OBSERVATIONS ON PLOIDY OF CELLS AND ON REPRODUCTIVE-PERFORMANCE IN PARTHENOGENETIC TURKEYS

Using flow cytometry, the ploidy levels of parthenogenetic turkeys wer e quantified from blastodisc stage to adulthood. Eggs were collected f rom noninseminated hens of the Beltsville Small White flock, known for their high degree of parthenogenesis, and the blastodermal cells from developing embryos were compared with those of embryos produced by he ns inseminated with semen from males of the same flock. Erythrocytes o f parthenogens from Day 10 of incubation to 27 mo of age were also use d for ploidy determination. Sperm and erythrocyte preparations from no rmal males of the above flock served as haploid and diploid standards, respectively. In parthenogenetically developing blastoderms, 40.3 +/- 14.5% of the cells were haploid and 48.9 +/- 11.9% diploid; blastoder ms from fertilized eggs had no haploid cells. The haploid cell content of parthenogens declined from the blastodermal stage to adult life, w ith 1.9 +/- 2.3% at 10 to 20 d of embryonic development, 1.5 +/- 1.4% at 21 to 29 d of development, 1.4 +/- 2.6% at 4 wk posthatch, and 1.3 +/- 1.9% in adulthood, although changes between the Ist mo after hatch and adult stage were not significant. It is possible, therefore, that parthenogenetic embryos with a low proportion of haploid cells could be the ones that survive to Day 10 of development and beyond, whereas those with a higher proportion of haploid cells fail to develop. The s emen volume of male parthenogens was significantly lower than that of normal males, although the concentration of spermatozoa and their fert ilizing capacity did not vary significantly between groups, suggesting that the germ cells of these parthenogens are capable of normal meios is and sperm maturation leading to a normal fertility.