Summary of tal-1, rbtn2, GATA-1, GATA-2, and βH1-globin mRNA expression patterns during murine gastrulation. Captions at the top of the figure indicate developmental stages. Abbreviations at the side of the figure indicate the different tissues in which signal was detected. EM, embryonic mesoderm; EXM, extraembryonic mesoderm; EE, extraembryonic ectoderm; TR, trophoblast giant cells or their precursors. Genes expressed at a particular stage and in a particular tissue are designated in the appropriate box.