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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Eight-h-old anucleate fragments of artificially activated mouse oocytes produced within 30 min after activation were fused with anucleate fragments of ovarian oocytes bisected at the GV stage and matured in vitro for 4-5 h. The resulting cybrids were inseminated soon after fusion and fixed 3-4 h or 14 h later. After 3-4 h of culture most of the sperm nuclei underwent decondensation. Early male pronuclei were observed sporadically. After overnight culture small or fully formed male pronuclei were present in monospermic and dispermic cybrids. The abortive nuclei, designated as stage IIa (earlier described by Borsuk and Tarkowski, 1989) were also observed and their occurrence was strongly correlated with the rate of polyspermy. In unfused (control) anucleate fragments of maturing and activated oocytes inseminated at the same time as the cybrids, male pronuclei were never observed. These results show that the cytoplasms of activated eggs and of maturing oocytes contain complementary factors required for the transformation of the sperm nucleus into the male pronucleus. The former has lost the capability to break down the sperm nucleus envelope but contains factors required for pronuclear growth. The latter is able only to initiate the process of transformation, i.e., to break down the nuclear envelope and decondense the denuded sperm chromatin. However, the activity of the factor responsible for nuclear envelope breakdown is limited because in cybrids penetrated by more than two spermatozoa, transformation of sperm nuclei was usually abnormal.
Mol Reprod Dev 1991 Jun
PMID:Anucleate fragments of parthenogenetic eggs and of maturing oocytes contain complementary factors required for development of a male pronucleus. 165 63

Three staining procedures to detect sperm acrosome integrity were compared via electron microscopy. Stains were applied to epididymal, freshly ejaculated, in vivo capacitated, and sonicated sperm cells in addition to spermatozoa displaying sequentially removed plasma and outer and inner acrosomal membranes. Sequential membrane removal procedures resulted in removal of plasma membranes from 73% of all sperm cells, removal of plasma and outer acrosomal membranes from 74% of all sperm cells, and removal of plasma and outer and inner acrosomal membranes from 87% of all sperm cells as determined by electron microscopy. Live/dead staining results were not statistically different from subjective microscopic motility evaluations (P less than 0.005) for epididymal, sonicated, freshly ejaculated, and in vivo capacitated sperm samples. All three stains assessed were similarly capable of detecting the acrosome status of freshly ejaculated and of sonicated spermatozoa compared to data obtained by electron microscopy (P = 0.010). However, only the Bryan-Akruk stain afforded data that were closely correlated with data obtained via electron microscopy for all sperm types assessed; the latter included in vivo capacitated spermatozoa and sperm cells rendered free of plasma membranes. Results confirmed an earlier report by successfully effecting sequential removal of rabbit acrosomal membranes and documented use of the Bryan-Akruk acrosomal stain for evaluation of sperm cell populations for fertilizing ability. These findings should prove useful in further investigations of mechanisms involved in achievement of fertilizing ability by rabbit spermatozoa.
Mol Reprod Dev 1990 May
PMID:Evaluation of rabbit sperm acrosomal integrity and fertilizing ability by use of vital stains. 169 80

The gene encoding glutamic acid decarboxylase (GAD), the key enzyme in the synthesis of the inhibitory neurotransmitter gamma-aminobutyric acid, is shown to be expressed in the testis of several different species. Nucleotide sequence analysis of a cDNA clone isolated from the human testis confirmed the presence of GAD mRNA in the testis. The major GAD mRNA in the testis was 2.5 kilobases. Smaller amounts of a 3.7-kilobase mRNA with the same size as GAD mRNA in the brain was also detected in the testis. In situ hybridization using a GAD-specific probe revealed GAD mRNA expressing spermatocytes and spermatids located in the middle part of rat seminiferous tubules. Studies on the ontogeny of GAD mRNA expression showed low levels of GAD mRNA in testes of prepubertal rats, with increasing levels as sexual maturation is reached, compatible with GAD mRNA expression in germ cells. In agreement with this, fractionation of cells from the rat seminiferous epithelium followed by Northern (RNA) blot analysis showed the highest levels of GAD mRNA associated with spermatocytes and spermatids. Evidence for the presence of GAD protein in the rat testis was obtained from the demonstration of GAD-like immunoreactivity in seminiferous tubules, predominantly at a position where spermatids and spermatozoa are found. Furthermore, GAD-like immunoreactivity was seen in the midpiece of ejaculated human spermatozoa, the part that is responsible for generating energy for spermatozoan motility.
Mol Cell Biol 1990 Sep
PMID:Expression of the neurotransmitter-synthesizing enzyme glutamic acid decarboxylase in male germ cells. 169 32

Transcripts encoding CAPL-B, an apparent member of the cyclic-nucleotide-regulated kinase subfamily in Aplysia californica, are found exclusively in the ovotestis and are concentrated in meiotic and postmeiotic spermatogenic cells. The CAPL-B polypeptide is present in mature spermatozoa, suggesting that the kinase plays a part in regulating events associated with fertilization.
Mol Cell Biol 1990 Dec
PMID:A relative of the catalytic subunit of cyclic AMP-dependent protein kinase in Aplysia spermatozoa. 170 Oct 24

The purpose of this study was to use fluorescence microscopy to determine the viability and acrosome status of fresh and frozen-thawed human spermatozoa. Sperm cells were stained with the viability stains Hoechst 33258 (H33258) alone, or propidium iodide (PI) alone, and PI in combination with FITC-conjugated Pisum sativum agglutinin (PSA). The PSA stains the acrosome contents of permeabilized acrosome-intact sperm. Viability by fluorescence microscopy was compared to conventional eosin nigrosin staining. The overall viability using H33258 was not significantly different from that using PI. Therefore, PI was used in combination with PSA for simultaneous measurement of viability and acrosome status at the same excitation wavelength (488 nm). By combining PI and PSA, four subgroups of cells could be detected: group I, PI-neg/PSA-neg--viable, physiologic acrosome reacted (AR); group II, PI-neg/PSA-pos--viable, non-AR; group III, PI-pos/PSA-neg--nonviable, non-AR; group IV, PI-pos/PSA-neg--nonviable, degenerative AR. The postthaw sperm exhibited a significantly greater percent of sperm that were acrosome reacted (both viable and degenerative) (groups I and IV) than the fresh semen. We conclude that frozen-thawed sperm may undergo premature break-down of the acrosome prior to interaction with the oocyte, thus explaining the reduced fertility potential of cryopreserved semen.
Mol Reprod Dev 1990 Oct
PMID:Assessment of the viability and acrosome status of fresh and frozen-thawed human spermatozoa using single-wavelength fluorescence microscopy. 170 Oct 95

In rat liver the asialoglycoprotein receptor is composed of three polypeptides, RHL-1, RHL-2 and RHL-3. In rat testis and spermatozoa a galactosyl receptor (RTG-r) which is immunologically related to RHL-2/3 has been described. We now report that in addition to its presence in the rat, an antigenic species of 54 kDa related to RHL-2/3 is present on rabbit, human, pig and mouse spermatozoa. Purified rabbit testis galactosyl receptor (RbTG-r) consists of two major proteins of 54 and 49 kDa, while purified rabbit liver galactose lectin consists of two major proteins of 43 and 40 kDa. In an ELISA the purified rabbit testis galactosyl receptor was shown to bind biotinylated heat solubilized rabbit zonae, while the purified liver galactose lectin did not. We conclude that one of the mammalian sperm's zona binding proteins is a galactose lectin of 54 kDa related to rat liver RHL-2/3.
Mol Cell Biochem 1991 May 15
PMID:A mammalian sperm lectin related to rat hepatocyte lectin-2/3. Purification from rabbit testis and identification as a zona binding protein. 171 96

To investigate surface glycoprotein changes during post-testicular maturation, plasma membranes were isolated from proximal caput, distal caput, and cauda epididymal rat spermatozoa. Membrane glycoproteins were identified on Western blots of SDS-PAGE fractionated samples using biotinylated lectins and Vecta-stain reagents; these were compared to glycoproteins present in cauda epididymal luminal fluid. Lens culinaris agglutinin, Pisum sativum agglutinin, peanut agglutinin, wheat germ agglutinin, Ricinus communis agglutinin, Ulaex europaeus agglutinin, and Dolichol biflorus agglutinin each bound a specific subset of the polypeptides present. Several types of glycoprotein changes were noted including their appearance, loss, alteration of staining intensity, and alteration of electrophoretic mobility. Some maturation-dependent sperm surface glycoproteins co-migrated with glycoproteins present in epididymal fluid. This approach of direct analysis of the glycoproteins in purified plasma membranes identifies a broader spectrum of maturation-related surface changes occurring within the epididymis than are noted with surface labeling procedures.
Mol Reprod Dev 1991 Aug
PMID:Glycoprotein changes in the rat sperm plasma membrane during maturation in the epididymis. 171 14

The acrosome reaction in mouse spermatozoa was induced by various means. These were 1) varying incubation time in T6 medium, 2) incubation in T6 medium with added A23187, 3) incubation in T6 medium with added dbcGMP and imidazole, 4) exposure to an electric field, and 5) a combination of incubation in a medium with dbcGMP and imidazole and electroporation. The mean percentages of acrosome-free spermatozoa obtained by these various methods and assessed on the basis of both Bryan's stain and immunolocalization by FITC-labeled monoclonal antibodies increased by steps from 36% to 67%, 73%, 86%, and 92%. Individual spermatozoa from the various treatments were afterwards microinjected under the zona pellucida of a mouse oocyte. The fertilization rate for eggs microinjected with a spermatozoon treated with A23187, dbcGMP, and imidazole, by electroporation and by a combination of the last two methods also increased by steps from 17% to 34%, 36%, and 70%, respectively. Ninety-five percent of the fertilized oocytes reached the early blastocyst stage, thirty-eight percent of these blastocysts implanted in pseudopregnant mice, and twenty-eight percent developed to term. These results indicated the varying degrees of success of different ways of inducing acrosomal loss in spermatozoa and their subsequent success rates in fertilization and further in vitro and in vivo development.
Mol Reprod Dev 1991 Dec
PMID:Enhancement of acrosome reaction and subzonal insemination of a single spermatozoon in mouse eggs. 175 Oct 38

Previous hemizona assay (HZA) results have illustrated a positive and significant correlation between the percentage of morphologically normal spermatozoa in the semen and the number of spermatozoa tightly bound to the zona pellucida. The present study was designed to evaluate the morphologic features using strict criteria of spermatozoa tightly bound to the zona pellucida. Semen samples of 4 normozoospermic and 11 teratozoospermic men were used to compare the percentage of normal spermatozoa in the semen with that found 1) after swim-up separation and 2) bound to the zona under HZA conditions. The mean (+/- SEM) % normal forms for normozoospermic men in semen, after swim-up and zona-bound spermatozoa were 21.5 +/- 1.6, 27.5 +/- 2.9, and 44.8 +/- 3.4, respectively. A significantly higher % of normal forms were found among zona-bound sperm compared to swim-up forms (p = 0.02) and seminal sperm (p = 0.02). The mean % of normal sperm forms present in semen, after swim-up and zona pellucida-binding for teratozoospermic men, were 3.7 +/- 0.9, 5.8 +/- 1.6 and 15.6 +/- 3.1, respectively. Significant differences existed between the % of normal sperm forms found in the swim-up and zona-bound spermatozoa (P = less than 0.01 and P = less than 0.0003, respectively) compared to the original ejaculates. Results indicate that a selective process against abnormal spermatozoa occurs at the site of the zona pellucida.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Reprod Dev 1991 Dec
PMID:Sperm selection capacity of the human zona pellucida. 175 Oct 39

The distribution of filamentous actin around the maturing sperm head and in spermatozoa of four species of Australian conilurine rodents was investigated at the light and electron microscopic levels. Similar results were obtained for all the species studied. Mechanically isolated spermatids had NBD-phallacidin-positive longitudinal bands of fluorescence over the dorsolateral surface and, in late spermatids, bands of bright fluorescence passed perpendicularly from the dorsal convex to ventral concave surface. TEM observations indicated that these regions corresponded to filaments of ectoplasmic specializations and granular filamentous material around the tubulobulbar complexes, respectively. In testicular and cauda spermatozoa NBD-phallacidin fluorescent material was present in the two ventral processes that extended from the upper concave surface of the sperm head; also fainter material occurred along the concave border and as a dorsocaudal spur. Its distribution was identical for testicular and cauda spermatozoa. TEM of late spermatids showed that in the ventral process closest to the apical hook there were between 170 and 245 filaments, which attached to the inner surface of the postacrosomal dense lamina; in the more caudal ventral process about 70 filaments occurred. No filaments were, however, visible in the mature spermatozoon but, after immunocytochemical labelling for actin, deposition of gold particles was evident over ventral processes of both late spermatids and cauda spermatozoa. Within the female tract these ventral processes made contact with the zona matrix and were taken into the egg cytoplasm unchanged in morphology. The possible functional significance of the filamentous actin in these structures is discussed.
Mol Reprod Dev 1991 Dec
PMID:Distribution of filamentous actin in and around spermatids and in spermatozoa of Australian conilurine rodents. 175 Oct 42


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