Glycan stem-cell markers are specifically expressed by spermatogonia in the adult non-human primate testis.
BACKGROUND
The glycan cell surface molecules, stage-specific embryonic antigen (SSEA)-1, -3 and -4 and tumor-rejection antigen (TRA)-1-60 and -1-81, are expressed in specific combinations by undifferentiated pluripotent cells, i.e. embryonic stem cells, induced pluripotent stem cells, embryonal carcinoma cells, primordial germ cells and embryonic germ cells. Upon differentiation of the cells, these markers vanish. Recently, it has been shown that also neonatal and adult mouse testes contain pluripotent cells. Here, we aimed at identifying in situ possibly pluripotent cells in the adult primate testis.


METHODS
Monoclonal antibodies raised against the glyco-epitopes SSEA-1, -3 and -4 and TRA-1-60 and -1-81, respectively, were tested to detect cells expressing the antigens, by immunohistochemistry on Bouin's-fixed and paraffin-embedded adult primate testes. Man, the new-world monkey, Callithrix jacchus (common marmoset), and the old-world monkey species, Macaca mulatta (Rhesus macaque) and Macaca silenus (Lion-tailed macaque), were included. The percentage of SSEA-4-positive cells in three adult marmoset testes was determined using flow cytometry.


RESULTS
Spermatogonia in the testes of C. jacchus were labeled by SSEA-4, TRA-1-60 and -1-81-antibodies. In the macaques, spermatogonia were detected by SSEA-4 and TRA-1-81-antibodies. TRA-1-61 did not bind to macaque spermatogonia. Also, SSEA-1 and -3 did not bind to spermatogonia in any species. In human testes, we never obtained any clear staining. The total percentage of SSEA-4-positive cells in marmoset testes was 8.6 +/- 1.61%.


CONCLUSIONS
SSEA-4 and TRA-1-81-antibodies may be very well suited for the identification and isolation of spermatogonia, and possibly also germline stem cells, in the non-human primate testis.
Müller
T
T
Stem Cell Research Group, German Primate Center, Kellnerweg 4, 37077 Göttingen, Germany.
Eildermann
K
K
Dhir
R
R
Schlatt
S
S
Behr
R
R
D000818:Animals; D000954:Antigens, Surface / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D002144:Callithrix / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D008251:Macaca / Q000378:metabolism*; D008253:Macaca mulatta / Q000378:metabolism; D008297:Male; D013093:Spermatogonia / Q000378:metabolism*; D055746:Stage-Specific Embryonic Antigens / Q000378:metabolism*; D013234:Stem Cells / Q000378:metabolism*; D013737:Testis / Q000378:metabolism*
D000954:Antigens, Surface; D015415:Biomarkers; D055746:Stage-Specific Embryonic Antigens