Accretion of lipids with long and very long chain polyenoic fatty acids in rat developing testis

LUQUEZ JM; ORESTI GM; OSSES N; REYES JG; AVELDAÑO MI; FURLAND NE

San Miguel de Tucuman

Congreso; XLV Reunión Nacional de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2009

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

The aim of this work was to survey developmental changes in the lipids that contain long-chain (C18-C22) and very long-chain (VLC) (C24-C32) polyunsaturated fatty acids (PUFA) in rat testis. Glycerophospholipids, cholesterol esters and triacylglycerols (TAG) had 20:4n-6 as their longest PUFA and no VLCPUFA altogether in sexually immature testis (P14). At that age, a minor triglyceride subclass, typical of the adult testis, mainly 1-O-alkyl-2,3-diacylglycerols (A-DAG), was not produced. The three neutral lipids accumulated important percentages of long and very long chain PUFA once the first round of spermatogenesis was completed and throughout adulthood. The major VLCPUFA of TAG, A-DAG and glycerophospholipids (24:4n-6 and 24:5n-6) increased at the same pace as their major PUFA, 22:5n-6.  The latter was the fatty acid that increased the most with development, since it was the main PUFA of all testicular lipids. The data are consistent with specific PUFA elongations, followed by a VLCPUFA desaturation and chain shortening, being activated with spermatogenesis in germ cells: 20:4n-6 -->22:4n-6 -->24:4n-6 -->24:5n-6 -->22:5n-6. This is supported by the expression (mRNA) in these cells of Elovl5 and Elovl2, two members of the Elovl (elongation-of-very-long-chain-fatty-acids) gene family involved in the elongation of C18-20 and C20-22 PUFA, respectively.