Disease relevance of Sperm Maturation

• Northern analysis showed that this is a functional gene [termed the polycystic kidney disease and receptor for egg jelly related gene ( PKDREJ )], but unlike polycystin-1, has a very restricted expression pattern; the approximately 8 kb transcript was found exclusively in testis, coincident with the timing of sperm maturation [1].
• It seems likely that the sulphapyridine moiety of sulphasalazine is responsible for the infertility seen, the effect being mediated at a late stage in sperm maturation [2].
• To study the effects of ethanol on epididymal sperm maturation, ethanol (3 g/kg body weight as 25%, v/v) was given by gastric intubation twice daily for 30 days, and in another group, rats given treatment for 30 days were withdrawn of treatment for a further period of 30 days to assess the reversibility of ethanol-induced changes [3].
• Taken together the data underscore the importance of estrogens and ERalpha in maintaining sperm maturation and preventing male infertility [4].
• Clusterin expression was demonstrated during sperm maturation and is overexpressed in different malignancies including breast and prostate carcinomas and anaplastic large-cell lymphomas [5].

High impact information on Sperm Maturation

• An acidic luminal pH (ref. 1-3) is involved in sperm maturation, and in maintaining sperm in an immotile state in the epididymis and vas deferens (2,4-6) [6].
• Dual function of the selenoprotein PHGPx during sperm maturation [7].
• Known defects in sperm maturation in these mice correlate with an impaired differentiation of the epididymis, which has similarities to the phenotype of mice with a targeted inactivation of the Ros receptor tyrosine kinase [8].
• Radioimmunoassay revealed that the CRBP within the caput epididymidis was localized in the initial segment and proximal region, areas known to be involved in the synthesis and secretion of factors necessary for sperm maturation [9].
• A hypothesis is presented concerning the role of cholesteryl sulfate as a membrane stabilizer and enzyme inhibitor during the maturation of spermatozoa in the epididymis [10].

Biological context of Sperm Maturation

• Apo J has been implicated in such diverse processes as sperm maturation, regulation of complement activation, programmed cell death, tissue remodelling and lipid transport [11].
• These data raise the possibility that pebp-2 is a novel participant in the MAP kinase signaling pathway, with a role in spermatogenesis or posttesticular sperm maturation [12].
• Impaired cauda epididymidal sperm motility and fertility (in vivo) of ethanol-treated rats imply the defective sperm maturation [3].
• These data indicate that UCHL1 is required for normal spermatogenesis and sperm quality control and demonstrate the importance of UCHL1-dependent apoptosis in spermatogonial cell and sperm maturation [13].
• MTP also showed phosphatidylethanolamine-binding activity (Kd = 1.95 x 10(-5) M, Bmax = 1.86 nmol/micrograms MTP), suggesting that the mouse 25-kDa protein is a member of the phospholipid-binding protein family and may have a role in lipid metabolism during sperm maturation [14].

Anatomical context of Sperm Maturation

• The N-terminal and mucin-like domains were absent from zonadhesin that bound to the egg extracellular matrix, suggesting that processing occurs during sperm maturation and/or capacitation [15].
• In addition, these findings demonstrate that late-stage spermatids are transcriptionally active and suggest that the RHL-1 receptor may have a functional role in sperm maturation and/or fertilization [16].
• No CGRP-RCP immunoreactivity was observed in other cells at less mature stages of sperm maturation, in Sertoli or interstitial (Leydig) cells, or in human spermatozoa [17].
• To explain the extensive epididymal abnormalities in the Hexb-/- mice, we propose that substrates for Hex, such as testis-derived glycolipids, cannot be catabolized and accumulate in lysosomes, leading to epididymal dysfunction and abnormalities in the epididymal luminal environment that supports sperm maturation [18].
• Prostaglandins (PGE2, PGF2 alpha) in the excurrent ducts of the male reproductive tract appear to be both modulators of ductal contractility for transport of spermatozoa and factors involved in the regulation of sperm maturation [19].

Associations of Sperm Maturation with chemical compounds

• P1 protamine contains a short arginine/serine-rich (RS) domain that is highly phosphorylated before being deposited into sperm chromatin and almost completely dephosphorylated during sperm maturation [20].
• These proteins are thought to play a role in sperm maturation, perhaps, it can be suggested now, by delivering retinoic acid to the sperm [21].
• l-Carnitine is an essential component of mitochondrial fatty acid beta-oxidation and plays a pivotal role in the maturation of spermatozoa within the male reproductive tract [22].
• Thus, one facet of the deleterious effects of estrogen on male reproductive functions may be interference with normal epididymal function, essential for undisturbed sperm maturation [23].
• Epididymal retinoic acid-binding protein (ERABP) is the major androgen-dependent protein present in the lumen of the epididymis and is thought to be involved in sperm maturation [24].

Gene context of Sperm Maturation

• Epididymal SPAM1 Is a Marker for Sperm Maturation in the Mouse [25].
• These data demonstrate the presence of the ADAM1a (Adam1a) and ADAM1b (Adam1b) genes in mouse, instead of the ADAM1 gene, and may imply different roles of ADAM1a and ADAM1b in spermatogenesis, sperm maturation, and/or fertilization [26].
• Acidic epididymal glycoprotein (AEG) is an androgen-regulated, epididymal secretory protein assumed to be involved in sperm maturation [27].
• Because glutamate is used as an osmolyte in somatic cells, the lack of EAAC1 reported here may disturb normal osmolyte balance in the proximal epididymal lumen and compromise sperm maturation, in particular the development of sperm volume regulatory mechanisms [28].
• These data suggest possible differential regulation of TGF-beta isoform expression in the male reproductive system and predict unique roles for individual TGF-beta isoforms in sperm maturation and maintenance [29].

Analytical, diagnostic and therapeutic context of Sperm Maturation

• The goal of this study was to begin to elucidate the profile of androgen-responsive genes that may be important for sperm maturation using the Affymetrix MGU74Av2 GeneChip oligonucleotide microarray platform [30].
• Immunoelectron microscopy revealed that distinct targeting pathways during spermiogenesis and sperm maturation in the epididymis result in trafficking of zonadhesin to the acrosomal matrix [31].

References