Studies on the Structure and Formation during Spermatogenesis of the Sulfoglycerogalactolipid of Rat Testis

Abstract

1974) Studies on the Structure and Formation during Spermatogenesis of the Sulfoglycerogalactolipid of Rat Testis. Can. I. Bioehem. 52, 689-697Structural studies on the major glycolipid of rat testis have confirmed our earlier identification of this compound as a 1-0-alkyl-2-0-acyl-glyce~yl-monogaIactoside sulfate. The acyl and alkyl groups are predominantly palmitoyl and palmityl groups, respectively. %he minor glycolipid found in the same tissue has been identified as the non-sulfated form of this glycolipid. Examination of the levels of the sulfoglycerogalactolipid in the testes of immature rats, hypophysectomized rats, and normal and sterile mice indicates that the majority of the compound is located in the germinal cells of the testis and that the primary spermatocytes are the earliest spermatogenic cells to contain high levels of the lipid. Galactolipid sulfotransferase also shows peak activity in the primary spermatocytes of rat testis. Kornblatt, M. J., Knapp, A., Levine, M., Schachter, H. &Murray, R. K. (1974) Studies on the Structure and Formation during Spermatogenesis of the Sulfoglycerogalactolipid of Rat Testis. Can. 1. Biochem. 52,689-697Cette ttude de la structure du principal glycolipide des testicules de rat confirme notre premibre identification de ce compos6 comme ttant le I-0-alkyl-2-0-acyl-glycCryl-monogalactoside sulfate. k s groupes acyle et alkyle sont surtout des groups palmitoyle et palmityle. Le glycolipide moins important retrouvt dans le meme tissu est la forme non sulfatte du principal glycolipide. L'examen des taux de sulfoglyc6rogalactolipide dans les testicules de rats non matures, de rats hypophysectomists, de souris sttriles et de souris nomales montre que la plus grande partie de ce cornperst se situe dans les cellules germinales des testicules et que les spermatocytes primaires ssnt les premieres cellules spermatogbnes i contenir des quantitts 6levtes de ce ligide. C'est aussi dans les spermatocytes primaires des testicules de rat que l'activitk de la galactolipide sulfotransftrase est la plus ClevCe.praduit par le journal] Introduction are, therefore, studying aspects of the structure We have recently reported (1 ) that the major and metabolism of this lipid in the mammalian glycolipid of rat testis is a sulfated glycerogalac-testis in an effort to estabiish its function in this tolipid, tentatively identified as a monoalkyl-tissue. In the present report, we present further monsacyl-glyceryl-monogdactoside sulfate. data on the structures of the sulfoglycerogalacIshiauka et al. (2,3) have reported the isolation tolipid of rat testis and of a related compound s f a similar compound from boar and guinea-found in rat testis as a minor component. Since pig testes and have established its structure to be a 1-0-alkyl-2-0-acyl-3-P(3'-sulfogalactosyl)-glycerol. This novel compound is present in substantial amounts in the testes of the rat, mouse, guinea pig, rabbit, pig, and we

Requirement of Seminolipid in Spermatogenesis Revealed by UDP-galactose:Ceramide Galactosyltransferase-deficient Mice

“…1b), in which only undifferentiated spermatogonia and somatic cells were found in the seminiferous tubules (20,21). The result with the Kit W/W-v mice is consistent with the deficiency of seminolipid in this mutant mouse (5). Seminolipid levels in other mutants are not known.…”

Galactosylceramidase deficiency causes sperm abnormalities in the mouse model of globoid cell leukodystrophy

“…This enzyme also catalyzes the hydrolysis of the terminal galactose from galactosyl-alkyl-acyl-glycerol (GalAAG), the precursor of seminolipid, a glycolipid expressed on the membrane of germ cells [11,12]. During spermatogenesis, the seminolipid is synthesized rapidly in the early phase spermatocytes and maintained in the subsequent germ cell stages [13][14][15]. The important physiological role that seminolipid and its precursor play during spermatogenesis was determined by the ceramide galactosyltransferase (CGT) knockout mouse [16,17].…”

Enrichment of sulfogalactosylalkylacylglycerol in a plasma membrane fraction from adult rat testis

“…A standard curve was developed using commercial bovine sulfatide (sulfogalactosylceramide): the reproducibility for seven separate standard curves was within 15%. The Kean assay detects all lipid-bound sulfate; however, since the only sulfolipid in rat testis is SGG (6,20), the above assay is in fact specific for SGG.…”

“…In the hope that complex carbohydrates might be involved in the interactions between environment and germinal cell surfaces during the differentiation process, an examination of the glycolipid compositions of mammalian testes and spermatozoa was undertaken and this led to the discovery by groups in Toronto (5,6 ) and Japan (7)(8)(9) that the major glycolipid in these tissues is a novel lipid, SGG. Galactosyldiacylglycerol (10) and galactosylalkylacylglycerol (1 1) had previously been reported in mammalian brain.…”

“…Since prepubertal rat testes and the testes of sterile mouse mutants contain little or no SGG, it has been suggested that the germinal cells carry most of the SGG present in mature mammalian testes ( 6 ) . SGG is believed to be synthesized by addition of sulfate to galactosylalkylacylglycerol in the early primary spermatocyte (6,19,20) ; SGG undergoes little turnover in living germinal cells during spermatogenesis and appears in mature spermatozoa in the epididymis approximately 5 weeks after its sulfation in early spermatocytes ( 2 0 ) . Sulfation occurs in the Golgi apparatus of these cells (21,22) and the newly synthesized SGG leaves the Golgi complex within an hour (22).…”