The Wnt/β-catenin signaling pathway is involved in regulating feather growth of embryonic chicks

Abstract

Avian feathers have robust growth and regeneration capability and serve as a useful model for decoding hair morphogenesis and other developmental studies. However, the molecular signaling involved in regulating the development of feather follicles is unclear. The purpose of this study was to investigate the role of the Wnt/β-catenin pathway in regulating feather morphogenesis in embryonic chicks through in ovo injection of different doses of Dickkopf-1 (DKK1, a specific inhibitor of the target of the Wnt/β-catenin pathway). A total of 120 fertilized embryo eggs were randomly divided into 4 treatments, including a noninjection group (control group) and groups injected with 100 μL of phosphate-buffered saline (PBS)/egg (PBS control group), 100 μL of PBS/egg containing 600-ng DKK1/egg (600-ng DKK1 group), and 100-μL PBS/egg containing 1,200-ng DKK1/egg (1,200-ng DKK1 group). Feathers and skin tissues were sampled on embryonic (E) day 15 and the day of hatching to examine the feather mass, diameter and density of feather follicles, and the protein expression of the Wnt/β-catenin pathway. The results showed that, compared with CON and PBS treatment, the injection of DKK1 into the yolk sac of chick embryos had no significant effect on the hatching rate and embryo weight ( P > 0.05), while it significantly decreased the relative mass of feathers in the whole body ( P < 0.05). The high dose of DKK1 (1,200-ng DKK1/egg) decreased the relative mass of feathers on the back, chest, belly, neck, wings, head, and legs, which was more obvious than that in the 600-ng DKK1 group, which presented a dose-dependent effect. In addition, DKK1 injection significantly downregulated the protein expression levels of β-catenin, transcription factor 4, Cyclin D1, and c-Myc ( P < 0.05). The immunofluorescence result of β-catenin was consistent with the Western blotting assay results. Altogether, these observations suggested that the Wnt/β-catenin signaling pathway is involved in regulating feather follicle development and feather growth during the embryonic development of chicks.

The in ovo injection of methionine improves intestinal cell proliferation and differentiation in chick embryos by activating the JAK2/STAT3 signaling pathway

“…Proteins were isolated from jejunum samples and analyzed as described previously ( Xie et al., 2020 ). Total protein was extracted from the intestinal tissues using radioimmunoprecipitation assay lysis buffer, and the protein concentration in the homogenates was determined using the BCA protein assay kit (Thermo Fisher Scientific, Rockford, Illinois, USA).…”

In ovo injection of CHIR-99021 promotes feather follicles development via activating Wnt/β-catenin signaling pathway during chick embryonic period

“… Zhou et al (2018) reported that activation of the Wnt/β-catenin signaling pathway regulates hair growth and cycle transition in mouse model. While injecting Dickkopf-related protein 1 ( DKK1 ), a secreted antagonist of the canonical Wnt signaling pathway, into chick embryos at E9 inhibits feather follicles development and feather growth via inhibiting the Wnt/β-catenin signaling pathway ( Xie et al, 2020 ).…”

“…The yolk sac is an extra-embryonic component surrounding the yolk and responses for nutrient absorption, digestion and transportation during incubation of the avian embryo, as well as during early term of mammalian embryonic development ( Yadgary et al, 2014 ). Yolk sac plays an important role during embryonic development, yolk sac feeding, or injection is exhibiting positive effects on embryonic development modulation ( Slawinska et al 2016 ; Chen et al 2020 ; Xie et al 2020 ). Previous studies have illustrated that CHIR-99021 has ability to influence morphogenesis and development of various organs and tissues including fat ( Chen et al, 2018 ), liver ( Russell and Monga, 2018 ; Perugorria et al, 2019 ), tooth ( Järvinen et al, 2018 ), lung ( Stewart 2014 ), skeletal muscle ( Girardi and Le Grand, 2018 ), and stomach ( Barker et al, 2010 ) via regulating the Wnt signaling pathway, besides, transcription factors and enzymes have been identified as key mediators participating in the processing.…”

“…Advantageously, CHIR-99021 changes epigenetic expression regulation genes and long intergenic non-coding RNA ( Wu et al 2013 ), while it does not produce significant concomitant toxicity ( Wu et al 2013 ; Naujok et al 2014 ). Moreover, in ovo injection is an efficient way to intervene embryonic development ( Slawinska et al 2016 ; Chen et al 2020 ; Xie et al 2020 ).…”

DL-methionine and DL-methionyl-DL-methionine increase intestinal development and activate Wnt/β-catenin signaling activity in domestic pigeons (Columba livia)

“…Proteins were isolated from jejunum samples and analyzed as described previously ( Xie et al., 2020 ). The expression levels were quantified using ImageJ software (version 1.8.0 112, National Institute of Health, Bethesda, MD).…”