; R o o t E n t r y F X : C o m p O b j b W o r d D o c u m e n t O b j e c t P o o l X : X : ' ( ) * + , - . / 0 1 F Microsoft Word 6.0 Document MSWordDoc Word.Document.6 ; ? 37 !8 u ! f: ? ? O 3 Abstract 9507677 Turpen Amphibians are a unique model system for studying the hematopoietic and immune systems. Two mesodermal regions of the Xenopus embryo, ventral blood islands and dorsal lateral plate, give rise to hematopoietic stem cells, the ppecursors of all red and white blood cells. This project will examine the contribution of dorsal and ventral regions to the profile of blood cells developing in the liver, which is colonized by hematopoietic cells. Since blood formation undergoes marked changes in the liver during metamorphosis the stem cell population will be examined to see if it changes during this period. The origin of T cells within the thymus, from the stem cells, will also be examined. The structure of the leukocyte common antigen , which is found on the surface of hematopoietic stem cells will also be determined. This antigen is linked to two adjacent cytoplasmic phosphatase domains and is involved in the transduction of signals from the surface of the cell to its interior. This project will isolate cDNA for the leukocyte common antigen expressed by developing hema topoietic stem cells and use DNA sequence analysis to compare the structure of the stem cell form to the form on other white blood cells. %%% This project which is looking at development of the hematopoietic and immune systems in Xenopus, will contribute to our understanding of the basic biology of the developing hematopoietic and immune systems. *** ; Oh +' 0 $ H l S u m m a r y I n f o r m a t i o n ( & D h R:WWUSERTEMPLATENORMAL.DOT Abstract Una Solomon Una Solomon @ Q%4 @ @ ,8 : Õ @ Microsoft Word 6.0 3 ; e = e l l l l l l l > 1 o T 2 > l > l l l l l l l l 6 Abstract 9507677 Turpen Amphibians are a unique model system for studying the hematopoietic and immune systems. Two mesodermal regions of the Xenopus embryo, ventral blood islands and dorsal lateral plate, give rise to hematopoietic stem cells, the precursors of all red and white blood cells. This project will examine the contribution of dorsal and ventral regions to the profile of blood cells developing in the liver, which is colonized by hematopoietic cells. Since blood formation undergoes marked changes in the liver during metamorphosis the stem cell population will be examined to see if it changes during this period. The origin of T cells within the thymus, from the stem cells, will also be examined. The structure of the leukocyte common antigen , which is found on the surface of hematopoietic stem cells will also be determined. This antigen is linked to two adjacent cytoplasmic phosphatase domains and is involved in the transduction of signals from the surface of the cell to its interior. This project will isolate cDNA for the leukocyte common antige
