Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe a patient with myopathy, sensorimotor neuropathy, hypogonadism, and infertility with abnormal sperm mobility and morphology. Analysis of the deltoid muscle DNA revealed a G to A change at nt 1102 in the twinkle gene and multiple mitochondrial DNA deletions. Histochemistry revealed "ragged-red" fibers and many cytochrome-c oxidase negative fibers (32%) that lacked the mitochondrial encoded respiratory chain subunits I and II and the nuclear encoded subunit VIc. Respiratory chain enzyme analysis showed severe deficiency of complex I, III, and IV. This patient has no documented family history of progressive external ophthalmoplegia, which suggests either a sporadic or autosomal-recessive syndrome. This case is a novel phenotype for twinkle gene mutations and multiple mitochondrial DNA deletion syndromes, as these syndromes generally follow an autosomal-dominant inheritance pattern.
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PMID:A novel clinical phenotype of myopathy, sensorimotor neuropathy, infertility, and hypogonadism with multiple mitochondrial DNA deletions. 1907 59

Infertility affects 10-15% of the population, of which approximately 40% is due to male etiology and consists primarily of low sperm count (oligozoospermia) and/or abnormal sperm motility (asthenozoospermia). Recently, it has been demonstrated that mtDNA substitutions can influence semen quality. In this study, we performed a sequence analysis of the mitochondrial cytochrome oxidase I (COXI) gene in 31 infertile men suffering from asthenozoospermia in comparison to 33 normozoospermic infertile men and 100 fertile men from the Tunisian population. A novel m.6307A>G mutation was found in sperm mitochondrial DNA (mtDNA). This mutation was found in six asthenozoospermic patients, and was absent in normozoospermic and fertile men. We also detected 21 known substitutions previously reported in the Human Mitochondrial Database. The m.6307A>G mutation substitutes a highly conserved asparagine at position 135 to serine. In addition, PolyPhen-2 analysis predicted that this variant is "probably damaging.
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PMID:A novel m.6307A>G mutation in the mitochondrial COXI gene in asthenozoospermic infertile men. 2371 56

Haploid round spermatids undergo differentiation and morphogenesis during spermiogenesis, resulting in mature spermatozoa. The molecular details underlying this transformation, however, remain poorly understood. In this study, we generated and analyzed germ cell-specific Spata19 knockout mice (Spata19(flox/flox) ; Stra8-Cre; hereafter termed "Spata19 cKO") to assess the model that SPATA19 contributes to mitochondrial function in differentiating spermatids. Spata19-cKO males were infertile, as their sperm exhibited disorganized mitochondrial structure; furthermore, their sperm-abundance of mitochondrial proteins, activities of mitochondrial respiratory chain complex IV, and ATP levels were significantly reduced. Yet, the infertility of Spata19-cKO males was rescued by intracytoplasmic sperm injection, so the sperm are capable of initiating development. Collectively, our findings suggest that SPATA19 plays an important role in sperm motility by regulating the organization and function of the mitochondria.
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PMID:Spata19 is critical for sperm mitochondrial function and male fertility. 2626 98