Transforming growth factor β mRNA and protein expression in the ovary of the chicken embryo

Research Progress on MicroRNAs Involved in the Regulation of Chicken Diseases

MicroRNAs (miRNAs) are small, non-coding RNA molecules that inhibit protein translation from target mRNAs. Accumulating evidence suggests that miRNAs can regulate a broad range of biological pathways, including cell differentiation, apoptosis, and carcinogenesis. With the development of miRNAs, the investigation of miRNA functions has emerged as a hot research field. Due to the intensive farming in recent decades, chickens are easily influenced by various pathogen transmissions, and this has resulted in large economic losses. Recent reports have shown that miRNAs can play critical roles in the regulation of chicken diseases. Therefore, the aim of this review is to briefly discuss the current knowledge regarding the effects of miRNAs on chickens suffering from common viral diseases, mycoplasmosis, necrotic enteritis, and ovarian tumors. Additionally, the detailed targets of miRNAs and their possible functions are also summarized. This review intends to highlight the key role of miRNAs in regard to chickens and presents the possibility of improving chicken disease resistance through the regulation of miRNAs.

Various LED Wavelengths Affected Myofiber Development and Satellite Cell Proliferation of Chick Embryos via the IGF-1 Signaling Pathway

An effect of monochromatic light illumination on muscle mass has been discovered in chickens; however, its effect on the development of embryonic muscle remains unclear. Our previous studies demonstrated that monochromatic green light promoted satellite cell proliferation and muscle growth in posthatching broilers. In this study, we investigated the effects and mechanisms of monochromatic light exposure on muscle development in late embryogenesis. Seven hundred and fifty fertile broiler eggs were randomly assigned to blue (B-group), green (G-group), red (R-group), white (W-group) lights or darkness (D-group) throughout the incubation period. The muscle weight and fiber size were highest in the G-group compared to the other groups during embryonic days (E) 17 to E20. The proliferation of satellite cells isolated from the G-group was highest, and in vivo green light remarkably increased the number of proliferating cell nuclear antigen (PCNA)-positive cells in skeletal muscle. Meanwhile, plasma IGF-1 was higher (15.5-16.2%) in the G-group than that in D- and R-groups, and the satellite cells isolated from the G-group had a more sensitive response to IGF-1. These findings demonstrate green monochromatic photobiomodulation promoted the muscle growth and satellite cell proliferation was related to the IGF-1 signaling pathway in late embryogenesis.

In ovo exposure to monochromatic lights affect posthatch muscle growth and satellite cell proliferation of chicks: role of IGF-1

To study the role of IGF-1 on stimulation with monochromatic light during incubation altering posthatch muscle growth, chicken embryos were exposed to blue light, green light, red light, white light or darkness throughout embryonic period and then were raised in white light conditions upon hatching. Comparing with the other treatment groups, the chicks in green light group had heavier hatching weights, higher muscle indexes and larger muscle fibers. Both in vivo and in vitro studies showed that the number and proliferative activity of satellite cells in green light group were the highest. Plasma IGF-1 level and skeletal muscle IGF-1R mRNA level were higher in green light group. Moreover, exogenous IGF-1 increased the proliferative activity of satellite cell in a dose-dependent fashion. These results suggest that stimulation with monochromatic green light during incubation promoted posthatch muscle growth and satellite cell proliferation of chicks through IGF-1 signaling.