Considerations of volume, mass, DNA, and arrangement of mitochondria in the midpiece of bull spermatozoa

Bahr, G. F.; Engler, W.F.

doi:10.1016/0014-4827(70)90526-4

Cited by 36 publications

(18 citation statements)

References 7 publications

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“…We anticipated the difference in energy demand according to the duration of motility of both systems to be reflected in the mtDNA load of single gametes. This assumption is in concordance with the observation that mammalian sperm contain 75-100 mitochondria [33,55], whereas teleost sperm merely contain up to 10 mitochondria [29,34]. Given that each mitochondrion is assumed to contain at least one copy of the mitochondrial genome [56], the estimated 10 copies of mtDNA per sperm in mouse [26] and 1.4 and 6.8 copies in human [23,24] appear to be unexpectedly low, whereas the estimated 5.73 6 2.28 mtDNA molecules per teleost sperm, with an observed maximum of 10 mitochondria per sperm, appear to be within our expectations.…”

Section: Discussionsupporting

confidence: 78%

“…Sperm of internal fertilizers, such as mammals, have both an elongated head with acrosome and midpiece [31][32][33]. Moreover, mammalian sperm contain as many as 75-100 mitochondria, which can be merged or fused to assemble extensive mitochondrial structures [31][32][33]. The data available for teleosts indicate the number of mitochondria only up to 10 per sperm [29,34,35].…”

Section: Introductionmentioning

confidence: 99%

“…As an adaptation to this environment, teleost spermatozoa have retained a simple structure, with a rounded head lacking an acrosome and a collar-like midpiece containing a few mitochondria [29,30]. Sperm of internal fertilizers, such as mammals, have both an elongated head with acrosome and midpiece [31][32][33]. Moreover, mammalian sperm contain as many as 75-100 mitochondria, which can be merged or fused to assemble extensive mitochondrial structures [31][32][33].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Estimating Mitochondrial DNA Content of Chinook Salmon Spermatozoa Using Quantitative Real-Time Polymerase Chain Reaction1

Wolff

Gemmell

2008

Biology of Reproduction

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Animal mitochondrial DNA (mtDNA) is predominantly inherited maternally. Various mechanisms to avoid the transmission of paternal mtDNA to offspring have been proposed, including the dilution of paternal mtDNA by maternal mtDNA in the zygote. The effectiveness of dilution as a barrier will be determined by the number of mtDNA molecules contributed by each parental gamete, and is expected to be highly variable among different taxa due to interspecific differences in mating systems and gamete investment. Estimates of this ratio are currently limited to few mammalian species, and data from other taxa are therefore needed to better understand the mechanisms of mitochondrial inheritance. The present study estimates mtDNA content in salmon sperm, the first nonmammalian vertebrate to be examined. Although highly divergent, it appears that the mtDNA content may be conserved within vertebrate taxa, indicating that the reduction of mtDNA is a key factor of spermatogenesis to ensure mitochondrial functionality on the one hand, and to avoid paternal leakage at a significant or detectable level on the other hand. We employ quantitative real-time PCR (Q-PCR) and demonstrate the accuracy and high reproducibility of our experiments. Furthermore, we compare and evaluate two standard approaches used for the quantification of genes, Q-PCR and blotting methods, in regard to their utility in the accurate quantification of mitochondrial genes.

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Section: Discussionsupporting

confidence: 78%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Estimating Mitochondrial DNA Content of Chinook Salmon Spermatozoa Using Quantitative Real-Time Polymerase Chain Reaction1

Wolff

Gemmell

2008

Biology of Reproduction

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“…The mammalian sperm contains about 72 mitochondria in the mitochondrial sheath of the middle piece of the flagellum (Bahr and Engler, 1970). Sperm mitochondria contain typical mitochondrial DNA, which is synthesized during meiosis and spermiogenesis .…”

Section: Mitochondriamentioning

confidence: 99%

Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 4: Intercellular bridges, mitochondria, nuclear envelope, apoptosis, ubiquitination, membrane/voltage‐gated channels, methylation/acetylation, and transcription factors

Hermo

Pelletier

Cyr

et al. 2009

Microscopy Res & Technique

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As germ cells divide and differentiate from spermatogonia to spermatozoa, they share a number of structural and functional features that are common to all generations of germ cells and these features are discussed herein. Germ cells are linked to one another by large intercellular bridges which serve to move molecules and even large organelles from the cytoplasm of one cell to another. Mitochondria take on different shapes and features and topographical arrangements to accommodate their specific needs during spermatogenesis. The nuclear envelope and pore complex also undergo extensive modifications concomitant with the development of germ cell generations. Apoptosis is an event that is normally triggered by germ cells and involves many proteins. It occurs to limit the germ cell pool and acts as a quality control mechanism. The ubiquitin pathway comprises enzymes that ubiquitinate as well as deubiquitinate target proteins and this pathway is present and functional in germ cells. Germ cells express many proteins involved in water balance and pH control as well as voltage-gated ion channel movement. In the nucleus, proteins undergo epigenetic modifications which include methylation, acetylation, and phosphorylation, with each of these modifications signaling changes in chromatin structure. Germ cells contain specialized transcription complexes that coordinate the differentiation program of spermatogenesis, and there are many male germ cell-specific differences in the components of this machinery. All of the above features of germ cells will be discussed along with the specific proteins/genes and abnormalities to fertility related to each topic.

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“…Within spermatogonia, there are an estimated 2,000-3,000 mitochondria (Hecht 1995). However, through a ubiquitin-dependent mechanism (Nakamura et al 2006), mitochondria are slowly depleted within the developing gamete, such that a mature spermatozoon only has 72 (Bahr and Engler 1970). Interestingly, whilst the remaining sperm mitochondria appear to be ubiquitinated within the cell, they are not proteolytically digested.…”

Section: Ubiquitinationmentioning

confidence: 92%

Proteomics of post-translational modifications of mammalian spermatozoa

Baker

2015

Cell Tissue Res

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It is hard to fathom that one of the most highly differentiated cells in the body, the spermatozoon, spends over half of its developmental life without the capacity for nuclear protein biosynthesis. This is even more incredible when considering that protein synthesis is switched off long before the sperm is mature. As such, in order to obtain full functionality, spermatozoa rely on post-translational modifications (PTM) of existing proteins. Many PTM have been shown to play a role in the development of a sperm cell. These include phosphorylation and glycosylation events that occur both in the epididymis and during capacitation. In addition, several other PTM such as disulfide cross-linking, ubiquitination, acetylation and methylation all play a role to both develop and enable a spermatozoon to achieve its final destiny.

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Considerations of volume, mass, DNA, and arrangement of mitochondria in the midpiece of bull spermatozoa

Cited by 36 publications

References 7 publications

Estimating Mitochondrial DNA Content of Chinook Salmon Spermatozoa Using Quantitative Real-Time Polymerase Chain Reaction1

Estimating Mitochondrial DNA Content of Chinook Salmon Spermatozoa Using Quantitative Real-Time Polymerase Chain Reaction1

Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 4: Intercellular bridges, mitochondria, nuclear envelope, apoptosis, ubiquitination, membrane/voltage‐gated channels, methylation/acetylation, and transcription factors

Proteomics of post-translational modifications of mammalian spermatozoa

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