Expression of cocaine- and amphetamine-regulated transcript (CART) in hen ovary

Abstract

BackgroundCocaine- and amphetamine-regulated transcript (CART), discovered initially by via differential display RT-PCR analysis of brains of rats administered cocaine, is expressed mainly in central nervous system or neuronal origin cells, and is involved in a wide range of behaviors, such as regulation of food intake, energy homeostasis, and reproduction. The hens egg-laying rate mainly depends on the developmental status of follicles, expression of CART have not been identified from hen follicles, the regulatory mechanisms of CART biological activities are still unknown. The objective of this study was to characterize the mRNA expression of CART in hen follicular granulosa cells and determine CART peptide localization and regulatory role during follicular development.MethodsSmall white follicles (1–2 mm in diameter) were treated for RNA isolation; Small white follicles (1–2 mm in diameter) and large white follicles (4–6 mm in diameter) were treated for immunohistochemical localization and large white follicles (4–6 mm in diameter), small yellow follicles (6–8 mm in diameter), large yellow follicles (9–12 mm in diameter), mature follicles (F5, F4, F3, F2, F1, >12 mm in diameter) were treated for RNA isolation and Real time PCR.ResultsThe results showed that full length of the CDS of hen CART was 336 bp encoding a 111 amino acid polypeptide. In the hen ovary, CART peptide was primarily localized to the theca layer, but not all, the oocyte and granulosa layer, with diffused, weaker staining than relative to the theca cell layer. Further, amount of CART mRNA was more (P < 0.05) in granulosa cells of 6–8 mm follicles compared with that in granulosa cells of other follicles. However, CART mRNA amount was greater in theca cells of 4–6 mm follicles relative to follicles of other sizes (P < 0.05).ConclusionsResults suggest that CART could play a potential role in developmental regulation of chicken follicles.

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

“…CART mRNA was initially reported to be primarily present in the hypothalamus and pituitary gland of adult laying hens and its peptide undetectable in the ovary ( Cai et al, 2015 ). Since, it has been established that CART mRNA is present within subsets of follicles with the highest expression in the theca layer of large white follicles compared to the pre-ovulatory follicles ( Li et al, 2017 ), ultimately suggesting that CART does in fact have a role, which has yet to be determined in avian species. When considering mammalian literature, CART has been identified to be under the control of LEP ( Douglass, 1995 ; Gautvik et al, 1996 ; Kristensen et al, 1998 ; Rogge et al, 2008 ), be responsible for regulating the stress response ( Koylu et al, 2006 ), the energy balance ( Kristensen et al, 1998 ; Rogge et al, 2008 ), and bone remodelling ( Elefteriou et al, 2005 ) in rodents, as well as ovarian follicle development in bovine ( Kobayashi et al, 2004 ; Sen et al, 2007 ).…”

Lipoamide Alleviates Oxidized Fish Oil-Induced Host Inflammatory Response and Oxidative Damage in the Oviduct of Laying Hens

“…Egg production is the main factor limiting the efficiency of egg utilization during the late egg-laying period, while ovary and oviduct aging is the main reason for the decline in egg production ( 31 , 32 ). Oxidative stress is deemed to be one of the dominant mechanisms underlying ovarian and oviduct aging ( 30 ).…”

“…The amount of estrogen secretion is related to follicle development and maturation. Besides, it is well known that the egg-laying rate of hens depends mainly on the follicle formation and ovulation process ( 31 ), the number of follicles often represents egg production. In a comparative transcriptomic analysis of duck ovaries with different egg-laying rates, 25 differential genes associated with follicle development were identified.…”

Ingestive Peptides – An Emerging Tool for Diagnostics and Therapeutics: A Review

“…So, CART maybe not a main negative regulatory factor during porcine follicular development, which is different from the single fetal animals (Li et al 2018). CART plays a role in the developmental regulation of chicken follicles (Li et al 2017a). CART can inhibit the production of estradiol in the bovine granulosa cell (Selvaraju et al 2013).…”