The fatty acid composition of the major phosphoglycerides of ram and human spermatozoa

The major individual phosphoglycerides of ram spermatozoa have specific fatty acid compositions, whereas human spermatozoan phosphoglycerides contain a similar pattern of fatty acids. The difference in the polyunsaturated:saturated fatty acid ratio of the spermatozoan phosphoglycerides between the two species were associated with the very high polyunsaturated fatty acid content of ram spermatozoan plasmalogens. The major unsaturated fatty acid of ram spermatozoa phospholipids, docosahexaenoic acid, was concentrated in the choline phosphoglycerides, whereas the chief saturates of ram and human spermatozoa, and docosahexaenoic acid in the latter, were largely located in the choline and ethanolamine diacylphosphoglycerides.

Determination of Sex Hormone-binding Globulin in Human Semen by Selective Ammonium Sulphate Precipitation*

A simple method was developed to measure the SHBG capacities of human serum, semen and sperm cells. After suitable dilution, disintegration and addition of labelled dihydrotestosterone-1,2-3 H or testosterone-1,2-3 H, the SHBG was precipitated by the addition of saturated ammonium sulphate in a final concentration of 42.3%. The precipitate was centrifuged and the activity of the non-bound, labelled steroid was counted in an aliquot of the supernatant. Subtraction of this result from the total activity yielded the SHBG-bound steroid in microgram/100 ml or nmol/l. Examination of 52 males gave normal values of means = 13.91 nmol/l (S.E.M. = 0,746) dihydrotestosterone binding globulin (DHTBG) and means = 11.67 nmol/l (S.E.M. = 0.555) testosterone binding globulin (TBG) in serum, while the concentrations in the seminal plasma were means = 10.89 nmol/l (S.E.M. = 0,723) DHTBG and means = 8.93 nmol/l (S.E.M. = 0.625) TBG. means = 5.57 ng/mg protein (S.E.M. = 0.516) DHTBG and means = 4.91 ng/mg protein (S.E.M. = 0.440) TBG were found in the disintegrated sperm cells.

Sterility of three brothers in connection with a disturbed carbohydrate metabolism in semen

Sterile semen of three brothers was investigated biochemically. Most strikingly was the strong similarity of both the amino acid and the carbohydrate composition of the semen. Inside the spermatozoa much more fructose and glucose was present than normally is found. It could be shown that in the seminal plasma peptides and proteins were present all containing more or less beta-alanine and all able to bind glucose and fructose. After incubation with labelled glucose it was evident that inside the spermatozoa enzymes requried for formation of lactic acid were lacking or inactive. Moreover labelled tyrosine and serine was found. Treatment with proviron did not improve carbohydrate metabolism but the amounts of present glucose and fructose inside the spermatozoa had strongly decreased. It is supposed that the sterility of the men is due to a disturbance in spermatogenesis.

Evidence for similar structural changes on binding of platinum anti-tumor agents to DNA and nucleosomes

The influence of Pt(II) compounds on the 31P NMR spectra of natural DNA, synthetic polynucleotides, and nucleosomes was investigated. With Pt complexes which are anti-tumor agents, a new peak or shoulder centered at approximately 1.2 ppm downfield from the untreated DNA signal was observed. When Pt compounds known not to be anti-tumor agents were studied, no such new signal was observed. The most reasonable explanation for the downfield resonance is that it is a consequence of a structural change induced in the DNA by the anti-tumor agent. Since the effect of the Pt compounds on nucleosomes was similar, the same structural change is probably occurring in DNA in solution and in nucleosomes. A nonalternating dG . dC polymer, but not alternating G . C or any A . T polymers, exhibited a similar spectral change and this finding suggests that the structural change in the DNA arises primarily from reaction of Pt anti-tumor agents with adjacent G residues.

A phosphorus NMR study of the reaction products of cis -diamminedichloroplatinum (II) with a double-helical oligonucleotide and with DNA

The structural distortion of oligonucleotides upon cis-PtCl2(NH3)2[d(T-C-T-C-G-G-T-C-T-C)-N7(5), N7(6)] reveals shifting of 4 phosphorus resonances due to platination. 3 Resonances could be assigned by selective 31P-irradiation, showing P(6) (P between the two Gs) to be shifted 1.5 ppm to low field. In the concomitant double strands P(6) is shifted 0.9 ppm to lower field. A similar peak has been observed in platinated salmon sperm DNA (37 degrees C), indicating that Pt-binding to GpG-fragments in DNA is similar to that found for the decanucleotide, so the distortion of DNA might be comparable.

Immunohistochemical localization of nuclear 3,5,3'-triiodothyronine receptor proteins in rat tissues studied with antiserum against C-ERB A/T3 receptor

We have previously raised an anti-c-erb A peptide antibody (designated 4B II) which immunoprecipitated in vitro transcription/translation products of c-erb A alpha 1 and beta. 4B II could recognize nuclear T3 receptor (NT3R) without distinction between difference in species and tissues. Using 4B II, we studied immunohistochemical localization of NT3R proteins in various tissues of the rat. Cryostat sections (4-6 microns) of selected rat tissues were incubated with 4B II at 4C overnight, followed by fluorescein-isothyocianate-conjugated anti-rabbit immunoglobulin G for 60 min at 25 C. The cellular localization of fluorescence in all tissues examined was exclusively nuclear. Under the same conditions, control sections stained with antiserum which had previously absorbed with c-erb A peptide or inactive serum showed no specific staining. In the brain the large nuclei, supposed to be neuronal, were strongly stained in the cerebral cortex and the granular layer of the cerebellum. In the kidney, cells in the glomerulus, the distal, but not the proximal, tubules, and the collecting ducts exhibited nuclear staining. Nuclear fluorescence was observed homogeneously in the heart and liver, but the intensity was much weaker in the latter. Less intense fluorescence was seen in the testis and spleen, although specific immunostaining was clearly observed in the nuclei of spermatocytes, Leydig cells, and the heads of the sperms in the testis, and many lymphocytes in the spleen. Nuclei of follicular cells of the thyroid exhibited very strong fluorescence, suggesting existence of plenty of NT3R proteins. The anterior pituitary showed strong immunostaining in most nuclei, and clear nuclear fluorescence was also detected in the intermediate lobe of the pituitary. The present study showed that NT3R distributes selectively in certain types of cells in many tissues and that the content of NT3R proteins seems to correlate with the concentration of c-erb A mRNA alpha 1 and beta among many organs.

Measurement of DNA breakage in specific germ-cell stages of male mice exposed to acrylamide, using an alkaline-elution procedure

DNA breakage in spermiogenic stages of the mouse was studied after exposure to acrylamide (AA), using an alkaline-elution technique. At daily intervals over a 3-week period following i.p. injection of 100 mg AA/kg, mature spermatozoa were recovered from treated ([3H]dThd-labeled) and control ([14C]dThd-labeled) animals, and were lysed together on polycarbonate filters; the DNA was eluted with a high-pH (12.0) buffer. Elution of germ-cell DNA from AA-exposed animals increased (more DNA-strand breaks) in stages sensitive to the dominant-lethal effects of AA (late spermatids to early spermatozoa) (Shelby et al., 1986). The stage-related pattern of AA-induced DNA breakage also paralleled the pattern of sperm alkylation and protamine alkylation found to be produced by AA (Sega et al., 1989). While dominant-lethal damage from AA exposure is greatest in the spermatids and early spermatozoa, no such damage was observed in pachytene spermatocytes and early spermatids (Shelby et al., 1986). Therefore, AA-induced DNA breakage was also studied directly in pachytene spermatocytes and in early spermatids at short intervals (up to 4 days) after exposure. DNA breakage was clearly detected in these cell stages, with maximum breakage occurring at 1 day after treatment. At later times, the breakage gradually decreased, presumably as a result of DNA repair. By the time these cell stages gave rise to functional spermatozoa, DNA breaks that could have produced dominant-lethal events had apparently been reduced to a level where no genetic effect could be observed.

Molecular characterization of nuclear basic protein HPI1, a putative precursor of human sperm protamines HP2 and HP3

The largest intermediate basic protein HPI1 (101 residues) from human sperm chromatin was isolated and characterized. The amino acid composition and sequence analysis of the protein and of tryptic peptides together with peptide mapping of endoproteinases Lys-C and Glu-C hydrolysates showed that the C-terminal region (residues 45-101) of HPI1 is identical to protamine HP2. These structural data strongly suggest that protein HPI1 is a precursor of human sperm protamines HP2 and HP3 (57 and 54 residues, respectively) as well as of two other intermediate basic proteins HPS1 and HPS2 (69 and 66 residues, respectively) sequenced previously.

Interactions of labeled epididymal secretory proteins with spermatozoa after injection of 35S-methionine in the mouse

The sequential interactions of epididymal secretory proteins with spermatozoa during epididymal transit were examined. Mice received injections of 35S-methionine, and the radiolabeled luminal fluid and sperm-associated proteins were analyzed by sodium dodecylsulfate-polyacrylamide gel electrophoresis at various times after injection. The majority of the luminal fluid and sperm-associated proteins were found in the caput epididymidis at 8 h; by 7 days, many of these proteins had been transported to the cauda epididymidis. Two classes of epididymal protein-sperm interactions were distinguished on the basis of regional synthesis and secretion. The major class consisted of proteins that were synthesized, secreted, and bound to spermatozoa in the caput epididymidis. In this class, however, the binding of proteins to the spermatozoa was variable. For example, a protein of 25 kDa remained associated with spermatozoa in substantial amounts during epididymal transit, while proteins of 40 and 35 kDa decreased in amount. Other proteins such as a protein of 18 kDa did not remain associated with spermatozoa. Another class of proteins (54, 44, 29 kDa) were synthesized and secreted from all epididymal regions but bound only to caput spermatozoa. Most of the epididymal proteins appeared to be tightly bound to the spermatozoa since spermatozoa already saturated with the unlabeled protein in the distal epididymis remained so even though the spermatozoa were surrounded by labeled proteins in the luminal fluid. These studies demonstrate that a variety of specific interactions occur between epididymal secretory proteins and spermatozoa as they migrate and mature in the epididymis.

Evidence for a calsequestrin-like calcium-binding protein in human spermatozoa

Human spermatozoa were investigated for the presence of protein(s) recognized by antibodies against calsequestrin, the high capacity, moderate affinity Ca2(+)-binding protein, originally described in striated muscle fibers. Western immunoblots of detergent-soluble sperm extracts probed with polyclonal antibodies raised against human skeletal muscle calsequestrin identified a strongly cross-reactive protein. This protein resembles muscle calsequestrin in many respects. In fact, its migration in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) is pH dependent, its apparent molecular mass being 64 kDa in alkaline SDS-PAGE and 44 kDa in neutral SDS-PAGE; its isoelectric point is acidic (4.6); it is metachromatically stained blue by the carboxycyanine dye, Stains-All; it is a Ca2(+)-binding protein (45Ca blot overlay). Indirect immunofluorescence experiments showed that the immunoreactive protein has an intracellular localization confined to the tail mid-piece. From these findings we conclude that human sperm cells express a protein structurally and antigenically related to skeletal muscle calsequestrin; a basis for a novel interpretation of Ca2(+)-mediated events in spermatozoa is thus provided.

High-resolution proton nuclear magnetic resonance characterization of seminolipid from bovine spermatozoa

The high-resolution one- and two-dimensional proton nuclear magnetic resonance (1H-NMR) characterization of seminolipid from bovine spermatozoa is presented. The 1H-NMR data was confirmed by gas-liquid chromatography-mass spectrometric analysis of the partially methylated alditol acetates of the sugar unit, mild alkaline methanolysis of the glyceryl ester, mobility on normal phase and diphasic thin-layer chromatography (HPTLC), and fast atom bombardment mass spectrometry (FAB-MS). The structure of the molecule corresponds to 1-O-hexadecyl-2-O-hexadecanoyl-3-O-beta-D-(3'-sulfo)-galactopyranosyl- sn-glycerol.

Regional differences in composition of the perforatorium and outer periacrosomal layer of the rat spermatozoon as revealed by immunocytochemistry

The rat perforatorium is the part of the perinuclear theca that underlies the acrosomic system. It appears to be composed of several polypeptides. The main objective of this study was to determine the distribution of seven of these perforatorial polypeptides in the head of the rat spermatozoon. For this purpose, polyclonal antibodies were affinity purified from these polypeptides and tested 1) for their distribution on electron-microscope sections of late spermatids and spermatozoa by immunogold labeling and 2) for their specificity on Western blots of denatured perforatorial polypeptides by immunoblotting. Immunoblotting showed that all seven of the prominent perforatorial polypeptides had epitopes in common. Immunogold labeling of spermatozoa showed that antibodies against the 13, 13.4, and 16 kDa polypeptides were restricted in their localization to the thicker apical portion of the perforatorium and to the inner zone of the ventral spur. However, antibodies against the 34, 43, 57, and 63 kDa polypeptides reacted with the entire perforatorium but, in addition, reacted with the inner part of the ventral spur and with a portion of the "outer periacrosomal layer" lying between the plasma membrane and the outer acrosomal membrane. These results suggest 1) that there are regional differences in protein composition of the perforatorium, of the outer periacrosomal layer, and of the postacrosomal dense lamina; and 2) that perforatorial polypeptides may not necessarily be restricted to the subacrosomal region, but may also compose portions of the outer periacrosomal layer and postacrosomal dense lamina. Based on both immunoblotting and immunocytochemical results, using an antiactin monoclonal antibody that recognizes all known isoforms of actin, actin was not detected in the perforatorium of step 19 spermatids or spermatozoa. Actin, however, together with the seven perforatorial polypeptides tested, was present in the subacrosomal space of elongating spermatids before the process of condensation of the perforatorium takes place.

Biological properties and partial purification of a growth factor from porcine spleen

3T3-Fibroblast growth is enhanced in a dose-dependent way by a factor isolated from porcine spleen after limited proteolysis. The factor is not dialyzable and is stable for 5 min at 100 degrees C and at pH 2 at room temperature. Trypsin or collagenase treatment does not affect its biological activity. The stimulation of cell growth is independent of serum concentration in the culture medium but is accelerated by insulin supplement. The biochemical properties of this factor indicate a novel growth promotor different from other growth factors.

[Evaluation of separating X- and Y-sperms by percoll density gradient centrifugation using sperms of transgenic mice carrying a transgene on Y-chromosome]

Using sperms of the transgenic mice carrying a human A gamma/beta-globin gene on Y-chromosome, we attempted to separate X- and Y-bearing sperms by the Percoll density gradient centrifugation. The ratio of X- and Y-sperms was determined by DNA dot blot hybridization procedure with sperm DNA. Sperm suspension collected from cauda epididymidis was loaded on the gradient composed of 7 Percoll concentrations (35-84%) and was centrifuged at 300 x g for 10, 15 or 20 minutes, respectively, at room temperature. After centrifugation, sperms were collected from each gradient fraction and washed with 0.85% saline solution. DNA was extracted from sperms, dotted and fixed on nitrocellulose filter, and was hybridized with the 32P-labeled DNA probe derived from the beta-globin gene. Each DNA spot was cut out, immersed in the liquid scintillator and was counted for radioactivity. There was no difference among the radioactivities in the DNA spots, indicating that the ratio of X- and Y-sperms was the same in all the gradient fractions of three different centrifugal conditions. The results suggests to be difficult to separate X- and Y-sperms by Percoll density gradient centrifugation, at least, using sperms from cauda epididymidis of mouse.

Glucosylceramide having a novel tri-unsaturated long-chain base from the spermatozoa of the starfish, Asterias amurensis

Glucosylceramide (Glc beta 1-1Cer) was isolated from the spermatozoa of the starfish, Asterias amurensis. The long-chain bases of the glycolipid consisted of dihydroxy (d18:2, d18:3, d19:3, and d22:2), and trihydroxy (t22:1) types. Long-chain aldehydes derived from them were analyzed mainly by proton nuclear-magnetic resonance to determine the detailed structures. Two of the tri-unsaturated bases were identified as (4E,8E,10E)-2-amino-4,8,10-octadecatriene-1,3-di ol (d18:3) and (4E,8E,10E)-2-amino-9-methyl-4,8,10-octadecatriene+ ++-1,3-diol (d19:3), which is a novel base. Both d22:2 and t22:1 had a cis double bond at the C9 or C13 position. All fatty acids were 2-hydroxylated (C14-C25): Most of them were saturated and unbranched. About 10% was mono-unsaturated and unbranched (C22-C25), while saturated but branched (iso- and anteiso-types) C15-C18 acids were found as minor components. The main fatty acids, which summed up to more than 93% of the fatty acids in the glucosylceramide, were n-14h:0, n-15h:0, n-16h:0, n-17h:0, n-18h:0, and n-24h:1.

The lack of protamine 2 (P2) in boar and bull spermatozoa is due to mutations within the P2 gene

The nuclei of spermatozoa in all mammals examined so far contain P1 protamine. A second protamine variant, protamine P2, has to date been isolated only from human and murine spermatozoa where it represents the major fraction of basic nuclear protein. In order to elucidate the reason for this unusual distribution of the protamine variants among mammals we have investigated the expression of protamine P2 in boar and bull. It can be shown that also in these species protamine 2 is transcribed and translated on low levels. Various mutational events though have altered the primary structure of the protein: In boar, a deletion of 8 aminoacids has removed a sequence motif from the amino-terminus of the molecule, which highly probable is of functional relevance. The bovine sequence, as a consequence of numerous point mutations has accumulated neutral and hydrophobic aminoacids which reduce the affinity of the protamine 2 to DNA.

Boar sperm membranes antigens. II. Reorganization of an integral membrane antigen during capacitation and acrosome reaction

The dynamics of the cell surface during the process of capacitation is impressively shown by means of a monoclonal antibody directed against the P86/5 antigen. This glycoprotein was located in the sperm plasma membrane using the colloidal gold method in combination with specimen preparation in toto. The antigen is absent at the rostral tip of non-capacitated spermatozoa, but forms clusters over the principal segment and the equatorial segment after induction of capacitation. This formation of microdomains with different properties may be a prerequisite for the onset of the acrosome reaction (AR). During AR the diffusion barrier for the P86/5 antigen breakes down and the antigen occupies now the rostral crescent-like area of the sperm head. These observations are discussed with respect to zona binding and induction of the AR in boar spermatozoa.

Boar sperm membranes antigens. I. Topography of a mobile glycoprotein of the sperm cell membrane

A monoclonal antibody, designated mAb P86/5, was generated by immunization of female Balb/c mice with a membrane vesicle fraction composed of the outer acrosomal membrane and plasma membrane (PM-OAM). As determined by fluorescence microscopy and electron microscopy P86/5 recognizes a sperm plasma membrane antigen that is restricted to the sperm head. In intact spermatozoa the P86/5-antigen is distributed over the surface of the sperm head with the exception of the rostral region. By comparing the antibody binding pattern generated at 4 degrees C and 25 degrees C, it could be shown that the P86/5-antigen is capable to diffuse freely within the cell membrane overlying the acrosome whereas its lateral mobility is restricted to the post-acrosomal region. The P86/5-antigen had a molecular weight of about 78 kDa as revealed by SDS-PAGE and western blotting. The glycoprotein nature of the P86/5-antigen was established by lectin affinity chromatography.

Characterization of an acrosomal matrix protein in hamster and bovine spermatids and spermatozoa

Experiments have been carried out characterizing an Mr 22,000 protein present in the acrosomes of hamster and bull spermatozoa. The Mr 22,000 protein is resistant to solubilization in detergent solutions containing high or low salt and has a pI of -5.2. With various lectins, the protein from hamster sperm was shown to be sparingly glycosylated with N-acetylglucosamine, mannose, and galactose while that from the bull demonstrated a slight reactivity for galactose. Using a specific monoclonal antibody (MAB 4/18), the Mr 22,000 polypeptide has been localized exclusively to the acrosomes of mature testicular and epididymal hamster and bovine sperm. Acrosomal components of differentiating bovine and hamster spermatids in tissue sections did not react with the monoclonal antibody, although the protein was present in immunoblots of round spermatids. In bovine sperm, MAB 4/18-staining at the ultrastructural level with immunogold-labeled second antibody was present as a reticulum throughout the acrosomal cap and as punctate aggregates in the equatorial segment. In hamster sperm, MAB 4/18-reactivity was present along the periphery of the acrosome in conjunction with matrix components (M1 and M2), as well as along the inner acrosomal membrane. These observations indicate that the acrosomes of bovine and hamster sperm possess an immunologically related Mr 22,000 protein and suggest that differences in MAB 4/18-staining of spermatids and spermatozoa is a result of epitope modification and/or a change in accessibility of the epitope to the antibody probe during the course of spermiogenesis. Based on its localization and solubility properties, we suggest that the Mr 22,000 protein, in conjunction with other polypeptides, forms a structural framework to maintain acrosomal shape and/or compartmentalize acrosomal contents.

Germ cell regulation of Sertoli cell transferrin mRNA levels

Sertoli cells cultured in the presence of germ cells responded by increasing the level of transferrin mRNA 3-fold as determined by solution hybridization and Northern blot analysis. In contrast, the steady state levels of other mRNAs, including sulfated glycoprotein 1 (SGP-1), sulfated glycoprotein 2 (SGP-2), transferrin receptor, regulatory subunit of cAMP dependent protein kinase, and ferritin light chain, were not influenced by coculture with germ cells. The transferrin mRNA stimulatory activity was found in conditioned medium from germ cells but was not associated with germ cell membrane components. The activity was abolished by treatment of the medium with trypsin. Partial characterization and isolation of the protein(s) from conditioned medium indicated that it has an apparent mol wt between 10 and 30 K. Studies using inhibitors of protein and nucleic acid synthesis indicated that the stimulation of transferrin mRNA by germ cell conditioned medium required both transcription and translation. Sertoli cell enriched (germ cell depleted) testes were obtained from male offspring of pregnant females irradiated at the 19th day of gestation. Testicular transferrin mRNA levels from irradiated rats decreased in comparison to levels in the normal rat, whereas SGP-2 mRNA levels were unchanged. These studies demonstrate that germ cell secretions may interact with Sertoli cells to specifically increase the level of transferrin mRNA and that this interaction may be a mechanism by which germ cells regulate the flow of iron across the seminiferous epithelium.

Characterization of rat testicular peritubular myoid cells in culture: alpha-smooth muscle isoactin is a specific differentiation marker

In frozen sections of testes from 20-day-old rats, alpha-smooth muscle (SM) isoactin was prominently immunostained in the peritubular tissue and in vascular walls, but not in areas populated by germinal cells, interstitial cells, or Sertoli cells. Peritubular myoid cell (PMC)-enriched preparations were isolated by two different procedures involving our previously published sequential enzymatic treatment ("conventional peritubular cell [PC]-enriched preparation") and by density-gradient purification of PMC from these preparations. The properties of different populations of PMC in culture were compared with respect to plating efficiency, rates of proliferation, and presence of cytoskeletal proteins. PMC, maintained in culture under defined conditions, contained proteins immunoreactive with monoclonal antibodies against alpha-SM isoactin. This was detected by immunostaining and by Western blots of cell extracts subjected to gel electrophoresis. Neither Sertoli cells, skin fibroblasts, bovine endothelial cells, nor glial cells contained alpha-SM isoactin detectable by the above techniques. We report the ontogeny of alpha-SM isoactin in the peritubular tissue of testes at different stages of gonadal development, and show that it is detectable within 8 days after birth. In addition, we describe immunocytochemical changes that occur during culture in various media of PMC prepared from testes of 20-day-old rats. We compare the use of alpha-SM isoactin as a differentiation marker for PMC with the use of desmin in facilitating the identification of PMC, and in following alterations in phenotype during culture in various culture media. Data presented demonstrate that about 81% of cells in the "conventional PC-enriched preparation," and about 94% of cells in the more purified populations of PMC were positive for alpha-SM isoactin in cells maintained in culture for 18 h after plating. These same PMC also were shown to express vimentin and plasminogen activator inhibitor, type 1. We conclude that alpha-SM isoactin is an excellent specific marker for PMC in seminiferous tubules and in culture.

[The evaluation of fertility characteristics in hens using fluorescence microscopy]

A method for the assessment of fertility in domestic hens is described. Vitelline membranes of fertilized eggs were coloured with fluorochrome DAPI, following which the DNA of sperms on these membranes has been examined with the help of fluorescence microscopy. After insemination with frozen semen there exist significant correlations between the number of sperms on the vitelline membranes on the one hand and 1) fertilization rates; 2) the length of fertile periods. Furthermore, it was observed that with higher numbers of sperms on the membranes, the length of the fertile periods tends to be shorter than with smaller numbers of sperm.

Characterization of membrane-associated actin in boar spermatozoa

Biochemical, immunological, and electron microscopic methods have been used to provide semi-quantitative estimates and to localize actin in membranes of boar spermatozoa. Immunoblots, using a monoclonal antibody raised against actin from chicken gizzard, detected the protein in caput and cauda sperm plasma membranes. Immunoassay indicated that approximately 1% of the total plasma membrane protein was actin. Monomeric actin accounted for more than one-half of the membrane actin. Approximately 30-40% of plasma membrane actin was insoluble in Triton X-100, and approximately 10% of the total actin remained insoluble after treatment with guanidine hydrochloride. The presence of F-actin in sperm plasma membranes and in plasma membrane detergent-insoluble proteins was detected by fluorescence microscopy using the specific probe NBD phallacidin. When S1 myosin subfragments attached to colloidal gold were used to localize F-actin by electron microscopy, the label was restricted to the outer acrosomal membrane of intact epididymal and ejaculated sperm. Filaments appeared in short arrays along the anterior region of the membrane. S1/gold labeled detergent-insoluble plasma membrane fractions but did not label the plasma membrane in intact sperm. Filaments were least prominent in intact caput spermatozoa and most prominent in ejaculated spermatozoa. We conclude that most actin associated with sperm membranes is in monomeric form in boar spermatozoa, but that actin filaments or protofilaments are components of the outer acrosomal membrane. These filaments may also associate with the plasma membrane overlying the acrosome.

Radial density distribution of chromatin: evidence that chromatin fibers have solid centers

Fiber diameter, radial distribution of density, and radius of gyration were determined from scanning transmission electron microscopy (STEM) of unstained, frozen-dried chromatin fibers. Chromatin fibers isolated under physiological conditions (ionic strength, 124 mM) from Thyone briareus sperm (DNA linker length, n = 87 bp) and Necturus maculosus erythrocytes (n = 48 bp) were analyzed by objective image-processing techniques. The mean outer diameters were determined to be 38.0 nm (SD = 3.7 nm; SEM = 0.36 nm) and 31.2 nm (SD = 3.6 nm; SEM = 0.32 nm) for Thyone and Necturus, respectively. These data are inconsistent with the twisted-ribbon and solenoid models, which predict constant diameters of approximately 30 nm, independent of DNA linker length. Calculated radial density distributions of chromatin exhibited relatively uniform density with no central hole, although the 4-nm hole in tobacco mosaic virus (TMV) from the same micrographs was visualized clearly. The existence of density at the center of chromatin fibers is in strong disagreement with the hollow-solenoid and hollow-twisted-ribbon models, which predict central holes of 16 and 9 nm for chromatin of 38 and 31 nm diameter, respectively. The cross-sectional radii of gyration were calculated from the radial density distributions and found to be 13.6 nm for Thyone and 11.1 nm for Necturus, in good agreement with x-ray and neutron scattering. The STEM data do not support the solenoid or twisted-ribbon models for chromatin fiber structure. They do, however, support the double-helical crossed-linker models, which exhibit a strong dependence of fiber diameter upon DNA linker length and have linker DNA at the center.

Higher transfection efficiency of genomic DNA purified with a guanidinium thiocyanate-based procedure

Efficient transfection of eukaryotic cells is dependent on the purity of the transfected genomic DNA. In an attempt to obtain a more reliable method of DNA purification we have modified the widely used protocol of Blin and Stafford to include a treatment with guanidinium thiocyanate. The DNA obtained following the present protocol transfects eukaryotic cells with higher efficiency.

Motion of individual human spermatozoa, both normal and lacking the outer dynein arms, during a continuous temperature rise

The effect of increasing temperature from 22-25 degrees C to 37 degrees C on various motion characteristics of individual normal human spermatozoa and spermatozoa lacking the outer dynein arms (LODA) was studied by using a new automatic microscopic tracking method. It was found that: 1) The curvilinear velocity (Vc, measured between 1-3 sec) of both normal and LODA spermatozoa, fluctuated more or less intensely between spermatozoa; this fluctuation was not thermodependent. 2) The average Vc in the two groups of spermatozoa increased with the rise in temperature at a similar rate (1 micron/sec/degrees C), but LODA spermatozoa had an initial Vc lower than that of normal spermatozoa (12.5 +/- 5.3 microns/sec and 34.2 +/- 8.2 microns/sec, respectively). 3) The profile of the Vc increase associated with the temperature rise was different for the two groups of spermatozoa: for LODA spermatozoa it was linear between 25-37 degrees C, whereas for normal spermatozoa a plateau was reached at about 31 degrees C. 4) Various patterns of trajectory were found for both normal and LODA spermatozoa; these patterns were unrelated to temperature. However, LODA spermatozoa had more linear trajectories than normal spermatozoa. 5) Plots derived from reaction rate theory showed that the activation enthalpy, delta H was a function of the increase of Vc for both normal and LODA spermatozoa, but that delta H was higher for LODA spermatozoa.

[Structure of the chromatin with long linker DNA]

The method of velocity sedimentation have been used to investigate ionic-strength-induced compaction of sea urchin sperm chromatin characterized by extremely long linker DNA (100 b.p.). The dependence of sedimentation coefficients of oligonucleosomes on the number of nucleosomes in the chain have been studied in the range of ionic strength from 0.005 to 0.085. Analysis of these data indicates that such structural parameters of sea urchin sperm chromatin fibre as the diameter of the chain and the length of the chain per nucleosome are quite similar to those of chromatin with shorter linker DNA, but the DNA packing ratio is higher. The structure of sea urchin sperm oligonucleosomes agrees well with the model of three-dimensional zig-zag-shaped chain with linker DNA forming a loop. The possible role of alpha-helical regions of the C-terminal domain of sea urchin sperm histone H1 in the long linker DNA folding is discussed.

Outer-arm dynein from trout spermatozoa: substructural organization

Outer-arm dynein purified from trout spermatozoa was disrupted by low-ionic-strength dialysis, and the resulting subunits were separated by sucrose density-gradient centrifugation. The intact 19 S dynein, containing the alpha- an beta-heavy chains, intermediate chains (ICs) 1-5 and light chains (LCs) 1-6, yielded several discrete particles: a 17.5 S adenosine triphosphatase (ATPase) composed of the alpha- and beta-chains ICs 3-5 and LC 1; a 9.5 S complex containing ICs 1 and 2 together with LCs 2, 3, 4, and 6; and a single light chain (LC 5), which sedimented at approximately 4 S. In some experiments, ICs 3-5 also separated from the heavy chain complex and were obtained as a distinct subunit. Further dissociation of the 17.5 S particle yielded a 13.1 S ATPase that contained the beta-heavy chain and ICs 3-5. The polypeptide compositions of the complexes provide new information on the intermolecular associations that occur within dynein. Substructural features of the trout dynein polypeptides also were examined. The heavy chains were subjected to vanadate-mediated photolysis at the V1 sites by irradiation at 365 nm in the presence of Mg2+, ATP, and vanadate. Fragment pairs of relative molecular mass (Mr) 245,000/185,000 and 245,000/170,000 were obtained from the alpha- and beta-heavy chains, respectively. Photolysis of these molecules at their V2 sites, by irradiation in the presence of vanadate and Mn2+, yielded fragments of Mr 160,000/270,000 and 165,000/250,000, respectively. These values confirm that the alpha- and beta-heavy chains have masses of 430,000 and 415,000 daltons, respectively. Immunological analysis using monoclonal antibodies revealed that one intermediate chain from trout dynein (IC 2) contains epitopes present in two different intermediate chains from Chlamydomonas dynein. This indicates that specific sequences within the dynein intermediate chains have been highly conserved throughout evolution.

Effects of freezing-thawing on the spermatozoon nucleus: a comparative chromatin cytophotometric study in the porcine and human species

Freezing-thawing effects on the nuclei of porcine and human spermatozoa were studied by determining native DNA percentage from fluorescence after acridine orange (AO) staining and by analyzing chromatin structure by a quantitative microspectrophotometric study of Feulgen-DNA complexes before and after freezing. The study of boar spermatozoa revealed no alteration in native DNA percentage after freezing. However, native DNA percentage decreased significantly in human spermatozoa. Feulgen-DNA content and sperm nuclear surface area decreased in both species after freezing. These results prompted us to hypothesize an overcondensation of sperm chromatin after freezing-thawing. This overcondensation may be related to the lower conception rates obtained with human and porcine semen after cryostorage via defective decondensation.

Immunomagnetic method to select human sperm without sperm surface-bound autoantibodies in male autoimmune infertility

Using supermagnetic polymer microspheres coated with anti-immunoglobulins, spermatozoa without autoantibodies bound on their surface can be isolated from a sperm population showing a variable percentage of cells with autoantibodies bound on their surface. This simple technique seems to induce no modification of semen qualities; therefore, the concentration of sperm after immunomagnetic separation might be useful for in vivo or in vitro insemination in infertile couples with autoimmune male infertility.

Evaluation of the semi-automated Autosperm semen analysis system. II. Comparison with conventional method, time-exposure photomicrography, and automated CellSoft system

Semen analysis results obtained by a recently developed semi-automated Autosperm system (Amsaten N.V.S.A. Corp., De Pinte, Belgium) were compared with those obtained by the conventional, time-exposure photomicrographic, and automated CellSoft system (Cryo Resources Inc., New York, NY) analyses. The Autosperm system either over- or underestimated the sperm concentration in comparison with the conventional analysis and more often underestimated the sperm concentration in comparison with the automated CellSoft system analysis. Comparison of the results for percent sperm motility by the conventional and Autosperm analyses showed that the latter tended to underestimate the percentage of fast-swimming spermatozoa and overestimate the percentage of slow-swimming spermatozoa. There were considerable variations in the measurement of sperm movement characteristics between the Autosperm and time-exposure photomicrographic and automated CellSoft system analyses, respectively. These findings demonstrate that the performance of the Autosperm system does not agree well with those of the currently available methods employed in the present study. Part of the disagreement in measurements of sperm parameters could be because of the subjective elements inherent in the semi-automated Autosperm analysis.

Evaluation of the semi-automated Autosperm semen analysis system. I. Accuracy and comparison with the conventional method and the automated Hamilton-Thorn system

The accuracy of measurements by the semi-automated Autosperm (Amsaten N.V.S.A. Corp., DePinte, Belgium) semen analysis system was assessed by recounting and manually tracking sperm recorded on videotape during analysis of 51 ejaculates. Mean inaccuracies in the analysis of sperm concentration and percentage motility were 15% and 22%, respectively. Measurements of sperm movement characteristics relied on the skill of the operator and discrepancies (means around 10%, maximum 57% to 184%) depended on the straightness of sperm paths. Although less expensive than the fully automated system, semen analysis by Autosperm is a subjective and labor-intensive method. Furthermore in comparison, data obtained using Autosperm also provide less information, and agreements of matched data with those obtained by the conventional methods were not significantly better.

Differences in lipoprotein composition between heads and tails of human sperm: an infrared spectroscopy study

Human spermatozoa and their fractions (heads and tails) have been studied by infrared spectroscopy. Protein conformation in isolated human spermatozoa heads, although predominantly of the alpha helix or random coil type, has a significant proportion of antiparallel B structure. Spectra of isolated spermatozoa tails show that proteins exist in this fraction preponderantly in pleated-sheet conformation (parallel and antiparallel). The quantity and type of lipids seem to be drastically different between heads and tails of spermatozoa. Head lipids are scarce and difficult to extract, and they are apparently tightly bound to proteins, highly unsaturated, and rich in free hydroxyl and carboxyl groups. Tail lipids are more abundant and more easily extractable. Head phospholipids are probably phosphatidylcholine, cephalins, and inositols, and tail phospholipids are preponderantly plasmalogen-type lecithins and sphingomyelins. The presence of specific infrared bands points to the existence in tails of important amounts of sulfur compounds, probably sulfolipids or sulfoglycolipids.

Genomic distribution of copia-like transposable elements in somatic tissues and during development of Drosophila melanogaster

The genomic distribution of elements of the copia, 412, B 104, mdg 1, mdg 4 and 1731 transposon families was compared by the Southern technique in DNA preparations extracted from brains, salivary glands and adult flies of two related Drosophila lines. The copia, 412 and mdg 1 sequences were also probed in DNA from sperm, embryos, and 1st and 2nd instar larvae. The homogeneity of the patterns observed shows that somatic transposition is unlikely to occur frequently. A correlation between mobility and the euchromatic or heterochromatic location of transposable elements is discussed. In addition, an explanation of the variable band intensities of transposable elements in Southern autoradiographs is proposed.

Identification of peanut agglutinin receptors on mouse testicular germ cells

Peanut agglutinin receptors expressed specifically in mouse testicular germ cells have been identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and lectin blotting techniques. Two major components were estimated to have molecular weights of 86,000 and isoelectric points of 6.1 +/- 0.3 and 6.2 +/- 0.3. Minor components with molecular weights of 71,000-74,000 and isoelectric points of 6.1 +/- 0.3 were also detected. Specific expression of these receptors on testicular germ cells was confirmed using the testes of mutant mice, Sld/Sld, devoid of germ cells.

Detection of sperm-bound antibodies in the male partners of infertile couples using the immunobead test

The aim of this investigation was to determine the incidence of sperm-bound antibodies in the male partners of an unselected infertile population using an immunologically specific test (IBT). With this method 34 out of 450 infertile men (7.55%) were positive for one or more of the immunoglobulins IgA, IgG and IgM. For IgG and IgA, the majority of antibody binding was located on the entire sperm with a minor amount bound to the head or tail. For the IgM, the majority of the binding was detected to the tail tip, and tail binding was observed only in a minority of cases.

Analysis of the membrane-interacting domain of the sea urchin sperm adhesive protein bindin

We have investigated the domain of the bindin polypeptide that selectively associates with gel-phase phospholipid vesicles. We found that small trypsin fragments of bindin retain the ability to selectively associate with gel-phase vesicles. The primary amino acid sequence of bindin suggests that these peptides are derived from the central portion of the polypeptide between residues 77 and 126, which is the most hydrophobic region of bindin. We have also employed 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine (TID) and novel, radioiodinated, photoactivatable derivatives of the polar head group of phosphatidylethanolamine (ASD-PE and ASA-PE) to identify membrane-associated polypeptide segments after the transfer of radiolabel from the probe to the bindin polypeptide. After photolysis, bindin was selectively labeled only from probes incorporated in gel-phase vesicles. The labeling of bindin was much more efficient from the head group probes ASA-PE and ASD-PE (8 and 2% of the total label, respectively) in comparison to the hydrophobic probe TID (less than 0.02% of the total label), suggesting that bindin is localized within the polar part of the bilayer. Protease mapping experiments with V8 protease, trypsin, and endoprotease Lys-C suggest that some of the probe label is distributed along the amino-terminal portion of bindin between residues 1 and 76 and the rest of the label is restricted to the segments between residues 77 and 126 which also selectively bind to gel-phase vesicles. The carboxyl-terminal portion of bindin between residues 127 and 236 is not labeled.

Intracellular pH regulates bovine sperm motility and protein phosphorylation

Bovine sperm in neat caudal epididymal fluid become motile in response to either pH elevation or dilution of the fluid. Buffers containing permeant weak acids at physiologic concentrations are able to mimic these effects of caudal fluid. These observations lead to the hypothesis that a pH-dependent epididymal fluid quiescence factor regulates bovine sperm motility by modulating sperm intracellular pH (pHi). Here we report that sperm pHi, measured with the fluorescent pH probe carboxyfluorescein, increases by approximately 0.4 units in response to either of these motility-initiating manipulations. At least 26 discrete phosphoprotein bands are distinguishable by sodium dodecylsulfate-polyacrylamide gel electrophoresis after incubation of intact caudal sperm with 32PO4. A prominent phosphoprotein, with Mr approximately 255,000 (pp255) and a relatively high specific radioactivity, is reversibly dephosphorylated in response to elevations in pHi that initiate sperm motility. Unlike most of the sperm phosphoproteins, the extraction of pp255 requires reducing agents. This phosphoprotein cosediments with the sperm heads but not the tail, midpiece, soluble, or plasma membrane fractions. No other pHi-dependent phosphorylation changes are apparent in gels of whole sperm extracts. However, subcellular fractionation allows the detection of increased phosphorylation of two plasma membrane phosphoproteins (Mr approximately 105,000 and 97,000) and decreased phosphorylation of another plasma membrane phosphoprotein (Mr approximately 120,000) in response to increasing pHi. This is the first report describing changes in endogenous phosphoproteins from intact motile and nonmotile bovine sperm that are regulated by pHi.

[Diagnostic in-vitro fertilization]

Unexplained sterility is one of the major problems in the treatment of childless couples. The reason for sterility can be the result of different factors such as andrological or anatomic-physiological dysfunctions. The therapeutic approach to treat patients with unexplained sterility at the Department of Obstetrics and Gynecology, University of Goettingen, is, to exclude those patients from further therapies who obviously have no chance to become pregnant by any technique of reproductive medicine. A so called "diagnostical IVF" gives information about the fertilization capacity of male and female gametes in vitro. The results of a one year study with 85 couples (tubal sterility = 57; idiopathic sterility = 28) indicated, that even with no differences in the number of oocytes retrieved, the fertilization and cleavage rates were significantly higher in the group of patients with tubal sterility (fertilization rate: 63.1% vs 46.1%; cleavage rate: 57.5% vs 40.6%). Thus the transfer rate in patients with unexplained sterility was about 15% lower (68.9%) than in patients with tubal sterility (85.6%). On the other hand, after embryo transfer the pregnancy rate was double in those patients with unexplained sterility (38.7 vs 15.7%). If there is no fertilization of the oocytes in at least two IVF cycles all attempts to fulfill the patients desire for a child seem useless. In contrast successful in vitro fertilization provide the bases for further intrauterine insemination cycles which can be assisted by psychotherapy. This regimen seems helpful to classify patients with unexplained sterility and avoids long lasting frustrating therapies.

[The adenosine phosphate content in human sperm and their motility]

Adenosine phosphoric acids (ATP, ADP, AMP) are of significance for the metabolic processes in living beings, including spermatozoa, as they are the principal donors of energy in all the reactions of biosynthesis. Besides, spermatozoa need the energy to perform a particular function-to move in the female genital tract to the ovum. It was stated that a decrease in the ATP levels reduced or ceased the translational motion of spermatozoa, therefore the investigations of adenosine phosphates in the spermatozoa were found to be mandatory. The authors studied the levels of ATP, ADP and AMP and the energy charge in the native human spermatozoa in the patients with oligo- and asthenospermia. Spermatozoa with morphologically and physiologically normal fertility were used as controls. The results obtained demonstrated that in oligospermic males the levels of ATP were slightly decreased whereas the levels of AMP significantly increased from 31.6 to 38 per cent. As a result there was a significant decrease in the ATP/ADP ratio. A more pronounced decrease in the ATP levels and an increase in the AMP levels were revealed in asthenospermic patients (12.6 and 40.5 per cent respectively. In the latter patients the ADP fraction decreased to 42.4 per cent versus 51.4 per cent in health and the energy charge underwent a more significant decrease: from 0.37 (normal) to 0.3. The results obtained are indicative of the possibility of using the aforementioned method for a comprehensive evaluation of the spermatozoan functional activity and the detection of asthenospermia-inducing mechanisms.

Immunogold distribution of actin during spermiogenesis in the normal rabbit and after experimental cryptorchidism

Immunogold procedures for actin detection were used in combination with experimental cryptorchidism in the rabbit as a model to shed more light on the function of subacrosomal actin during spermiogenesis. In the normal testis, actin was localized in the perinuclear substance (PNS) from round spermatid onward but it was not detected in late spermatids. Actin labeling in each type of spermatid was essentially unmodified after 24 hr of cryptorchidism. However, among relevant immediate and delayed effects, discontinuous acrosomes overlying a continuous PNS with normal actin labeling were noted. Nuclear invaginations were seen in combination with subacrosomal dilatations; at this site actin labeling was found only in the PNS closely apposed to the nuclear envelope. In subacrosomal areas lacking PNS, actin labeling also was lacking. These results suggest that the subacrosomal actin (F-actin) is a component of the PNS that is tightly bound to the nuclear envelope rather than the overlying inner acrosomal membrane. Therefore, a function for the subacrosomal actin either in anchoring the acrosome to the nucleus or in capping the inner acrosomal membrane appears unlikely. The data rather suggest a capping function for the nuclear membrane during spermiogenesis.