Figure 4.
Southern analysis of Euglena DNA hydrolyzed with BamH1 + EcoRI (BE) reveals few U3-tRNAArg but multiple U3-U5 gene linkages. (A) Hybridization with probes corresponding to the Euglena U3 and tRNAArg genes, and to a region upstream of the U3 gene (UpStr U3) but containing the Euglena microsatellite EgMS7 [47] sequence, all as described in Methods. MW: a mixture of Invitrogen™ λ DNA/HindIII, 1 Kb Plus and λ DNA/High Molecular Weight Markers. (B) Hybridization with a Euglena U5 probe. (C) Probes corresponding to the IGS sequence of the U3-U5 linkage families A and B (both sub-families B1 and B2) confirm the genomic PCR results. Bands co-hybridizing with U3, U5 and IGS probes are indicated by the asterisks. The IGS probes frequently hybridized to large restriction fragments and gave low signal intensities, despite long autoradiographic exposures. Accordingly, in the case of the IGS lanes only, the contrast was uniformly adjusted over the entire lane to aid in the identification of hybridizing band(s).