Interphase nuclei of skin cells have been studied in chick embryos from 12 to 14 incubation days, when the anatomical phenotype of the female gonads is distinguished from that of the male gonads. Out of thousand male cells and thousand female cells, these results were obtained: a) the total number of the heterochromatic bodies for nucleus is greater for the male than for the female embryos (m: 9.21 ± 0.18; f: 6.89 ± 0.10); b) the total area of the heterochromatic bodies for nucleus is greater for the male than for the female embryos (m: 56.9 ± 1.6 $\mu^{2}$; f: 45.9 ± 1.0 $\mu^{2}$); c) 41% female nuclei have an heterochromatic body considerably greater than the others. These data may be utilized in order to diagnose the sexual genotype of young embryos, in which morphological differences between ovary and testis structures are not recognizable.
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Con il contributo del Ministero per i Beni e le Attività Culturali