The ultrastructure of the sperm and motile spermatozeugmata released from the freshwater mussel Anodonta grandis (Mollusca, Bivalvia, Unionidae)

1994 ◽  
Vol 72 (8) ◽  
pp. 1452-1461 ◽  
Author(s):  
John W. Lynn
Keyword(s):  
Amorphous Matrix ◽  
Anterior Part ◽  
Freshwater Mussel ◽  
Sperm Nucleus ◽  
Sperm Head ◽  
Gill Chamber ◽  
Flagellar Beat ◽  
Membrane Bound ◽  
Distal Centriole ◽  
Anodonta Grandis

Mature sperm are released from Anodonta grandis as multiple spherical spermatozeugmata, which are complexes measuring 40–50 μm and containing up to 2800 sperm when fully populated. The 1.5 × 4.0 μm cylindrical sperm head is anchored in the spherical spermatozeugma periphery, with the 35 μm long flagella projecting perpendicular to the surface. Rotational and progressive motility is achieved by an apparently asynchronous but sequential flagellar beat. An acellular 80-nm lamina around the spherical spermatozeugma encircles a central fluid-filled sphere called the globe. Each sperm head is embedded in a chamber formed by extensions of the 80-nm lamina and in contact with the sperm plasmalemma in a flagellar collar posterior to the 5 mitochondria at the base of the sperm nucleus. A proximal centriole located in a fossa in the nucleus base is connected to a distal centriole by a dense amorphous matrix. The distal centriole is locked to the flagellar collar via 9 striated, bifurcated pericentriolar processes. The anterior part of the sperm contains an acrosome-like region containing 0.1 μm diameter membrane-bound vesicles. The spermatozeugma complexes may survive up to 24 h and may serve to transport sperm to the gill chamber of the female mussel.

A High Resolution Cytochemical Study of Nuclear ATPase in Human Spermatozoa

1975 ◽  
Vol 33 ◽  
pp. 594-595
Author(s):  
A. Sosa ◽  
L. Calzada
Keyword(s):  
High Resolution ◽  
Atpase Activity ◽  
Nuclear Membrane ◽  
Human Sperm ◽  
Sperm Nucleus ◽  
Human Spermatozoa ◽  
Cytochemical Study ◽  
Membrane Bound ◽  
Sperm Nuclei ◽  
Interchromatin Space

The dependence of nuclear metabolism on the function of the nuclear membrane is not well understood. Whether or not the function of the nuclear membrane is partial or totally responsible of the repressed template activity of human sperm nucleus has not at present been elucidated. One of the membrane-bound enzymatic activities which is concerned with the mechanisms whereby substances are thought to cross cell membranes is adenosintriphosphatase (ATPase). This prompted its characterization and distribution by high resolution photogrammetry on isolated human sperm nuclei. Isolated human spermatozoa nuclei were obtained as previously described. ATPase activity was demonstrated by the method of Wachstein and Meisel modified by Marchesi and Palade. ATPase activity was identified as dense and irregularly distributed granules confined to the internal leaflet of the nuclear membrane. Within the nucleus the appearance of the reaction product occurs as homogenous and dense precipitates in the interchromatin space.

scholarly journals Distribution of DNA damage in the human sperm nucleus: implications of the architecture of the sperm head

2020 ◽  
Vol 22 (4) ◽  
pp. 401
Author(s):  
MaríaPaz Herráez ◽  
Silvia González-Rojo ◽  
Cristina Fernández-Díez ◽  
Marta Lombó
Keyword(s):  
Dna Damage ◽  
Human Sperm ◽  
Sperm Nucleus ◽  
Sperm Head

144 Dynamic of Sperm Subpopulations in Red Deer Capacitated Samples

2018 ◽  
Vol 30 (1) ◽  
pp. 212
Author(s):  
M. Ramón ◽  
M. Iniesta-Cuerda ◽  
A. Martín-Maestro ◽  
P. Peris-Frau ◽  
I. Sánchez-Ajofrín ◽  
...  
Keyword(s):  
Red Deer ◽  
Lateral Displacement ◽  
Semen Analysis ◽  
Sperm Head ◽  
Change Points ◽  
Computer Assisted ◽  
Change Over Time ◽  
Flagellar Beat ◽  
Time Table ◽  
Over Time

An ejaculate is a mixture of sperm subpopulations (SP) with varying motility characteristics. Moreover, males with high percentages of fast and linear-moving sperm have high rates of fertility (Ramón et al. 2003 Biol. Reprod. 89, 110). The objective was to assess dynamics, over time, of SP of capacitated red deer sperm. Thawed sperm were selected with 45/90% Percoll, diluted at 10 × 106 sperm mL−1 in SOF plus 10% oestrous sheep serum and incubated for 2 h at 38.5°C under 5% CO2. Sperm motility was assessed by computer-assisted semen analysis at 1, 5, 15, 30, 45, 60, and 120 min and 24 h. Sperm were classified as described previously (Martínez-Pastor et al. 2005 Biol. Reprod. 72, 316-327) and the evolution of SP during capacitation was characterised with piece-wise regression that identified change points. Five sperm SP were identified based on velocity according to an actual path (VCL), velocity according to a straight path (VSL), velocity according to the average, smoothed path (VAP), linearity (LIN), straightness (STR), wobble (WOB), amplitude of lateral displacement of sperm head (ALH), and frequency of the flagellar beat (BCF). Sperm in SP1 were fast, linear sperm with high ALH; they corresponded to capacitated sperm. In contrast, SP5 were slow, non-linear sperm, with low ALH (Table 1). The dynamics of each SP differed over time was different along the time. Percentages of SP1, SP4, and SP3 were significantly decreased at 60, 90, and 100 min, whereas percentages of SP2 and SP5 did not change over time. This study was consistent with previous reports that kinematic sperm characteristics change over time. Table 1.Sperm subpopulations (SP) based on kinematic end points.

Population ecology of the freshwater mussel Anodonta grandis grandis in a Precambrian Shield lake

1990 ◽  
Vol 68 (9) ◽  
pp. 1931-1941 ◽  
Author(s):  
J. D. Huebner ◽  
D. F. Malley ◽  
K. Donkersloot
Keyword(s):  
Yellow Perch ◽  
Live Weight ◽  
Freshwater Mussel ◽  
Dry Weight ◽  
Fine Sand ◽  
Turnover Time ◽  
Experimental Lakes Area ◽  
Precambrian Shield ◽  
Sublittoral Zone ◽  
Anodonta Grandis

Anodonta grandis grandis is found in about half of 50 Experimental Lakes Area lakes surveyed but is abundant in only some of these lakes, including lake 377. Lake 377 is a typical small Precambrian Shield lake, 27.7 ha in area and 17.9 m in maximum depth, with [Ca2+] of [Formula: see text], conductivity of 25 μmho∙cm−1 (1 mho = 1 S), and alkalinity of [Formula: see text]. The water renewal time of approximately 187 days is shorter than that of most Precambrian Shield lakes. Bottom sediments in the sublittoral zone ranged from fine sand through granules to cobbles and boulders. Several species of possible glochidial host fish including yellow perch were collected from lake 377. The size of the mussel population, estimated by depth-stratified random sampling, was 36 800 ± 12 000 (± 95% confidence interval). Mean density was 0.133 mussels/m2 lake surface, and maximum density was 4.3 mussels/m2. Mussels were most abundant in the 1.5- to 3.1-m depth stratum. Mean lengths and weights in collections ranged from 77 to 87 mm and from 43 to 56 g, respectively. Maximum length and weight were 117.9 mm and 109.6 g, respectively. Based on external annuli, mussels live to 15+ years in lake 377. Flesh and shell averaged 25.1 and 23.2% of live weight, respectively. Calcium constituted 44.7% of the ash weight of shell. We estimated a standing dry weight biomass of mussels of 330–390 mg∙m−2 and dry weight production of 60 mg∙m−2∙year−1. This is [Formula: see text] of the estimated annual dry weight algal production. The shells of live mussels contain [Formula: see text] of the total calcium in lake 377. Despite oligotrophic conditions and low [Ca2+], lake 377 supports a substantial population of A. g. grandis growing at a moderate rate. Lake 377 may be a favourable habitat for this species because of its short water-turnover time.

scholarly journals Motility of spermatozoa at surfaces

Reproduction ◽  
2003 ◽  
pp. 259-270 ◽  
Author(s):  
DM Woolley
Keyword(s):  
Three Dimensional ◽  
Neck Region ◽  
Sperm Head ◽  
Solid Boundary ◽  
Cylindrical Shape ◽  
Two Dimensional ◽  
Flagellar Beat ◽  
Planar Shape ◽  
Planar Wave

The hydrodynamic basis for the accumulation of spermatozoa at surfaces has been investigated. The general conclusion is that when spermatozoa arrive at a surface, they will remain there if the vector of the time-averaged thrust is directed towards that surface. This can arise in two basic ways. First, consider spermatozoa that maintain a three-dimensional waveform and roll (spin) as they progress: in this case, it is argued that the conical (rather than cylindrical) shape of the flagellar envelope will establish the direction-of-thrust necessary for capture by the surface. (Additional findings, for spermatozoa of this type, are that the swim-trajectory is curved and that the direction of its curvature reveals the roll-direction of the cell.) Second, consider spermatozoa that maintain a strictly two-dimensional waveform at the surface: in this case, spermatozoa can be captured because the plane-of-flattening of the sperm head is tilted slightly relative to the plane of the flagellar beat. The sperm head is acting as a hydrofoil and, in one orientation only, it comes to exert a pressure against the surface. (This pressure may possibly, in vivo, aid the penetration of the zona pellucida.) The hydrofoil action of sperm heads may explain any bias in the circling direction of spermatozoa that execute two-dimensional waves at surfaces. Finally, a more complex phenomenon is where interaction of the spermatozoa with the surface appears to induce a three-dimensional to two-dimensional conversion of the flagellar wave (thus permitting the hydrofoil effect described). This is characteristic of sperm with 'twisted planar' rather than helical waves. In mammalian spermatozoa, approximately half the beat cycle is planar and the other half generates a pattern of torque causing the head to roll clockwise (seen from ahead), producing a torsion of the neck region of the flagellum. It is the gradual suppression of this torsion, by either impedance at the solid boundary or by raised viscosity, that converts the 'twisted planar' shape into a planar wave.

267 DIFFERENCES IN BULL SPERM NUCLEAR SHAPE BETWEEN FLOW-SORTED AND NON-SORTED SPERM USING FOURIER HARMONIC ANALYSIS

2009 ◽  
Vol 21 (1) ◽  
pp. 231
Author(s):  
J. R. Schindler ◽  
R. L. Monson ◽  
K. L. Willenburg ◽  
J. J. Parrish
Keyword(s):  
Longitudinal Axis ◽  
Sperm Nucleus ◽  
Sperm Head ◽  
Nuclear Shape ◽  
Harmonic Amplitude ◽  
Head Shape ◽  
Hoechst 33342 ◽  
Fourier Harmonic ◽  
Frozen Semen ◽  
Sorting Process

The objective of the study was to evaluate sperm nuclear shape in sex-sorted and non-sorted semen using Fourier Harmonic Amplitudes (FHA). Frozen semen was obtained from a single commercially available source. Mature bulls (n = 15) from the same breed with an average age of 4.42 ± 2.08 years were collected and the semen was either frozen or X-chromosome sorted using a flow cytometer and then frozen. Frozen straws were transported to the lab and analyzed for FHA. Briefly, straws were thawed and cells were incubated with 1.6 μm Hoechst 33342. Cells were then washed, fixed, dried to a slide and analyzed for nuclear head shape. Harmonic amplitudes 0 to 5 (HA0–HA5), derived from FHA, were previously shown to be an accurate, objective, and repeatable measure of sperm nuclear shape. HA0 describes the overall nuclear size of the sperm, whereas HA1 describes the anterior head, HA2 the length of the sperm along the longitudinal axis, and HA3 to 5 the distal, post-nuclear curvature of the sperm head. Each unit of semen was evaluated for motility and FHA. There was a significant decrease in motility in the sorted group (77 ± 1% v. 54 ± 3%; P < 0.0001). Multivariate ANOVA showed that there were differences between the sorted and non-sorted groups in HA1 to 4 (P < 0.02). Harmonic amplitude means ± SD (microns) for sorted and non-sorted treatments are as follows: HA1 (0.117 ± 0.003 v. 0.109 ± 0.003), HA2 (1.087 ± 0.005 v. 1.063 ± 0.005), HA3 (0.139 ± 0.003 v. 0.130 ± 0.003), and HA4 (0.201 ± 0.004 v. 0.191 ± 0.004), respectively. The nuclear shape of X-sorted sperm is longer and more pinched in both the anterior and posterior head. Interestingly there was no difference in HA0 (P = 0.119) indicating that the overall size of the sperm head is not affected by the sorting process. The differences in harmonic amplitudes may be due to the size and a restricted location of the X v. Y chromosome in the sperm nucleus.

scholarly journals Core Histones Are Constituents of the Perinuclear Theca of Murid Spermatozoa: An Assessment of Their Synthesis and Assembly during Spermiogenesis and Function after Gametic Fusion

2021 ◽  
Vol 22 (15) ◽  
pp. 8119
Author(s):  
Lauren E. Hamilton ◽  
Morgan Lion ◽  
Luis Aguila ◽  
João Suzuki ◽  
Genevieve Acteau ◽  
...  
Keyword(s):  
Chromatin Remodeling ◽  
De Novo ◽  
Sperm Nucleus ◽  
Sperm Head ◽  
Cell Fractionation ◽  
Cellular Processes ◽  
Functional Potential ◽  
Core Histones ◽  
Perinuclear Theca ◽  
And Function

The perinuclear theca (PT) of the eutherian sperm head is a cytoskeletal-like structure that houses proteins involved in important cellular processes during spermiogenesis and fertilization. Building upon our novel discovery of non-nuclear histones in the bovine PT, we sought to investigate whether this PT localization was a conserved feature of eutherian sperm. Employing cell fractionation, immunodetection, mass spectrometry, qPCR, and intracytoplasmic sperm injections (ICSI), we examined the localization, developmental origin, and functional potential of histones from the murid PT. Immunodetection localized histones to the post-acrosomal sheath (PAS) and the perforatorium (PERF) of the PT but showed an absence in the sperm nucleus. MS/MS analysis of selectively extracted PT histones indicated that predominately core histones (i.e., H3, H3.3, H2B, H2A, H2AX, and H4) populate the murid PT. These core histones appear to be de novo-synthesized in round spermatids and assembled via the manchette during spermatid elongation. Mouse ICSI results suggest that early embryonic development is delayed in the absence of PT-derived core histones. Here, we provide evidence that core histones are de novo-synthesized prior to PT assembly and deposited in PT sub-compartments for subsequent involvement in chromatin remodeling of the male pronucleus post-fertilization.

Accumulation of Cd by a freshwater mussel (Pyganodon grandis) is reduced in the presence of Cu, Zn, Pb, and Ni

1999 ◽  
Vol 56 (3) ◽  
pp. 467-478 ◽  
Author(s):  
A R Stewart
Keyword(s):  
Water Column ◽  
Half Life ◽  
Metal Uptake ◽  
Freshwater Mussel ◽  
Laboratory Studies ◽  
Metal Mixture ◽  
Nonequilibrium Conditions ◽  
Pyganodon Grandis ◽  
Anodonta Grandis ◽  
Concentration Levels

The effects of a metal mixture on Cd bioavailability and uptake in the freshwater mussel Pyganodon grandis (formerly Anodonta grandis grandis) were investigated in a limnocorral experiment in a Precambrian Shield lake during the summer of 1992. Differences in the partitioning of Cd in water, sediment, and mussels were identified between limnocorrals treated with Cd alone or with Cd and a mixture of metals (Cu, Zn, Pb, and Ni) at three concentration levels. Loss of Cd from the water column was slower in treatments with the metal mixture (22- to 34-day half-life) than in the treatment with Cd alone (11-day half-life). Despite the higher concentrations of Cd in the water column in treatments with the mixture of metals, the mussels accumulated proportionally less Cd as the metal concentrations increased. These relationships were observed in mussels exposed for 40 days ([Cd] <4.4 µg·L-1) and 80 days ([Cd] = 4-14 µg·L-1). The uncoupling of the effects of the metal mixture on Cd bioavailability and uptake suggests that laboratory studies may be appropriate for characterizing metal uptake in mussels exposed to mixtures of metals under nonequilibrium conditions. The significant deviation in the behavior of Cd in the presence of the metal mixture emphasizes the need to further investigate regulatory approaches that focus on individual contaminants.

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