Enzymes involved in the biosynthesis of the very-long-chain polyunsaturated fatty acids of rat spermatogenic cell sphingolipids

SANTIAGO VALTIERRA, F.X.; ORESTI, G.M.; AVELDAÑO, M.I.

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

The sphingolipids (SL) of rodent germ cells contain very-longchainpolyunsaturated fatty acids (V), in nonhydroxy (n-V) and 2-hydroxy(h-V) forms, whose biosynthesis requires the expression ofseveral elongases (Elovl) and a fatty acid 2-hydroxylase (Fa2h). Ourobjective was to characterize the expression of these enzymes as afunction of postnatal development and germ cell differentiation. Weemployed qPCR for mRNA levels, Western blot and immunofluorescencefor protein expression, and [3H]-labeled precursors for enzymeactivity. Elovl4, involved in C24-C34 fatty acid biosynthesis, wasexpressed at the mRNA, but not at the protein level, at early prepuberalages. Such mRNA was a product of Sertoli cells. Elovl4 mRNAand protein were both produced by germ cells. In agreement withthe relative abundance of n-V in their SL, the Elovl4 enzymatic activitywas higher in the premeiotic pachytene spermatocytes than inpostmeiotic round and late spermatids (p