Triploidy and intersexuality in adult commercial layers

The cause of masculinisation of the left ovary and the outgrowth of the vestigial right gonad was investigated in intersexual hens. Tumour-like cell masses, resembling mouse tubular adenomas of the ovary, were observed in the majority of masculinised left gonads. Except for one male and two intersexuals, testosterone concentrations were below detectable levels. For oestrogen, progesterone and the oestrogen : progesterone ratio all differences were significant, except for the difference between the intersex and the male. Histochemically this cell mass showed weak androgen-synthesising activity. These intersexual gonads showed similarities to normal testicular tissue. Karyotyping revealed 3n-autosomes and a ZZW sex chromosome constitution. The early and almost complete absence of cortical follicular structures was most notable and may have been the cause of the sex reversal.