reproduction > ovary > normal histology > development early-advanced previtellogenic stages

see also: Location - Structure - Oocyte maturation - Granulosa cells
early previtellogenic stage (ovary staging 0-1)


Juvenile female zebrafish, total body length 12 mm; age 4w; H&E staining
This image represents an early previtellogenic stage in ovary development, with predominant occurrence of early oocyte stages i.e. oogonium, primary oocytes stage 1, and occasional stage 2.
In this image, the following elements are present: In the intra-ovary stroma, occasional apoptotic bodies are present. The stroma tissue of the mesentery between the ovary and the liver contains eosinophilic peritoneal cells.
early previtellogenic stage (ovary staging 0-1) - primitive pole


Juvenile female zebrafish, total body length 10 mm; age 5w; H&E staining
Ovaries with progressed maturation may still contain only primitive developmental stages, especially in the rostral and caudal poles; this suggests that the growth of these organs emerges from these regions.

In this image, the following elements are present:
early previtellogenic stage (ovary staging 1-2)


Juvenile female zebrafish, total body length 11 mm; age 4w; H&E staining
The images below represent various parts of the same ovary.
The following elements are present:
intermediate previtellogenic stage (ovary staging 2)


Juvenile female zebrafish, total body length 10 mm; age 5w; H&E staining
This image represents an intermediate previtellogenic maturation stage of the ovary. This specimen contains early stages of development up to stage 3 primary oocytes: Various stages of oocyte maturation can be observed simultaneously, since maturation of oogonia is asynchronous.
Stroma and liver are also present.
intermediate previtellogenic stage (ovary staging 2) - primitive pole


Juvenile female zebrafish, total body length 10 mm; age 5w; H&E staining
Generally, further maturing ovaries still have clusters of early oocytes, particularly in the poles of the organ.
Such a region is represented in this image, showing the following elements:
advanced previtellogenic stage (ovary staging 2-3)


Juvenile female zebrafish, total body length 14 mm; age 6w; H&E staining
At advanced previtellogenic maturation stages of the ovary, the section is dominated by stage 2 and stage 3 primary oocytes, with obvious clearing of the cytoplasm. The follicle cells of the stage 3 show more prominent than those of previous stages.
In this image, the following elements are present: Maturation from oogonium is asynchronous, and therefore Various stages of oocyte maturation are present simultaneously.






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