Cystathionine gamma-lyase expression during avian embryogenesis.

Cystathionine gamma-lyase (CSE) is a key enzyme in the trans-sulphuration pathway for the biosynthesis of cysteine from methionine and catalyses the hydrolysis of cystathionine into cysteine. It has been reported to be expressed in mammalian liver and kidney but so far no comprehensive developmental expression analysis of CSE has been available. We cloned a 600 bp fragment of chick CSE cDNA and analysed its expression pattern during avian embryonic development until embryonic day 13. We found CSE expression in various developing organs including the notochord, eye, neural tube, limb bud mesenchyme and sclerotomal compartment of the somites. Notably, prominent expression was found in renal epithelia throughout kidney development, i.e. in the tubular structures of pronephros, mesonephros and metanephros. Our data introduce CSE as a novel marker gene to study avian kidney development.