Characterization and tissue-specific expression of the Drosophila transaldolase gene.

Transaldolase (TAL) is an enzyme of the non-oxidative part of the pentose phosphate pathway which produces reductive potential in the form of NADPH as well as ribose 5-phosphate for incorporation into nucleotides. Developmental analysis via reverse transcriptase-polymerase chain reaction, immunoblots, enzymatic activity, in situ hybridization and immunocytochemistry demonstrate that TAL is expressed during all developmental stages in Drosophila. The tal locus is unique and contains two small introns. The first two introns in the human gene are situated at the same locations in the coding sequence as in Drosophila. Analysis of TAL protein levels and expression patterns reveals that it is also expressed in all larval tissues examined with particularly high levels in the fat body. Interestingly, we describe specific TAL expression only in non-neuronal cells in the larval brain.