In-vivo gene transfer induces transgene expression in cells and secretions of the mouse cauda epididymis.

Mouse cauda epididymis were in-vivo transfected using the lipid FuGENE 6 as gene vector. Two gene constructions were employed: the p-GeneGRIP which codifies for the Green Fluorescent Protein (GFP) and the pSEAP-control that expresses an alkaline phosphatase as a secretion. Transfection was detected by fluorescence and appeared in the nucleus and cytoplasm of epithelial cells.

Photoperiod-induced apoptosis in the male genital tract epithelia of the golden hamster.

The aim of this study was to identify some details of the changes induced by a short-day light regime (8:16 light:dark) on the male genital tract and accessory sex glands of the golden hamster Mesocricetus auratus. We principally examined the presence of apoptotic cells in the epithelium from different regions of the epididymis, seminal vesicles, prostate and coagulating gland. We detected an increase in the percentage of apoptotic cells in situ using the TUNEL technique in animals that were maintained for 6, 8 or 12 weeks in a short photoperiod.

Transfection of spermatozoa in bivalve molluscs using naked DNA.

Spermatozoa from the bivalve molluscs Mytilus galloprovincialis, Mytilus chilensis and Chamelea gallina were transfected in vitro using the p-GeneGrip construct, which encodes green fluorescent protein. The efficiency of transfection after brief incubation was assessed by fluorescence and confocal laser microscopy, and was about 58.5-70.

Age-induced apoptosis in the male genital tract of the mouse.

We have examined the effects of ageing on the increase in apoptotic cells numbers in the male genital tract of the house mouse (Mus musculus). We have found that not all organs have the same response. There is an induction of apoptosis in both the epididymis and ventral prostate.

Abdominal temperature induces region-specific p53-independent apoptosis in the cauda epididymidis of the mouse.

It is widely accepted that temperature regulates gene expression and function in the epididymis. However, the significance of reduced temperature of the scrotum in cell survival had not often been examined. Our hypothesis was that the experimental increase of the temperature could induce apoptosis.

Generation of transgenic mice by transfection of pronuclear embryos using lipid-DNA complexes.

We had previously developed a methodology to introduce foreign DNA into mouse eggs and embryos using cationic lipids as vectors. In this report we use this technique to produce transgenic animals. Mouse embryos at the pronuclear stage were transfected using a mixture of a plasmid DNA, encoding for a nuclear form of beta-galactosidase, and a commercial lipid transfection reagent.

Regulation of foreign DNA uptake by mouse spermatozoa.

We have studied some features of DNA uptake in both mature and immature mammalian spermatozoa. Mature sperm collected from the cauda epididymis are able to incorporate foreign DNA in a buffer containing only salts and calcium. Immature spermatozoa, however, are unable to bind DNA.

Phosphatidylinositol-3 kinase acts in parallel to the ERK MAP kinase in the FGF pathway during Xenopus mesoderm induction.

Phosphoinositide 3-kinases (PI3Ks) are lipid kinases that can phosphorylate phosphaditylinositides leading to the cell type-specific regulation of intracellular protein kinases. PI3Ks are involved in a wide variety of cellular events including mitogenic signalling, regulation of growth and survival, vesicular trafficking, and control of the cytoskeleton. Some of these enzymes also act downstream of receptor tyrosine kinases or G-protein-coupled receptors.

Transfection of mouse eggs and embryos using DNA combined to cationic liposomes.

We have used plasmid DNA in combination with cationic liposomes to transfect mouse eggs and embryos. The plasmid was rhodamine labeled, which allowed a direct visualization of the DNA uptake by the cells. Immature eggs, collected from the ovaries, were easily transfected, but once the egg was ovulated the zona pellucida (ZP) acted as a barrier and prevented transfection.

CD52 mRNA is modulated by androgens and temperature in epididymal cell cultures.

Cultured rat epididymal tissue explants formed >90% pure, adherent growing epithelial cell monolayers. Despite their flattened and apparently androgen receptor-negative phenotype, these cells for a short period kept characteristics of the epididymal duct epithelium, i.e.

Effect of antibodies against seminal vesicle secretion on fertility in the rat.

Fertile female Wistar rats were immunised against rat and mouse seminal vesicle secretion (SVS) to test the production of allo-antibodies and the effect of the antibodies elicited on fertility. Twenty-six per cent of the rat and mouse SVS-immunised females were infertile after the treatment. The sera were titrated by ELISA and used in Western blots to detect the proteins recognised.

Binding of seminal vesicle proteins to the plasma membrane of rat spermatozoa in vivo and in vitro.

The association of seminal vesicle (SV) proteins with rat spermatozoa has been studied in vivo and in vitro. SV proteins bind to the sperm plasma membrane after ejaculation but are removed progressively from the sperm plasma membrane in the female genital tract. Although some of these remain bound to spermatozoa when they reach the oviducts, they do not seem to be present at the time of fertilization.

Treatment of human spermatozoa with seminal plasma inhibits protein tyrosine phosphorylation.

It has long been known that seminal plasma contains factors that influence the fertilizing capacity of spermatozoa in many different ways. However, little is understood of the biochemical cascades triggered when spermatozoa and seminal plasma interact. In this study, we examined how incubation with seminal plasma affected protein tyrosine phosphorylation in human spermatozoa.

Molecules involved in mammalian sperm-egg interaction.

To achieve fertilization, sperm and egg are equipped with specific molecules which mediate the steps of gamete interaction. In mammals, the first interaction between sperm and egg occurs at an egg-specific extracellular matrix, the zona pellucida (zp). The three glycoproteins, ZP1, ZP2, and ZP3, that comprise the zp have been characterized from many species and assigned different roles in gamete interaction.

Regulation of mouse epididymal epithelium in vitro by androgens, temperature and fibroblasts.

The epididymal epithelium provides the microenvironment for sperm maturation. However, the molecular basis of epididymal function is still poorly understood because of the limitations of in vivo systems. For this reason, we have developed an in vitro culture system for mouse epididymal epithelial cells.

Fate and distribution of seminal plasma proteins in the genital tract of the female rat after natural mating.

This paper describes the distribution and fate of seminal plasma proteins in the rat female genital tract after insemination, using immunological detection in tissue sections and in fluids collected from different regions. The localization of seminal plasma proteins in the uterus and the vagina correlated with that of spermatozoa, suggesting that passive transport mechanisms operate in these regions. No seminal plasma proteins were detected in the oviduct, indicating that their presence is probably restricted to the uterine environment.

Photoperiod-induced changes in the proteins secreted by the male genital tract of the rodent Octodon degus.

The proteins secreted by the male genital tract were analyzed in the seasonally breeding rodent Octodon degus. The protein patterns from the fluids collected from sexually active animals were compared with those from animals in resting period, with others which were previously castrated, and with castrated animals which received testosterone replacement treatment. Fluids from cauda epididymides (CE), seminal vesicles (SV) and prostate glands (PG) were collected, and analyzed by polyacrylamide gel electrophoresis followed by different staining methods and densitometry.

Interaction of a tyrosine kinase from human sperm with the zona pellucida at fertilization.

A 95-kilodalton mouse sperm protein with characteristics of a protein tyrosine kinase has been identified as a receptor for ZP3, a glycoprotein in the egg's extracellular matrix. The structure of the human homolog was determined by screening an expression library from human testis; a testis-specific complementary DNA was isolated that encodes a protein similar to receptor tyrosine kinases and appears to be expressed only in testicular germ cells. Antibodies against a synthetic peptide from the intracellular domain recognized a 95-kilodalton human sperm protein that contains phosphotyrosine; human ZP3 stimulates the kinase activity of this sperm protein.

Structure of the vaginal plugs generated by normal rats and by rats with partially removed seminal vesicles.

Normal male rats generate vaginal plugs that appear to be firmly apposed to the vagino-cervical junction and permit a large number of spermatozoa to reach the uterus. A few spermatozoa form entangled masses inside these plugs, as revealed by light microscopy. Males in which the seminal vesicles have been partially removed produce plugs that are smaller and softer than those generated by normal males, and the plugs display a cup-like structure at the proximal end.

Role of fluid from seminal vesicles and coagulating glands in sperm transport into the uterus and fertility in rats.

The relationship between the quantity of seminal vesicle secretion in the ejaculate, the percentage of spermatozoa reaching the uterus and fertility was studied in rats. Different portions of seminal vesicles were removed from male rats; 15 min after coitus (day 0), the numbers of spermatozoa in the uterus and vagina were counted and the vaginal plug characteristics were noted. Fertility was evaluated by the number of fetuses on day 14.

Electrophoretic pattern of rodent seminal vesicle proteins as revealed by silver staining.

Electrophoresis of seminal vesicle secretions (SVS) from several rodents showed a very simple pattern composed of 3-5 main protein bands when an anionic dye (Coomassie brilliant blue) was used. However, use of a silver staining method showed a more complex protein spectrum, and several minor components of 12-90 kD, were clearly revealed. Western blotting using antibodies to SVS demonstrated that these minor protein components were not serum contaminants.

Comparative analysis of the neck region in spermatids and spermatozoa of some orthopteran insects.

The ultrastructure of the neck region and the participation of noncovalent and disulphide bonds in the head-tail attachment were analyzed in spermatids and spermatozoa of some orthopteran species from the families Tettigoniidae and Acrididae. This study combined conventional electron microscopy with cytochemical procedures to detect acidic proteins and lysine-rich basic proteins, and with treatments using the disruptive agents sodium dodecyl sulfate (SDS) and dithiothreitol (DTT). The organization of the neck region differs in spermatozoa among species in the families analyzed.

Effects of melatonin on gonadal steroids and glucose plasma levels in frogs (Rana perezi and Rana temporaria).

The effect of melatonin treatment on the Gonosomatic Index (GSI), ovarian germinal epithelium, plasma estradiol and testosterone levels was studied in Rana perezi females in December. No significant changes were observed in GSI, estradiol, and testosterone levels in melatonin treated animals when compared with saline injected controls, but the percentage of previtellogenic follicles decreased in animals treated with melatonin (100 micrograms). The effect of melatonin treatment on glucose level was studied in Rana perezi females in December and Rana temporaria males in February.

In vivo effect of melatonin and gonadotropin-releasing hormone on testicular function in Rana temporaria.

Studies concerning pineal-gonadal interactions and investigations about the effect of the putative pineal hormone melatonin in male amphibians are very scarce. In this work we investigate the effects of melatonin, synthetic gonadotropin-releasing hormone (GnRH), or both when injected in Rana temporaria males. We conclude that melatonin inhibits spermiation and spermatogonial multiplication when injected alone or with GnRH.