Expression of the CCAAT-binding factor NF-Y in Caenorhabditis elegans.

NF-Y is a conserved trimer with histone-like subunits that binds and activates the common CCAAT promoter element.C.elegansNF-Y genes present two CeNF-YAs, a unique feature in kingdoms other than plants, one CeNF-YB and one CeNF-YC. The expression of both CeNF-YAs is restricted to the gonads and developing embryos, whereas the histone-like CeNF-YB- and CeNF-YC are also present in the pharyngeal bulb, in the neurons of ganglia surrounding the pharynx and in sensory organs of the head. Moreover, in infertile, 12-day-old worms, expression of the three subunits falls dramatically in the gonads. Our data indicate that NF-Y is not ubiquitously expressed.