TY - JOUR
T1 - Male differentiation of germ cells induced by embryonic age-specific sertoli cells in mice
AU - Ohta, Kohei
AU - Yamamoto, Miyuki
AU - Lin, Yanling
AU - Hogg, Nathanael
AU - Akiyama, Haruhiko
AU - Behringer, Richard R.
AU - Yamazaki, Yukiko
PY - 2012/4/1
Y1 - 2012/4/1
N2 - Retinoic acid (RA) is a meiosis-inducing factor. Primordial germ cells (PGCs) in the developing ovary are exposed to RA, resulting in entry into meiosis. In contrast, PGCs in the developing testis enter mitotic arrest to differentiate into prospermatogonia. Sertoli cells express CYP26B1, an RAmetabolizing enzyme, providing a simple explanation for why XY PGCs do not initiate meios/is. However, regulation of entry into mitotic arrest is likely more complex. To investigate the mechanisms that regulate male germ cell differentiation, we cultured XX and XY germ cells at 11.5 and 12.5 days postcoitus (dpc) with an RA receptor inhibitor. Expression of Stra8, a meiosis initiation gene, was suppressed in all groups. However, expression of Dnmt3l, a male-specific gene, during embryogenesis was elevated but only in 12.5-dpc XY germ cells. This suggests that inhibiting RA signaling is not sufficient for male germ cell differentiation but that the male gonadal environment also contributes to this pathway. To define the influence of Sertoli cells on male germ cell differentiation, Sertoli cells at 12.5, 15.5, and 18.5 dpc were aggregated with 11.5 dpc PGCs, respectively. After culture, PGCs aggregated with 12.5 dpc Sertoli cells increased Nanos2 and Dnmt3l expression. Furthermore, these PGCs established male-specific methylation imprints of the H19 differentially methylated domains. In contrast, PGCs aggregated with Sertoli cells at late embryonic ages did not commit to the male pathway. These findings suggest that male germ cell differentiation is induced both by inhibition of RA signaling and by molecule(s) production by embryonic agespecific Sertoli cells.
AB - Retinoic acid (RA) is a meiosis-inducing factor. Primordial germ cells (PGCs) in the developing ovary are exposed to RA, resulting in entry into meiosis. In contrast, PGCs in the developing testis enter mitotic arrest to differentiate into prospermatogonia. Sertoli cells express CYP26B1, an RAmetabolizing enzyme, providing a simple explanation for why XY PGCs do not initiate meios/is. However, regulation of entry into mitotic arrest is likely more complex. To investigate the mechanisms that regulate male germ cell differentiation, we cultured XX and XY germ cells at 11.5 and 12.5 days postcoitus (dpc) with an RA receptor inhibitor. Expression of Stra8, a meiosis initiation gene, was suppressed in all groups. However, expression of Dnmt3l, a male-specific gene, during embryogenesis was elevated but only in 12.5-dpc XY germ cells. This suggests that inhibiting RA signaling is not sufficient for male germ cell differentiation but that the male gonadal environment also contributes to this pathway. To define the influence of Sertoli cells on male germ cell differentiation, Sertoli cells at 12.5, 15.5, and 18.5 dpc were aggregated with 11.5 dpc PGCs, respectively. After culture, PGCs aggregated with 12.5 dpc Sertoli cells increased Nanos2 and Dnmt3l expression. Furthermore, these PGCs established male-specific methylation imprints of the H19 differentially methylated domains. In contrast, PGCs aggregated with Sertoli cells at late embryonic ages did not commit to the male pathway. These findings suggest that male germ cell differentiation is induced both by inhibition of RA signaling and by molecule(s) production by embryonic agespecific Sertoli cells.
KW - De novo DNA methylation
KW - Male germ cell differentiation
KW - Primordial germ cells
KW - Sertoli cells
KW - Sex differentiation
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UR - http://www.scopus.com/inward/citedby.url?scp=84864070390&partnerID=8YFLogxK
U2 - 10.1095/biolreprod.111.095943
DO - 10.1095/biolreprod.111.095943
M3 - Article
C2 - 22262692
AN - SCOPUS:84864070390
SN - 0006-3363
VL - 86
JO - Biology of reproduction
JF - Biology of reproduction
IS - 4
M1 - 112
ER -