THY1 is a surface marker of porcine gonocytes

Gonocytes are important for the study of spermatogenesis. Identification and isolation of gonocytes has been reported in rodents but not in pigs due to a lack of molecular markers for gonocytes. The objective of this study was to identify THY1 expression in porcine testicular tissue and subsequently utilise THY1 as a marker to isolate and enrich porcine gonocytes from testes of newborn piglets. Immunohistochemical analysis showed that THY1 was expressed in gonocytes. Double-immunofluorescent analysis of THY1 and ZBTB16 indicated that THY1 and ZBTB16 were partially co-localised in gonocytes. Double-immunofluorescent analysis of both THY1 and GATA4 suggested that THY1(+) cells were not Sertoli cells. Magnetic-activated cell sorting of THY1(+) cells yielded a cell population with an enrichment of UCHL1(+) gonocytes 3.4-fold of that of the unsorted testicular cell population. Western blot and quantitative reverse transcription-polymerase chain reaction analyses confirmed that the selected THY1(+) fraction had a higher expression of UCHL1 than the unsorted cells. In conclusion, the study demonstrated that THY1 is a surface marker of gonocytes in testes of pre-pubertal boars and could be utilised to identify and isolate porcine gonocytes. The findings will also facilitate culture and manipulation of male germline stem cells.