RESULTS
The cryofracture technique seems to have provided images with greater internal detail of the oocytes. Thus, one can observe oocytes of different size classes permeated by a conjunctive membrane (Fig. 1a). In the fractured oocytes, abundant yolk vesicles and their imprints in the cytosol were observed, when the vesicles detached during maceration (Fig. 1b-e, h). In addition, it was possible to observe a region with funneling and several folds of the membrane and zona pellucida, corresponding to the micropyle (Fig. 1h).
As the structures were enlarged, evident columnar theca cells were observed (Fig. 1b-d, 2a-b), which, together with the squamous follicular cells (Fig. 1b, e, g), form the envelope of the oocyte (Fig. 1a-i). The communication between these cells, mainly between the follicular cells and the oocyte, is carried out by a junction zone between these components, called the zona pellucida (Fig. 1b-g, 2a). It is noteworthy that the zona pellucida appears as an irregular region with several pores along its length (Fig. 1f-g).
Finally, it should be noted that the connective membrane observed in the ovaries is organized in the form of loops and reaches all the germ cells, with emphasis on the projection of blood vessels that guarantee the supply of oxygen and nutrients to the oocytes (Fig. 1i, 2c-d).