Genetic selection over many years has significantly improved the growth rate of broilers and increased the number of eggs laid by egg laying chicken breeds. Selection has improved desired parameters, but has caused some negative effects as well. Adverse effects of selection may negatively affect embryonic development. The number of live and apoptotic blastodermal cells (BCs) at the X stage of embryogenesis may be a good indicator of changes in selected individuals. In this paper, a comparison of the number of live and apoptotic BCs was made for three lines of quail: Pharaoh (F33), meat-type line, selected for body weight; egg laying line (S33), selected for egg number; and laying line (S22), additionally selected (for 17 generations) for high yolk cholesterol content. Apoptotic BCs were separated by the magnetic activated cell sorting (MACS) method. The percentage of live and apoptotic BCs was different (P≤0.01) for F33 (35.8% and 64.2%, respectively) and S33 (60.0% and 36.4%). The number of apoptotic BCs for F33 embryos (45 098) was higher (P≤0.01) compared to the number of apoptotic BCs for S33 embryos (26 667). The selection for high yolk cholesterol content caused an increase (P≤0.01) in the total number of BCs from 78 403 (S33) to 14 0139 (S22). The percentage of apoptotic BCs was lower (P≤0.01) in the S22 line (17.1%) compared to the S33 line (36.4%). The results showed that it is possible to evaluate the effects of selection in the early stage of embryonic development.