TABLE 2.

FGF9 and FGFR1-4 expression intensity in postnatal stage.

	cell type	pnd 10	pnd 20	pnd 35	pnd 65
FGF9	Spermatids	+	+	++	++
	spermatocytes	+	+	++	++
	spermatogonia	−	−	−	−
	Leydig cells	+	++	++	+
FGFR1	spermatids	++	++	++	++
	spermatocytes	++	++	++	++
	spermatogonia	++	++	++	++
	Leydig cells	++	++	++	++
FGFR2	spermatids	−	+	++	++
	spermatocytes	−	+	−	−
	spermatogonia	+	+	−	−
	Leydig cells	+	+	++	++
FGFR3	spermatids	++	+	++	++
	spermatocytes	++	+	++	++
	spermatogonia	++	−	++	++
	Leydig cells	++	++	++	+
FGFR4	spermatids	−	+	+	+
	spermatocytes	−	+	+	+
	spermatogonia	+	+	+	+
	Leydig cells	+	+	+	+

“–” indicates negative protein expression; “+” indicated positive protein expression “++” indicates a stronger positive expression compared to “+”