Differentially expressed gene enrichment analysis during different feather regeneration periods in Landes geese (Anser anser)

Feathers are significant byproducts of poultry, and the state of feather growth and development plays a crucial role in their economic value. The present study utilized the Landes geese (LD) geese as models to analyze the expression of core genes involved in feather regeneration and those related to the inflammatory response in plucked and unplucked skin tissues through transcriptome comparison. In the older LD geese at the age of 180 days (spLD180), 624 differential expressed genes (DEGs) were detected at 5 days post-plucking (481 upregulated and 143 downregulated), and 1,854 DEGs were identified at 14 days post-plucking (1,350 upregulated and 540 downregulated). In the younger 90 days old LD geese (SpLD90), 694 DEGs were detected at 5 days (513 upregulated and 181 downregulated) and 1,155 DEGs at 14 days (888 upregulated and 267 downregulated). These DEGs were significantly enriched in Gene Ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and Protein-Protein Interaction Networks (PPI) associated with inflammatory responses (e.g., leukocyte-mediated immunity), feather regeneration (e.g., epidermis development), and melanogenesis (e.g., melanin biosynthetic process). Compared to younger geese, older geese could recover more quickly from mechanic injuries than younger geese as there detected a more significant decrease in expression levels of pro-inflammation genes in spLD180. Through comparative analysis, we reached the following conclusions: mechanical damage to skin tissues (such as feather plucking) induces immediate inflammatory and anti-inflammatory reactions. Both the innate and adaptive immune systems participate in the defensive process as soon as damage occurs. Feather plucking stimulates a new feather cycle, characterized by the emergence of new follicles accompanied by melanogenesis and distribution. Age plays a critical role in the duration of the feather cycle, as geese of different ages exhibit distinct transcriptional features related to anti-inflammatory responses and feather regeneration.