STRUCTURE OF THE ACTIN MULTIGENE FAMILY OF SOYBEAN (Glycine max)

Abstract

Soybean actin is encoded by a small multigene family composed of seven or eight genes. This chapter discusses a study that was conducted to understand the structure of the actin multigene family of soybean. In this study, seven members of this multigene family were isolated from a library of the soybean genome cloned in Charon 4A. The complete sequence of the coding regions of three of these genes was determined, and the 5” ends and flanking regions of several additional soybean actin genes were also sequenced. The positions of the three introns in each soybean actin gene examined were identical; however, their sequences and lengths varied. The introns were similar to the introns found in animal genes in that they conform to the GT–AG rule, are AT rich, and contain termination codons in all three translational reading frames. Despite the fact that the soybean actin introns occur in the same locations within the members of this multigene family, the introns of the actin genes of other organisms such as Drosophila, sea urchin, and yeast do not occur at these locations. The positions of introns in other actin genes vary widely.