Fig. 4

Spatial distribution of poly A tail length of bcd mRNA along the A-P axis of Drosophila using PAT analysis. Poly A tail (PAT) analysis of bcd mRNA isolated from 3 consecutive 60 μm sections (A, B, C; E, F, G) from ten nc 13 embryos starting from the anterior tip and cutting to the posterior as indicated at the bottom. A, B, C internal PCR primer control of bcd to evaluate abundance and quality of the isolated RNAs. D DNA size marker. E, F, G PAT analysis showing increased sizes of smears suggesting that the poly A tail lengths change with the location along the A-P axis. H calculated poly A tail length