Fig 1.
Representative photographs from stage I (the formation of ovigerous cords) (A) and stage III (the formation of follicles) (B).
Collagen type I (green) is colocalised with the proliferation marker Ki67 (red, marked with arrow). Nuclei are counterstained with DAPI. Scale bar: 25 μm. * ovigerous cords/ primordial follicles, S stroma.
Table 1.
List of genes and primers used for qRT-PCR.
Fig 2.
Morphometric analyses of the non-stromal component of the ovarian cortex during bovine fetal ovarian development.
Data are presented as means ± SEM. Samples were grouped into 5 stages of ovarian development based on their histological morphology: ovigerous cord formation (n = 7, stage I), ovigerous cord breakdown (n = 4, stage II), follicle formation (n = 3, stage III), ovarian surface epithelium (OSE) formation (n = 8, stage IV) and tunica albuginea formation (n = 5, stage V). One-way ANOVA with post hoc Tuckey’s test were used to analyse the data. * P < 0.05, ** P < 0.01, *** P < 0.001, **** P < 0.0001. Volume density is the percentage of cortex that is the non-stromal compartment.
Fig 3.
Germ and stem cell-specific genes in fetal ovarian development.
Expression levels of genes for each animal are plotted against gestational age in days (n = 16 or 17).
Fig 4.
Genes specific for GREL cells in fetal ovarian development.
Expression levels of genes for each animal are plotted against gestational age in days (n = 16 or 17).
Fig 5.
Granulosa cell-specific genes in fetal ovarian development.
Expression levels of genes for each animal are plotted against gestational age in days (n = 16 or 17).
Table 2.
Pearson’s correlation coefficients between markers for germ and stem cells and all genes examined and gestational age.
The intensity of the background colour indicates the strength of the significance of the correlation. Blue is a negative correlation and red is a positive correlation. (aP < 0.05, bP < 0.01, cP < 0.01; n = 17).
Table 3.
Pearson’s correlation coefficients between markers for GREL and granulosa cells and all genes examined and gestational age.
The intensity of the background colour indicates the strength of the significance of the correlation. Blue is a negative correlation and red is a positive correlation. (aP < 0.05, bP < 0.01, cP < 0.01; n = 17).