Identification of hypothalamic genes in associating with food intake during incubation behavior in domestic chicken

Abstract

The molecular mechanism underlying in the onset and maintenance of incubation behavior are not fully understood, and it is still unknown the reason why White Leghorn, a layer strain, hens never display incubation behavior. Therefore, to explore specific hypothalamic genes regulating incubation behavior, cap analysis of gene expression (CAGE) were applied to comparison between incubating Silkie and laying White Leghorn hens. In addition, mRNA expression of some differentially expressed genes (DEGs) and melanocortinergic appetite genes including agouti‐related peptide (AgRP) and pro‐opiomelanocortin (POMC) was also analyzed on Silkie hens under natural anorexia and starvation. The CAGE identified 217 hypothalamic DEGs in incubating Silkie hens, and that of two, transthyretin (TTR) and prolactin‐releasing peptide (PrRP), suggested as appetite gene, were markedly up– and down‐regulated in incubating hens, respectively. In addition, AgRP and POMC expression also increased in incubating bird. mRNA expression of TTR, PrRP, and appetite genes were not differed significantly by starvation, although TTR mRNA expression was relatively high in fasting hens. Consequently, transcriptome by CAGE identified a number of hypothalamic genes differentially expressed by incubation behavior in Silkie hens. Of these, it is suggested that TTR and PrRP may, at least in part, be related to adaptation to natural anorexia in incubating Silkie chickens.

Should I Lay or Should I Grow: Photoperiodic Versus Metabolic Cues in Chickens

“…In the presence of elevated insulin concentrations, POMC and CART expression has been reported to elevate, while the expression of NPY is inhibited ( Porte et al, 2002 ; Honda et al, 2007 ; Shiraishi et al, 2008 ). This is of particular interest as POMC has been found to increase in incubating Silkie hens, a period known to be associated with high PRL levels, compared to their laying counterparts ( Sharp et al, 1989 ; Dawson, 2008 ; Takeda and Ohkubo, 2019 ). As AdipoR1 is upregulated in the presence of PRL, it would be expected that adiponectin levels would elevate during this period, yet concentrations have been observed to decline through to the end of production in turkey hens ( Diot et al, 2015 ), requiring further investigation to determine its role throughout a production cycle.…”

Hypothalamic transcriptome profile from laying period to incubation period of Changshun green-shell laying hens

“…In avians, the analysis of mRNA expression pattern showed that POMC was mainly expressed in the pituitary, brain, hypothalamus ( Gerets et al, 2000 ; Liu et al, 2020 ). Hypothalamic POMC is identified to be associated with food intake in chickens ( Takeda and Ohkubo, 2019 ). Increasing evidence has indicated the important role of POMC in regulating the avian reproduction, including incubation behavior.…”

“…Meanwhile, increased POMC in hypothalamus can cause appetite reduction of incubating avians, which is considered to be a prerequisite to initiate incubation. Transcriptome analysis further revealed that POMC seemingly occupied a key position in the regulatory network of incubating avian hypothalamus ( Liu et al, 2018 ; Takeda and Ohkubo, 2019 ). Consistently, POMC were observed to increase in incubating Changshun hens.…”

“…The down-regulated hypocretin ( HCRT ) and up-regulated pro-opiomelanocortin ( POMC ) in the hypothalamus of incubating geese may be responsible for appetite reduction ( Liu et al, 2018 ). Similarly, transcriptome by cap analysis of gene expression identified 217 hypothalamic DEGs including appetite-related transthyretin ( TTR ) and prolactin-releasing peptide ( PrRP ) in incubating Silkie hens ( Takeda and Ohkubo, 2019 ). In tree swallows ( Tachycineta bicolor ), 188 DEGs were identified in hypothalamus between territory establishment and incubation ( Bentz et al, 2019 ).…”