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Show posters on the hill Testing Cell Transplantation Methods in the Planarian Schmidtea mediterranea Mark Gurling, James C. Jenkin, Alejandro Sanchez Alvarado Department of Neurobiology and Anatomy School of Medicine ± ollowing amputation Sc-hmidtea mediterranea can regenerate any missing tissue necessary to restore full function to the animal. Regeneration proceeds at the wound site when an aggregation of neoblasts, known as a blastema, is formed. Neoblasts are planarian stem cells and are the only proliferating population in the animal. They are believed to be pluripotent and necessary for planarian regeneration. These cells are constantly entering the cell cycle and therefore can be eliminated through irradiation. Irradiated animals were amputated producing tail fragments and prepharyngeal (no head) fragments. These fragments were injected with neoblast fractions acquired through fluorescence activated cell sorting (FACS) in two radio-sensitive groups. Following injection, fragments were fixed daily over a 6 day time course. Fixed fragments were stained with H3P antibody and Tyramide signal amplification to observe the mitotic activity of the injected neoblasts. Tyramide signal was visible in the unirradiated positive control animals only; no fragments had visible signal. Two possible explanations are: 1) current injection protocol is j^k Testing Cell Transplantation Methods in the Planarian Schmidtea mediterranea A Jl Mark Gurling, James C. Jenkin, Alejandro Sanchez Alvarado Murk J a"** Department of Neurobiology and Anatomy School of Medicine Planarian Regeneration hi 2d 3d 4d 5d 7d I ! Earlier e\|x-iimcnts show lh;it neoblaMv iv>poiui io miun b> migrating to the Planarian regeneration Neoblast> vofkvi al tile wound Mle forming a wound \ite. The time ii nkcN tor ;i hktsititia to lomi is direcil) proportional to Ha-tK'inn. I his i-. titi: ontiin trout uhivh litM 1 issue is ueneroled. the Iciiuth of the animal thai has been exposed to radiation nix- --ii.uk1 J ret*ion > Normal I \ \ H3 Antibody Staining ¦\n antibody UUPi is used in !:»K-I iu.-oMj>^ m tiie worm. It recogn specific region on a prolcin found within the nucleus of dividing c insufficient and neoblasts are not entering the fragments. 2) Neoblasts are dying before or shortly after injection; possibly due to exposure during purification and/or injection. Further experimentation should be done. Fluorescent marking of injected cells is needed to determine where the cells are entering the animal fragments and whether or not they are remaining there. Optimization of future studies will require testing injections of cells at various times after irradiation and amputation. This would allow us to test if the proliferation signals from the wound site are cumulative. If so, increased levels of these factors may improve our chances of triggering mitoses in the injected cell population. |