chain, medlum chain and very long chain fatty aids.Thus, we need to examine such tissues as those associated with the genus Cuphea in which fully mature seeds contain dominant fatty acids in the C,, C,, and C,, range. Once the precise mechanisms involved in controlling chain length is defined, then molecular biological approaches can be employed to modify existing high lipid agricultural crops in order to produce any of fatty acids desired by industry. The same approach can be used for introducing genes from the jojoba plant to known crop plants such as rapeseed. Still another approach would be to design a plant to produce more seeds per plant and hence more lipid per plant. Probably the level of lipiaseed is limited by the capacity of the seed morphology to handle the added lipid load. Thus, future research may make possible the design of h g h lipid crops into which specific genes have been introduced either to make specific fatty acids or increase yields. All these goals must be integrated into a plant that has favorable agronomic properties for a given part of the world. L i t e r a t u r e I Z? K. Stumpj; in: New Comprehensive Biochemistry, Vol. 7 (A. Neuberger and L. L. M . van Deenen, general editors). Fatty acid metabolism and its regulation (S. Numa, editor) pp. 155-180 (1984), Elsevier, Amsterdam.
ByLeonL. G e r s h b e i n , K. B a b u r a o andKanuSheladia *Lipids extracted withethyl ether from Zpoolsofhaireach fromcaucasian (ages: 13-14and 15-18yr) andBlack teenagers (17and 18yr) weresaponified and the unsaponifiable portions chromatographed over alumina toward concentration of the hydrocarbons. Of these, the paraffins were further enriched by use of silica gel columns, the petroleum ether eluate containing the saturated members; elution with solvents of increasing polarity gave rise to cuts highin squalene together with small amounts of otherolefins.Temperaturrprogrammed gas chromatography was applied to the determination of the saturated hydrocarbon peaks, the branched and cyclic components which occurred at far lower levels, being ascertained by a heated pre-column containing Linde Molecularsieves (5 &.The n -p d i n s displayedpeaksofCl5-C3,, with several of up to C15 being more conspicuous with the Black pools. The present preliminary data point possibly to a higher total hydrocarbon content in the Blacks especially,as reflectedin the elevated saturated hydmcarbon contents. In terms of pg/g haiq the recoveries of squalene were 1642 and 1746 of a total of 1870 and 1987 for the respective white pools while the corresponding values were 2273 and 1640 of overall yields of 6935 and 3656 for the Black hair. The ratios of squalene to nonsqualene hydrocarbons were 7.2 for the Caucasian pools and 0.5 and 0.8 for the Black teenagers.
