Figure 4.

Northern analysis of α-tubulin mRNA levels. A, Developing cotton fiber. Fiber age is shown in DPA. B, Root, hypocotyl, cotyledon, and ungerminated pollen. Approximately 2 μg of total RNA was electrophoresed in each lane. The membrane was stripped and rehybridized to each probe in succession, as described in Methods. The α-tubulin probes (described in Table II) are as follows: total α-tubulins, tua2ORF; GhTua1, tua1UTR; GhTua2/3, tua2UTR; GhTua4, tua4UTR; and GhTua5, tua5UTR. For the gene-specific probes, hybridization and washing were carried out under stringencies sufficient to eliminate cross-hybridization (Fig. 3). The ribosomal probe gh26S was used to quantify differences in RNA loading.