Sexual reproduction is marked by the fusion of the sperm cell with the oocyte during fertilization to produce the diploid zygote, in which the lipids in the sperm plasma membrane play an important role. Due to the loss of most cell organelles and DNA transcription, spermatozoa lack protein expression and vesicular transport. However, the lipids of the sperm plasma membrane undergo complicated dynamic changes, which may facilitate the capacitation, binding with zona pellucida, acrosome reaction and fusion of the sperm cell with the oocyte. This paper summarizes the progress in the studies of the lipids in the sperm plasma membrane, their composition, structure, peroxidation, metabolism and role in fertilization.
Acrosome Reaction ; Animals ; Cell Membrane ; chemistry ; Fertilization ; Humans ; Male ; Membrane Lipids ; metabolism ; Sperm Capacitation ; Spermatozoa ; chemistry

OBJECTIVETo investigate the progesterone-binding site on the normal fertile human sperm membrane after 2 hours of in vitro capacitation.

METHODSViable spermatozoa were selected by a swim-up method. After 2 hours of in vitro capacitation, multipoint saturation binding experiments were performed. Sperm suspension and increasing concentrations of progesterone-11alpha-glucuronide-[125I] iodotyramine (125I-P) were added to 7 total binding tubes respectively, and equal amounts of sperm suspension and 125I-P were added to another 7 corresponding non-specific binding tubes in the presence of 10 micromol/L progesterone. After incubation for 1 hour at 4 degrees C, the radioactivity of both the tubes and the pellets after centrifugation was measured respectively. The equilibrium dissociation constant (Kd) and maximum binding capacity (Bmax) were calculated using the mathematical model of single site multi-point saturation method of Scatchard function and least-squares regression.

RESULTSKd was (0.61 +/- 0.04) nmol/L and Bmax was (830 +/- 344) sites/cell. The significance test of the regression equation indicated that r = -0.980, P < 0.01.

CONCLUSIONThere is a high affinity and low capacity binding site for the progesterone (progesterone receptor) on the normal fertile human sperm membrane.

Adult ; Cell Membrane ; chemistry ; Humans ; Male ; Progesterone ; Radioligand Assay ; Receptors, Progesterone ; analysis ; Sperm Capacitation ; Spermatozoa ; chemistry

OBJECTIVESTo investigate the localization and positive percentage of progesterone receptor (PR) on the human sperm surface.

METHODSAfter in vitro capacitation, progesterone binding sites on the sperm were quantitatively analyzed by fluorescence microscopy and flow cytometry using fluorescein isothiocyanate-labeled bovine serum albumin-progesterone complex (P-BSA-FITC).

RESULTSThe spermatozoa stained by P-BSA-FITC mainly showed two labeling patterns, with the green fluorescence on the whole acrosomal region or the equatorial acrosomal region only and the stainless postacrosomal and tail regions. The percentage of progesterone-binding sperm was (30.2 +/- 2.4)%.

CONCLUSIONSThere is selective expression of PR on the human sperm acrosome surface.

Adult ; Cell Membrane ; chemistry ; Flow Cytometry ; Humans ; Male ; Microscopy, Fluorescence ; Receptors, Progesterone ; analysis ; Spermatozoa ; chemistry

OBJECTIVETo study the effect of the split of sperm nuclei on the yield of RNA from human sperm.

METHODSHuman sperm were purified by two sequential centrifugations through 40:80 discontinuous gradients of Percoll. Human leukocytes separated from peripheral blood were used as the control. Total RNAs from purified sperm and leukocytes were extracted with both TRIzol and RNeasy Kit. The RNAs from equal number of cells were reverse-transcribed, and quantified by the levels of beta-ACTIN mRNA, which were evaluated by real time polymerase chain reaction.

RESULTSTRIzol failed to digest majority of sperm nuclei even the incubation time was prolonged to 1 h, while no sperm nucleus was found under the light microscope after 1 min digestion with RLT buffer of the RNeasy Kit. Both reagents can digest the nuclei of human leukocytes well. The amount of RNA per 10(6) sperms isolated with RNeasy Kit (149.8+/-24.5 ng) was 4-fold higher (P=0.01) than that extracted with TRIzol (35.5+/-4.0 ng per 10(6) spermatozoa; n=3). The similar yields of the leukocyte RNAs extracted with RNeasy Kit and TRIzol [(765.5+/-229.8) and (958.8+/-201.0) ng per 10(6) cells respectively; n=3, P=0.168] excluded the possibility of different efficacy of these two reagents in RNA isolation.

CONCLUSIONThe split of sperm nuclei is important to the yield of RNA in the human sperm RNA extraction. The nucleus may be the major area for human sperm RNA repositories.

Cell Nucleus ; chemistry ; Humans ; Male ; Polymerase Chain Reaction ; RNA ; analysis ; RNA, Messenger ; analysis ; Spermatozoa ; chemistry

Spermatogenesis is a complex developmental process in which a diploid progenitor germ cell transforms into highly specialized spermatozoa. During spermatogenesis, membrane remodeling takes place, and cell membrane permeability and liquidity undergo phase-specific changes, which are all associated with the alteration of membrane lipids. Lipids are important components of the germ cell membrane, whose volume and ratio fluctuate in different phases of spermatogenesis. Abnormal lipid metabolism can cause spermatogenic dysfunction and consequently male infertility. Germ cell membrane lipids are mainly composed of cholesterol, phospholipids and glycolipids, which play critical roles in cell adhesion and signal transduction during spermatogenesis. An insight into the correlation of membrane lipids with spermatogenesis helps us to better understand the mechanisms of spermatogenesis and provide new approaches to the diagnosis and treatment of male infertility.
Cell Adhesion ; Cell Membrane ; chemistry ; Cholesterol ; chemistry ; Glycolipids ; chemistry ; Humans ; Infertility, Male ; Male ; Membrane Lipids ; chemistry ; Phospholipids ; chemistry ; Signal Transduction ; Spermatogenesis ; Spermatozoa ; cytology

OBJECTIVESTo evaluate the application of Coomassie brilliant blue (CBB) G250 staining for the detection of human sperm deformity rate, rate of intact acrosome and acrosome reaction.

METHODSThe smear of spermatozoa before and after capacitation and induced acrosome reaction with progesterone (P) were stained with 0.05% CBB G250 and Wright-Giemisa solution respectively, and visualized with light microscopy. The deformity rate of spermatozoa, rate of intact acrosome and acrosome reaction were calculated.

RESULTSThere was no any difference in detection of deformity rate of spermatozoa and rate of intact acrosome with CBB G250 and Wright-Giemisa staining(P < 0.05). The sperm population of acrosome reaction with induced P was divided by CBB staining into two types: positive staining with dark violet blue on acrosome cap and pale or negative staining on the same area. The rate of the latter was increasing with increasing inductive time, maybe representative of the rate of acrosome reaction. The mean rate was(75.1 +/- 3.8)% after induced for 1 h.

CONCLUSIONSCBB G250 staining is a reliable method for assessment of the human sperm morphology and acrosome reaction.

Acrosome ; metabolism ; Acrosome Reaction ; Humans ; Male ; Rosaniline Dyes ; chemistry ; metabolism ; Spermatozoa ; cytology ; enzymology ; Staining and Labeling

AIMTo establish a method for cynomolgus monkey sperm cryopreservation in a chemically defined extender.

METHODSSemen samples were collected by electro-ejaculation from four sexually mature male cynomolgus monkeys. The spermatozoa were frozen in straws by liquid nitrogen vapor using egg-yolk-free Tes-Tris mTTE synthetic extender and glycerol as cryoprotectant. The effects of glycerol concentration (1 %, 3 %, 5 %, 10 % and 15 % [v/v]) and its equilibration time (10 min, 30 min, 60 min and 90 min) on post-thaw spermatozoa were examined by sperm motility and sperm head membrane integrity.

RESULTSThe post-thaw motility and head membrane integrity of spermatozoa were significantly higher (P0.05) for 5 % glycerol (42.95 +/- 2.55 and 50.39+/- 2.42, respectively) than those of the other groups (1%: 19.19 +/- 3.22 and 24.84 +/- 3.64; 3%: 34.23 +/- 3.43 and 41.37 +/- 3.42; 10%:15.68 +/- 2.36 and 21.39 +/- 3.14; 15%: 7.47 +/- 1.44 and 12.90 +/- 2.18). The parameters for 30 min equilibration(42.95 +/- 2.55 and 50.39 +/- 2.42) were better (P0.05) than those of the other groups (10 min: 31.33 +/- 3.06 and 38.98 +/- 3.31; 60 min: 32.49 +/- 3.86 and 40.01 +/- 4.18; 90 min: 31.16 +/- 3.66 and 38.30 +/- 3.78). Five percent glycerol and 30 min equilibration yielded the highest post-thaw sperm motility and head membrane integrity.

CONCLUSIONCynomolgus monkey spermatozoa can be successfully cryopreserved in a chemically defined extender, which is related to the concentration and the equilibration time of glycerol.

Animals ; Cryopreservation ; Cryoprotective Agents ; Glycerol ; chemistry ; Macaca fascicularis ; Male ; Semen Preservation ; Spermatozoa ; cytology

Both the primed in situ (PRINS) and the peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH) techniques constitute alternatives to the conventional (fluorescence in situ hybridization, FISH) procedure for chromosomal investigations. The PRINS reaction is based on the use of a DNA polymerase and labeled nucleotide in an in situ primer extension reaction. Peptide nucleic acid probes are synthetic DNA analogs with uncharged polyamide backbones. The two procedures present several advantages (specificity, rapidity and discriminating ability) that make them very attractive for cytogenetic purposes. Their adaptation to human spermatozoa has allowed the development of new and fast procedures for the chromosomal screening of male gametes and has provided efficient complements to FISH for in situ assessment of aneuploidy in male gametes.
Aneuploidy ; Humans ; Male ; Peptide Nucleic Acids ; chemistry ; Primed In Situ Labeling ; methods ; Spermatozoa ; metabolism

OBJECTIVETo study the significance of the change of protamine content in the management of male infertility.

METHODSSperm nuclear proteins extracted from 199 infertile patients were analyzed by polyacrylamide gel-electrophoresis and scanning microdensitometry.

RESULTSForty-two (21%) cases of the total number had normal sperm nuclear proteins and 157 (79%) had aberrant ones, which mainly presented the interruption of HPRR and abnormality of P2 protamine. Thirty patients were selected at random from 157 abnormal cases for clinical treatment. After the treatment, the sperm nuclear proteins were extracted and analyzed and the results demonstrated that 11 cases (36.6%) improved markedly, 5 (16.6%) restored to normal and the other 16 (46.6%) remained unchanged.

CONCLUSIONThere is a reduced level or selective absence or even complete selective absence of protamines in infertile patients. Protamines may act as a parameter for evaluating the treatment effect of infertile males and protamine content can be influenced by a certain or several factors.

Adult ; Electrophoresis, Polyacrylamide Gel ; Humans ; Infertility, Male ; metabolism ; Male ; Oligospermia ; metabolism ; Protamines ; analysis ; Spermatozoa ; chemistry

OBJECTIVETo study the genotoxicity of carbon disulfide by detecting DNA damage in mice sperm with single-cell gel electrophoresis assay (SCGE).

METHODSSCGE was used to detect sperm DNA damage. The index of DNA damage, tail length and tail moment were used to evaluate the extent of DNA damage.

RESULTSIn three dosage groups, the rate of DNA damage (67.14%, 84.29% and 91.00%, respectively), index of DNA damage intensity (507, 656 and 745, respectively), tail length (5.87, 8.81 and 13.49 microm, respectively) and tail moment (1.30, 1.63, 2.66 microm, respectively) were significantly increased, while the percentage of head of the comet was significantly decreased (84.55%, 73.84% and 55.71%, respectively). A significant changes were clearly observed in all dosage groups compared to those of the control group (P<0.05).

CONCLUSIONSCGE which is a quick and sensitive method to detect DNA damage induced by CS2 may be used to monitor carcinogen and mutagen.

Animals ; Carbon Disulfide ; toxicity ; Comet Assay ; DNA Damage ; Male ; Mice ; Spermatozoa ; chemistry ; drug effects