Figure 7.

Immunodetection of MURA and MURB Proteins.

(A) The alternatively spliced transcripts and calculated molecular masses of the respective protein products (in kD) are shown above the MuDR diagram. The polypeptide domains used for generation of antibodies are indicated below the diagram.

(B) Specificity of purified antibodies against the GST tag alone (5 μg) and yeast protein extracts (10 μg) expressing His-tagged full-length MURA and MURB proteins that were used for affinity purification of antibodies. M, molecular mass markers (in kD).

(C) Detection of MURA in mature embryos and pollen of various maize lines by immunoblot analysis. The sample array contains non-Mutator lines (hybrid A188/B73 and inbred W23), the a1-mum2 reporter line with no copies of MuDR, an epigenetically silenced bz2-mu1 high-copy MuDR line, and active Mutator lines, including the original purple Mutator line derived by Robertson (1978). As a result of pollen sterility, the pollen extract was prepared from a young tassel of the Robertson's line (asterisk).

(D) Immunodetection of MURB using different antibodies. The root samples were separated on higher percentage gels to demonstrate that the predominant MURB band consists of two distinct polypeptides. Other annotations are as in (C).

(E) Immunoanalysis to demonstrate the presence of MURB and MURA polypeptides in other maize lines, including those reported previously to have no MURB protein, and in other plant species.

(F) Accumulation of MURA and MURB proteins in developmentally staged tissues of non-Mutator inbred line W23 and the original Robertson's purple Mutator line.