Portal de Periódicos da CAPES

Cell affinity determining heterospecific graft intolerance in hydra

1973; Elsevier BV; Volume: 5; Issue: 2 Linguagem: Inglês

10.1016/s0040-8166(73)80016-3

1532-3072

Carol A. Bibb, Richard D. Campbell,

Erythrocyte Function and Pathophysiology

Column segments taken from hydra of different species can be grafted together; they separate after a period ranging from hours to weeks, depending on the species pair. The healing and separation processes were studied in homografts and heterografts by light and electron microscopy, using seven species of the genera Hydra, Chlorohydra and Pelmatohydra. In homografts, the edge cells show pseudopodial activity and attach and adhere rapidly. Heterografts show some normal tissue healing activities, but the poorer heterotypic cell adhesions result in the tissues eventually separating. In combinations where the tissues heal poorly initially, the tissues fall apart soon after grafting. In other heterografts, cell attachments arise which resemble septate desmosomes, and there is sufficient healing to hold the tissues together for at least several days. Later a constriction develops at the graft site and progresses until the unlike tissues are pinched apart. This constriction appears to represent not immunological rejection, but rather a replacement of the heterotypic cell junctions by homospecific attachments, leading to a gradual separation of the tissues.