Localisation of two classes of acetylcholine receptor-like molecules in sperms of different animal species.

The distribution of different classes of acetylcholine (ACh) receptor-like molecules in sperms of different invertebrate and vertebrate species is described. ACh receptor molecules belong to one of two classes: muscarinic receptors (mAChRs), associated with signal transduction mechanisms in the inner domain of the cell, and nicotinic receptors (nAChRs), capable of opening Na+ channels when activated by the ligand. Molecules immunologically related to mAChRs and to ACh can be identified by specific antibodies, and revealed by immunofluorescent or immunogold staining; the nicotinic receptor-like molecules are localised as curare-sensitive affinity sites for alpha-bungarotoxin. In all species studied, both classes of receptors were found, with a similar distribution. Muscarinic-like molecules were found mainly in the sperm head regions of most species; such a localisation may be correlated to a function in sperm-egg interaction, for instance in the regulation of the block to polyspermy. Nicotinic-like molecules are present mainly in the tail and in the post-acrosomal region of most animals, thus confirming their function in the regulation of sperm propulsion, but are also present at the acrosomal region of most species. The distribution patterns of the different classes of molecules indicate that both may be involved in sperm-egg interactions, in addition to their known function in the regulation of sperm propulsion.

Notulae seminologicae. 5. Mathematical evaluation of interdependent submicroscopic sperm alterations.

This paper concerns the mathematical evaluation of sperm quality as examined by electron microscopy. Proceeding with a Bayesian technique, we have developed a formula considering all statistical possibilities for defects of the examined sperm to be present in a sperm cell, the total number of affected spermatozoa, and, as consequence, that of sperm devoid of defects, also considering the probability of association characteristics of some of them. The formula has been studied in three applications. The first concerns the number of healthy spermatozoa present in ejaculates of fertile men. We have found an enormous variability, but we have observed that the minimal number of spermatozoa free of defects assuring a normal fertility seems to be a little higher than 2 x 10(6). The second and third examples concern varicocele and assisted fertilization. In both cases the formula allows a precise simultaneous evaluation of the totality of studied characters and a determination of the number of spermatozoa free from defects. This comparative analysis shows that the formula is sufficiently sensitive to distinguish the different degrees of the varicocele condition and the various possibilities of fertility power in cases of natural or artificial insemination. In this way we will easily control the level of improvement of sperm quality in cases of varicocele treated pharmacologically or surgically, or we will better predict the success of artificial insemination.

Notulae seminologicae. 4. Mathematical evaluation of submicroscopical alterations in spermatozoa of sterile men with varicocele.

In this paper the mathematical formula recently proposed by Baccetti & Mirolli in this journal is used for the quantitative electron microscopical evaluation of six submicroscopical defects frequently present in the spermatozoa ejaculated by patients affected by various degrees of varicocele. All these characteristics are independent from each other and are in some way related to imperfect sperm maturation. They concern the shape and position of the acrosome, the status of the chromatin, of the mitochondria, of the axoneme, the individuality of the cell. The incidence in the sperm population of these submicroscopical characters is clearly related to the degree of the affection as estimated by usual clinical parameters. This demonstrates that the electron microscopical sperm analysis evaluated by the present formula is a very sensitive tool in revealing fine prognostical parameters.

HIV-particles in spermatozoa of patients with AIDS and their transfer into the oocyte.

By immunocytochemistry and in situ hybridization at the electron microscopy level, and by the PCR technique, we have shown that HIV-1 binds and enters normal sperm; that viral particles, their antigens, and nucleic acid are present in sperm from HIV-1 infected men; and that such sperm can transfer HIV-1 like particles to normal human oocytes. We also present evidence that a galactosylceramide-like compound is present on the sperm membrane and could function as an alternative receptor for HIV.

Notulae seminologicae. 1. New combinations of Kartagener's syndrome.

In this note new consequences of the Kartagener's syndrome are described. In males the syndrome involved a diffused sperm immaturity; in one female severe skeletal defects were present probably resulting from bad organization of the renal apparatus.

Notulae seminologicae. 2. The 'short tail' and 'stump' defect in human spermatozoa.

In this note several cases of stunted tails involving the total sperm population in sterile humans are described. Half of the cases are classified as 'short tailed' spermatozoa, the other half as 'stump defect' previously described in bulls. Both defects are referred in details at electron microscopical level.

Evaluation of the antifertility activity of the broom Spartium junceum in the mammalian male.

Male adult rabbits and rats treated with Spartium junceum showed a significant decrease in fertility, demonstrated by a lower number of pregnancies. The target of the drug seems to be the acrosomal protease system, the activity of which appears greatly reduced, while the morphology of testicular cells and epididymal spermatozoa is only partially affected. The antifertility effect is completely reversible.

Studies on varicocele. II. The inhibin secretion.

In this paper a previous interpretation given by the authors concerning one of the ways varicocele can affect fertility is confirmed. Moreover, it is definitely demonstrated that the high temperature stimulates inhibin secretion (and probably the testosterone-estradiol conversion) in the Sertoli cells, while the somatomedin secretion in vitro seems to be unaffected. It means that the action of the temperature on the germinal cells seems to be mediated by the pathway: inhibin (plus estradiol)-->pituitary-->FSH. Inhibin in the Golgi complex of Sertoli and germinal cells has been detected by electron microscopical immunocytochemical techniques.

Studies on varicocele. 1. Submicroscopical and endocrinological features.

In this study we have selected a group of patients affected by a more or less severe condition of varicocele. After the evaluation of spermatogenesis and sperm function by electron microscopy we have demonstrated that the sperm malformations are mostly due to immaturity. Subsequently we have observed low FSH levels in the blood, concomitant with inhibin high contents, and we have studied Sertoli cells at submicroscopical level. In conclusion we suggest the following mode of action of varicocele in endocrinologically and spermatologically altered patients: varicocele----Sertoli cells----increased inhibin----hypophysis----decreased FSH----decreased testosterone----aberrant spermatogenesis----immature spermatozoa. The research will continue.

HIV particles detected in spermatozoa of patients with AIDS.

In this paper the Authors describe the presence of HIV particles on and in mature spermatozoa either ejaculated by AIDS patients or incubated in vitro with HIV. Both kinds of spermatozoa have particles localized around the sperm organelles. In the first case, the nucleoid of the virus can be enveloped by a membrane-like coat or be devoid of it and form buddings in the plasma membrane. In the in vitro infected spermatozoa, only membrane enveloped nucleoids are present, and no process of budding can be found. The Authors conclude considering that the spermatozoa of the AIDS patients can be penetrated by the virus particles in different moments of their life, and show the HIV particles in different stages of their cycle: some of them have freshly penetrated the sperm, and are still contained in a membrane-like coat, others are replicated and are budding through the sperm plasma membrane. On the contrary, in vitro infected spermatozoa have only freshly penetrated virus particles, and lack buddings and membrane-free nucleoids. The presence of the HIV virus in spermatozoa is substantiated by labelling with monoclonal or polyclonal anti-HIV antibodies.

A "miniacrosome" sperm defect causing infertility in two brothers.

A sperm defect causing infertility in two brothers is described. The malformation, named the "miniacrosome sperm defect," occurs in the total sperm population. It involves both the nuclei, which have a roundish apex, and the acrosomes, which are small, located in an apical position on the top of the nucleus, and sometimes ring-shaped. The midpiece and tail segments are normal, and the sperm are perfectly motile but fail to fertilize zona-free hamster ova in vitro. In spermatids, the absence of a microtubular manchette and reduction of the Golgi complex are evident.

Spermatozoa and relationships in Palaeognath birds.

In this paper the authors describe the ultrastructure of the mature spermatozoon and the spermatid in Struthio camelus and Dromaius novaehollandiae. The first species is characterized by a rod-like perforatorium within an endonuclear canal in the anterior third of the nucleus, while the second is characterized by an extremely reduced completely extranuclear perforatorium. Other differences are in the sperm dimensions, the number of mitochondria and the length of the axonemal accessory fibers. Considering both the present data and previous findings, Palaeognath birds appear to be a peculiar and monophyletic group, characterized by: 1), a conical acrosome surrounding the nucleus; 2), a fibrous sheath around most of the axoneme; and 3), an elongated distal centriole occupying the entire midpiece. Within this group, Tinamiformes seem to be more primitive than Struthioniformes. In the latter order Dromaius is distinctly different from the reduced Struthio and Rhea which are closely related to one another by the presence of a rod-like endonuclear perforatorium.

Morphogenesis of the decapitated and decaudated sperm defect in two brothers.

The "decapitated sperm" defect, found in both of two sterile brothers, may be assumed to have a genetic origin. The present material suggests that the term "decapitated spermatozoa" is not exact, because detached heads and tails were found in the brothers' ejaculate that could be regarded as "decapitated tails" and "decaudated heads." The present report describes frequent, more or less advanced stages of detachment. Both heads and tails showed a normal structure in which only the postnuclear region was deficient, lacking basal plate and implantation fossa. A break at a different level of the midpiece, and therefore three kinds of separation, were observed. The defect, according to the present research, must originate in the testicular region, whereas the detachment occurs in the epididymis.

Localization of acrosomal enzymes in Arthropoda, Echinodermata and Vertebrata.

The presence and localization of acrosin and hyaluronidase have been detected by immunocytochemistry in animals belonging to different phyla and characterized by the different structure of the acrosomal complex. Acrosin is widely distributed from Insecta to Echinodermata and Vertebrata; hyaluronidase has a similar diffusion, but seems to be absent from an Insect and from Echinodermata. The presence of extraacrosomal layer and perforatorium seems not to be related to that of the two enzymes, that are absent from Teleost species devoid of acrosome or having only a pseudoacrosome.

Crater defect in human spermatozoa.

This report describes the "crater defect" in human spermatozoa, a malformation that consists of a nuclear and acrosomal invagination present in 100% of the cells, whereas tail structure and motility are fairly normal. The defect occurs during spermiogenesis. A possible concomitance with abnormalities in the microtubular apparatus involved in the sperm molding is discussed.

Immunocytochemistry and sperm pathology.

In this paper the Authors describe the localization of some significative proteins (acrosin, actin, tubulin, vimentin) detected by immunocytochemical methods in human infertile spermatozoa and correlate their distribution with the ultrastructural characteristics of the same spermatozoa, in order to clarify the structural bases of infertility.

Action of gossypol on rat germinal cells. II. The acrosome.

The action of gossypol on the acrosomal complex in rats has been investigated by microscopical and submicroscopical methods. The drug displays its morphological action only on spermatozoa during the transit through the epididymis, causing malformations and vesiculations. It appears to exert a primary action on the S-S groups formation, disturbing morphological molding occurring in this period and inhibiting capacitation.

Calcium ultrastructural localization in Xenopus laevis eggs following activation by pricking or by calcium ionophore A 23187.

In the egg of Xenopus laevis a cortical network of smooth endoplasmic reticulum (SER) surrounds and interconnects each cortical granule (CG) (Campanella and Andreuccetti, '77). This network is a possible intracellular site of calcium storage to be called into action for CG exocytosis. In our experiments, Xenopus eggs, unfertilized or activated by pricking or by calcium ionophore A 23187, have been fixed in osmium-pyroantimonate for calcium localization. Our data show that deposits can be detected only in activated eggs. The calcium chelator edetate (EGTA) and x-ray microprobe analysis demonstrate that they contain calcium. Deposits are found on liposomes and on all intraovular cytomembranes, which therefore appear to be possible sites of calcium sequestration. In the case of ionophore-activated eggs, deposits are detectable independently of the presence of extracellular calcium. These data show that in Xenopus at activation an intracellular liberation of calcium occurs similar to that described in other species. Furthermore, the fact that antimony deposits are observed only after activation makes Xenopus eggs appropriate material in which to follow the temporal and spatial sequence of appearance of the deposits during the early stages of activation. Our results show that antimony deposits appear first in SER vesicles between the plasma membrane and CGs and then spread to the rest of the egg cytomembranes. These data corroborate our hypothesis that in Xenopus the cortical SER network is the first intracellular site where calcium is released at activation. The possible mechanism of calcium release and propagation along the egg cortex is discussed.

The Sertoli cell in lizards.

Sertoli cells of lizards are characterized by variable size, abundant smooth and rough endoplasmic reticulum, multivesicular bodies, lipid vacuoles probably related to the spermatogenic cycle, and mitochondria of normal size. The cytoskeleton contains actin, particularly abundant in the cell periphery, vimentin all around the nucleus and throughout the rest of the cytoplasm. Moreover, microtubules are distributed in the cell periphery. The junctional complexes demonstrate the presence of a very efficient blood-testis barrier, containing tight, gap, tight-gap, septate-like, desmosome-like, and "Sertoli-Sertoli" junctions. In the last, the actin layer interposed between the plasma membrane and the subsurface cistern is absent. The desmosome-like junctions are surrounded by 7-nm filaments and not by intermediate filaments.

Ultrastructural abnormalities in respiratory cilia and sperm tails in a patient with Kartagener's syndrome.

Ultrastructural abnormalities of spermatozoa and respiratory cilia have been reported in a male patient with Kartagener's syndrome and infertility. In this patient both respiratory cilia and sperm tails showed defects in radial spokes and dynein arms. Such defects are heretofore undescribed in the same subject with immotile cilia syndrome. Absence of both inner and outer dynein arms and absence of the inner dynein arms only were detected in spermatozoa and in respiratory tract cilia, respectively. Moreover, total absence of axoneme was seen in several sperm tails from this patient. The possibility that the features described are of genetic origin is discussed.