Fig. 1
Identification of the critical period in molecular, hormone and histological level of sex differentiation in Spotted knifejaw. A Gonad development of Spotted knifejaw. a-d: Primary gonad(26 dph-60 dph) development; e–h: Testis development for male spotted knifejaw; i-l: Ovary development for female spotted knifejaw; m-r: Adult gonad characteristics. B Visualization PGCs (Primordial germ cells) in Spotted knifejaw by Vasa antibody. a-d: Ovay signal for 120dph female. e–h: Testis signal for 120dph male. C Hormone levels during early development of gonad.*, P < 0.05. dph:days post hatching; 11-KT:11-ketotestosterone; E2: 17β-estradiol. D Relative expression of sex-related genes from 6 to 360 dph. *, P < 0.05; **, P < 0.01. E Timeline of the critical period for sex differentiation in Spotted knifejaw. Ed: efferent duct; Cd: central efferent duct; BSg: type B spermatogonia; ASg: type A spermatogonia; Ow: Ovary wall; Bm: basement membrane; Ol: ovigerous lamellae; Ep: early perinucleolus stage spermatocyte; PO: primary oocyte; Oc: ovary cavity Og: oogonia; St: spermatozoon; Psp: primary spermatocyte; Ssp: Secondary spermatocytes. Scale: A: a, e-m, P = 250 μm, b = 50 μm. c, d, n, o, q, r = 25 μm; B: a-h = 40 μm