1 Department of Maternal and Fetal Health, Samuel Lunenfeld Research Institute,
Mount Sinai Hospital, University of Toronto, Ontario M5G 1X5, Canada
2 Department of Cell Biology, Duke University Medical Center, Durham, NC 27710,
USA
3 Department of Internal Medicine and Pharmacology, University of Texas
Southwestern Medical Center, Dallas, TX 75390, USA
4 Division of Nephrology, St Michael's Hospital, University of Toronto, Toronto,
Ontario M5B 1W8, Canada
Author for correspondence (e-mail:
quaggin{at}mshri.on.ca)
Accepted 7 May 2004
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SUMMARY |
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Key words: Pod1, Tcf21, Sf1, Gonadogenesis, Testis development, Sex reversal, Leydig cell
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Introduction |
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Further reproductive development of the internal and external genitalia is
determined by the presence or absence of a functioning testis. The internal
genitalia derive from either the Müllerian (paramesonephric) or
Wölffian (mesonephric) ducts, which initially are present in both XX and
XY embryos. Sertoli and Leydig cells produce three hormones that mediate male
sex differentiation. Sertoli cells produce anti-Müllerian hormone (AMH),
which causes regression of the Müllerian ducts. Leydig cells produce
testosterone, which induces the formation from the Wölffian ducts of
seminal vesicles, epididymis, vas deferens, and the peptide hormone
insulin-like 3 (Insl3), which is essential for normal testes descent. In the
absence of testicular hormones, the Wölffian ducts regress and the
Müllerian ducts form the oviducts, Fallopian tubes, uterus and upper
vagina in the female developmental pathway
(Byskov and Hoyer, 1994).
Although Sry unequivocally initiates the male developmental
pathway, most of the mechanisms that mediate testes development remain to be
defined. Gene knockout studies have established essential roles in early
gonadal development for several transcription factors, including Wilms tumor
suppressor 1 (WT1) (Kreidberg et
al., 1993), lim-containing homeodomain protein (Lhx9)
(Birk et al., 2000
), and the
orphan nuclear receptor steroidogenic factor 1 (Sf1)
(Parker et al., 1996
), but the
precise mechanisms by which these genes contribute to gonadogenesis remain
undefined. Even less is known about the transcriptional pathways downstream of
these genes that establish specific gonadal cell lineages, and this remains a
key area for ongoing investigations.
Transcription factors with the basic helix-loop-helix (bHLH) motif play
crucial roles in cell fate determination and differentiation in a variety of
tissues, including the gonads. For example, the bHLH factor Hand1 is
required for gonadal development in C. elegans
(Mathies et al., 2003),
whereas the bHLH gene FIG alpha (Figla) is required for
formation of the primordial follicles in the mammalian ovary
(Soyal et al., 2000
). To date,
however, no bHLH factors have been implicated in mammalian testes development
or prenatal sex differentiation.
We previously identified a bHLH protein named Pod1 and generated a null
Pod1 allele through homologous recombination in embryonic stem cells
(Quaggin et al., 1999;
Quaggin et al., 1998
).
Pod1 KO mice displayed defects in kidney, facial muscle, and splenic
development, and died at birth from respiratory failure due to an absence of
alveoli (Lu et al., 2000
;
Lu et al., 2002
;
Quaggin et al., 1999
). We
subsequently noted that the external genitalia were feminized in XY
Pod1 KO pups (data not shown), prompting us to examine the role of
Pod1 in gonadal development. We show here that the absence of
Pod1 in the urogenital ridges leads to ectopic expression of Sf1,
aberrantly committing a population of urogenital progenitor cells to a
steroidogenic cell fate in both XX and XY gonads, and disrupting normal
processes of gonadal development.
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Materials and methods |
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X-gal staining
Whole genital ridges containing the mesonephros and gonads from embryos at
11.5 and 12.5 dpc were dissected in phosphate-buffered saline (PBS) and
transferred to lacZ fixative for 30 minutes at room temperature, as
described (Partanen et al.,
1996). Samples were then rinsed in wash buffer and incubated in
lacZ stain at 37°C for 20-50 minutes, and post-fixed in 10%
formalin for 2 hours. The gonads from XX and XY embryos at 18.5 dpc were
dissected and fixed in lacZ fixative for 1 hour at room temperature.
After rinsing in lacZ wash buffer, the gonad was immersed in 30%
sucrose overnight at 4°C, and embedded in OCT. Ten micrometer thick
sections were cut with a microtome blade on a Leica CM-3050 cryostat. Samples
were rinsed in wash buffer, then incubated in lacZ stain for 1-4
hours, post-fixed in 10% formalin and counterstained with nuclear Fast
Red.
Whole-mount double-label immunohistochemistry
Embryonic genital ridges were dissected and fixed overnight in 4%
paraformaldehyde at 4°C. Samples were then washed in PBS and blocked in a
solution of 3% BSA, 1% heat-inactivated goat serum, and 0.1% Triton X-100 in
PBS for 2-3 hours at room temperature before staining with antibodies. The
primary antibodies used were anti-CD31/PECAM (Pharmingen, Ontario, Canada;
1:300 dilution), anti-laminin (1:300 dilution), anti-Sf1 (1:500 dilution),
anti-ß-galactosidase (Promega, Madison, WI, USA; 1:200 dilution) and
anti-GFP (Molecular Probes, Eugene, OR; 1:2000 dilution). Samples were
incubated in the primary antibodies and rocked at 4°C overnight. After
washing four times for at least 1 hour in PBT, samples were incubated with
secondary antibodies for 1 hour. The secondary antibodies used were
Cy3-conjugated goat anti-rat IgG (Jackson Laboratories, Ontario, Canada; 1:500
dilution) to detect anti-CD31, Cy3-conjugated donkey anti-mouse IgG (Jackson
Laboratories; 1:200 dilution) to detect anti-ß-galactosidase and
FITC-conjugated goat anti rabbit IgG (Jackson Laboratories; 1:500) to detect
anti-laminin, anti-GFP or anti-Sf1. Samples were finally washed four times for
1 hour in PBT and mounted in DABCO (Sigma) for subsequent confocal microscopy
with a Zeiss LSM 410 laser scanning confocal microscope.
Migration assays
XY gonads from 12.5 dpc ICR (albino outbred strain; JAX Laboratories, Bar
Harbor, ME, USA) or Pod1/ mice were
assembled with mesonephroi from 11.5 dpc GFP-positive mice and co-cultured on
an agar block for 46 to 72 hours, as described
(Martineau et al., 1997). A
total of 20 experiments were performed with 10 mice of each genotype. The
GFP-positive mice were generated in the laboratory of Dr A. Nagy and express
enhanced green fluorescent protein ubiquitously (gift of A. Nagy, Samuel
Lunenfeld Research Institute). Organ cultures were collected and fixed, and
wholemounts were immunostained for GFP and CD31, and visualized by confocal
microscopy as described above.
In situ hybridization
In situ hybridization was performed on paraformaldehyde-fixed/OCT-embedded
sections, as described (Conlon and Rossant,
1992). Whole-mount in situ hybridization was performed, as
previously described (Wilkinson and Nieto,
1993
). Probes used for in situ hybridization were the murine
Scc probe, a 0.5-kb EcoRI-BamH1 fragment
(Martineau et al., 1997
),
Sox9 (mouse, pSox9, 0.5-kb SmaI fragment)
(Wright et al., 1995
), mouse
11 beta-hydroxylase (Domalik et
al., 1991
) (564 bp fragment), Dhh
(Yao et al., 2002
),
Dmc1 (a gift from David Page, MIT; which contains bases 602-1245 of
the Dmc1 gene, GenBank NM 010059), Wnt4 (a gift from Andy
McMahon at Harvard; includes the entire coding region), follistatin
(a gift from Martin Matzuk at Baylor; consists of a 846 bp fragment of the
3' UTR of the follistatin cDNA). Digoxigenin-labeled probes
were prepared according to the Boehringer-Mannheim-Roche protocol.
Analysis of apoptosis
Apoptosis analysis was performed on paraffin sections using TUNEL labeling
methods. Embryonic genital ridges were dissected and fixed in 10% formaldehyde
at 4°C and embedded in paraffin wax. After dewaxing, samples were
rehydrated and digested, before being pre-incubated with One-Phor-ALL-buffer
(Amersham Pharmacia Biotech, Canada) for 10 minutes and incubated with TdT
solution mix, which includes 1xone-Phor-ALL-buffer; 6 nM Biotin-16-dUTP
(Roche Applied Science, Canada), 1 µM dATP; 0.2 U TdT enzyme and 0.01%
Triton X-100, for 2 hours at 37°C. Samples were then incubated in ABC
solution (VectaStain Kit; Vector Laboratories, Burlingame, CA 94010) and
further developed with DAB (Peroxidase Substrate Kit DAB, Vector Laboratories)
color staining. Samples were counterstained with Hematoxylin, dehydrated,
mounted and photographed.
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Results |
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Pod1 is expressed in both XX and XY gonads during embryogenesis
The dramatic gonadal phenotype in male and female Pod1 KO mice
could reflect either intrinsic defects in the gonads or secondary effects due
to lack of Pod1 expression in other sites. To investigate
Pod1 expression, we took advantage of a lacZ reporter gene
incorporated into the KO allele in Pod1+/ mice. At
11.5 dpc, lacZ staining was observed in both XY and XX urogenital
ridges (Fig. 2A,B). Sections
taken from the stained urogenital ridges demonstrated that Pod1
expression in both sexes localized primarily to the coelomic epithelium of the
gonad, and to the boundary region between the gonad and mesonephros
(Fig. 2C,D). At 12.5 dpc,
lacZ expression persisted in both XY and XX gonads
(Fig. 2E,F), with somewhat
higher expression seen in XY gonads (Fig.
2G,H), mostly concentrated in the coelomic epithelium.
|
Early gonad development is disrupted in Pod1 KO mice
To pinpoint when the Pod1 KO gonads first exhibit abnormalities,
we examined earlier stages of gonad development. Gonads are distinguishable
from the mesonephros by approximately 10.5 dpc. In males, the Sertoli cells
cluster around the primordial germ cells at 12.0 dpc to initiate
testicular cord formation, and by 12.5 dpc, the testes can be grossly
distinguished from the ovaries because they are larger and exhibit a
male-specific vascular pattern.
At 11.0 dpc, differences were already observed between Pod1 KO and wild-type gonads. Both XY and XX Pod1 KO gonads were slightly shortened in length and had an irregular surface (data not shown). At 12.5 dpc, testes from Pod1 KO embryos lacked the features of normal testes noted above, and instead resembled Pod1 KO ovaries (Fig. 3A,B). Both XY and XX Pod1 KO gonads displayed morphological abnormalities, including a large invagination of the surface epithelium near the anterior end of the gonad (Fig. 3A,B).
|
To further assess testicular cord formation in Pod1 KO testes, we examined expression of laminin and CD31/PECAM. Laminin is a component of the basal lamina deposited by Sertoli cells that delineates testicular cords, whereas PECAM is a membrane protein specific to germ cells and vascular cells. Wild-type testes at 12.5 dpc displayed numerous cords that were clearly outlined by the laminin staining (Fig. 4A). The coelomic epithelium was a well-organized, single layer containing cylindrical epithelial cells above an intact basal lamina (Fig. 4C). The characteristic male-specific coelomic vessel was clearly visible in the mesenchyme just beneath the coelomic epithelium (Fig. 4C). By contrast, the Pod1 KO testes at 12.5 dpc were disorganized and lacked distinct testicular cords (Fig. 4B). The coelomic epithelium was highly irregular and contained numerous invaginations. The basal lamina was disrupted in regions, and germ cells were directly adjacent to the coelomic epithelium near the basal lamina. No coelomic vessel was observed (Fig. 4D) but, unlike the wild-type testes, numerous vascular circuits extended through the interior of the gonad and contacted the coelomic epithelium. The germ cells, which migrate from the base of the allantois through the gut mesentery and enter the gonads between 10.5 and 11.5 dpc, were present in comparable numbers in both wild-type and Pod1 KO testes at 12.5 dpc, as determined by PECAM labeling (Fig. 4C,D).
|
Vascular development is abnormal in Pod1 KO gonads because of an intrinsic defect in the gonad
Endothelial cell migration from the mesonephros into the developing gonad
is an early event in testis development
(Brennan et al., 2002). We
therefore used co-culture migration assays to determine whether defective
endothelial cell migration contributed to the abnormal development of the
coelomic vessel and other vessels in the mutant testes. GFP-expressing
wild-type mesonephroi were combined with wild-type or Pod1 KO 12.5
dpc XY gonads, and co-cultured for 48 to 72 hours
(Fig. 5A,B). By 48 hours, a
GFP-positive vascular network was clearly observed in wild-type gonads but was
absent from Pod1 KO gonads. Although this result is interesting and
may explain the defects in vascular patterning observed in the mutant gonads,
it is not clear whether Pod1 is normally required within the gonad for
endothelial cell migration to occur, or if other morphological defects in the
mutant gonads are responsible for the block in migration.
|
Sertoli cells can still differentiate in Pod1 KO testes
Sertoli cells are the first somatic lineage to arise in the testes and are
believed to play a crucial role in its subsequent differentiation and
organization. To determine whether Sertoli cell differentiation was disrupted
in Pod1 KO testes, we examined the expression patterns of two Sertoli
cell-specific markers, Sox9 and desert hedgehog (Dhh). At
12.5 dpc, both Sox9 and Dhh were highly expressed in the
wild-type testes (Fig. 6A,C),
but were absent in wild-type ovaries (Fig.
6B,D). Both Sox9 and Dhh were expressed in the
Pod1 KO testes, although transcript levels were decreased,
particularly in the anterior domain (Fig.
6A,C). Real-time PCR data analysis showed no difference in
Sry expression between Pod1 KO and
Pod1+/ XY gonads (data not shown). These results
suggest that Pod1 is not required for Sertoli cell differentiation
(as these cells express Sertoli cell-specific markers), but rather that it may
be required for the maintenance or expansion of the Sertoli cell population.
As expected, neither Sox9 nor Dhh were expressed in Pod1 KO
ovaries. By 18.5 dpc, no Sox9 or Dhh expression was observed
in XY Pod1 KO gonads (not shown), although this may reflect the
degeneration of the mutant gonads rather than a disruption of later Sertoli
cell development.
|
Although Scc also is required for steroid hormone synthesis in the postnatal ovary, mouse ovaries normally do not express Scc in utero (Fig. 6F). Pod1 KO ovaries had marked upregulation of Scc relative to wild-type ovaries (Fig. 6F). As in XY Pod1 KO mice, this expression concentrated at the posterior region of the Pod1 KO ovary, whereas the anterior end of the gonad again appeared to be fused with the adrenal primordium (Fig. 6F).
At 11.5 dpc, Scc expression is restricted to the adrenal primordia of wild-type XX and XY embryos, but is precociously expressed throughout the gonads within the urogenital ridges of Pod1 KO XX and XY mice (Fig. 6G,H), demonstrating that the steroidogenic cell lineage is not only expanded but also differentiates prematurely in Pod1 mutants.
To determine whether other cytochrome P450 steroidogenic enzymes also were aberrantly expressed, we performed in situ analysis for the adrenal-specific enzyme, steroid 11ß-hydroxylase (11ß-OH). In contrast to Scc, this enzyme was appropriately restricted to the adrenal primordia in both wild-type and Pod1 KO embryos, suggesting that the absence of Pod1 does not cause a general dysregulation of steroid hydroxylase expression (Fig. 6I,J). Furthermore, these results show that although no clear morphologic boundary can be seen between the adrenal primordial and the gonad in Pod1 KO embryos, these tissues are distinguishable at the molecular level.
XX markers are expressed in Pod1 KO gonads
To determine how early ovarian development is affected in XX Pod1
mutant gonads, early markers of XX gonad formation were examined
(Fig. 7). We performed in situ
analysis for Wnt4 and follistatin, both markers of XX
somatic cells, and Dmc1, a marker for XX germ cells entering meiosis.
Wnt4 is normally expressed within the gonads of XX but not XY mice at
12.5 dpc. Wnt4 was expressed in both mutant and wild-type XX gonads
at this stage. Of note, expression of Wnt4 in the mesonephros was
increased in both XX and XY mutants, as compared with controls, but the
significance of this is not clear. Follistatin
(Menke and Page, 2002) was
also expressed in both mutant and wild-type XX gonads, but at a somewhat
reduced level in mutants. Finally, Dmc1
(Menke et al., 2003
)
expression was also observed in Pod1 mutant XX gonads. These results
demonstrate that both somatic cells and germ cells initiate aspects of normal
ovarian development, but this is clearly disrupted by 18.5 dpc, as no meiotic
germ cells are observed in Pod1/ XX gonads
at this stage.
|
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Discussion |
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We show here for the first time that Pod1 is expressed in the
indifferent gonad at 11.5 dpc, subsequently localizing to the interstitial
region as the testes form discrete compartments. By 18.5 dpc, the
Pod1-directed lacZ reporter in testes was expressed in
peritubular myoid cells, fetal Leydig cells, and pericytes surrounding blood
vessels, whereas lacZ-expressing cells in the ovaries were found in
the medulla and the interstitial spaces between the primordial follicles. We
also noted lacZ expression directed by Pod1 regulatory
sequences in the coelomic epithelium of the gonad and mesonephric stromal
cells at the boundary between the gonad and mesonephros. Thus, the gonadal
abnormalities seen in Pod1 KO mice, which are apparent by the
indifferent gonad stage at 11.5 dpc, may reflect intrinsic defects in cells
that arise directly in the indifferent gonad. However, Pod1 is also
expressed in regions from which progenitor cells migrate into the gonads to
generate several somatic lineages in the interstitial region of the testes
(Karl and Capel, 1998;
Martineau et al., 1997
).
Although further studies with cell-specific KO of Pod1 are needed, it
is likely that both intragonadal and extragonadal expression of Pod1
is required for normal development of the gonads.
One striking defect in Pod1 KO testes is the absence of the
characteristic coelomic vessel. Furthermore, vascular abnormalities were
observed throughout both XX and XY gonads. Migration assays showed that
endothelial cell migration from wild-type GFP-expressing mesonephroi into XY
KO gonads was markedly decreased compared with wild-type gonads. This
observation most likely explains the absence of the male-specific coelomic
vessel and its branches in the testes, as these structures are known to derive
from migrating endothelial cells (Brennan
et al., 2002). Gonadal pericytes, which are intimately associated
with endothelial cells, also express Pod1. Defects in pericyte
differentiation have previously been described in Pod1 KO mice
(Cui et al., 2003
), and
pericytes are absent in Pod1 KO gonads. Disrupted pericyte
development in Pod1 KO mice may contribute to the observed vascular
defects, as previous studies have shown that genetic or physical ablation of
pericytes leads to defects in vascular remodeling
(Benjamin et al., 1998
;
Hellstrom et al., 1999
;
Lindahl et al., 1997
).
To further define the basis for the abnormal urogenital development in
Pod1 KO mice, we examined the expression of markers of different
gonadal cell lineages. Two markers of Sertoli cells, Sox9 and
Dhh, were still expressed in Pod1 KO testes (albeit at
reduced levels), demonstrating that the initial stages of Sertoli cell
development can proceed in the absence of Pod1. Similarly, early
female somatic markers are expressed in XX but not XY mutants, which
illustrates that initial stages of the female developmental pathway can also
occur without Pod1. By contrast, we observed striking changes in the
expression of the steroidogenic enzyme Scc in both XX and XY
Pod1 KO embryos. Although Scc is not expressed in wild-type
ovaries during embryogenesis, Scc was strongly expressed in the
gonads of both XX and XY Pod1 KO embryos. Because the adrenal
primordia did not clearly separate from the gonads in Pod1 KO
embryos, we wondered whether the cells expressing Scc in the
Pod1 KO gonads might be ectopically located adrenal cells, as
reportedly occurs in Wnt4 KO mice
(Heikkila et al., 2002).
However, the adrenal-specific steroidogenic enzyme 11ß-OH was not
expressed in the corresponding region of either XX or XY Pod1 KO
gonads, suggesting that the Scc-expressing cells in Pod1 KO
gonads are not ectopic adrenal cells. Collectively, our data demonstrate that
the absence of Pod1 permits ectopic expression of Scc in the
genital ridge, rather than expanding the field of adrenocortical cells into
the genital ridge.
How might the absence of Pod1 be associated with the dysregulated
expression of Scc? Previous transfection studies have shown that
Scc expression is activated by the orphan nuclear receptor Sf1
(Clemens et al., 1994), which
plays key roles in steroidogenesis and development of the adrenal glands and
gonads (Luo et al., 1999
). In
Pod1 KO embryos, Sf1 expression was increased both in the coelomic
epithelium and at the boundary between the gonad and mesonephros, two regions
where Pod1 is normally expressed. Furthermore, Sf1 was co-expressed
with the ß-galactosidase reporter that replaced the first exon of the
Pod1 gene, demonstrating ectopic expression of Sf1 in
Pod1-expressing cells. Together, these findings support the model
that Pod1 normally represses Sf1 expression in these sites in a cell
autonomous manner, and thus concomitantly prevents the ectopic expression of
Scc. Consistent with this model, Pod1 repressed Sf1 promoter
activity in mouse Y1 and MA-10 steroidogenic cell lines in a dose-dependent
manner (data not shown). Moreover, mutation of the E box at 82 to
77 markedly decreased Sf1 promoter activity, as previously
described (Tamura et al.,
2001
). Although previous studies have shown that Pod1 can bind to
the E-box in the smooth muscle
-actin and p21 promoters
(Funato et al., 2003
;
Hidai et al., 1998
;
Lu et al., 1998
), the E-box in
the Sf1 promoter does not contain the Pod1 consensus sequence
determined through binding-site selection (P. Igarashi, unpublished).
Furthermore, Pod1 was unable to bind to the Sf1 E-box element in
EMSAs, even in the presence of the cofactor E12 (data not shown). Instead, we
found that Pod1 can inhibit the binding of Usf1 to the Sf1 E-box in a
dose-dependent manner (data not shown), thus preventing the action of this
known activator of Sf1 expression
(Daggett et al., 2000
)
although co-immunoprecipitation results failed to show that Pod1 directly
interacts with the Usf1 protein. Collectively, our results suggest that Pod1
represses Sf1 expression in an indirect manner.
Although our results do not prove that the ectopic expression of Sf1 causes
the impaired gonadogenesis in Pod1 KO mice, they do demonstrate a
striking association between Pod1 deficiency and dysregulated Sf1
expression. Based on this association, we propose that Pod1 normally represses
Sf1 expression in a pluripotent interstitial progenitor cell
population, and that dysregulated expression of Sf1 in Pod1 KO mice
commits them to differentiate prematurely or excessively towards the
steroidogenic cell lineage (Fig.
8C). Similar ectopic expression of Sf1 in embryonic stem cells
forced them to differentiate towards a steroidogenic cell fate, and to express
Scc (Crawford et al.,
1997). In the XY gonad, we further propose that expansion of the
Leydig cell population is associated with the loss of peritubular myoid cells
and pericytes, thereby disrupting the organization of testicular structure and
vasculature. Although the different cell types in the embryonic ovary are less
well defined, a similar increase in the steroidogenic lineage was observed,
suggesting that Pod1 plays similar roles in both sexes during the
early stages of gonad formation. Regardless of the underlying mechanism, our
studies show that Pod1 is essential for testis and ovary development,
and establish a novel transcriptional pathway for allocating the somatic cell
lineages within the gonad.
Despite the expanded domain of Sf1 and Scc expression,
neither XX nor XY pups underwent virilization of internal or external
genitalia, and the testes failed to descend. These findings suggest that the
biosynthesis of all three mediators of male sex differentiation is impaired in
XY Pod1 KO mice. As noted above, ectopic Sf1 expression in embryonic
stem cells induced the expression of Scc but did not induce the full
complement of steroidogenic enzymes
(Crawford et al., 1997).
Studies of KO mice and of patients with impaired sex differentiation suggest
that multiple genes interact to direct the complex developmental events in
gonadogenesis and sex differentiation
(Parker et al., 1999
); thus,
the combined activation of several genes may be needed to induce the
biosynthesis of the hormones that mediate male sex differentiation.
Alternatively, it remains possible that the impaired virilization in
Pod1 KO mice results from degeneration of Leydig cells and/or the
vascular defects described above. Nonetheless, our data are consistent with
analyses of humans with autosomal dominant and recessive inactivating
mutations in SF1 (Achermann et al.,
1999
; Achermann et al.,
2002
), suggesting that precise regulation of Sf1 is required for
normal gonadal development.
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ACKNOWLEDGMENTS |
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Footnotes |
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REFERENCES |
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Achermann, J. C., Ito, M., Hindmarsh, P. C. and Jameson, J. L. (1999). A mutation in the gene encoding steroidogenic factor-1 causes XY sex reversal and adrenal failure in humans. Nat. Genet. 22,125 -126.[CrossRef][Medline]
Achermann, J. C., Ozisik, G., Ito, M., Orun, U. A., Harmanci,
K., Gurakan, B. and Jameson, J. L. (2002). Gonadal
determination and adrenal development are regulated by the orphan nuclear
receptor steroidogenic factor-1, in a dose-dependent manner. J.
Clin. Endocrinol. Metab. 87,1829
-1833.
Benjamin, L. E., Hemo, I. and Keshet, E.
(1998). A plasticity window for blood vessel remodelling is
defined by pericyte coverage of the preformed endothelial network and is
regulated by PDGF-B and VEGF. Development
125,1591
-1598.
Birk, O. S., Casiano, D. E., Wassif, C. A., Cogliati, T., Zhao, L., Zhao, Y., Grinberg, A., Huang, S., Kreidberg, J. A., Parker, K. L. et al. (2000). The LIM homeobox gene Lhx9 is essential for mouse gonad formation. Nature 403,909 -913.[CrossRef][Medline]
Brennan, J., Karl, J. and Capel, B. (2002). Divergent vascular mechanisms downstream of Sry establish the arterial system in the XY gonad. Dev. Biol. 244,418 -428.[CrossRef][Medline]
Byskov, A. G. and Hoyer, P. E. (1994). Embryology of mammalian gonads and ducts. In The Physiology of Reproduction (ed. E. Knobil and J. D. Neill), pp.487 -536. New York, NY: Raven Press.
Clemens, J. W., Lala, D. S., Parker, K. L. and Richards, J. S. (1994). Steroidogenic factor-1 binding and transcriptional activity of the cholesterol side-chain cleavage promoter in rat granulosa cells. Endocrinology 134,1499 -1508.[Abstract]
Colvin, J. S., Green, R. P., Schmahl, J., Capel, B. and Ornitz, D. M. (2001). Male-to-female sex reversal in mice lacking fibroblast growth factor 9. Cell 104,875 -889.[Medline]
Conlon, R. A. and Rossant, J. (1992). Exogenous
retinoic acid rapidly induces anterior ectopic expression of murine Hox-2
genes in vivo. Development
116,357
-368.
Crawford, P. A., Sadovsky, Y. and Milbrandt, J. (1997). Nuclear receptor steroidogenic factor 1 directs embryonic stem cells toward the steroidogenic lineage. Mol. Cell. Biol. 17,3997 -4006.[Abstract]
Cui, S., Schwartz, L. and Quaggin, S. E. (2003). Pod1 is required in stromal cells for glomerulogenesis. Dev. Dyn. 226,512 -522.[CrossRef][Medline]
Daggett, M. A., Rice, D. A. and Heckert, L. L.
(2000). Expression of steroidogenic factor 1 in the testis
requires an E box and CCAAT box in its promoter proximal region.
Biol. Reprod. 62,670
-679.
Domalik, L. J., Chaplin, D. D., Kirkman, M. S., Wu, R. C., Liu, W. W., Howard, T. A., Seldin, M. F. and Parker, K. L. (1991). Different isozymes of mouse 11 beta-hydroxylase produce mineralocorticoids and glucocorticoids. Mol. Endocrinol. 5,1853 -1861.[Abstract]
Funato, N., Ohyama, K., Kuroda, T. and Nakamura, M.
(2003). Basic helix-loop-helix transcription factor
epicardin/capsulin/Pod-1 suppresses differentiation by negative regulation of
transcription. J. Biol. Chem.
278,7486
-7493.
Gubbay, J., Collignon, J., Koopman, P., Capel, B., Economou, A., Munsterberg, A., Vivian, N., Goodfellow, P. and Lovell-Badge, R. (1990). A gene mapping to the sex-determining region of the mouse Y chromosome is a member of a novel family of embryonically expressed genes. Nature 346,245 -250.[CrossRef][Medline]
Gubbay, J., Vivian, N., Economou, A., Jackson, D., Goodfellow, P. and Lovell-Badge, R. (1992). Inverted repeat structure of the Sry locus in mice. Proc. Natl. Acad. Sci. USA 89,7953 -7957.[Abstract]
Heikkila, M., Peltoketo, H., Leppaluoto, J., Ilves, M.,
Vuolteenaho, O. and Vainio, S. (2002). Wnt-4 deficiency
alters mouse adrenal cortex function, reducing aldosterone production.
Endocrinology 143,4358
-4365.
Hellstrom, M., Kalen, M., Lindahl, P., Abramsson, A. and
Betsholtz, C. (1999). Role of PDGF-B and PDGFR-beta in
recruitment of vascular smooth muscle cells and pericytes during embryonic
blood vessel formation in the mouse. Development
126,3047
-3055.
Hidai, H., Bardales, R., Goodwin, R., Quertermous, T. and Quertermous, E. E. (1998). Cloning of capsulin, a basic helix-loop-helix factor expressed in progenitor cells of the pericardium and the coronary arteries. Mech. Dev. 73, 33-43.[CrossRef][Medline]
Karl, J. and Capel, B. (1998). Sertoli cells of the mouse testis originate from the coelomic epithelium. Dev. Biol. 203,323 -333.[CrossRef][Medline]
Koopman, P., Munsterberg, A., Capel, B., Vivian, N. and Lovell-Badge, R. (1990). Expression of a candidate sex-determining gene during mouse testis differentiation. Nature 348,450 -452.[CrossRef][Medline]
Kreidberg, J. A., Sariola, H., Loring, J. M., Maeda, M., Pelletier, J., Housman, D. and Jaenisch, R. (1993). WT-1 is required for early kidney development. Cell 74,679 -691.[Medline]
Lindahl, P., Johansson, B. R., Leveen, P. and Betsholtz, C.
(1997). Pericyte loss and microaneurysm formation in
PDGF-B-deficient mice. Science
277,242
-245.
Lu, J., Richardson, J. A. and Olson, E. N. (1998). Capsulin: a novel bHLH transcription factor expressed in epicardial progenitors and mesenchyme of visceral organs. Mech. Dev. 73,23 -32.[CrossRef][Medline]
Lu, J., Chang, P., Richardson, J. A., Gan, L., Weiler, H. and
Olson, E. N. (2000). The basic helix-loop-helix transcription
factor capsulin controls spleen organogenesis. Proc. Natl. Acad.
Sci. USA 97,9525
-9530.
Lu, J. R., Bassel-Duby, R., Hawkins, A., Chang, P., Valdez, R.,
Wu, H., Gan, L., Shelton, J. M., Richardson, J. A. and Olson, E. N.
(2002). Control of facial muscle development by MyoR and
capsulin. Science 298,2378
-2381.
Luo, X., Ikeda, Y., Lala, D., Rice, D., Wong, M. and Parker, K. L. (1999). Steroidogenic factor 1 (SF-1) is essential for endocrine development and function. J. Steroid. Biochem. Mol. Biol. 69,13 -18.[CrossRef][Medline]
Martineau, J., Nordqvist, K., Tilmann, C., Lovell-Badge, R. and Capel, B. (1997). Male-specific cell migration into the developing gonad. Curr. Biol. 7, 958-968.[Medline]
Mathies, L. D., Henderson, S. T. and Kimble, J.
(2003). The C. elegans Hand gene controls
embryogenesis and early gonadogenesis. Development
130,2881
-2892.
McLaren, A. (1991). Development of the mammalian gonad: the fate of the supporting cell lineage. BioEssays 13,151 -156.[Medline]
Menke, D. B. and Page, D. C. (2002). Sexually dimorphic gene expression in the developing mouse gonad. Gene Expr. Patterns 2,359 -367.[CrossRef][Medline]
Menke, D. B., Koubova, J. and Page, D. C. (2003). Sexual differentiation of germ cells in XX mouse gonads occurs in an anterior-to-posterior wave. Dev. Biol. 262,303 -312.[CrossRef][Medline]
Morohashi, K. I. and Omura, T. (1996).
Ad4BP/SF-1, a transcription factor essential for the transcription of
steroidogenic cytochrome P450 genes and for the establishment of the
reproductive function. FASEB J.
10,1569
-1577.
Parker, K. L. (1998). The roles of steroidogenic factor 1 in endocrine development and function. Mol. Cell. Endocrinol. 145,15 -20.[CrossRef][Medline]
Parker, K. L. and Schimmer, B. P. (1997).
Steroidogenic factor 1: a key determinant of endocrine development and
function. Endocr. Rev.
18,361
-377.
Parker, K. L., Ikeda, Y. and Luo, X. (1996). The roles of steroidogenic factor-1 in reproductive function. Steroids 61,161 -165.[CrossRef][Medline]
Parker, K. L., Schedl, A. and Schimmer, B. P. (1999). Gene interactions in gonadal development. Annu. Rev. Physiol. 61,417 -433.[CrossRef][Medline]
Partanen, J., Puri, M. C., Schwartz, L., Fischer, K. D.,
Bernstein, A. and Rossant, J. (1996). Cell autonomous
functions of the receptor tyrosine kinase TIE in a late phase of angiogenic
capillary growth and endothelial cell survival during murine development.
Development 122,3013
-3021.
Quaggin, S. E., Vanden Heuvel, G. B. and Igarashi, P. (1998). Pod-1, a mesoderm-specific basic-helix-loop-helix protein expressed in mesenchymal and glomerular epithelial cells in the developing kidney. Mech. Dev. 71,37 -48.[CrossRef][Medline]
Quaggin, S. E., Schwartz, L., Post, M. and Rossant, J.
(1999). The basic-helix-loop-helix protein Pod-1 is critically
important for kidney and lung organogenesis.
Development 126,5771
-5783.
Rice, D. A., Kirkman, M. S., Aitken, L. D., Mouw, A. R.,
Schimmer, B. P. and Parker, K. L. (1990). Analysis of the
promoter region of the gene encoding mouse cholesterol side-chain cleavage
enzyme. J. Biol. Chem.
265,11713
-11720.
Sinclair, A. H., Berta, P., Palmer, M. S., Hawkins, J. R., Griffiths, B. L., Smith, M. J., Foster, J. W., Frischauf, A. M., Lovell-Badge, R. and Goodfellow, P. N. (1990). A gene from the human sex-determining region encodes a protein with homology to a conserved DNA-binding motif. Nature 346,240 -244.[CrossRef][Medline]
Soyal, S. M., Amleh, A. and Dean, J. (2000).
FIGalpha, a germ cell-specific transcription factor required for ovarian
follicle formation. Development
127,4645
-4654.
Tamura, M., Kanno, Y., Chuma, S., Saito, T. and Nakatsuji, N. (2001). Pod-1/Capsulin shows a sex- and stage-dependent expression pattern in the mouse gonad development and represses expression of Ad4BP/SF-1. Mech. Dev. 102,135 -144.[CrossRef][Medline]
Wilkinson, D. G. and Nieto, M. A. (1993). Detection of messenger RNA by in situ hybridization to tissue sections and whole mounts. Methods Enzymol. 225,361 -371.[Medline]
Wright, E., Hargrave, M. R., Christiansen, J., Cooper, L., Kun, J., Evans, T., Gangadharan, U., Greenfield, A. and Koopman, P. (1995). The Sry-related gene Sox9 is expressed during chondrogenesis in mouse embryos. Nat. Genet. 9, 15-20.[Medline]
Yao, H. H., Whoriskey, W. and Capel, B. (2002).
Desert Hedgehog/Patched 1 signaling specifies fetal Leydig cell fate in testis
organogenesis. Genes Dev.
16,1433
-1440.