Table 1.

X-box sequence in the promoter region of xbx-1 and its putative orthologs

Species	Locationa	X-box Sequenceb
C. elegans	-79 to -66 ATG	G T T T C C AT	G G T A A C
C. briggsae	-93 to -80 ATG	G T T T C C AT	G G T T A C
Drosophila	-68 to -54 ATG	G T T G C T AGT	A G C A A C
Human	-67 to -54 ATG	G C T C C C AT	G G C A A C
Consensus X-box		G T N R C C N (0-3)	R G Y A A C

Note: The sequence of the five prime end of the mouse ortholog has not yet been completed and thus the presence of an X-box could not be evaluated.

^aATG denotes translational start site.

^bR = G/A; Y = C/T; N = G/A/T/C; bold denotes a match to the mammalian X-box consensus sequence (Emery et al., 1996).