Research Article
Tomar NS, Goel A, Mehra M,
Abstract
Turkey hens show spontaneous parthenogenesis (embryo development without any male contribution) which is influenced by genetic and environmental factors. Chromosome pattern and differential expression of genes associated with parthenogenetic development in turkey eggs were investigated in the present study. The metaphase spread obtained from parthenogenetic embryos was classified as haploid, diploid, polyploidy or aneuploidy based on the proportion of ‘n’ number of chromosomes. With the advancement of embryonic age, per cent of haploid cell (38.73 to 20.44) or other ploidy decreased while those of diploid cell increased (21.10 to 42.06) and the transition of ploidy continued till 48 h of embryo dveleopment. Early developmental stages presented higher ratios of W chromosomes in comparison to Z chromosomes while ZW combination was absent. Freshly laid parthenogenic eggs had higher Sox2 gene expression, but 24hrs old embryo had higher Sox3, GATA-4 or PouV genes expression. Expression of male specific genes (DMRT and AMH) was higher in 12 h or older parthenogenetic embryos, but the female specific genes, ASW and P450 were expressed more in freshly laid parthenogenetic eggs. It is concluded that transition of ploidy from haploid to diploid or poly-ploidy continued till 48 h or beyond parthenogenetic development. Significantly higher expression of Sox3 or GATA-4 gene in parthenogenetic embryos could potentially be used as marker gene for indication of parthenogenesis in turkey.