Absence of a sex vesicle in meiotic foetal germ cells is consistent with an XY sex chromosome constitution.
Sex vesicles were not seen in meiotic germ cells isolated from male and female foetal adrenals, although they were readily identified in adult male meiotic germ cells prepared by the same air-drying method. It is suggested that the failure of the XY germ cells from the male adrenals to develop a sex vesicle is due to their embarking on oogenesis rather than spermatogenesis, and that the absence of a sex vesicle does not necessarily indicate lack of a Y chromosome.
D000311:Adrenal Glands / Q000196:embryology; D000818:Animals; D005260:Female; D005854:Germ Cells / Q000166:cytology*; D008297:Male; D008540:Meiosis; D051379:Mice; D009866:Oogenesis; D010053:Ovary / Q000166:cytology; D013737:Testis / Q000166:cytology; D014960:X Chromosome; D014998:Y Chromosome