Disruption of a Spermatogenic Cell-Specific Mouse Enolase 4 (Eno4) Gene Causes Sperm Structural Defects and Male Infertility

ArticleinBiology of Reproduction 88(4) · February 2013with26 Reads
DOI: 10.1095/biolreprod.112.107128 · Source: PubMed
Sperm utilize glycolysis to generate ATP required for motility and several spermatogenic cell-specific glycolytic isozymes are associated with the fibrous sheath (FS) in the principle piece of the sperm flagellum. We used proteomics and molecular biology approaches to confirm earlier reports that a novel enolase is present in mouse sperm. We then found that a pan-enolase antibody, but not antibodies to ENO2 and ENO3, recognized a protein in the principal piece of the mouse sperm flagellum. Database analyses identified two previously uncharacterized enolase family-like candidate genes, 64306537H0Rik and Gm5506. Northern analysis indicated that 64306537H0Rik (renamed Eno4) was transcribed in testes of mice by Postnatal Day 12. To determine the role of ENO4, we generated mice using ES cells in which an Eno4 allele was disrupted by a gene trap containing a beta galactosidase (beta-gal) reporter (Eno4+/Gt). Expression of beta-gal occurred in the testis and male mice homozygous for the gene trap allele (Eno4Gt/Gt) were infertile. Epididymal sperm numbers were two-fold lower and sperm motility was reduced substantially in Eno4Gt/Gt mice compared to wild type (WT) mice. Sperm from Eno4Gt/Gt mice had a coiled flagellum and a disorganized FS. The Gm5506 gene encodes a protein identical to ENO1 and also is transcribed at a low level in testis. We conclude that ENO4 is required for normal assembly of the FS and provides most of the enolase activity in sperm, and that Eno1 and/or Gm5506 may encode a minor portion of the enolase activity in sperm.
    • "The genetics of spermatogenesis and the relation of its imperfection with infertility has absorbed many attentions among molecular and cellular biologist recently [18][19][20]. Meanwhile, the polymorphisms in some key genes such as androgen receptor [21], tumor necrosis factor-a [22], and folate metabolizing genes [23][24][25]reported that might be associated with male infertility. "
    [Show abstract] [Hide abstract] ABSTRACT: The genome condensation in the sperm head is resulted with replacing of histones by protamines during spermatogenesis. It is reported that defects in the protamine 1 (PRM1) and/or 2 (PRM2) genes cause male infertility. Located on chromosome 16 (16p13.2) these genes contain numerous unstudied single nucleotide polymorphisms. This study aimed to investigate the association of c.−190 C>A and g.298 G>C transversions that respectively occur in PRM1 and PRM2 genes with idiopathic oligozoospermia. In a case–control study, we collected blood samples from 130 idiopathic oligozoospermia and 130 fertile men. Detection of c.−190 C>A and g.298 G>C polymorphisms performed by direct sequencing and PCR–RFLP methods respectively. An in silico analysis was performed by ASSP, NetGene 2, and PNImodeler online web servers. Our data revealed that g.298 G>C transversion in PRM2 was not associated with oligozoospermia (P > 0.05). Whereas, −190CA and −190AA genotypes in PRM1 gene were associated significantly with increased risk of oligozoospermia (P = 0.0017 and 0.0103, respectively). Also carriers of A allele (CA+AA) for PRM1 c.−190 C>A were at a high risk for oligozoospermia (OR 3.2440, 95 % CI 1.8060–5.8270, P = 0.0001). Further, in silico analysis revealed that c.−190 C>A transversion may alter transcription factor interactions with the promoter region of PRM1. The results revealed that the c.−190 C>A transversion may involve in the susceptibility for oligozoospermia and could be represented as a noninvasive molecular marker for genetic diagnosis of idiopathic oligozoospermia.
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    • "Four of them (fibronectin [FN1] , sulfhydryl oxidase 1, angiotensin-converting enzyme and epididymal secretory protein E1) have also a testicular or epididymal origin and all of them have been related to sperm maturation. Other of these SPproteins more expressed in P3, as alpha-enolase or alkaline phosphatase (ALP), have been related to sperm motility [54,55] . Noticeable, deoxyribonuclease −2-alpha, an acid endonuclease secreted by male accessory glands, is involved in the degradation of exogenous DNA [56] and it also provides a bactericide activity protecting sperm in the transit along female genital tract [57]. "
    [Show abstract] [Hide abstract] ABSTRACT: Biological significance: This proteomic study provides the major characterization of the boar SP-proteome with >250 proteins first reported. The boar SP-proteome is described so that a spectral library can be built for relative 'label free' protein quantification with SWATH approach. This proteomic profiling allows the creation of a publicly accessible database of the boar SP-proteome, as a first step for further understanding the role of SP-proteins in reproductive outcomes as well as for the identification of biomarkers for sperm quality and fertility.
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    • "Neither fructose-fuelled glycolysis nor the pentose phosphate pathway would by-pass blocks further down the glycolytic pathway. This is consistent with the infertility or sub-fertility of Gapdhs −/− , Pgk2 −/− and Eno4 Gt/Gt knockout male mice, which lack testis-specific forms of the glycolytic enzymes glyceraldeyhde-3-phosphate dehydrogenase, phosphoglycerate kinase and enolase, respectively (Danshina et al., 2010; Miki et al., 2004; Nakamura et al., 2013). In sperm, these enzymes are required for glycolysis steps 6, 7 and 9 (Fig. 8A). "
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