Flow-cytometric analysis of membrane integrity of stallion sperm in the face of agglutination: the “zombie sperm” dilemma

Abstract Purpose To define the effect of sperm agglutination, associated with incubation under capacitating conditions, on accuracy of membrane assessment via flow cytometry and to develop methods to mitigate that effect. Methods Sperm motility was measured by CASA. Sperm were stained with PI-PSA or a novel method, LD-PSA, using fixable live/dead stain and cell dissociation treatment, before flow-cytometric analysis. Using LD-PSA, acrosome reaction and plasma membrane status were determined in equine sperm treated with 10 μm A23187 for 10 min, followed by 0, 1, or 2 h incubation in capacitating conditions. Results Using PI-PSA, measured membrane integrity (MI; live sperm) was dramatically lower than was total motility (TMOT), indicating spurious results (“zombie sperm”). Sperm aggregates were largely of motile sperm. Loss of motility after A23187 treatment was associated with disaggregation and increased MI. On disaggregation using LD-PSA, MI rose, and MI then corresponded with TMOT. In equine sperm incubated after A23187 treatment, as the percentage of live acrosome-reacted sperm increased, TMOT decreased to near 0. Conclusion Flow cytometry assesses only individualized sperm; thus, agglutination of viable sperm alters recorded membrane integrity. As viable sperm become immotile, they individualize; therefore, factors that decrease motility, such as A23187, result in increased measured MI. Disaggregation before assessment allows more accurate determination of sperm membrane status; in this case we documented a mismatch between motility and live acrosome-reacted equine sperm that may relate to the poor repeatability of A23187 treatment for equine IVF. These findings are of profound value to future studies on sperm capacitation.

Download Full-text

“Decoding the Dots”: The ImageStream system (ISS) as a novel and powerful tool for flow cytometric analysis

Open Life Sciences ◽

10.2478/s11535-007-0044-8 ◽

2008 ◽

Vol 3 (1) ◽

pp. 1-10 ◽

Cited By ~ 8

Author(s):

Ewa Zuba-Surma ◽

Magdalena Kucia ◽

Mariusz Ratajczak

Keyword(s):

Flow Cytometry ◽

Laser Scanning ◽

Digital Image Analysis ◽

Fluorescent Microscopy ◽

Flow Cytometric Analysis ◽

Cell Analysis ◽

Photometric Analysis ◽

Flow Cytometric ◽

Novel Method ◽

Laser Scanning Cytometer

AbstractThe aim of this article is to provide a brief review of the ImageStream system (ISS). The ISS technology was developed as a novel method for multiparameter cell analysis and subsequently as a supportive tool for flow cytometry (FC). ISS integrates the features of FC and fluorescent microscopy collecting images of acquired cells for offline digital image analysis. The article presents an overview of the main characteristics of ISS and a comparison between ISS, FC and the laser scanning cytometer (LSC). We reviewed ISS applications focusing on those involved in cellular phenotyping and provide our own experience with using ISS as a supportive tool to classical FC and demonstrate the compatibility between FC and ISS photometric analysis as well as the advantages of using ISS to confirm FC results.

Download Full-text

120 Use of fixable dyes to analyze equine sperm membrane integrity and acrosome reaction after A23187 treatment

Reproduction Fertility and Development ◽

10.1071/rdv32n2ab120 ◽

2020 ◽

Vol 32 (2) ◽

pp. 187

Author(s):

I. Ortiz ◽

M. Felix ◽

H. Resende ◽

C. Love ◽

K. Hinrichs

Keyword(s):

Flow Cytometry ◽

Repeated Measures ◽

Semen Analysis ◽

Flow Cytometric Analysis ◽

Membrane Integrity ◽

Fluorescein Isothiocyanate ◽

Computer Assisted ◽

Cell Agglutination ◽

Staining Protocol ◽

Viable Sperm

Conventional IVF is not successful in the horse, and current work is focused on factors affecting sperm capacitation in this species. Challenges arise in assessing equine sperm incubated in media containing capacitation promotors, as some of these factors cause sperm head-to-head binding (aggregation). Our preliminary microscopic findings showed that sperm aggregates are largely of viable sperm, whereas nonviable sperm individualize. Thus, data obtained using technologies that analyse only individual cells and gate out aggregates, such as flow cytometry, may not accurately represent the study population. We developed a fixable live/dead/acrosome staining protocol (LD-PSA) that minimizes sperm aggregation. The aim of this study was to evaluate the percentage of viable and acrosome-reacted equine sperm after A23187 treatment, using either LD-PSA or a standard staining protocol (PI-PSA). Sperm from 9 ejaculates were suspended in Hanks’ balanced salt solution (HBSS) and exposed for 10min at 37°C to vehicle (V) or to 10 µM A23187 (C10). The sperm were washed, resuspended in HBSS medium with added lactate and pyruvate and containing 7mgmL−1 of bovine serum albumin (BSA), and assessed immediately (0h) or incubated at 37°C for 2h (the period needed for equine sperm to respond to A23187). Motility was analysed using computer-assisted semen analysis. Each treatment was stained by PI-PSA: propidium iodide and fluorescein isothiocyanate-Pisum sativum agglutinin (PSA) in DPBS; and by LD-PSA: Live/Dead Fixable Red, paraformaldehyde 2%, Triton×1%, and FITC-PSA in Dulbecco's phosphate-buffered saline with Accumax (Stem Cell Technologies), a commercial proprietary cell agglutination inhibitor, before flow cytometric analysis. Differences were analysed using repeated-measures two-way ANOVA. The% total motile sperm (TMOT) for V and C10 treatments were 76.3±3.0 and 71.2±4.7 at 0h (P>0.05), and 70.5±14.8 and 2.4±0.8 at 2h (P<0.05). On flow cytometry, the percentage of events outside the gate for V sperm (0h and 2h combined) was 31.9% in PI-PSA and 21.9% in LD-PSA samples (P<0.01). Measured viability in V samples was significantly lower when stained with PI-PSA than with LD-PSA at 0h (49.2±4.6 vs. 67.1±4.9) and tended to be lower (P=0.07) at 2h (44.0±4.9 vs. 55.1±2.8). Notably, the viability recorded in PI-PSA was 26 percentage points lower than was the TMOT at both 0h and 2h, indicating nonrepresentative results, as nonviable sperm should not be motile. By LD-PSA, this difference was 9 points at 0h and 15 points at 2h. Vehicle sperm showed significantly higher AR values in PI-PSA than in LD-PSA at 0h (30.4±4.0 vs. 17.7±2.4) and 2h (41.9±4.5 vs. 24.0±1.8), as did C10 sperm at 0h (28.9±2.7 vs. 18.0±2.5). The lower values for viability than total motility likely reflect agglutination of viable sperm and thus their exclusion from analysis on flow cytometry. The anti-clumping measures employed in the LD-PSA protocol were associated with increased correspondence of measured viability with TMOT. Thus, LD-PSA may offer a more accurate technique to assess viability and acrosome status of equine sperm incubated in capacitating conditions.

Download Full-text

Kriopreservasi Semen Kambing Boer dengan Konsentrasi Pengencer Nira Aren dan Gliserol Berbeda

Jurnal Ilmu dan Teknologi Peternakan Tropis ◽

10.33772/jitro.v6i1.5422 ◽

2019 ◽

Vol 6 (1) ◽

pp. 1

Author(s):

Muhammad Riyadhi ◽

Anis Wahdi ◽

Muhammad Rizal

Keyword(s):

Sperm Motility ◽

Membrane Integrity ◽

Egg Yolk ◽

Boer Goat ◽

Palm Juice ◽

Sperm Membrane ◽

Live Sperm

ABSTRAK Penelitian bertujuan untuk mengetahui efektivitas nira aren sebagai pengencer alternatif dalam proses pembekuan (kriopreservasi) semen kambing boer.Kriopreservasi semen kambing boer menggunakan pengencer tris-gliserol-kuning telur (P1 73-7-20%), nira aren-gliseol-kuning telur(masing-masing P2 74-6-20%, P3 73-7-20%, dan P4 72-8-20%) dan andromed (P5 tanpa mengandung kuning telur dan gliserol). Parameter evaluasi meliputi motilitas, viabilitas, dan membrane plasma utuh setelah pengenceran, ekuilibrasi dan thawing. Evaluasi motilitas pasca thawing menunjukkan P5 52% berbeda nyata (P<0.05) dengan P1 42%, selanjutnya P5 dan P1 berbeda sangat nyata (P<0.05) dengan P2 8%, P3 6% dan P4 12%. Viabilitas pasca thawing menunjukkan P5 65,4% tidak berbeda nyata (P>0,05) dengan P1 61,8%, akan tetapi P5 dan P1 berbeda sangat nyata (P<0.05) dengan P2 26,2%, P3 29,8%, dan P4 34%. Membran plasma utuh (MPU) pasca thawing menunjukkan P5 66,2% tidak berbeda nyata (P>0,05) dengan P1 65,4%, akan tetapi keduanya berbeda sangat nyata (P<0.05) dengan P2 39%, P3 38%, dan P4 36,2%. Disimpulkan kriopreservasi semen kambing boer dengan pengencer nira aren dan gliserol pada konsentrasi berbeda belum dapat dipergunakan sebagai sumber bibit berdasarkan standar nasional Indonesia.Kata Kunci : Kambing boer, semen, nira arenABSTRACTThe experiment was conducted to determine the effect of sugar palm juice as alternative extender for cryopreservation process of boer semen.Tris-glycerol-egg yolk (P1 73-7-20%), Sugar palm juice-glyserol-egg yolk (P2 74-6-20%, P373-7-20%, dan P4 72-8-20%), and andromed (P5) used as a extender in the cryopreservation process of boer semen. Sperm motility (%), live sperm (%) and sperm membrane integrity (%) were recorded after diluted, equilibration and freeze-thawing. Result of post thawing motility showed that P5 52% was significantly different (P <0.05) with P1 42%, then P5 and P1 were significantly different (P <0.05) with P2 8%, P3 6% and P4 12%. Viability after thawing showed P5 65.4% was not significantly different (P> 0.05) with P1 61.8%, but P5 and P1 significantly different (P <0.05) with P2 26.2%, P3 29.8 %, and P4 34%. Spermmembrane integrity post-thawing showed P5 66.2% was not significantly different (P> 0.05) with P1 65.4%, but both were very significantly different (P <0.05) with P2 39%, P3 38% and P4 36.2%. Conclusions, sugar palm juice-glycerol-egg yolk with differentconcentrationsineffectively as an alternative extenderin cryopreservation of boer semen.Keywords: boer goat, semen, sugar palm juice

Download Full-text

Multiparameter Flow Cytometric Analysis of Antibiotic Effects on Membrane Potential, Membrane Permeability, and Bacterial Counts of Staphylococcus aureus andMicrococcus luteus

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.4.827-834.2000 ◽

2000 ◽

Vol 44 (4) ◽

pp. 827-834 ◽

Cited By ~ 159

Author(s):

David J. Novo ◽

Nancy G. Perlmutter ◽

Richard H. Hunt ◽

Howard M. Shapiro

Keyword(s):

Staphylococcus Aureus ◽

Flow Cytometry ◽

Membrane Potential ◽

Membrane Permeability ◽

Micrococcus Luteus ◽

Flow Cytometric Analysis ◽

Bacterial Counts ◽

Flow Cytometric ◽

Permeability Parameter ◽

Particle Counts

ABSTRACT Although flow cytometry has been used to study antibiotic effects on bacterial membrane potential (MP) and membrane permeability, flow cytometric results are not always well correlated to changes in bacterial counts. Using new, precise techniques, we simultaneously measured MP, membrane permeability, and particle counts of antibiotic-treated and untreated Staphylococcus aureus andMicrococcus luteus cells. MP was calculated from the ratio of red and green fluorescence of diethyloxacarbocyanine [DiOC2(3)]. A normalized permeability parameter was calculated from the ratio of far red fluorescence of the nucleic acid dye TO-PRO-3 and green DiOC2(3) fluorescence. Bacterial counts were calculated by the addition of polystyrene beads to the sample at a known concentration. Amoxicillin increased permeability within 45 min. At concentrations of <1 μg/ml, some organisms showed increased permeability but normal MP; this population disappeared after 4 h, while bacterial counts increased. At amoxicillin concentrations above 1 μg/ml, MP decreased irreversibly and the particle counts did not increase. Tetracycline and erythromycin caused smaller, dose- and time-dependent decreases in MP. Tetracycline concentrations of <1 μg/ml did not change permeability, while a tetracycline concentration of 4 μg/ml permeabilized 50% of the bacteria; 4 μg of erythromycin per ml permeabilized 20% of the bacteria. Streptomycin decreased MP substantially, with no effect on permeability; chloramphenicol did not change either permeability or MP. Erythromycin pretreatment of bacteria prevented streptomycin and amoxicillin effects. Flow cytometry provides a sensitive means of monitoring the dynamic cellular events that occur in bacteria exposed to antibacterial agents; however, it is probably simplistic to expect that changes in a single cellular parameter will suffice to determine the sensitivities of all species to all drugs.

Download Full-text

Chromosome doubling in Cattleya tigrina A. Rich

Scientia Plena ◽

10.14808/sci.plena.2019.110202 ◽

2019 ◽

Vol 15 (11) ◽

Author(s):

Thays Saynara Alves Menezes-Sá ◽

Maria de Fátima Arrigoni-Blank ◽

Andréa Santos da Costa ◽

Janay De Almeida Santos-Serejo ◽

Arie Fitzgerald Blank ◽

...

Keyword(s):

Flow Cytometry ◽

Propidium Iodide ◽

Chromosome Doubling ◽

Flow Cytometric Analysis ◽

Leaf Tissue ◽

Stomatal Index ◽

Chromosome Duplication ◽

Flow Cytometric ◽

Young Leaves ◽

Commercial Value

Chromosome doubling induction in orchids may benefit their production for resulting in flowers of higher commercial value, larger size and higher content of substances that intensify the color and fragrance when compared with diploid orchids. This work aimed to induce and confirm artificial polyploidization, using flow cytometry and stomatal analysis. Explants were treated with colchicine at concentrations of 0, 2.5, 7.5, and 12.5 mM, for 24 and 48 hours and with oryzalin, at concentrations of 0, 10, 30, and 50 μM, for three and six days. For the flow cytometric analysis, a sample of leaf tissue was removed from each plant, crushed to release the nuclei and stained with propidium iodide. In addition to flow cytometry, the ploidy of the antimitotic treated plants was evaluated by stomata analysis. Young leaves were used where the density, functionality and stomatal index were evaluated. Colchicine provided induction of satisfactory polyploidy in C. tigrina at all concentrations and times of exposure, obtaining a greater number of polyploid individuals in the concentration of 12.5 mM for 48 hours. Oryzalin did not induce chromosome duplication at the tested concentrations.

Download Full-text

Flow cytometric analysis of herpes simplex virus type 1 susceptibility to acyclovir, ganciclovir, and foscarnet.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.41.12.2686 ◽

1997 ◽

Vol 41 (12) ◽

pp. 2686-2692 ◽

Cited By ~ 32

Author(s):

I Pavić ◽

A Hartmann ◽

A Zimmermann ◽

D Michel ◽

W Hampl ◽

...

Keyword(s):

Flow Cytometry ◽

Herpes Simplex Virus ◽

Herpes Simplex ◽

Cytopathic Effect ◽

Flow Cytometric Analysis ◽

Flow Cytometric ◽

Resistant Strains ◽

Simplex Virus

We established a quantitative flow cytometric method for determination of herpes simplex virus type 1 (HSV-1) susceptibility to acyclovir (ACV), ganciclovir, and foscarnet in vitro. Susceptibility was defined in terms of the drug concentration which reduced the number of cells expressing HSV-1 glycoprotein C (gpC) with a fluorescence intensity of > or =10(2) by 50% (IC50). Flow cytometry allowed us to use a high (1.0) as well as a low (0.005) multiplicity of infection, and determination of the IC50 was possible after one or more viral replicative cycles. IC50s were dependent on virus input and on time postinfection. In mixture experiments, 1 to 2% resistant viruses added to a sensitive strain could be detected. The results obtained by flow cytometry showed a good qualitative correlation with those achieved by cytopathic effect inhibitory assay. However, flow cytometry might detect more quantitative differences in drug susceptibility, especially among resistant strains, as confirmed also by determination of intracellular drug phosphorylation. The mean IC50s for ACV-sensitive strains were 0.45 to 1.47 microM, and those for ACV-resistant strains were between 140 and 3,134 microM. Flow cytometric analysis was fast and accurate, automatizable, and highly reproducible. Flow cytometry may be a more powerful tool than standard cytopathic effect-based assays and could have advantages for the detection of low levels of drug resistance or mixtures of sensitive and resistant virus strains.

Download Full-text

A novel method for the combined flow cytometric analysis of cell cycle and cytochrome c release

Cell Death and Differentiation ◽

10.1038/sj.cdd.4401480 ◽

2004 ◽

Vol 11 (10) ◽

pp. 1153-1154 ◽

Cited By ~ 14

Author(s):

A Mohr ◽

R M Zwacka ◽

K-M Debatin ◽

K Stahnke

Keyword(s):

Cell Cycle ◽

Cytochrome C ◽

Flow Cytometric Analysis ◽

Cytochrome C Release ◽

Flow Cytometric ◽

Combined Flow ◽

Novel Method

Download Full-text

Flow cytometric analysis of virus-like particles and heterotrophic bacteria within coral-associated reef water

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315406013476 ◽

2006 ◽

Vol 86 (3) ◽

pp. 563-566 ◽

Cited By ~ 29

Author(s):

Nicole L. Patten ◽

Justin R. Seymour ◽

James G. Mitchell

Keyword(s):

Flow Cytometry ◽

Bacterial Community ◽

Heterotrophic Bacteria ◽

Flow Cytometric Analysis ◽

Water Layer ◽

Dead Coral ◽

Overlying Water ◽

Virus Like Particles ◽

Flow Cytometric ◽

Diseased Coral

Using flow cytometry, two distinct populations of virus-like particles (VLP) and heterotrophic bacteria were defined within the 12 cm water layer immediately overlying healthy, diseased and dead acroporid corals. Bacterial abundances were similar in overlying water for all coral types, however, VLP were 30% higher above diseased corals than healthy or dead corals. Mean virus to bacteria ratios (VBR) were up to 30% higher above diseased corals than above healthy or dead coral or in distant water. Concomitant with increasing VLP concentrations within 5 cm of coral surfaces, VBR distributions were generally highest above healthy and diseased coral and depressed above dead coral. These results suggest fundamental shifts in the VLP and bacterial community in water associated with diseased corals.

Download Full-text

176 Localization and Quantitative Expression of Phospholipase C Zeta in Equine Sperm Using Commercial Antibodies

Reproduction Fertility and Development ◽

10.1071/rdv30n1ab176 ◽

2018 ◽

Vol 30 (1) ◽

pp. 228

Author(s):

R. A. Gonzalez-Castro ◽

J. K. Graham ◽

E. M. Carnevale

Keyword(s):

Flow Cytometry ◽

Phospholipase C ◽

Fluorescence Intensity ◽

Molecular Probes ◽

Calcium Oscillations ◽

Oocyte Activation ◽

Flow Cytometric ◽

Live Sperm ◽

Commercial Antibodies ◽

Flow Cytometric Evaluation

Fertilization failure in vivo and in vitro (intracytoplasmic sperm injection, ICSI) can be caused by the inability of sperm to elicit intracellular calcium oscillations and to induce oocyte activation. Phospholipase C zeta (PLCz) is sperm-associated protein that can induce oocyte activation. Male infertility has been associated with PLCz deficiency in various species, although this has not been studied in the stallion. We hypothesised that the location and amount of PLCz on sperm varies among stallions. The aim of this study was to validate commercial antibodies (Ab) to detect PLCz on stallion sperm, and then to use these Ab to quantify the amount of PLCz, using flow cytometry, with the long-term goal of correlating PLCz on sperm with stallion fertility. Frozen-thawed sperm were analysed (20 stallions in 3 replicates) using 2 commercial Ab (anti-mouse PLCz M163 and anti-human PLCz H50, Santa Cruz Biotechnology, TX, USA). Western blot and immunofluorescence microscopy were used to validate Ab binding. For microscopy, sperm DNA was counterstained with 1 µg mL−1 Hoechst 33258. For flow cytometry, samples were incubated with Live Dead Fixable Far Red Stain Kit (Molecular Probes, Eugene, OR, USA), fixed, permeabilized, incubated overnight with primary Ab, and labelled with conjugated secondary Ab (anti-rabbit IgG Alexa Fluor 488, Molecular Probes). Green and far red mean fluorescence intensity (MFI) were measured for 20,000 cells per sample. Results are presented as mean ± SEM. Wilcoxon test, Spearman rank correlation, and linear regression were performed for analyses. Immunoblot analyses for both commercial Ab identified an immunoreactive band of ~70 kDa in sperm heads, tails, and whole sperm; β-tubulin was used as loading control and for normalization. Microscopy revealed PLCz in the acrosomal and post-acrosomal regions, connecting piece, midpiece, and tail. Post-acrosomal localization was the pattern most frequently observed (55%), followed by acrosomal plus post-acrosomal regions (25%). The PLCz labelling was observed on >85% of midpiece and tail regions, independent of Ab used. Flow cytometric evaluation revealed that percentage of live sperm was 47 ± 2%. Similar fluorescence intensity was exhibited for both Ab (M163 and H50) with a wide range of values among stallions [M163, mean 30.7 ± 1.9 × 103 (range, 8.8-82.2 × 103); H50: 25.5 ± 3.2 × 103 (7.3-55.0 × 103)]. The percentage of live sperm within a sample was not associated with Ab MFI. However, when samples were gated for live/dead cells, live sperm exhibited higher (P < 0.001) MFI than dead sperm for M163 (42.6 ± 6.0 v. 30.6 ± 3.9 × 103) and H50 (38.4 ± 4.7 v. 25.6 ± 3.7 × 103). There was a strong and positive correlation between M163 and H50 MFI for total sperm and live sperm (total: r = 0.81, P < 0.001; live: r = 0.71; P < 0.001). In conclusion, 2 anti-PLCz commercial antibodies detected equine PLCz, and the PLCz was localised on the sperm as described. Flow cytometric evaluation showed that stallions have different quantities of PLCz on their sperm, and this may provide a mean to determine if PLCz on stallion sperm is associated with fertility.

Download Full-text