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Reproduction (Cambridge, England) Oct 2021Sperm in most mammalian species including rat, mice and human are kept completely quiescent (motionless) and viable for up to a few weeks in the cauda epididymis before...
Sperm in most mammalian species including rat, mice and human are kept completely quiescent (motionless) and viable for up to a few weeks in the cauda epididymis before ejaculation. Vigorous motility is initiated almost instantly upon sperm release from cauda during ejaculation. The molecular mechanisms that suppress sperm motility but increase cell survival during storage in cauda epididymis are not known. Intracellular signaling via phosphorylation cascades is quick events that may regulate motility and survival of transcriptionally inactive sperm. Pathscan intracellular signaling array provided the preliminary picture of cell signaling in quiescent and motile rat sperm, indicating upregulation of cell-survival pathways in quiescent sperm, which were downregulated during motility activation. Interactome of signaling proteins involved in motility activation was constructed by Search Tool for the Retrieval of Interacting Genes (STRING) software, which identified mitogen activated protein kinase-p38 (MAPK-p38), AKT, mTOR and their downstream target p70S6K as the key kinases regulating sperm function. Further validation was achieved by western blotting and pathway activators/inhibitors. Immunofluorescence localized the kinase proteins in the sperm mid-piece region (mitochondria), a known extra-nuclear target for these signaling pathways. Activators of these kinases inhibited sperm motility but increased viability, and vice versa was true for inhibitors, in most of the cases. Activators and inhibitors also affected sperm mitochondrial membrane potential, ATP content and reactive oxygen species (ROS) levels. Data suggest that sperm motility and survival are inversely complementary and critically regulated by intracellular cell signaling. Aberrant cell signaling in caudal sperm may affect cell survival (sperm concentration) and motility of ejaculated sperm.
Topics: Animals; Epididymis; Male; Mice; Rats; Signal Transduction; Sperm Midpiece; Sperm Motility; Spermatozoa
PubMed: 34486982
DOI: 10.1530/REP-21-0202 -
Society of Reproduction and Fertility... 2007In mammalian sperm, the flagellar midpiece and principal piece contain different signalling molecules and ion channels. For example, the soluble adenylyl cyclase (sAC),... (Review)
Review
In mammalian sperm, the flagellar midpiece and principal piece contain different signalling molecules and ion channels. For example, the soluble adenylyl cyclase (sAC), which is required for activation of motility, is restricted to the midpiece, while the plasma membrane calcium channels CatSper1 and CatSper2, which are required for hyperactivation of motility, are restricted to the principal piece. The midpiece and principal piece are partially separated by a barrier called the annulus, yet despite this and the differential distribution of signalling molecules, they normally appear to work together to produce a wave that propagates smoothly down the tail. Under certain circumstances, however, the two segments can act independently. This is the case for sperm of Ste5Jcs l mutant mice, which swim with stiff midpieces but vigorously-beating principal pieces, due apparently to a defect in the mitochondria.
Topics: Animals; Ion Channels; Male; Mice; Signal Transduction; Sperm Motility; Sperm Tail
PubMed: 17644973
DOI: No ID Found -
Journal of Assisted Reproduction and... Feb 2010To evaluate whether the morphology of the sperm midpiece observed by high magnification microscopy relates to sperm centrosomal function.
PURPOSE
To evaluate whether the morphology of the sperm midpiece observed by high magnification microscopy relates to sperm centrosomal function.
METHODS
Sperm selected by conventional microscopy were defined as controls. By high magnification microscopy, sperm with straight midpieces were defined as Group 1, while those with tapering midpieces were defined as Group 2. Heterologous ICSI of human sperm into bovine oocytes was used to assess human sperm centrosomal function and analysis of sperm aster formation.
RESULTS
The total rate of sperm aster formation was 80.5% in Group 1, which was significantly higher (P < 0.05) than the rate of 33.3% seen for Group 2. Furthermore, sperm aster formation rates tended to be higher for Group 1 than for the controls.
CONCLUSIONS
This study demonstrates improvement of sperm aster formation rates by selecting sperm on the basis of midpiece morphology. The injection of selected sperm bearing morphologically straight midpieces may contribute to improved expression of sperm centrosomal function, providing a positive effect on fertilization after ICSI.
Topics: Animals; Cattle; Centrosome; Chromatin; Female; Humans; Male; Micromanipulation; Microscopy; Microscopy, Electron; Oocytes; Sperm Injections, Intracytoplasmic; Sperm Midpiece; Sperm-Ovum Interactions; Spindle Apparatus
PubMed: 20012684
DOI: 10.1007/s10815-009-9371-1 -
Biology Letters Aug 2010Evolutionary biologists have argued that there should be a positive relationship between sperm size and sperm velocity, and that these traits influence a male's sperm...
Evolutionary biologists have argued that there should be a positive relationship between sperm size and sperm velocity, and that these traits influence a male's sperm competitiveness. However, comparative analyses investigating the evolutionary associations between sperm competition risk and sperm morphology have reported inconsistent patterns of association, and in vitro sperm competition experiments have further confused the issue; in some species, males with longer sperm achieve more competitive fertilization, while in other species males with shorter sperm have greater sperm competitiveness. Few investigations have attempted to address this problem. Here, we investigated the relationship between sperm morphology and sperm velocity in house mice (Mus domesticus). We conducted in vitro sperm velocity assays on males from established selection lines, and found that sperm midpiece size was the only phenotypic predictor of sperm swimming velocity.
Topics: Analysis of Variance; Animals; Biological Evolution; Cell Size; Crosses, Genetic; Male; Mice; Sperm Midpiece; Sperm Motility; Spermatozoa
PubMed: 20147311
DOI: 10.1098/rsbl.2009.1027 -
Andrology Jan 2020Bulls are of great importance in the productive chain and for this reason they should have a good semen quality. There is no doubt that sperm morphology is very...
BACKGROUND
Bulls are of great importance in the productive chain and for this reason they should have a good semen quality. There is no doubt that sperm morphology is very important to bull fertility, although little is known about how exactly the abnormal morphologies may affect sperm functions.
OBJECTIVES
To detail the morphological description of the aplastic midpiece defect (AMD), as well as to understand its consequences for male fertility based on membrane and acrosome status, mitochondrial membrane potential and DNA integrity parameters.
MATERIALS AND METHODS
The bulls were divided into two groups: control, consisting of satisfactory potential breeders (n = 3); and AMD, consisting of unsatisfactory potential breeders with a high percentage of AMD (n = 3). Bulls were evaluated by the breeding soundness evaluation; five ejaculates were collected from each animal and analyzed by flow cytometry.
RESULTS
Spermatozoa from AMD group exhibited lower sperm motility and vigor (p < 0.05). In addition, it also exhibited lower mitochondrial membrane potential (p < 0.05), a higher percentage of spermatozoa with DNA fragmentation (p < 0.05), lower acrosome and plasma membrane integrity (p < 0.05), and higher lipid bilayer sperm membrane disorganization (p < 0.05) in comparison with control bulls.
DISCUSSION
These findings may be due to oxidative stress and a reduction of the energy production capacity in addition to an alteration in the structural composition of the sperm cell. Moreover, semen with a high percentage of AMD may also be undergoing apoptosis.
CONCLUSION
Bulls with a high percentage of AMD in their semen are not suitable for reproduction. Furthermore, it suggests there is a putative genetic basis for this sperm defect.
Topics: Animals; Cattle; Fertility; Male; Sperm Midpiece; Spermatozoa
PubMed: 30908900
DOI: 10.1111/andr.12618 -
Animals : An Open Access Journal From... Oct 2019The morphological and morphometric characterization of spermatozoa has been used as a taxonomic and phylogenetic tool for different species of mammals. We evaluated and...
The morphological and morphometric characterization of spermatozoa has been used as a taxonomic and phylogenetic tool for different species of mammals. We evaluated and compared the sperm morphometry of five neotropical primate species: , and of family Atelidae; and (=) and (=) of family Cebidae. After the collection of semen samples, the following parameters were measured on 100 spermatozoa from each specimen: Head Length, Head Width, Acrosome Length, Midpiece Length, Midpiece Width and Tail Length. Considering the available literature on sperm morphometry, we gathered data of 75 individuals, from 20 species, 8 genera and 2 families. These data were superimposed on a phylogeny to infer the possible direction of evolutionary changes. Narrower and shorter spermatozoa seem to be the ancestral form for Cebidae, with a trend toward wider and larger heads in derived groups. The spermatozoa of Atelidae may show an increase in total length and midpiece length. Sperm heads would have become narrower in the more derived groups of . Sperm length may increase in the more derived species in both families. Our results are discussed in the context of sperm competition and sexual selection.
PubMed: 31640171
DOI: 10.3390/ani9100839 -
Biochemical and Biophysical Research... Sep 2018Chorea-acanthocytosis (ChAc) is an autosomal recessive hereditary disease characterized by neurodegeneration in the striatum and acanthocytosis caused by...
Mouse model of chorea-acanthocytosis exhibits male infertility caused by impaired sperm motility as a result of ultrastructural morphological abnormalities in the mitochondrial sheath in the sperm midpiece.
Chorea-acanthocytosis (ChAc) is an autosomal recessive hereditary disease characterized by neurodegeneration in the striatum and acanthocytosis caused by loss-of-function mutations in the Vacuolar Protein Sorting 13 Homolog A (VPS13A) gene, which encodes chorein. We previously produced a ChAc-model mouse with a homozygous deletion of exons 60-61 in Vps13a, which corresponded to the human disease mutation. We found that male ChAc-model mice exhibited complete infertility as a result of severely diminished sperm motility. Immunocytochemical study revealed that chorein-like immunoreactivity is abundant only in the midpiece, mitochondria-rich region, of the sperm of wild type mice. They showed no significant differences from wild types in terms of the adenosine 5'-triphosphate (ATP) concentration of their sperm, sperm count, or sexual activity. Electron microscopy revealed abnormal ultrastructural morphology of the mitochondria in the midpiece of sperm from ChAc-model mice. These results suggest that chorein is essential in mouse sperm for the maintenance of ultrastructural mitochondrial morphology and sperm motility.
Topics: Animals; Disease Models, Animal; Humans; Infertility, Male; Male; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Knockout; Microscopy, Electron, Transmission; Mitochondria; Mutation; Nerve Tissue Proteins; Neuroacanthocytosis; Sperm Midpiece; Sperm Motility; Vesicular Transport Proteins
PubMed: 29928881
DOI: 10.1016/j.bbrc.2018.06.096 -
Nature Communications Dec 2016An extensive array of reproductive traits varies among species, yet the genetic mechanisms that enable divergence, often over short evolutionary timescales, remain...
An extensive array of reproductive traits varies among species, yet the genetic mechanisms that enable divergence, often over short evolutionary timescales, remain elusive. Here we examine two sister-species of Peromyscus mice with divergent mating systems. We find that the promiscuous species produces sperm with longer midpiece than the monogamous species, and midpiece size correlates positively with competitive ability and swimming performance. Using forward genetics, we identify a gene associated with midpiece length: Prkar1a, which encodes the R1α regulatory subunit of PKA. R1α localizes to midpiece in Peromyscus and is differentially expressed in mature sperm of the two species yet is similarly abundant in the testis. We also show that genetic variation at this locus accurately predicts male reproductive success. Our findings suggest that rapid evolution of reproductive traits can occur through cell type-specific changes to ubiquitously expressed genes and have an important effect on fitness.
Topics: Animals; Gene Expression Regulation; Genetic Fitness; Genotype; Male; Peromyscus; Quantitative Trait Loci; Species Specificity; Spermatozoa
PubMed: 27910854
DOI: 10.1038/ncomms13652 -
Reproduction in Domestic Animals =... May 2024The study investigated midpiece defects in sperm from a 5-year-old Brangus bull with a high rate of semen batch rejection, due to morphologically abnormal sperm, with no...
The study investigated midpiece defects in sperm from a 5-year-old Brangus bull with a high rate of semen batch rejection, due to morphologically abnormal sperm, with no reduction in sperm kinematics. A comprehensive evaluation was conducted over a 16-month period, involving 28 ejaculates. Notably, despite the high proportion of midpiece defects (average 37.73%, from 3% to 58%), the study revealed stable sperm production, with no discernible differences in the kinematic data before and after cryopreservation. Electron microscopy identified discontinuities in the mitochondrial sheath, characteristic of midpiece aplasia (MPA). The anomalies were attributed to be of genetic origin, as other predisposing factors were absent. Additionally, the electron microscopy unveiled plasma membrane defects, vacuoles and chromatin decondensation, consistent with previous findings linking acrosome abnormalities with midpiece defects. The findings underscored the necessity of conducting thorough laboratory evaluations before releasing cryopreserved semen for commercialization. Despite substantial morphological alterations, the initial semen evaluation data indicated acceptable levels of sperm kinematics, emphasizing the resilience of sperm production to severe morphological changes. This case report serves as a contribution to the understanding of midpiece defects in bull sperm, emphasizing the need for meticulous evaluation and quality control in semen processing and commercialization.
Topics: Male; Animals; Cryopreservation; Cattle; Semen Preservation; Semen Analysis; Spermatozoa; Biomechanical Phenomena; Sperm Midpiece; Sperm Motility; Acrosome
PubMed: 38745503
DOI: 10.1111/rda.14585 -
Human Cell Apr 2016The aim of this study was to investigate the relationship between apoptotic markers present in human spermatozoa, namely phosphatidylserine translocation (PST) from the...
The aim of this study was to investigate the relationship between apoptotic markers present in human spermatozoa, namely phosphatidylserine translocation (PST) from the inner to the outer layer of the cytomembrane and the active form of caspase-3 (c3) versus the fertilizing potential of male gametes in conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) models. A total of 116 male patients treated with their partners for infertility underwent basic semen analysis and an assessment of the presence of PST and the active c3 in sperm using flow cytometry. Forty patients underwent IVF, group A, while 76 patients underwent ICSI, group B. The fertilizing potential of the gametes was measured as the percentage of oocytes with pronuclei present after either procedure. PST and active c3 were identified in vital gametes, mainly in the midpiece area. Concentration, motility, morphology, and viability of spermatozoa strongly negatively correlated with both markers. In group A, a negative correlation between both markers and the success rate of conventional IVF was observed (r = -0.4, p = 0.04 for PST; r = -0.4, p = 0.02 for active c3, respectively). In group B, the success rate of ICSI did not correlate with either marker (r = -0.2, p = 0.85 for PST and r = 0.1, p = 0.51 for active c3). The two apoptotic markers localized in the sperm midpiece area may affect their function not only by decreasing basic andrologic parameters but also by reducing the probability of conception. Therefore, analysis of PST and active c3 in the sperm of patients undergoing infertility treatment should be recommended.
Topics: Apoptosis; Caspase 3; Female; Fertilization; Fertilization in Vitro; Humans; Male; Oocytes; Phosphatidylserines; Sperm Injections, Intracytoplasmic; Sperm Midpiece; Sperm Motility
PubMed: 26791536
DOI: 10.1007/s13577-015-0129-z