Background: Fowl adenovirus is of major concern to the poultry industry worldwidely. In order to monitor the prevalent status of Fowl adenovirus in China, a total of 1920 clinical samples from apparently healthy birds in the 25 sites of poultry flocks, Slaughterhouse and living bird markets from 8 provinces in eastern China were collected and detected by PCR, sequencing, and phylogenetic analysis. Results: The epidemiological survey showed that Fowl adenoviruses were detected in living bird markets, and circulating in a variety of fowl species, including chickens, ducks, goose and pigeons. Among the 1920 clinical samples, 166 samples (8.65%) were positive in the fowl adenovirus PCR detection. In this study, totally all the 12 serotypes (serotypes of 1, 2, 3, 4, 5, 6, 7, 8A, 8B, 9, 10 and 11) fowl adenoviruses were detected, the most prevalent serotype was serotype 1. Phylogenetic analysis indicated that 166 FAdVs of 12 serotypes were divided into 5 fowl adenovirus species (Fowl aviadenovirus A, B, C, D, E). Conclusions: In the epidemiological survey, 8.65% of the clinical samples from apparently healthy birds were positive in the fowl adenovirus PCR detection. Totally all the 12 serotypes fowl adenoviruses were detected in a variety of fowl species, which provided abundant resources for the research of fowl adenoviruses in China. The newly prevalent FAdV serotypes provides valuable information for the development of an effective control strategy for FAdV infections in fowls.

Fibroblast growth factor 9 (FGF9) is crucial for the growth and development of hair follicles (HFs); however, its role in sheep wool growth is unknown. Here, we clarified the role of FGF9 in HF growth in the small-tailed Han sheep by quantifying FGF9 expression in skin tissue sections collected at different periods. Moreover, we evaluated the effects of FGF9 protein supplementation on hair shaft growth in vitro and FGF9 knockdown on cultured dermal papilla cells (DPCs). The relationship between FGF9 and the Wnt/β-catenin signaling pathway was examined, and the underlying mechanisms of FGF9-mediated DPC proliferation were investigated. The results show that FGF9 expression varies throughout the HF cycle and participates in wool growth. The proliferation rate and cell cycle of FGF9-treated DPCs substantially increase compared to that of the control group, and the mRNA and protein expression of CTNNB1, a Wnt/β-catenin signaling pathway marker gene, is considerably lower than that in the control group. The opposite occurs in FGF9-knockdown DPCs. Moreover, other signaling pathways are enriched in the FGF9-treated group. In conclusion, FGF9 accelerates the proliferation and cell cycle of DPCs and may regulate HF growth and development through the Wnt/β-catenin signaling pathway.

In order to develop an appropriate method for high-throughput detection of avian metapneumovirus, a quadruple real-time reverse-transcription polymerase chain reaction assay was established with four pairs of specific primers and four specific probes based on the G or M gene of aMPV-A, aMPV-B, aMPV-C and aMPV-D. Its specificity and sensitivity were evaluated, and clinical samples were tested by the method. The results showed that all the four subgroups of avian metapneumovirus can be detected in the quadruple real-time RT-PCR assay simultaneously, with a detection limit of 100–1000 cRNA copies/reaction. The other common poultry viruses were negative. In the avian clinical sample detection, 39 out of 1920 clinical samples collected from 8 provinces were positive. Compared with published RT-PCR assays, the κ value of the quadruple real-time RT-PCR assay in 1920 avian clinical samples was 1.000 (P < 0.001). The established method could be used for the rapid detection of the four subgroups of avian metapneumovirus with high specificity and high sensitivity.

The proliferation and maturation of hair follicles in follicular papilla cells are predominantly governed by miRNAs, which significantly influence the cell cycle, apoptosis, and proliferation. miR-370-3p has been associated with several biological processes and targets SMAD4, a crucial component in hair follicle development. Tissue expression profiling revealed significant differences in miR-370-3p levels between skin tissues of the two sheep breeds in January and October, as well as between tissues of the Xinji fine-wool sheep and Small-tail Han sheep. SMAD4 exhibited significant differences in tissue-specific expression in the heart, spleen, skin, lungs, and muscles from Xinji fine-wool sheep and Small-tail Han sheep. Bioinformatics analysis and dual-luciferase reporter assays validated the regulatory interaction between miR-370-3p and SMAD4. CCK-8 experiments demonstrated that miR-370-3p’s targeting of SMAD4 suppressed cell growth. Cell cycle analysis demonstrated that miR-370-3p’s targeting of SMAD4 influenced the cell cycle. Annexin V-FITC/PI dual labeling demonstrated that miR-370-3p’s targeting of SMAD4 promoted cell apoptosis. RT-qPCR data demonstrated that miR-370-3p’s targeting of SMAD4 elevated the expression of JUN, c-MYC, and TCF7L2 while suppressing β-catenin expression. Western blot (WB) analysis demonstrated that miR-370-3p targeting of SMAD4 significantly promoted c-MYC expression while inhibiting CCND1, CCND2, and β-catenin expression. miR-370-3p and SMAD4 exhibit spatiotemporal expression differences in sheep skin tissues, with widespread expression across various tissues. Furthermore, it confirmed that miR-370-3p targets SMAD4 to inhibit follicular papilla cell proliferation, promote apoptosis, and influence the cell cycle.

Introduction: Animal hair growth is an important research topic in the field of breeding. Hair growth is affected by circulating exosomes in the plasma, and sheep wool fiber thickness is altered by intravenous injection of miRNA mimics.Methods: This study investigated the effect of miRNAs in circulating exosomes on an animal’s hair growth. Circulating exosomes were isolated from Xinji fine-wool and small-tailed Han sheep plasma using a two-phase system. A blank control group (NC), groups of model mice injected with exosomes from Xinji fine-wool sheep (XPE), and groups of model mice injected with exosomes from small-tailed Han sheep group (SPE) were set up as three groups of hair regeneration models.Results: The results showed that the diameter of hair follicles in the XPE group was significantly smaller than that of the NC and SPE groups (P < 0.05), and the diameter of hair follicles in the SPE group was significantly larger than that of the NC and XPE groups (P < 0.05). There was no significant difference in the number of hair follicles among the three groups directly (P > 0.05). The diameter of hairs in the SPE group was highly significantly greater than that in the NC and XPE groups (P < 0.001), and the diameter of hairs in the XPE group was significantly greater than that in the NC and SPE groups (P < 0.01). In addition, the expression of the hair follicle growth markers Lef1, Wnt10b, Dkk1, b-catenin, Ptch1, and Shh indicated that circulating exosomes can accelerate the hair follicle development cycle. The expression of the hair melanin synthesis genes FZD3 and FZD4 indicated that circulating exosomes can affect hair follicle melanin synthesis. Immunohistochemistry results showed that the SPE group had greater levels of a-SMA protein. miR-31-5p, miR-133b, miR-433-3p, and miR-218 were similarly expressed in different samples, and the expression of all these miRNAs was significantly greater in the SPE group compared with the XPE group (P < 0.05). Circulating exosomes in Xinji fine-wool and small-tailed Han sheep altered the hair growth in mice.

Wool quality and yield are two important economic livestock traits. However, there are relatively few molecular studies on lncRNA for improving sheep wool, so these require further exploration. In this study, we examined skin tissue from the upper scapula of Super Merino (SM) and Small-Tailed Han (STH) sheep during the growing period. The apparent difference was verified via histological examination. High-throughput RNA sequencing identified differentially expressed (DE) long non-coding (lncRNAs) and messenger RNAs (mRNAs). The target gene of DE lncRNA and DE genes were enrichment analyzed using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). A Reverse Transcription quantitative Polymerase Chain Reaction (RT-qPCR) was used to verify randomly selected DE lncRNAs and mRNAs. Finally, the DE, RAC2, WNT11, and FZD2 genes, which were enriched in the Wnt signaling pathway, were detected via immunohistochemistry. The results showed that a total of 20,888 lncRNAs and 31,579 mRNAs were identified in the skin tissues of the two sheep species. Among these, 56 lncRNAs and 616 mRNAs were differentially expressed. Through qRT-PCR, the trends in the randomly selected DE genes’ expression were confirmed to be aligned with the RNA-seq results. GO and KEGG enrichment analysis showed that DE lncRNA target genes were enriched in GO terms as represented by epidermal and skin development and keratin filature and in KEGG terms as represented by PI3K-Akt, Ras, MAPK, and Wnt signaling pathways, which were related to hair follicle growth and development. Finally, immunohistochemistry staining results indicated that RAC2, WNT11, and FZD2 were expressed in dermal papilla (DP). The lncRNAs MSTRG.9225.1 and MSTRG.98769.1 may indirectly participate in the regulation of hair follicle growth, development, and fiber traits by regulating their respective target genes, LOC114113396(KRTAP15-1), FGF1, and IGF1. In addition, MSTRG.84658.1 may regulate the Wnt signaling pathway involved in the development of sheep hair follicles by targeting RAC2. This study provides a theoretical reference for improving sheep breeding in the future and lays a foundation for further research on the effects of MSTRG.84658.1 and the target gene RAC2 on dermal papilla cells (DPC).