EXPRESSION OF THE WINGED HELIX GENES FKH-4 AND FKH-5 DEFINES DOMAINS IN THE CENTRAL-NERVOUS-SYSTEM

The 'winged helix' or 'forkhead' transcription factor gene family is d efined by a common 100 amino acid DVA binding domain which is a varian t of the helix-turn-helix motif. Here we describe the structure and ex pression of the mouse fkh-4 and fkh-5 genes. The two genes encode prot eins of 427 and 324 amino acids, respectively, with highly similar win ged helix domains. Both genes are expressed in adjacent domains in the developing diencephalon from the headfold stage onward. Linkage analy sis localised fkh-5 to chromosome 9 at 34.5 centiMorgans (cM) and fkh- 4 to chromosome 19 at 10.5 cM. The potential relationship of the two g enes to the mouse mutations staggerer and small thymus (for fkh-5) and muscle deficient (for fkh-4) is discussed.