Discussion
Our findings will facilitate the study of HF cycle and offer researchers a suitable model for human hair research.
Methods
Skin samples from 10 different postnatal (P) days Yorkshire pigs was collected to determine the key time points of the first HF cycle in pig by H&E staining, immunofluorescence staining, q-PCR and western-blot.
Results
By morphological observation and detection of markers at different stages, pig HF cycle was classified into three main periods - the first anagen until P45, catagen (P45-P85), telogen (P85-P100), and next anagen (>P100). In addition, we examined the expression of important genes AE15, CD34, Versican, Ki67 et al. related to the HF cycle at different stages of pig HF, indicating that pig and human share similarities in morphology and marker gene expression patterns of HF cycle.