Abstract
Both reproduction and immunity are the roots to live for a creature. Evolutionally, the reproductive system developed earlier than the immune system. In particular, the appearance of lymphocytes was phylogenically delayed farther than that of sperm and ovum. Dr. Haeckel first documented that “ontogenesis is a brief and rapid recapitulation of phylogenesis”. However, lymphocytes mature ontogenically earlier than the appearance of haploid germ cells in a high creature. Therefore, the ontogenic relation between the reproductive and immune organs reverses with their phylogenic relation. Because the immune tolerance has already been established at puberty when the meiosis starts in gonads, the haploid but not the diploid cells express various autoimmunogenic antigens. This raises a possibility that self immune system attacks and rejects own haploid germ cells. In this review article, the author discuss a developmental contradiction of the relation between gonads and lymphoid organs in a high creature from both phylogenic and ontogenic aspects.
