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

Xuejing Yu,Lihua Lyu,Wenzhong Liu,Jianbo Yao,Xiaolei Yao,Jianshan Xie,Zhiwei Zhu,Pengfei Li

doi:10.1186/s40659-017-0123-x

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.

Highlights

Cocaine- 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
Cloning and sequence analysis of hens CART CDS A complete hen CART CDS was obtained by PCR, 336 bp in length
In order to examine the relationship of hen CART and its counterparts in various other organisms, a phylogenetic tree of CART peptides from hen and other species was constructed (Fig. 2)

Summary

Introduction

Cocaine- 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 reproductive performance of hens, especially the egg-laying rate depends mainly on the developmental status of follicles, Follicular development process has the priority features. Granulosa cells begin to proliferate, and theca gradually forms in connective tissue outside the basement membrane, and central egg yolk accumulates. In these small follicles, only a single follicle per day is selected from the cohort of follicles of 6–8 mm in diameter into the pre-ovulatory hierarchy to begin rapid growth and final differentiation. Atresia in follicles >1 mm diameter was invariably of the bursting

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