesis* / Q000235:genetics; D006023:Glycoproteins / Q000235:genetics / Q000502:physiology; D007987:Gonadotropin-Releasing Hormone / Q000096:biosynthesis* / Q000235:genetics; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D006080:Ovarian Follicle / Q000378:metabolism / Q000502:physiology*; D010902:Pituitary Gland / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011897:Random Allocation; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary
D038681:Follistatin; D015292:Glycoprotein Hormones, alpha Subunit; D006023:Glycoproteins; D012333:RNA, Messenger; C014995:gonadotropin inhibitor; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone