FIGURE 2

FIGURE 2

Developmental trajectory of gonads from ZW and ZZ fish. (A,C,E,G,I,K,M,N) ZW gonads. (B,D,F,H,J,L): ZZ gonads. (A,B) 10dpf. (C,D) 14dpf. (E,F) 19dpf. (G,H) 22dpf. (I,J) 26dpf. (K,L)30dpf. At 19dpf and earlier, ZW and ZZ gonads were histologically similar, but at 22dpf and later, oocytes were developing in ZW, but not ZZ gonads. At 26dpf, some ZZ gonads showed clusters of spermatogonia, and at 30dpf, most ZZ gonads were still immature testes that were organized into cysts containing spermatogonia and spermatocytes. No ZZ gonad studied showed any oocytes at any developmental stage, but instead, showed direct development into testes. (M) At 26dpf, some ZW gonads were mostly ovary with a few pycnotic cells. (N) At 30dpf, some ZW gonads were mostly testes with a few pycnotic cells. Abbreviations: *, gonocytes; g, gonad; I and II, Stage I and Stage II oocytes; in, intestine; li, liver; o, oocyte; pc, pycnotic cell; sc, spermatocyte; sg, spermatogonium.