Eva Brozova1, Katerina Simeckova1, Zdenek Kostrouch2, Marta Kostrouchova1 In this study, we functionally characterized NHR-40, a member of an extended group of supplementary nuclear receptors (Robisnon-Rechavi et al, J. Mol. Evol. 2005, 60: 577-586). We show that
nhr-40 is expressed in 3 isoforms that are regulated by two promoters organized in tandem. The function of NHR-40 was studied by RNA interference, by overexpression of
nhr-40 and using a mutant strain, RB840, which carries a deletion in the first intron. We show that NHR-40 regulates embryonic and early larval development. This phenotype is connected with defective movement and muscle cell development. This adds NHR-40 to the growing list of nematode NHRs involved in the regulation of development.. Acknowledgement: We thank Drs. A. Fire for vectors and host used in RNAi, M.W. Krause for support and advice, The C.elegans Gene Knockout Consortium for preparation of the deletion strain RB840. The work was supported by grants 303/03/1115 and 301/ 05/0859 from the Czech Science Foundation and by the grant 0021620806 from the Ministry of Education, Youth and Sports of the Czech Republic.