XB-IMG-147824
Xenbase Image ID: 147824
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Fig. 2. Gene expression patterns of the in vitro-induced heart rudiments. (A) Comparison of early gene expression patterns between the intact
(undissociated) and dissociated/reaggregated animal caps after activin treatment (100 ng/ml). The left-hand column indicates the time course of gene
expressions in the intact but activin-induced animal caps. Neural and mesoderm differentiation markers (XSox2 and Xbra/XWnt-11/XNot, respectively)
expressed constantly when the animal caps were treated with activin for more than 3 h. Conversely, the expressions of XGATA-4 (a marker for both heart
and anterior endoderm), XHex (for anterior endoderm), and XSox17β (for pan-endoderm) disappeared by treating with activin for more than 9 h. Note that
XNkx2.5, an early heart-field marker, was never detected in these samples. The right-hand column shows the profile of gene expressions in the animal caps
after the combined activin and dissociation/reaggregation treatments. In contrast to the profile in the left-hand column, the expressions of the neural and
mesoderm markers were faded out by exposure to activin for more than 5 h. The expressions of XGATA-4 and XHex were maintained for at least 9 h after
the beginning of activin treatment. Note that XNkx2.5 was initially detected at 5 h after the beginning of activin treatment and gradually increased its expression
level. ODC, loading control; (RT-), negative control lacking reverse transcriptase. (B) Gene expression patterns in the intact or reaggregated animal caps
cultured for 3 days. Non-activin-induced cells expressed none of the markers even after they were subjected to the dissociation/reaggregation protocol (lanes
1 and 3). Activin treatment (100 ng/ml, 5 h) induced the expression of the pan-neural (NCAM), muscle (ms-actin), and notochord (Col II) markers in intact animal
caps cultured for 3 days (lane 2). No heart-specific marker was detected in these samples. By contrast, the reaggregates consisting of activin-induced cells
exclusively expressed all of the heart-differentiation markers, such as XNkx2.5, XGATA-4, XTbx5, XMHCα, XTnIc, and XANF (lane 4). The expression of
endodermin (edd), a pan-endoderm marker, was induced by activin treatment, irrespective of dissociation/reaggregation (lanes 2 and 4). EF1α, loading control;
(RT-), negative control lacking reverse transcriptase. Image published in: Ariizumi T et al. (2003) Copyright © 2003. Reproduced with permission of the Publisher, University of the Basque Country Press. Larger Image Printer Friendly View |