Development of mitochondrial helical sheath in the middle piece of the mouse spermatid tail: Regular dispositions and synchronized changes

Otani, Hiroki; Tanaka, Osamu; Kasai, Kei‐Ichiro; Yoshioka, Takafumi

doi:10.1002/ar.1092220106

Cited by 92 publications

(54 citation statements)

References 19 publications

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“…Additionally, concurrent to the loss of the majority of the cytoplasm occurring during spermiogenesis (the differentiation of spermatids into sperm), some mitochondria are lost in residual bodies. The 22-75 remaining mitochondria rearrange in tubular structures that are helically anchored around the anterior portion of the nine outer dense fibres (ODFs) and of the axoneme, constituting the midpiece (Otani et al 1988, Ho & Wey 2007Fig. 3).…”

Section: Sperm Mitochondriamentioning

confidence: 99%

Mitochondria functionality and sperm quality

Amaral¹,

Lourenço²,

Marques³

et al. 2013

Reproduction

448

332

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Although mitochondria are best known for being the eukaryotic cell powerhouses, these organelles participate in various cellular functions besides ATP production, such as calcium homoeostasis, generation of reactive oxygen species (ROS), the intrinsic apoptotic pathway and steroid hormone biosynthesis. The aim of this review was to discuss the putative roles of mitochondria in mammalian sperm function and how they may relate to sperm quality and fertilisation ability, particularly in humans. Although paternal mitochondria are degraded inside the zygote, sperm mitochondrial functionality seems to be critical for fertilisation. Indeed, changes in mitochondrial integrity/functionality, namely defects in mitochondrial ultrastructure or in the mitochondrial genome, transcriptome or proteome, as well as low mitochondrial membrane potential or altered oxygen consumption, have been correlated with loss of sperm function (particularly with decreased motility). Results from genetically engineered mouse models also confirmed this trend. On the other hand, increasing evidence suggests that mitochondria derived ATP is not crucial for sperm motility and that glycolysis may be the main ATP supplier for this particular aspect of sperm function. However, there are contradictory data in the literature regarding sperm bioenergetics. The relevance of sperm mitochondria may thus be associated with their role in other physiological features, particularly with the production of ROS, which in controlled levels are needed for proper sperm function. Sperm mitochondria may also serve as intracellular Ca 2C stores, although their role in signalling is still unclear.

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Section: Sperm Mitochondriamentioning

confidence: 99%

Mitochondria functionality and sperm quality

Amaral¹,

Lourenço²,

Marques³

et al. 2013

Reproduction

448

332

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“…For knockout epididymal spermatozoa, the most conspicuous defect was detected using MitoTracker, and this concerns the mitochondrial sheath. This sheath, normally arranged as a regularly formed solenoid around the flagellum of the sperm cells (Fawcett, 1975;Ho and Wey, 2007;Otani et al, 1988) is severely disrupted, leaving one or two clusters of MitoTracker-stained mitochondria at the middle piece region (Fig. 5A,B).…”

Section: Mitochondrial Sheath Abnormalities In the Tssk1/2 Knockoutmentioning

confidence: 99%

Functional transformation of the chromatoid body in mouse spermatids requires testis-specific serine/threonine kinases

Shang

Baarends

Hoogerbrugge

et al. 2010

Journal of Cell Science

116

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SummaryThe cytoplasmic chromatoid body (CB) organizes mRNA metabolism and small regulatory RNA pathways, in relation to haploid gene expression, in mammalian round spermatids. However, little is known about functions and fate of the CB at later steps of spermatogenesis, when elongating spermatids undergo chromatin compaction and transcriptional silencing. In mouse elongating spermatids, we detected accumulation of the testis-specific serine/threonine kinases TSSK1 and TSSK2, and the substrate TSKS, in a ring-shaped structure around the base of the flagellum and in a cytoplasmic satellite, both corresponding to structures described to originate from the CB. At later steps of spermatid differentiation, the ring is found at the caudal end of the newly formed mitochondrial sheath. Targeted deletion of the tandemly arranged genes Tssk1 and Tssk2 in mouse resulted in male infertility, with loss of the CB-derived ring structure, and with elongating spermatids possessing a collapsed mitochondrial sheath. These results reveal TSSK1-and TSSK2-dependent functions of a transformed CB in post-meiotic cytodifferentiation of spermatids.

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“…The mitochondria in the sheath are elongated, crescent shaped, and aligned end-to-end in helices wrapped around the outer dense fibers which in turn surround the flagellar axoneme (21). Pallini et al (22) purified sonication-and sodium dodecyl sulfate (SDS)-resistant structures from sperm mitochondria, known as capsules, that retain the size and shape of the outer membranes of sperm mitochondria.…”

mentioning

confidence: 99%

Asthenozoospermia in Mice with Targeted Deletion of the Sperm Mitochondrion-Associated Cysteine-Rich Protein (Smcp) Gene

Nayernia

Adham

Burkhardt‐Göttges

et al. 2002

Molecular and Cellular Biology

111

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The sperm mitochondria-associated cysteine-rich protein (SMCP) is a cysteine-and proline-rich structural protein that is closely associated with the keratinous capsules of sperm mitochondria in the mitochondrial sheath surrounding the outer dense fibers and axoneme. To investigate the function of SMCP, we generated mice with a targeted disruption of the gene Smcp by homologous recombination. Homozygous mutant males on a mixed genetic background (C57BL/6J ؋ 129/Sv) are fully fertile, while they are infertile on the 129/Sv background, although spermatogenesis and mating are normal. Homozygous Smcp ؊/؊ female mice are fertile on both genetic backgrounds. Electron microscopical examination demonstrated normal structures of sperm head, mitochondria, and tail. In vivo experiments with sperm of Smcp ؊/؊ 129/Sv mice revealed that the migration of spermatozoa from the uterus into the oviduct is reduced. This result is supported by the observation that sperm motility as determined by the computer-assisted semen analysis system (CASA) is significantly affected as compared to wild-type spermatozoa. In vitro fertilization assays showed that Smcpdeficient spermatozoa are able to bind to the oocyte but that the number of fertilized eggs is reduced by more than threefold relative to the wild-type control. However, removal of the zona pellucida resulted in an unaffected sperm-egg fusion which was monitored by the presence of pronuclei and generation of blastocyts. These results indicate that the infertility of the male Smcp ؊/؊ mice on the 129/Sv background is due to reduced motility of the spermatozoa and decreased capability of the spermatozoa to penetrate oocytes.Mitochondria are confined to a structure known as the mitochondrial sheath in the midpiece of mammalian spermatozoa. The mitochondria in the sheath are elongated, crescent shaped, and aligned end-to-end in helices wrapped around the outer dense fibers which in turn surround the flagellar axoneme (21). Pallini et al. (22) purified sonication-and sodium dodecyl sulfate (SDS)-resistant structures from sperm mitochondria, known as capsules, that retain the size and shape of the outer membranes of sperm mitochondria. The integrity of capsules is maintained by disulfide bridges, and purified capsules from bull sperm contain three proteins, including a peculiar hydrophilic protein containing a large amount of proline (26%) and cysteine (18%), the sperm mitochondria-associated cysteine-rich protein (SMCP). For many years, SMCP was thought to be a 20-kDa selenoprotein and the predominant capsular protein (7), but recent work demonstrates that those attributes belong to phospholipid hydroxide glutathione peroxidase, which functions as a cytosolic enzyme in somatic cells and an enzymatically inactive structural protein in the mitochondrial capsule (33). Electron microscope immunocytochemistry localizes mouse SMCP to the outer mitochondrial membranes and intermitochondrial spaces of the mitochondrial sheath (8). Since SMCP is neither a selenoprotein nor the major capsule protein...

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Development of mitochondrial helical sheath in the middle piece of the mouse spermatid tail: Regular dispositions and synchronized changes

Cited by 92 publications

References 19 publications

Mitochondria functionality and sperm quality

Mitochondria functionality and sperm quality

Functional transformation of the chromatoid body in mouse spermatids requires testis-specific serine/threonine kinases

Asthenozoospermia in Mice with Targeted Deletion of the Sperm Mitochondrion-Associated Cysteine-Rich Protein (Smcp) Gene

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