Structure of yellow lupine genes coding for mitotic cyclins

Cell cycle progression in eukaryotes is controlled by complexes of p34 prot ein:kinases and cyclins. For the first time in plants, we have established the sequence of four yellow lupine mitotic cyclin Fl genes. Their coding re gions and expression pattern were also characterised recently. Structure of all the four lupine genes is similar: they consist of nine exons and eight introns, analogously located, except Luplu;CycB1;3 lacking 7th intron. Ana lysis of 5'-regulatory sequences of two of them showed that both comprise M -specific activators (MSA), common to plant genes induced in late G2 and ea rly M. Putative repressor binding sites CDE/CHR found in animal G2-specific promoters can also be detected in lupine genes. Controlling region of Lupl u;CycB1;4 gene that is highly activated by IAA, contains up to 7 auxin resp onse elements, while insensible to IAA Luplu;CycB1;4 gene have no such moti fs. Further studies should be undertaken to determine precisely the functio ns of putative regulatory elements in the expression of lupine mitotic cycl ins.