XB-IMG-159760
Xenbase Image ID: 159760
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Fig. 6. Changes in gonad structure during sexual differentiation. A. The earliest signs of ovarian differentiation at NF53; Left panel shows the ovary composed of cortex, and medulla (m) with cavity (ovarian secondary cavity); stroma (st) is located between cortex and medulla; all oogonia (g) are attached to the surface epithelium (se); Right panel shows the cross section of the ovary through its internodal region; the medulla is absent and stroma fills the center of the gonad; scale 20 µm. B. The earliest signs of testis differentiation at NF53; there is no division into cortex and medulla; spermatogonia (g) detach from surface epithelium and disperse within whole gonads; scale 20 µm. C. EM image of ovarian cortex at NF54; oogonium (g) is directly attached to the surface epithelial cell (se) and completely enclosed by it; basal lamina is present (arrows) under the somatic cell (se) and separate the cortex from underlying stroma where stromal cells (st) are surrounded by extracellular matrix (ECM). D. EM image of testis surface at NF54; spermatogonium (g) is enclosed by pre-Sertoli cell (pSc) and does not contact surface epithelium (se); thin sheets of extracellular matric (arrows) separate somatic cells and underlie sterile surface epithelium. E. Numerous desmosome-like cell junctions (arrows) are present between somatic cells of the ovarian cortex; there are no cell junctions between somatic and germ cell. F. In developing testis, cell junctions (arrows) are limited only to surface region; stromal cell (st) is easily distinguishable due to dark cytoplasm. G. Immunolocalization of laminin in developing ovary, indicating location of two basal laminae: under cortex (arrow) and around medulla (arrowhead). H. Immunolocalization of laminin in developing testis, indicating location of many branches of basal laminae (arrowheads) dispersed in the gonad and located also under thin surface epithelium. I. Scheme of early ovary; ingressing stroma locates between the cortex (containing oogonia) and sterile medulla (m), two basal laminae (arrows) separate stroma (st) from the cortex and medulla; all germ cells are connected to surface epithelium. J. Scheme of early testis; ingressing stroma separates spermatogonia and somatic cells (pre-Sertoli cells, pSc) from sterile surface epithelium. Scale bars: A,B,G,H 20 µm; C-F 2 µm. Image published in: Piprek RP et al. (2017) Copyright © 2017. Image reproduced with permission of the Publisher, Elsevier B. V.
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