TheZglp1−/−male germ cells developed nor-
mally until at least P7 (fig. S5, A and B). Sub-
sequently, they exhibited severe impairment
in the first wave of spermatogenesis: unlike in
females, they entered into meiotic prophase
but mostly failed to progress beyond the zy-
gotene stage, resulting in a large fraction of
abnormal pachytene cells both at P15 and
P20 (fig. S5, A to F). TheZglp1−/−adults ex-
hibited severe defects in spermatogenesis
and were infertile (fig. S5, G and H) ( 14 , 15 ).
Nonetheless, upon aging, a small fraction of
theZglp1−/−cells generated round or elongated
spermatids, which, with intracytoplasmic sperm
injection, contributed to apparently healthy off-
spring (fig. S5, I to O). Thus, in females,Zglp1
is essential for activating the oogenic program,
including meiotic prophase, whereas in males,it is dispensable for germ cell sex determina-
tion but is required in the spermatogonia for
an efficient completion of meiotic prophase.ZGLP1 is sufficient to create the foundation of
the oogenic fate
Next, we explored the regulation and function
ofZglp1. We examined the expression ofZglp1
and other relevant genes by mPGCLC-derivedNagaokaet al.,Science 367 , eaaw4115 (2020) 6 March 2020 2of9
Fig. 1. Identification of a TF inducing the oogenic fate.(A) Left: Top, Scheme
for the oogenic fate induction by BMP2- or Dox-induced TF overexpression
with or without RA in mPGCLCs. m220, m220 feeder cells; SCF, stem cell factor;
FR10, forskolin and rolipram (10mM each). Bottom: Vectors for the Dox-inducible
system. D4Z4, an insulator; EF1a, elongation factor 1apromoter; CDS, a coding
DNA sequence from a candidate gene; IRES, internal ribosome entry site; Neo,
neomycin-resistance gene; Pac, puromycin-resistance gene; pB-TR,piggyBacterminal
repeat; rtTA, reverse tetracycline transactivator; tetO/mCMV, tetracycline operator
fused to the minimal cytomegalovirus promoter. Right: Percentages of SYCP3+cell
induction among GFP+(BV+and SC+) mPGCLC-derived cells at c9 under the
conditions indicated. For each condition, mPGCLC-derived cells were imaged so that
a minimum of 20 BV+and SC+cells were included per image and at least 10 such
images were acquired from two to four biological replicates. (B) Representative
images for the expressions of GFP (BV and SC) (cyan), DDX4/mCherry (magenta),
and SYCP3 (yellow) in mPGCLC-derived cells at c9 under the conditions indicated.
Cells were counterstained with DAPI (gray). Scale bars, 10mm.RESEARCH | RESEARCH ARTICLE