ZOO 2700 Lecture Notes - Lecture 10: Monogenea, Haptor, Mucus
28 Mar 2018
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Document Summary
Most of the dunn phylogenies contain the word (cid:494)worm(cid:495) Apomorphies: multi-ciliated epidermis and gastrodermis, protonephridia (2 cilia per terminal cell, negative pressure, flames cell: characterized by 2 cilia or more, in flatworms only. 2: solenocyte: terminal cell with one flagellum, hermaphroditic. Muscles at right angles allow species to move through space: muscular waves-swimming. Diffusion super important, surface to volume a problem. Cut up planarian: the pieces would regrow, up to a max of 279 pieces. Pluripotent: ability to differentiate into all zygotic cell types. Likely even totipotent (differentiation into all zygotic cell types + extraembryonic tissues) In other systems, exist only transiently during early embryonic development. Transplantation of a single neoblast into a lethally irradiated (=stem cell depleted) worm rescued the recipient and gave rise to a perfectly healthy animal of the donor genotype. Planaria have neoblast cells throughout their lives.
