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

Mitochondrial PGAM5 modulates methionine metabolism and feather follicle development by targeting Wnt/β-catenin signaling pathway in broiler chickens

BACKGROUND

Poor feather growth not only affects the appearance of the organism but also decreases the feed efficiency. Methionine (Met) is an essential amino acid required for feather follicle development; yet the exact mechanism involved remains insufficiently understood.

METHODS

A total of 180 1-day-old broilers were selected and randomly divided into 3 treatments: control group (0.45% Met), Met-deficiency group (0.25% Met), and Met-rescue group (0.45% Met in the pre-trial period and 0.25% Met in the post-trial period). The experimental period lasted for 56 d, with a pre-trial period of 1-28 d and a post-trial period of 29-56 d. In addition, Met-deficiency and Met-rescue models were constructed in feather follicle epidermal stem cell by controlling the supply of Met in the culture medium.

RESULTS

Dietary Met-deficiency significantly (P < 0.05) reduced the ADG, ADFI and F/G, and inhibited feather follicle development. Met supplementation significantly (P < 0.05) improved growth performance and the feather growth in broilers. Met-rescue may promote feather growth in broilers by activating the Wnt/β-catenin signaling pathway (GSK-3β, CK1, Axin1, β-catenin, Active β-catenin, TCF4, and Cyclin D1). Compared with Met-deficiency group, Met-rescue significantly (P < 0.05) increased the activity of feather follicle epidermal stem cell and mitochondrial membrane potential, activated Wnt/β-catenin signaling pathway, and decreased the content of reactive oxygen species (P < 0.05). CO-IP confirmed that mitochondrial protein PGAM5 interacted with Axin1, the scaffold protein of the disruption complex of the Wnt/β-catenin signaling pathway, and directly mediated Met regulation of Wnt/β-catenin signaling pathway and feather follicle development.

CONCLUSIONS

PGAM5 binding to Axin1 mediates the regulation of Wnt/β-catenin signaling pathway, and promotes feather follicle development and feather growth of broiler chickens through Met supplementation. These results provide theoretical support for the improvement of economic value and production efficiency of broiler chickens.

Dietary fermented mixed ingredient product enhances growth performance and intestinal stem cell-mediated epithelial regeneration through Wnt/β-catenin pathway in layer chicks

This study aimed to investigate the effects of dietary supplements of fermented mixed ingredient product (FMIP) on the growth performance, intestinal health, and immune performance of layer hens during the brooding period. Four hundred eighty healthy one-day-old layer chicks were randomly divided into four groups (six replicates/group, twenty hens/replicate) and were fed with different experimental diets for eight weeks (from day 1 to day 56): (1) Corn-soybean-base diet (CON); (2) Chlortetracycline group (CTC; CON diet supplemented with 0.5g/kg chlortetracycline); (3) 4 % fermented mixed ingredient product (4 % FMIP); (4) 8 % fermented mixed ingredient product (8 % FMIP). The results showed that, compared with the CON group, feeding with CTC, 4 % or 8 % FMIP increased the average daily feed intake (ADFI), average daily gain (ADG), immune organs index, serum IgA, IgM, and IgG levels, as well as the apparent metabolic rates of dry matter, crude protein, crude fiber, and crude ash (P < 0.05). Meanwhile, FMIP supplementation improved jejunal morphology and barrier function, as reflected by increased villus height and transepithelial electrical resistance, decreased DAO activity in serum, and up-regulated Occludin protein expression (P < 0.05). Additionally, FMIP supplementation significantly increased protein expression of the stem cell markers (SOX9 and Lgr5), proliferative cell marker (PCNA), and differentiated absorptive cell marker (Villin) (P < 0.05). The immunofluorescence results were consistent with the above results, and FMIP groups have the same effects as the CTC group. Furthermore, the CTC or 4 % FMIP treatment group resulted in a remarkable increase in Wnt/β-catenin signaling proteins (including β-catenin, TCF4, c-Myc, and Cyclin-D1) compared with the CON group (P < 0.05). In conclusion, dietary supplementation of 4 % FMIP improves growth and immune performance, and promotes the intestinal stem cell expansion of layer chicks through Wnt/β-catenin pathway activation.

Characterization of circRNA expression profiles associated with non-Mendelian inheritance in feather growth of chickens

1. Non-coding RNAs, such as miRNAs, play a crucial role in chicken feather growth rate. However, circular RNA (circRNA) expression profiles in fast- and slow-feathering chickens that follow and do not follow Mendelian inheritance are unclear.2. The circRNA expression profiles was analysed by RNA sequencing of hair follicles of slow-feathering chickens that follow genetic rules and fast-feathering chickens that did not follow genetic rules. Differentially expressed circRNA-miRNA-mRNA competing endogenous RNA (ceRNA) network was then constructed and the key factors and regulation mechanisms controlling feather growth rate were identified.3. The results revealed that 67 circRNAs were significantly differentially expressed in hens, including 22 up-regulated and 45 down-regulated circRNAs in non-Mendelian inheritance-mediated fast-feathering hens compared with Mendelian inheritance-mediated slow-feathering hens. In addition, 16 significantly differentially expressed circRNAs were identified in cockerels, including nine up-regulated and seven down-regulated circRNAs in non-Mendelian inheritance-mediated fast- compared with Mendelian inheritance-mediated slow-feathering cocks. Moreover, circRNA-mediated ceRNA regulation of hair follicle formation was particularly abundant in the Jak-STAT, Wnt and Toll-like receptor signalling pathways. Furthermore, circABI3BP was seen to be a crucial circRNA in regulating feather growth rate, by binding with gga-miR-1649-5p to regulate SSTR2 expression.4. In conclusion, this study analysed circRNA expression profiles in fast- and slow-feathering chickens that follow and do not follow Mendelian inheritance, which laid the foundation for understanding the role of circRNA in chicken feather growth rate.

In ovo injection of AZD6244 suppresses feather follicle development by the inhibition of ERK and Wnt/β-catenin pathways in goose embryos (Anser cygnoides)

1. Feathers are an important product from poultry, and the state of feather growth and development plays an important role in their economic value.2. In total, 120 eggs were selected for immunoblotting and immunolocalisation experiments of ERK and β-catenin proteins in different developmental stages of goose embryos. The ERK protein was highly expressed in the early stage of goose embryo development, while β-catenin protein was highly expressed in the middle stage of embryo development.3. The 120 eggs were divided into four treatment groups, including an uninjected group (BLANK), a group injected with 100 µl of cosolvent (CK), a group injected with 100 µl of AZD6244 containing cosolvent in a dose of 5 mg/kg AZD6244 containing cosolvent (AZD5) and a group injected with 100 µl of AZD6244 containing cosolvent in a dose of 15 mg/kg AZD6244 containing cosolvent (AZD15). The eggs were injected on the ninth day of embryonic development (E9). Samples were collected at E21.5 to observe feather width, feather follicle diameter, ERK and Wnt/β-catenin pathway protein expression.4. The AZD5 and AZD15 doses were within the embryonic safety range compared to the BLANK and CK groups and had no significant effect on the survival rate and weight at the inflection point, but significantly reduced the feather width and feather follicle diameter (p < 0.05). The AZD6244 treatment inhibited ERK protein phosphorylation levels and blocked the Wnt/β-catenin pathway, which in turn significantly down-regulated the expression levels of FZD4, β-catenin, TCF4 and LEF1 (p < 0.05), with an inhibitory effect in the AZD15 group being more significant. The immunohistochemical results of β-catenin and p-ERK were consistent with Western blot results.5. The small molecule inhibitor AZD6244 regulated the growth and development of feather follicles in goose embryos by the ERK and Wnt/β-catenin pathways.

Dermal FOXO3 activity in response to Wnt/β-catenin signaling is required for feather follicle development of goose embryos (Anser cygnoides)

Feather is an important economic trait of poultry, and growth and development state of feathers plays an important role in the economic value of poultry. Dermal fibroblasts are required for structural integrity of the skin and for feather follicle development. How FOXO3 affects feather follicle development as skin tissues change during goose embryo (Anser cygnoides) development and growth is not well understood. Here, we demonstrate that in vitro culture of single feathers and skin tissue results in changes in feather morphological structure by adding drugs to the culture medium that affect FOXO3 expression. We used feather follicles to show that during growth, the root location of feathers, the dermis layer, affects cell proliferation and apoptosis and regulates the expression of major genes in the Wingless-types/beta-catenin (Wnt/β-catenin) signaling pathway through the activity of FOXO3 in dermal fibroblasts. Feathers and dorsal skin tissues develop the correct structure, but feather length and width and feather follicle diameter change significantly (p < 0.05) without significant changes in feather follicle density (p > 0.05). Transfected dermal fibroblasts also showed that FOXO3 affected the formation and development of feather follicles in the embryonic stage by regulating the Wnt/β-catenin signaling pathway. Therefore, this study reveals the critical role of dermal fibroblast-FOXO3-induced Wnt/β-catenin signaling in promoting the formation and development of embryonic feather follicles.

Transcriptome and Weighted Gene Co-Expression Network Analysis for Feather Follicle Density in a Chinese Indigenous Breed

Feather follicle density plays an important role in appealing to consumers' first impressions when making purchasing decisions. However, the molecular network that contributes to this trait remains largely unknown. The aim of this study was to perform transcriptome and weighted gene co-expression network analyses to determine the candidate genes relating to feather follicle density in Wannan male chickens. In total, five hundred one-day-old Wannan male chickens were kept in a conventional cage system. Feather follicle density was recorded for each bird at 12 weeks of age. At 12 weeks, fifteen skin tissue samples were selected for weighted gene co-expression network analysis, of which six skin tissue samples (three birds in the H group and three birds in the L group) were selected for transcriptome analysis. The results showed that, in total, 95 DEGs were identified, and 56 genes were upregulated and 39 genes were downregulated in the high-feather-follicle-density group when compared with the low-feather-follicle-density group. Thirteen co-expression gene modules were identified. The red module was highly significantly negatively correlated with feather follicle density (p < 0.01), with a significant negative correlation coefficient of -0.72. In total, 103 hub genes from the red module were screened. Upon comparing the 103 hub genes with differentially expressed genes (DEGs), it was observed that 13 genes were common to both sets, including MELK, GTSE1, CDK1, HMMR, and CENPE. From the red module, FOXM1, GTSE1, MELK, CDK1, ECT2, and NEK2 were selected as the most important genes. These genes were enriched in the DNA binding pathway, the heterocyclic compound binding pathway, the cell cycle pathway, and the oocyte meiosis pathway. This study suggests that FOXM1, GTSE1, MELK, CDK1, ECT2, and NEK2 may be involved in regulating the development of feather follicle density in Wannan male chickens. The results of this study reveal the genetic structure and molecular regulatory network of feather follicle density in Wannan male chickens, and provide a basis for further elucidating the genetic regulatory mechanism and identifying molecular markers with breeding value.

Multi-Stage Transcriptome Analysis Revealed the Growth Mechanism of Feathers and Hair Follicles during Induction Molting by Fasting in the Late Stage of Egg Laying

Induced molting is a common method to obtain a new life in laying hens, in which periodic changes in feathers are the prominent feature. Nevertheless, its precise molecular mechanism remains unclear. In this study, feather and hair follicle samples were collected during fasting-induced physiological remodeling for hematoxylin-eosin staining, hormone changes and follicle traits, and transcriptome sequencing. Feather shedding was observed in F13 to R25, while newborns were observed in R3 to R32. Triiodothyronine and tetraiodothyronine were significantly elevated during feather shedding. The calcium content was significantly higher, and the ash content was significantly lower after the changeover. The determination of hair follicle traits revealed an increasing trend in pore density and a decrease in pore diameter after the resumption of feeding. According to RNA-seq results, several core genes were identified, including DSP, CDH1, PKP1, and PPCKB, which may have an impact on hair follicle growth. The focus was to discover that starvation may trigger changes in thyroid hormones, which in turn regulate feather molting through thyroid hormone synthesis, calcium signaling, and thyroid hormone signaling pathways. These data provide a valuable resource for the analysis of the molecular mechanisms underlying the cyclical growth of hair follicles in the skin during induced molting.

Expression of FOXO3 in the skin follicles of goose embryos during embryonic development

1. The Forkhead box O3 (FOXO3) transcription factor is a crucial regulator in controlling cell metabolism, proliferation, apoptosis, migration and response to oxidative stress. However, FOXO3 has not previously been studied much in the embryonic skin follicles of geese.2. This study used Zhedong white geese (Anser cygnoides), Jilin white geese (Anser cygnoides) and Hungarian white geese (Anser anser). The feather follicle structure in the dorsal skin during embryonic stages was examined with haematoxylin and eosin (HE) and Pollak staining. The FOXO3 protein content in the embryonic dorsal skin from feather follicles was detected using western blotting and quantitative real-time PCR.3. The mRNA expression level of FOXO3 in the dorsal skin of Jilin white geese was highly expressed on embryonic day 23 (E23; P < 0.01), while mRNA expression of FOXO3 was highly expressed in the feather follicle of Hungarian white geese at E28 (P < 0.01). The expression of FOXO3 protein mainly concentrated in the early embryonic phase among these goose breeds (P < 0.05). This suggested that FOXO3 plays a crucial role in the development and growth of embryonic dorsal skin of feather follicles. The location of the FOXO3 protein was determined using the IHC technique, which further verified the effect of FOXO3 in the dorsal skin for feather follicles during embryogenesis.4. The study demonstrated the differential expression and localisation of the FOXO3 gene among different goose species. It was speculated that the gene could potentially improve goose feather follicle development and feather-related traits and provide a basis for further understanding of FOXO3 function in the dorsal tissue of goose embryos.

Identification of genes involved in regulating the development of feathered feet in chicken embryo

The genetic and developmental factors driving the diverse distribution and morphogenesis of feathers and scales on bird feet are yet unclear. Within a single species, Guangxi domestic chickens exhibit dramatic variety in feathered feet, making them an accessible model for research into the molecular basis of variations in skin appendages. In this study, we used H&E staining to observe the morphogenesis of feathered feet, scaled feet and wings skin at different embryonic stages in Longsheng-Feng chickens and Guangxi Partridge chickens. We selected 4 periods (E6, E7, E8, and E12) that play an important role in feather development and performed transcriptome sequencing to screen for candidate genes associated with feathered feet. Through comparison and analysis of transcriptome data, we identified a set of differently expressed genes (DGEs), which were enriched in appendage organ development, hindlimb morphogenesis, activation of transcription factor binding, and binding of sequence-specific DNA in the cis-regulatory region. In addition, we identified some feathered feet-related genes by analyzing the classical signaling pathways that regulate feather development. Finally, we identified candidate genes that regulate feathered feet formation, which include TBX5, PITX1, ZIC1, FGF20, WNT11, WNT7A, WNT16, and SHH. Interestingly, we found that TBX5 was significantly overexpressed in the skin of the feathered feet and had the highest expression at E7 (P < 0.01), whereas PITX1 expression was significantly reduced at E7(P < 0.01). It is hypothesized that TBX5 and PITX1 regulate the development of hair follicles through the Wnt/β-catenin signaling pathway at E7. Our results provide a theoretical basis for investigating the molecular regulatory mechanisms underlying the formation of chicken feathered feet.

Molecular Regulatory Mechanisms in Chicken Feather Follicle Morphogenesis

In China, the sale of freshly slaughtered chickens is becoming increasingly popular in comparison with that of live chickens, and due to this emerging trend, the skin and feather follicle traits of yellow-feathered broilers have attracted a great deal of research attention. The feather follicle originates from the interaction between the epidermis and dermis in the early embryonic stage. Feather follicle morphogenesis is regulated by the Wnt, ectodysplasin (Eda), epidermal growth factor (EGF), fibroblast growth factor (FGF), bone morphogenetic protein (BMP), sonic hedgehog (Shh), Notch, and other signaling pathways that exist in epithelial and mesenchymal cells. The Wnt pathway is essential for feather follicle and feather morphogenesis. Eda interacts with Wnt to induce FGF expression, which attracts mesenchymal cell movement and aggregates to form feather follicle primordia. BMP acts as an inhibitor of the above signaling pathways to limit the size of the feather tract and distance between neighboring feather primordia in a dose-dependent manner. The Notch/Delta pathway can interact with the FGF pathway to promote feather bud formation. While not a part of the early morphogenesis of feather follicles, Shh and BMP signaling are involved in late feather branching. This review summarizes the roles of miRNAs/lncRNA in the regulation of feather follicle and feather growth and development and suggests topics that need to be solved in a future study. This review focuses on the regulatory mechanisms involved in feather follicle morphogenesis and analyzes the impact of SNP sites on feather follicle traits in poultry. This work may help us to understand the molecular regulatory networks influencing feather follicle growth and provide basic data for poultry carcass quality.

Transient agonism of the sonic hedgehog pathway triggers a permanent transition of skin appendage fate in the chicken embryo

Vertebrate skin appendage early development is mediated by conserved molecular signaling composing a dynamical reaction-diffusion-like system. Variations to such systems contribute to the remarkable diversity of skin appendage forms within and among species. Here, we demonstrate that stage-specific transient agonism of sonic hedgehog (Shh) pathway signaling in chicken triggers a complete and permanent transition from reticulate scales to feathers on the ventral surfaces of the foot and digits. Resulting ectopic feathers are developmentally comparable to feathers adorning the body, with down-type feathers transitioning into regenerative, bilaterally symmetric contour feathers in adult chickens. Crucially, this spectacular transition of skin appendage fate (from nodular reticulate scales to bona fide adult feathers) does not require sustained treatment. Our RNA sequencing analyses confirm that smoothened agonist treatment specifically promotes the expression of key Shh pathway-associated genes. These results indicate that variations in Shh pathway signaling likely contribute to the natural diversity and regionalization of avian integumentary appendages.

The idiosyncratic genome of Korean long-tailed chicken as a valuable genetic resource

Today, breeds with ornamental traits such as exceptionally long tail feathers are economically valuable. However, the genetic basis of long-tail feathers is yet to be understood. To provide better understanding of long tail feathers, we sequenced Korean long-tailed chicken (KLC) genomes and compared them with genomes of other chicken breeds. We first analyzed the genome structure of KLC and its genomic relationship with other chickens and observed unique characteristics. Subsequently, we searched for genomic regions under selection. Feather keratin 1-like enriched region and several genes were found to have novel putative functions and effects on the long tail trait in KLC. Our findings support the value of KLC as a unique genetic resource and cast light on the genetic basis of long tail traits in avian species. We expect this novel knowledge to provide new genomic evidence and options for designing and implementing genetic improvements of ornamental chicken productivity through precision crossbreeding aids.

Dietary replacement of soybean meal by fermented feedstuffs for aged laying hens: effects on laying performance, egg quality, nutrient digestibility, intestinal health, follicle development, and biological parameters in a long-term feeding period

This study aimed to investigate the effects of dietary supplementation with fermented soybean meal (FSM) or fermented miscellaneous meal (FMM, cottonseed meal: coconut meal = at a 1:1 ratio) on the intestinal health, laying performance, egg quality, and follicle development of laying hens. A total of 1,008 54-wk-old laying hens were randomly divided into 7 treatment groups and fed a corn-soybean base diet in addition to 2%, 4%, and 8% FSM or FMM. The results showed that fermentation increased the contents of crude protein, amino acids (Ser, Gly, Cys, Leu, Lys, His, and Arg), and organic acids (butyric acid, citric acid, succinic acid) and decreased the contents of neutral and acid detergent fiber in the soybean and miscellaneous meals (P < 0.05). Compared with the results found for the control group, feeding with 4% FSM increased the egg production, egg mass and average daily feed intake (ADFI), and feeding with 4% FMM increased the ADFI of laying hens (P < 0.05). Furthermore, feeding with 8% FMM reduced the productive performance and laying performance, supplementation with 4% FSM increased the eggshell strength and weight, and 2 to 4% FSM increased the egg albumen height and Haugh unit (P < 0.05). Moreover, 2 to 8% FSM or 2 to 4% FMM enhanced the apparent digestibility of dry matter, crude protein, and NDF for laying hens (P < 0.05). The relative weight, villus height, crypt depth, and villus:crypt ratio of the jejunum were higher in the 4% FSM- and FMM-fed groups (P < 0.05). Moreover, diamine oxidase (DAO) activity, transepithelial electrical resistance (TEER), and the expression of tight junction proteins (ZO-1, Occluding, and Claudin1), the intestinal stem cell marker Lgr5, and the proliferation cell marker proliferating cell nuclear antigen (PCNA) was upregulated in the jejunum of laying hens fed 4% FSM and FMM (P < 0.05). The relative weight of the ovaries, and the number of small yellow follicles and large white follicles were elevated after 4% FSM or FMM supplementation. Furthermore, the levels of serum follicle-stimulating hormone and luteinizing hormone were increased in the 4% FSM and FMM groups (P < 0.05). In conclusion, the supplementation of laying hen feed with FSM and FMM improved the laying performance, egg quality, intestinal barrier function, and follicle development of aged laying hens, and 4% FSM supplementation was optimal.

RNA sequencing reveals lncRNA-mediated non-mendelian inheritance of feather growth change in chickens

Background

Long non-coding RNAs (lncRNAs) play an essential role in biological processes. However, the expression patterns of lncRNAs that regulate the non-Mendelian inheritance feather phenotypes remain unknown.

Objective

This study aimed to compare the expression profiles of lncRNAs in the follicles of the late-feathering cocks (LC) and late-feathering hens (LH) that followed genetic rules and the early-feathering hen (EH) and early-feathering cock (EC) that did not conform to the genetic laws.

Methods

We performed RNA sequencing and investigated the differentially expressed lncRNAs (DElncRNAs) between the early- and late-feathering chickens, which function by cis-acting or participate in the competing endogenous RNA (ceRNA) network.

Results

A total of 53 upregulated and 43 downregulated lncRNAs were identified in EC vs. LC, and 58 upregulated and 109 downregulated lncRNAs were identified in EH vs. LH. The target mRNAs regulated by lncRNAs in cis were enriched in the pentose phosphate pathway, TGF-β signaling pathway and Jak-STAT signaling pathway in EC vs. LC and were associated with the TGF-β signaling pathway, Wnt signaling pathway, p53 signaling pathway and Jak-STAT signaling pathway in EH vs. LH. In addition, the lncRNA-mediated ceRNA regulatory pathways of hair follicle formation were mainly enriched in the TGF-β signaling pathway, Wnt signaling pathway, melanogenesis, and calcium signaling pathways. The levels of ENSGALG00000047626 were significantly higher in the late-feathering chickens than in the early-feathering chickens, which regulated the expression of SSTR2 by gga-miR-1649-5p.

Conclusion

This study provides a novel molecular mechanism of lncRNA’s response to the feather rate that does not conform to the genetic laws in chickens.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13258-022-01304-2.

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

The Wingless-types/beta-catenin (Wnt/β-catenin) signaling pathway plays an important role in embryonic development and affects the physiological development processes of feather follicles. To investigate the role of Wnt/β-catenin pathway in regulating feather follicles morphogenesis, in ovo injection of CHIR-99021, an activator of the Wnt/β-catenin signaling pathway, was conducted in chick embryo model. Initially, a total of 40 embryos were used to assess feather follicles morphogenesis and the expression of β-catenin (E9–E17). The histological results showed that feather follicle morphogenesis was mainly completed from E9 to E17. β-catenin was involved in the processing of the appearance of dermal cell condensation (E9) and the completion of the feather follicles morphogenesis (E17). Next, a total of 160 fertilized eggs were randomly divided into 8 groups for in ovo injection at E9, including a Normal Saline injected group (CON) and the 500, 1,000, 2,000, 5,000, 10,000, 50,000, and 100,000 ng CHIR-99021 groups. Dorsal skin tissue samples were collected at E17 for investigating feather follicles morphology and expressions of β-catenin and lymphoid enhancerbinding factor-1 (LEF1) at gene and protein levels. The results showed that feather follicle diameter in the injected groups were significantly (P < 0.05) increased with limit dose-independence compared to the CON group. CHIR-99021 significantly (P < 0.05) influenced the mRNA expressions of catenin beta-1 (CTNNB1) and downstream target LEF1. In ovo injection of CHIR-99021 caused that β-catenin and LEF1 were significantly (P < 0.05) increased followed the increased doses as determined by western blotting. The immunochemical results showed that β-catenin was detected in the dermal papilla of feather follicles. Given these results, this study suggests to developmental biology that in ovo injection of CHIR-99021 promoted feather follicles morphogenesis and development via activating Wnt/β-catenin signaling pathway and upregulating downstream target LEF1 during embryonic period in chick embryo model. Moreover, CHIR-99021 may be a strong candidate to promote the animal feather/hair industry, especially as a reference for bird feather production.

In Ovo Injection of CHIR-99021 Promotes Feather Follicle Development via Modulating the Wnt Signaling Pathway and Transcriptome in Goose Embryos (Anser cygnoides)

Feather performs important physiological functions in birds, and it is also one of the economic productions in goose farming. Understanding and modulating feather follicle development during embryogenesis are essential for bird biology and the poultry industry. CHIR-99021 is a potent Wnt/β-catenin signaling pathway activator associated with feather follicle development. In this study, goose embryos (Anser cygnoides) received an in ovo injection of CHIR-9902, which was conducted at the beginning of feather follicle development (E9). The results showed that feather growth and feather follicle development were promoted. The Wnt signaling pathway was activated by the inhibition of GSK-3β. Transcriptomic analyses showed that the transcription changes were related to translation, metabolism, energy transport, and stress in dorsal tissue of embryos that received CHIR-99021, which might be to adapt and coordinate the promoting effects of CHIR-99021 on feather follicle development. This study suggests that in ovo injection of CHIR-99021 is a potential strategy to improve feather follicle development and feather-related traits for goose farming and provides profiling of the Wnt signaling pathway and transcriptome in dorsal tissue of goose embryos for further understanding of feather follicle development.

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

This experiment was undertaken to investigate the effects of parental dietary DL-methionine (DL-Met) and DL-methionyl-DL-methionine (DL-Met-Met) supplementation on the intestinal development of young squabs. A total of 108 pairs of breeding pigeons and 432 one-day-old squabs were randomly divided into 3 groups: the control group (CON) was fed a basal diet (CP = 15%) and the experimental groups were fed a basal diet supplemented with 0.3% DL-Met or DL-Met-Met. Each pair of breeding pigeons nourished 4 young squabs, and 8 squabs from each treatment were randomly sampled at the end of the experiment. The results indicated that DL-Met and DL-Met-Met supplementation improved the intestinal morphology and structure in the squabs, as reflected by the increased relative intestinal weight of each small intestinal segment, villus height, and villus to crypt ratio. In addition, DL-Met and DL-Met-Met supplementation significantly increased the protein expression of cell proliferation markers (Ki67 and PCNA) and tight junction proteins (ZO-1 and Claudin-1) in the jejunum and strengthened the fluorescence signal intensity of Ki67, PCNA and Villin. Moreover, the expression of Wnt/β-catenin signaling pathway-related proteins (Frizzled 7 [FZD7], p-GSK-3β, Active β-catenin, β-catenin, TCF4, c-Myc, and Cyclin D1), and intestinal peptide transporter 1 (PepT1) in the jejunum was considerably higher in the treatment group than in the CON group (P < 0.05), with the DL-Met-Met group having the highest expression. Consistently, the molecular docking results predicted the possibility that DL-Met or DL-Met-Met binds to the membrane receptor FZD7, which mediates Wnt/β-catenin signaling. Collectively, the improvement of the intestinal development in squabs after parental dietary 0.3% DL-Met and DL-Met-Met supplementation could be through activation of Wnt/β-catenin signaling pathway, and DL-Met-Met is superior to DL-Met. Our findings may provide basic data for further optimizing the feeding formula of breeding pigeons and improving the growth and development of squabs.

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

The intestinal health of chick embryos is vital for their life-long growth, and exogenous nutrition intervention may provide sufficient nutrition for embryonic development. In the present study, we investigated the effect of in ovo injection of L-methionine (L-Met) on the intestinal structure and barrier function of chick embryos. There were 4 groups of treatments: the control (CON) group injected with phosphate-buffered saline (PBS) and the other 3 groups injected with 5, 10, and 20 mg L-Met/egg, respectively. The injection was performed on embryonic day 9 (E9), and intestinal samples were collected on the day of hatching for analysis. The results showed that, compared with the CON group, the groups administered an in ovo injection of L-Met increased relative weights of the duodenum, jejunum, and ileum (P < 0.05). Hematoxylin and eosin (H&E) staining showed that the groups injected with 5, 10, and 20 mg L-Met significantly increased villus height and crypt depth (P < 0.05). Moreover, in ovo injection of 10 mg L-Met also increased the transepithelial electrical resistance (TEER) of the jejunum (P < 0.05). Injection with 10 and 20 mg L-Met increased the expression of the tight junction proteins (ZO-1 and claudin-1) and the fluorescence signal intensity of Ki67 and villin proteins (P < 0.05). Further, the protein expression of phospho-Janus kinase 2 (p-JAK2) and phospho-signal transducer and activator of transcription 3 (p-STAT3) was significantly increased by 10 or 20 mg L-Met injection (P < 0.05). In conclusion, the injection of L-Met, especially at a dose of 10 mg, showed beneficial effects on the intestinal integrity of chick embryos due to the activation of the JAK2/STAT3 signaling pathway. Our results may provide new insights for regulating the intestinal development of embryonic chicks and the rapid growth of chicks after hatching.

The novel target of esophageal squamous cell carcinoma: lncRNA GASL1 regulates cell migration, invasion and cell cycle stagnation by inactivating the Wnt3a/β-catenin signaling

Long non-coding RNA (lncRNA) Growth-Arrest Associated LncRNA 1 (GASL1) is a lncRNA with a suppressive role in glioma, prostate carcinoma and gastric carcinoma, whereas its involvement in esophageal cancer is unknown. In the present study, we used RT-qPCR to detect the expression of GASL1 in esophageal cancer cell carcinoma (ESCC) cell lines, and constructed the overexpression and interference plasmids of GASL1 and the interference plasmid of DKK1. CCK8 was used to detect the cell proliferation level, clone formation experiment was used to detect the cell clonal formation ability, flow cytometry was used to detect the cell cycle level, and wound healing and Transwell experiments were respectively used to detect the cell invasion and migration. The interference and overexpression plasmids of GASL1 were injected into mice subcutaneously for tumor-bearing experiment. The body weight, tumor growth curve, and tumor weight of mice were recorded, and western blot was used to detect the expression of proliferation-, invasion-, and migration-related proteins and the expression of Wnt3a/β-catenin signal-related proteins in tumor tissues. LncRNA GASL1 was down-regulated in ESCC cell lines, and GASL1 inhibited ESCC cell progression and regulated cell cycle arrest in ESCC cells. In vivo, GASL1 inhibited tumor growth. GASL1 decreased the protein levels of DDK1, Wnt3a, β-catenin, and c-MYC in ESCC cell lines. Interfering DKK1 activates Wnt3a/β--catenin signal to reverse the inhibitory effects of GASL1 on proliferation, cell cycle acceleration, invasion, and migration. In conclusion, lncRNA GASL1 regulates cell migration, invasion and cell cycle stagnation by inactivating the wnt/β-catenin signaling.