| Oleosins are unique and abundant proteins on the surface of subcellular oil bodies in seeds. Oleosins have been found in the sporophytic seeds of angiosperms. I studied the oleosin from the female gametophyte of gymnosperm pine as well as sporophytic seeds of angiosperms Brassica and maize. The cDNA sequence of an oleosin from Pinus ponderosa and the genomic DNA sequences of oleosins from Brassica napus and Zea mays were determined.; The phylogenic relationship of 20 oleosins, including those from sporophytic and gametophytic tissues of angiosperms and gymnosperms, was deduced.; All the three members of maize (Zea mays, L., MO17) oleosin gene family, which are expressed in the kernel, were studied. ole16, ole17 and ole18 encode OLE16, OLE17 and OLE18, respectively, and are expressed in scutellum, axis and aleurone layer of the kernels in proportional amounts. OLE16 is a member of L (low MW) isoform and OLE17 and OLE18 are members of H (high MW) isoform. ole16 and ole18 have been mapped at single loci on chromosomes 2 and 5, respectively, and ole17 is predicted at a single locus on chromosome 1. The oleosin genes and their encoded oleosins in the Illinois High oils and Illinois Low Oils maize lines were found to be similar to those in other maize genotypes.; The MW variations of maize oleosins in diverse inbreds were studied. OLE18 occurred in many MW variants. OLE17 was present as a few MW variants. OLE 16 had no apparent MW variants. In some inbreds such as FR2 and CM555, one of H isoform was absent.; The amounts of H and L isoforms were in one to one ratio in all genotypes examined. The regulation of such an expression of the H and L isoform of the genes was studied. The control of the equality of H and L isoforms is likely at the translation and/or posttranslation step due to oleosin interaction. |
