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Fig. 2. Temporal and spatial expression of Xenopus Pop-1. (A) RT-PCR analyses of embryonic Xenopus Pop-1 expression during different developmental stages as indicated. RT-PCR was performed using total RNA isolated from embryos which were cultured until the indicated developmental stages. The temporal expression of Xpop-1 was compared to the developmental expression profile of other cardiac marker genes. Abbreviations used: CA, cardiac actin; MHC, myosin heavy chain α; ANF, atrial natriuretic factor; H4, histone 4. The RT-reaction was performed with H4 primers. (B) Expression of Xenopus Pop-1 in different adult tissues as indicated. RT-PCR was performed using total RNA isolated from the indicated adult tissues. Xpop-1 transcripts were only detected in the adult heart. (C) Spatial expression of Xpop-1 and Nkx2.5 at stage 30. Transverse sections demonstrate the specific expression of Xpop-1 in the myocardium (mc). Nkx2.5 transcripts are abundant in the myocardium but in contrast to Xpop-1, Nkx2.5 is additionally, albeit weaker, expressed in tissue fated to become the dorsal roof of the pericardium (pc) and in the pharyngeal pouches (arrow heads). (D) Expression pattern of Xpop-1 in the developing heart chambers at stages 33, 36, and 41. Abbreviations used: a, atrium; v, ventricle; o, outflow tract. |
