Genes differentially expressed in fiber 1 day post anthesis (dpa)

A method was developed to isolate RNA from 1 dpa fiber. ESTs derived from this and other cotton mRNAs were sequenced and assembled into contigs. Contigs composed of EST unique to libraries of interest and unique singletons were represented on a microarray. Microarrays were hybridized with labed nucleic acids derived from whole 1 dpa ovules and 1 dpa fiber to identify genes differentially regulated during fiber initiation. Genes with known expression in fiber were included to validate the microarray. Analysis of the gene ontology (GO) of differentially expressed genes suported previously reported aspects of fiber initiation such as an increase in protein biosynthesis. An increase in the "membrane" was indicated by the GO analysis ans supported by increased staining of fiber initial ER. Analysis of individule genes differentially regulated in fiber initials indicated calcium may play a role in fiber deveopment which was also supported by an increase in calcium in fiber initials. Keywords: comparative hybridization Overall design: The microarray represents 11143 gene models. One gene model is represented by 5 different oligonucleotides, 8604 gene models are represented by 4 different oligonucleotides, 1706 gene models are represented by 3 different oligonucleotides, 831 gene models are represented by 3 of the same oligonucleotides and one gene model is represented by 2 different oligonucleotides. Each micro array is hybridized with a labelled nucleic acid derived form RNA isolated from 1 dpa fiber or 1 dpa ovules harvested on different days from field grown plants. One is a dye swap.