After 12-16 wk, the gonads begin to differentiate, and both oogonia
and spermatagonia are present.
spermatogonia and Only oogonia
and primary primary spermatocytes are growth oocytes are present.
The quantity of Characeae oogonia
is in its maximum.
For ovaries, we counted oogonia
and oocytes in sections stained with hematoxylin and eosin.
In some individuals, ovaries contained only oogonia
, but in other females at a more advanced stage of development and with larger ovaries, both oogonia
and primary oocytes in the perinucleolar stage were present.
4B), gonadal tubules constitute groups of oogonia
in division that are still attached to the gonadal tubule wall (oocyte diameter, < 15 [micro]m).
Phase Subphase Description Immature Only oogonia
and primary oocytes present.
In all cases of testis-ova, oogonia
were present throughout the testicular tissue (Figure 3).
At 10[degrees]C, female germinal follicles contained primarily vitellogenic oocytes, with the majority still oogonia
or young oocytes.
Key criteria included the presence of oogonia
and primitive testicular tissue in the gonads of bisexual juveniles, the presence of brown body atretic structures in testes of mature sex-changed males as evidence of prior female function, and the occurrence of transitional individuals whose gonads contained both developing male and regressing female tissue types (Sadovy de Mitcheson and Liu, 2008).
and stage 1 oocytes were seen in the gonad cavity of an 18-too-old female, whereas in the gonad of 2-y-old females, all stages of oogenesis could be distinguished, although mature oocytes were not abundant.
1992) but excludes precursor cells such as previtellogenic follicles (PVFs) or oogonia