Elovl4 and Fa2h expression during rat spermatogenesis: a link to the very-long-chain PUFA typical of germ cell sphingolipids

SANTIAGO VALTIERRA, FLORENCIA X.; PENALVA, DANIEL A.; LUQUEZ, JESSICA M.; FURLAND, NATALIA E.; VAZQUEZ, CLAUDIA; REYES, JUAN G.; AVELDANO, MARTA I.; ORESTI, GERARDO M.

JLR PAPERS IN PRESS

AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

Año: 2018

0022-2275

The sphingolipids (SL) of rodent spermatogenic cells (spermatocytes, spermatids) and spermatozoa contain nonhydroxylated and 2-hydroxylated versions of very-long-chain (C26 to C32) PUFA (n-V and h-V, respectively), not present in Sertoli cells. Here we investigated the expression of selected fatty acid elongases (Elovl), with a focus on Elovl4, and a fatty acid 2-hydroxylase (Fa2h), in rat testes with postnatal development and germ cell differentiation. Along with Elovl5 and Elovl2, Elovl4 was actively transcribed in the adult testis. Elovl4 mRNA levels were high in, though the protein was absent from, immature testes and Sertoli cells. The Elovl4 protein was a germ cell product. All cells under study elongated [3H]arachidonate to tetraenoic and pentaenoic C24 PUFA, but only germ cells produced C26 to C32 PUFA. Spermatocytes displayedthe highest Elovl4 protein levels and enzymatic activity. Fa2h mRNA was produced exclusively in germ cells, mostly round spermatids. As a protein, Fa2h was mainly concentrated in late spermatids, in the step of spermiogenesis in which they elongate and their heads change shape. The expression of Elovl4 and Fa2h thus correlate with the abundance of n-V and h-V in the SL of rat spermatocytes and spermatids, respectively