The putative receptor PTPg is expressed widely during murine and avian embryogenesis(Jeannine Mendrola and Kay Heubner, Thomas Jefferson Unversity), One project in my lab involves the analysis of the potential role of PTPg in primitive hematopoesis in the chick. In ovo, both blood vessels and blood cells first appear in the region surrounding the embryo. This can be replicated in embryos cultured on egg white-agarose plates. We have used synthetic oligodeoxynucleotides (ODNs) to investigate wheter or not the expression of PTPg is required for primitive hematopoesis. The embyos are treated with ODNs whose sequence is complementary to the PTPg mRNA (antisense) or with ODNs of the same composition in a scrambled sequence as a control. The inhibition of PTPg expression appears to result in an inhibition in blood formation.

 

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Left: expression of chick PTPg in stage 18 embryos	Right: expression of the neural crest marker HNK-1
Chick embryos were incubated for 24 hours, isolated and treated with lipofectin in Opti-MEM medium (left panels), antisense oligonucleotide targeting PTPg mRNA (center panels) or an oligonucleotide with the same nucleotide composition in a scrambled order (right panels). The embryos were then cultured on egg white-agarose plates and the appearance of blood formation was detected visually.