Frequency and cytological aspects of diploid parthenogenesis in turkey eggs.

Naturally occurring parthenogenesis in unfertilized turkey eggs was encountered at this station in 1952. Since its discovery, selective breeding on a family basis has been practiced yearly in an attempt to further intensify this trait in certain lines of turkeys and chickens.Cytological studies likewise have been conducted and various experimental procedures employed in an attempt to develop a clearer picture of just where and the manner by which diploidy is restored. Available Cytological data and indirect evidence secured in related studies indicate that restoration of diploidy in unfertilized turkey ova is due to suppression of the second polar body. It would appear that in the absence of sperm, meiosis II is not completed. Chromosomes of the second polar body and those of the egg pronucleus probably never completely separate and subsequently the unfertilized ovum resumes development with a diploid complement of chromosomes.Four potential uses of unfertilized turkey eggs and parthenogenetic poults in biological research are given.