Semiquantitative RT-PCR analysis of the seven GaSus genes in cotton plants ( G. arboreum, A2 ). The RNA were prepared from different tissues and over fiber development: root (R), stem (S), young leaf (L), petal (P), ovule at 0 dpa (day post anthesis) and fiber samples from bolls at 5, 10, 15, and 20 dpa. Primers specific to the seven GaSus were used, and the PCR products amplified from genomic DNA (g) containing at least one introns were taken as controls to exclude any DNA contamination. A constitutive ubiquitin gene (UBQ7, accession no. DQ116441) was used as an internal control to normalize differences in template concentrations.