Participation of the inositol 1,4,5-trisphosphate-gated calcium channel in the zona pellucida- and progesterone-induced acrosome reaction and calcium influx in human spermatozoa / 亚洲男科学杂志(英文版)

The acrosome reaction is a prerequisite for fertilization, and its signaling pathway has been investigated for decades. Regardless of the type of inducers present, the acrosome reaction is ultimately mediated by the elevation of cytosolic calcium. Inositol 1,4,5-trisphosphate-gated calcium channels are important components of the acrosome reaction signaling pathway and have been confirmed by several researchers. In this study, we used a novel permeabilization tool BioPORTER® and first demonstrated its effectiveness in spermatozoa. The inositol 1,4,5-trisphosphate type-1 receptor antibody was introduced into spermatozoa by BioPORTER® and significantly reduced the calcium influx and acrosome reaction induced by progesterone, solubilized zona pellucida, and the calcium ionophore A23187. This finding indicates that the inositol 1,4,5-trisphosphate type-1 receptor antibody is a valid inositol 1,4,5-trisphosphate receptor inhibitor and provides evidence of inositol 1,4,5-trisphosphate-gated calcium channel involvement in the acrosome reaction in human spermatozoa. Moreover, we demonstrated that the transfer of 1,4,5-trisphosphate into spermatozoa induced acrosome reactions, which provides more reliable evidence for this process. In addition, by treating the spermatozoa with inositol 1,4,5-trisphosphate/BioPORTER® in the presence or absence of calcium in the culture medium, we showed that the opening of inositol 1,4,5-trisphosphate-gated calcium channels led to extracellular calcium influx. This particular extracellular calcium influx may be the major process of the final step of the acrosome reaction signaling pathway.

Participation of the inositol 1,4,5-trisphosphate-gated calcium channel in the zona pellucida- and progesterone-induced acrosome reaction and calcium influx in human spermatozoa / 亚洲男科学杂志(英文版)

The acrosome reaction is a prerequisite for fertilization, and its signaling pathway has been investigated for decades. Regardless of the type of inducers present, the acrosome reaction is ultimately mediated by the elevation of cytosolic calcium. Inositol 1,4,5-trisphosphate-gated calcium channels are important components of the acrosome reaction signaling pathway and have been confirmed by several researchers. In this study, we used a novel permeabilization tool BioPORTER® and first demonstrated its effectiveness in spermatozoa. The inositol 1,4,5-trisphosphate type-1 receptor antibody was introduced into spermatozoa by BioPORTER® and significantly reduced the calcium influx and acrosome reaction induced by progesterone, solubilized zona pellucida, and the calcium ionophore A23187. This finding indicates that the inositol 1,4,5-trisphosphate type-1 receptor antibody is a valid inositol 1,4,5-trisphosphate receptor inhibitor and provides evidence of inositol 1,4,5-trisphosphate-gated calcium channel involvement in the acrosome reaction in human spermatozoa. Moreover, we demonstrated that the transfer of 1,4,5-trisphosphate into spermatozoa induced acrosome reactions, which provides more reliable evidence for this process. In addition, by treating the spermatozoa with inositol 1,4,5-trisphosphate/BioPORTER® in the presence or absence of calcium in the culture medium, we showed that the opening of inositol 1,4,5-trisphosphate-gated calcium channels led to extracellular calcium influx. This particular extracellular calcium influx may be the major process of the final step of the acrosome reaction signaling pathway.

Time for preparing a mouse model of autoimmune premature ovarian failure / 中国组织工程研究

BACKGROUND: Studies have confirmed that anti-zona zona antibodies can accelerate the destruction and depletion of oocytes, thereby causing premature ovarian failure. OBJECTIVE: To investigate the time of establishing autoimmune premature ovarian failure model in BALB/c mice induced by zona pellucida 3 peptides. METHODS: Thirty healthy female BALB/c mice (7-8 weeks) were randomly divided into immune experimental group (20 mice) and the control group (10 mice). In the experimental group, the mice were given immunization injection starting at 0 week, 0.15 mL of immune reagent injected into the soles at both sides and the lower abdomen. The vaginal exfoliated cell smears were observed every morning to observe the changes in the estrous cycle of the mice. After 2 weeks of injection, 0.15 mL of immune enhancement agent was injected subcutaneously into the same site. On the first day of weeks 4 and 6, the immune agent or immune enhancement agent was injected alternatively. Blood samples were collected before each injection and the serum sex hormone level was measured by enzyme-linked immunosorbent assay. Finally, ovarian tissue and uterus morphology were observed. RESULTS AND CONCLUSION: There was no difference in serum follicle stimulating hormone and estrogen levels between the first immunization injection and 2 weeks after the injection. The serum estrogen level in the experimental group was significantly lower than that in the control group at 4 weeks after injection. The serum estrogen level of the experimental group was significantly lower than that of the control group at 6 weeks after injection (P < 0.05), and meanwhile the serum follicle stimulating hormone level was significantly higher than that of the control group (P < 0.01). The degree of ovarian interstitial fibrosis in the experimental group was more obvious than that in the control group. The ovarian volume decreased and the uterus atrophied in the experimental group. The number of primitive follicles, primary follicles and secondary follicles in mice was significantly lower in the experimental group than the control group, and the number of atresia follicles was significantly higher than the control group (P < 0.05). Therefore, 75 μg of zona pellucida 3 peptides can be used to establish an autoimmune premature ovarian failure disease model in BALB/c mice, and a good modelling effect can be achieved at 6 weeks after immunization.

Current progress in single sperm cryopreservation / 中华男科学杂志

Sperm cryopreservation has been widely used in assisted reproduction, but conventional techniques are not suitable for the cryopreservation of small numbers of sperm. The application of the single sperm cryopreservation technique has significantly improved the clinical treatment of cryptozoospermia and non-obstructive azoospermia. Ever since Cohen et al first developed the method of single sperm cryopreservation in 1997, constant efforts have been made to develop the carriers for this technique. In this review, we mainly discuss the existing methods and clinical outcomes of single sperm cryopreservation.

Thinning and drilling laser-assisted hatching in thawed embryo transfer: A randomized controlled trial / 대한생식의학회지

OBJECTIVE: In frozen and thawed embryos, the zona pellucida (ZP) can be damaged due to hardening. Laser-assisted hatching (LAH) of embryos can increase the pregnancy rate. This study compared thinning and drilling of the ZP before frozen embryo transfer (FET). METHODS: Patients were randomly allocated into two groups for LAH using thinning or drilling on day 2 after thawing. Twenty-five percent of the ZP circumference and 50% of the ZP thickness was removed in the thinning group, and a hole 40 µm in diameter was made in the drilling group. RESULTS: A total of 171 in vitro fertilization/intracytoplasmic sperm injection FET cycles, including 85 cycles with drilling LAH and 86 cycles with thinning LAH, were carried out. The thinning group had a similar β-human chorionic gonadotropin-positive rate (38.4% vs. 29.4%), implantation rate (16.5% vs. 14.4%), clinical pregnancy rate (36.0% vs. 25.9%), miscarriage rate (5.8% vs. 2.4%), ongoing pregnancy rate (30.2% vs. 23.5%), and multiple pregnancy rate (7.0% vs. 10.6%) to the drilling LAH group. There were no significant differences in pregnancy outcomes between subgroups defined based on age (older or younger than 35 years) or ZP thickness (greater or less than 17 µm) according to the LAH method. CONCLUSION: The present study demonstrated that partial ZP thinning or drilling resulted in similar outcomes in implantation and pregnancy rates using thawed embryos, irrespective of women's age or ZP thickness.

Efficacy of CZP3 DNA vaccine immune infertility enhanced by electric pulse method / 中国免疫学杂志

Objective:To analyze the immunocontraceptive efficacy of CZP3 DNA vaccine by electric pulse stimulating and the correlation between antibody level and antifertility. Methods: The mice were immunized with 5, 10, 20 and 50 μg DNA vaccine pcDNA3. 0-CZP3 respectively and were stimulated at leg muscle by electric pulse. Detect the antibody level of each mice group and the highest antibody titer by ELISA. After mated with male mice for three weeks,calculated infertility rate of mice,the average litter size of each immune group and did statistical analysis. Results:Compared with the intramuscular injection alone,the electric pulse stimulation could increase serum antibody titers of mice significantly, the antibody titer of 50 μg group which was stimulated by electric pulse reached 1∶4 000. Moreover,the infertility of the mice increased and the mice average litter size reduced along with the increase of CZP3 antibody level significantly. Statistical analysis showed that the antibody level and the average litter size had a negative correlation. Conclusion:The electric pulse stimulation can improve the immune level and reduce the fertility efficiency of mice significantly,therefore establishes a foundation for further application of CZP3 DNA vaccine in stray dog contraception.

Outcome of modified intracytoplasmic sperm injection using zona pellucida -bound spermatozoa in male ;infertility / 中国基层医药

Objective To investigate the treatment outcome of modified intracytoplasmic sperm injection (ICSI)using zona pellucida(ZP)-bound sperm.Methods 82 patients with less,weak,abnormal sperm disease who were conformed to ICSI,were divided into traditional ICSI group and the group of modified ICSI using ZP-bound sperm according to ICSI case number.The results of normal fertilization rate,cleavage rate,high-quality embryo rate, planting rate,clinical pregnancy rate and early abortion rate were compared.Results The women's age,the sterility year,mature egg rate,normal fertilization rate,cleavage rate in the two groups had no statistically significant differ-ences (all P>0.05).The planting rate and clinical pregnancy rate of the observation group (46.6%,63.3%)were higher than those of the control group(38.5%,53.6%),but there were no statistically significant differences(all P>0.05).The using embryo rate and high-quality embryo rate of the observation group (73.9%,51.0%)were signifi-cantly higher than those of control group(65.8%,38.6%),the differences were statistically significant(χ2 =5.84,χ2 =11.6,all P<0.05).Conclusion Modified ICSI using ZP-bound sperm can effectively improve the embryos quality in ICSI.

Analysis of the Causes of Total Fertilization Failure in Vitro Fertilization-Embryo Transfer / 现代生物医学进展

Fertilization is a crucial step for origin of life.During Assisted Reproductive Technologies (ART),total fertilization failure is complex and unpredictable.Total fertilization failure may related to some abnormal cellular mechanistic events,such as:any stage of sperm and cumulus-oocyte-complexes penetration,sperm-zona pellucida binding / penetration,sperm-oocyte membrane binding,oocyte activation,sperm discondensation or pronuclear formation.Most of total fertilization failure could be solved by intracytoplasmic sperm injection.But oocytes of some patient still can't fertilize successfully,even though assisted oocyte activation be used.As for total fertilization failure patients in ART,combining the mature of oocyte,sperm quality and some trail to improve clinical protocol in later cycle may prevent failure to happen again.

Effects of granulocyte-macrophage colony-stimulating factor (GM-CSF) on the anti-fertility efficacy of canine zona pellucida glycoprotein 3 (CZP3) DNA vaccine / 中华微生物学和免疫学杂志

Objective To investigate the effects of GM-CSF (granulocyte-macrophage colony-stimulating factor) as an immune adjuvant on the anti-fertility efficacy of canine zona pellucida glycoprotein 3 (CZP3) DNA vaccine.Methods RT-PCR and quantitative real-time PCR were performed to analyze the effects of GM-CSF on the maturation of antigen presenting cells (APCs) and the enrichment of APCs at injection site.Female BALB/c mice were immunized with CZP3 DNA vaccine pcDNA3-CZP3 alone or in combination with genetic adjuvant pcDNA3-GM-CSF by using the method of electrical impulses.ELISA (enzyme-linked immunosorbent assay) was used to detect the levels of IgG and sIgA (secretory IgA) antibodies in serum samples and genital tracts and the levels of IL-4 and IFN-γ in serum samples.MTT method was used to analyze the proliferation of spleen T cells in mice.The binding ability of serum anti-CZP3 antibody to native mouse oocytes was analyzed by indirect immunofluorescence assay.All of the female BALB/c mice were coupled with male mice of the same age six weeks after the first-dose vaccination.Litter size at birth in each group was counted and the differences between different groups were comparatively analyzed.ResultsImmunizing the mice with pcDNA3-CZP3 and GM-CSF significantly promoted the expression of CD80, CD83 and CD86 (P<0.05) and increased the sIgA antibody level in genital tract and IgG level in serum (P<0.01).Moreover, the levels of IL-4 and IFN-γ in serum samples were significantly up-regulated (P<0.05) and the proliferation of spleen T cells was significantly enhanced (P<0.05).Results of the indirect immunofluorescence assay showed that the fluorescence intensity and density on mouse egg surface were positively correlated with the level of antibody in serum.Results of the anti-fertility test suggested that GM-CSF significantly reduced the litter size in mice immunized with pcDNA3-CZP3 vaccine (P<0.05).Conclusion GM-CSF could be used as an effective adjuvant to enhance the anti-fertility efficacy of CZP3 DNA vaccine.

The effect of the site of laser zona opening on the complete hatching of mouse blastocysts and their cell numbers / 대한생식의학회지

OBJECTIVE: We studied the effect of the site of laser zona opening on the complete hatching of mouse blastocysts and the cell numbers of the completely hatched blastocysts. METHODS: Mouse blastocysts were randomly allocated to the inner cell mass (ICM) group (zona opening performed at the site of the ICM, n=125), the trophectoderm (TE) group (zona opening performed opposite to the ICM, n=125) and the control group (no zona opening, n=125). RESULTS: The rate of complete hatching of the blastocysts was not significantly different in the ICM and the TE group (84.8% vs 80.8%, respectively; p=0.402), but was significantly lower in the control group (51.2%, p<0.001). The cell numbers in the completely hatched blastocysts were comparable in the control group, the ICM group, and the TE group (69±19.3, 74±15.7, and 71±16.8, respectively; p=0.680). CONCLUSION: These findings indicate that the site of laser zona opening did not influence the rate of complete hatching of mouse blastocysts or their cell numbers.

Protease activity involvement in the passage of mammalian sperm through the zona pellucida

The interaction between acrosome-reacted sperm and zona pellucida proteins is not yet fully understood. Serine protease acrosin and its zymogen proacrosin have been proposed to fulfill this function due to their capacity to bind zona pellucida glycoproteins. However, the molecular mechanism underlying this interaction has been merely speculative. Here we show that fucoidan (a sulfated polysaccharide) and solubilized zona pellucida glycoproteins, but not soybean trypsin inhibitor, are able to detach bound spermatozoa, which suggests that live sperm binds to the zona pellucida in a non-enzymatical way. Interestingly, mild proteolytic digestion with acrosin or trypsin does not modify the structure of the zona pellucida, but rather results in fewer spermatozoa binding to the zona. These results agree with a model where the active site of acrosin digests the zona pellucida and binds through the polysulfate-binding domain through a three-dimensional zona structure rather than a single ligand.

Efficiency of laser-assisted intracytoplasmic sperm injection in a human assisted reproductive techniques program / 대한생식의학회지

OBJECTIVE: Laser-assisted intracytoplasmic sperm injection (LA-ICSI), also known as micro-opening or thinning of the zona pellucida (ZP) prior to ICSI, may help to reduce mechanical damage to the oocyte during the procedure. The aim of the present study was to evaluate and analyze the efficacy of our institutional LA-ICSI program, which features laser-assisted ZP thinning prior to ICSI, in comparison with conventional ICSI (C-ICSI), performed on patients with different clinical characteristics. METHODS: Patients undergoing a total of 212 ICSI cycles were randomly divided into an LA-ICSI group (106 cycles) and a conventional ICSI group (106 cycles). To reduce tissue damage, we thinned the ZP by approximately 70%, using a laser, before ICSI. Patients thus treated formed the LA-ICSI group. Comparisons included the morphological quality of transferred embryos, blastocyst development of the remaining embryos, and clinical pregnancy, in terms of ICSI method and patient characteristics. RESULTS: Fertilization, development of remaining embryos, and pregnancy rate were significantly higher in the LA-ICSI group compared with the C-ICSI group. Fertilization, embryonic development, and the pregnancy rate were all improved in younger patients (<38 years of age) and in those who underwent a low number of IVF-ET attempts (<3 trials). In addition, the pregnancy rate was increased in older patients. CONCLUSION: LA-ICSI may be useful in improving the chance of pregnancy in all ICSI patients.

Assisted hatching em reprodução assistida: uma meta-análise de ensaios clínicos controlados / Assisted hatching in assisted reproduction: a meta-analysis of clinical controlled trials

O objetivo desta meta-análise foi avaliar o efeito da assisted hatching (AH) sobre os resultados dos ciclos de reprodução assistida: gravidez clínica, nascimento vivo, gestação múltipla, aborto e implantação embrionária, sendo avaliados os artigos publicados em periódicos indexados ao PubMed por dois autores independentes. Foram levantados 51 ensaios clínicos controlados que avaliaram o efeito da AH, sendo 40 excluídos, resultando em 11 artigos completamente avaliados. Não houve diferença significativa na taxa de gestação clínica (44,41 versus 41,30%; p=0,19, AH versus controle, respectivamente) e na taxa de nascimento vivo (36,33 versus 34,79%, p=0,63), porém, foi identificada uma tendência de aumento na taxa de gestação múltipla (18,44 versus 15,02%, p=0,05). Também não foi identificada diferença significativa na taxa de aborto (6,66 versus 6,21%, p=0,83), mas observou-se um aumento significativo na taxa de implantação embrionária (24,32 versus 21,23%, p=0,02). A partir desses resultados, pode-se concluir que, até o momento, não existe evidência suficiente para suportar o uso da AH de rotina para ciclos de reprodução assistida com transferência de embriões frescos, uma vez que não houve aumento na taxa de gravidez clínica e/ou na taxa de nascimento vivo.

The aim of this meta-analysis was to evaluate the effect of assisted hatching on the outcome of assisted reproduction cycles: clinical pregnancy, live birth, multiple pregnancy, abortion and embryonic implantation, by assessing articles published in journals indexed in PubMed by two independent authors. Fifty-one controlled trials that evaluated the effect of assisted hatching were analyzed, and 40 of them were excluded, resulting in 11 articles fully assessed. There was no significant difference in clinical pregnancy rate (44.41 versus 41.30%, p=0.19, assisted hatching versus control, respectively), and in the live birth rate (36.33 versus 34.79%, p=0.63), but we identified a trend toward increased rate of multiple pregnancies (18.44 versus 15.02%, p=0.05). We also did not identify any significant difference in the rate of abortion (6.66 versus 6.21%, p=0.83), but a significant increase in the rate of embryo implantation was observed (24.32 versus 21.23%, p=0.02). From these results, we have concluded that, until now, there is not sufficient evidence to support the use of assisted hatching for routine assisted reproduction cycles with fresh embryo transfer, since there has not been an increase in clinical pregnancy rate and/or the rate of live birth.

The effect of CpG ODN on the immune responses and immune-contraception induced by ZP~(121-140) synthetic peptide / 中国免疫学杂志

Objective:To investigate the effect of CpG ODN on the immune responses and immune-contraception induced by ZP~(121-140) synthetic peptide.Methods: BALB/e mice were given an injection into the left tibialis anterior muscle of ZP~(121-140) synthetic peptide with 20 μg CpG ODN or CFA,then the mice were given other injections at 2,4,6 weeks using the same formulation.The mice' s blood was collected before each vaccination and after the last vaccination every 2 weeks.The specific IgG and IgA in sere and non-specific cytokines IFN-γ,TNF-α,IL-10 in vaginal mucosa were measured by ELISA.The ovarial pathological changes were undertaken using hemattxylin and eosin-stained paraffin sections.Results:The specific IgG in sera and IgA in vaginal mucosa induced by ZP~(121-140) synthetic peptide combined with CpG ODN were no more than those of ZP~(121-140) synthetic peptide combined with CFA.There were significant increases in IFN-γ,and TNF-α when CpG ODN was mixed with ZP121-140 synthetic peptide and the increase of CpG ODN was more significant than that of CFA.Otherwise there was a significant decrease in IL-10 when CpG ODN was mixed with ZP~(121-140) synthetic peptide and the decrease of CpG ODN was more significant than thai of CFA.There was no significant difference in the rate of pregnancy between CpG ODN group and CFA group,but the average number of birth mice in CpG ODN group was less than that in CFA group.No pathological changes were found in the ovaries of experimental mice.Conclusion: The adjuvant effect of CpG ODN is more advantageous than that of CFA in contraception vaccine research.

Binding characteristics of sperm with recombinant human zona pellucida glycoprotein-3 coated beads.

Background & objectives: An inability or decreased ability of spermatozoa to bind to the zona pellucida (ZP), an extracellular glycoproteinaceous matrix surrounding egg, is one of the plausible causes of idiopathic infertility. It will be clinically useful to distinguish this condition from other causes of infertility. An assay system, investigating binding of human sperm with ZP glycoprotein may prove useful in this regard. We attempted to develop a simple assay system to analyse the binding of capacitated human spermatozoa to human zona pellucida glycoprotein-3 (ZP3) using baculovirus-expressed recombinant human ZP3 coated beads. Methods: Recombinant baculovirus-expressed ZP3 was purified, labelled with biotin and coated on streptavidin sepharose beads. An in vitro assay system was optimized to study binding of capacitated human sperm to ZP3 coated beads. Results: A higher percentage of baculovirus-expressed recombinant human ZP3 coated beads showed significant (P<0.05) binding of capacitated human sperm as compared to beads coated with fetuin. An inhibition in the binding of sperm to ZP3 coated beads was observed in presence of cold recombinant human ZP3. Further, prior incubation of ZP3 coated beads with monoclonal antibodies (MAbs) against ZP3 but not against ZP2 resulted in the decrease in number of sperm bound to bead. Interpretation & conclusion: An in vitro assay system to study the binding of human sperm to ZP3- primary sperm receptor was established, which may be useful to determine the functional competence of spermatozoa.

Preparation of recombinant human zona pellucida 3 protein and its immunologic activity / 中国免疫学杂志

Objective:To prepare and purify recombinant human zona pellucida 3 protein,and to study its immunologic activity.Methods:The E.coli BL21 containing recombinant plasmid pGEX4T-1/ huZP3 was induced to express GST-fusion protein by IPTG.After a series of purification procedure,the purified protein was analyzed by SDS-PAGE.After the mice immunized with rhuZP3,the antibody responses against rhuZP3 were detected by ELISA.Results:The soluble fusion protein was expressed,and purity of rhuZP3 was 95%.Moreover, purity of rhuZP3 could be recognized by anti-human ZP3 in ELISA.Conclusion:The rhuZP3 is obtained through the preparation of prokaryotic expression system and anti-rhuZP3 antibody has immunological activity.

Binding of Lectins to the Zona Pellucida on Sperm-oocytes Interaction in the Pig / 대한불임학회지

OBJECTIVE: Lectins are cell-agglutinating and sugar specific proteins or glycoproteins of non-immune origin that precipitate glycoconjugates having saccharides of appropriate complementarity. Because of these properties, plant lectins have been used to help characterize the carbohydrate moieties of glycoproteins in the zona pellucida (ZP) of several mammalian species including pigs. Treatment of oocytes with various lectins blocks sperm binding to the ZP in various mammalian species. This study was undertaken to examine the distribution of sugar residues in the ZP of pig oocytes matured in vitro and the ability of spermatozoa to bind to ZP and in vitro penetration in oocytes treated with fluorescein isothiocyanate (FITC)-labelled lectins. MATERIALS AND METHODS: The lectins of Banderiaea simplicifolia (BS-II, bind to beta-D-Nacetylglucosamine), Canavalin ensiformis (Con A, bind to alpha-D-Mannose), Lens culinaris (LCA, bind to alpha-D-Mannose), Ricinus communis (RCA-I, bind to beta-D-Galactose) and Ulex europaeus (UEA-I, bind to alpha-L-Fucose) were examined for spermatozoa penetration, binding capacity to ZP and distribution of lectins. RESULTS: The penetration rates were significantry (p<0.05) higher in control oocytes (63%) than those treated with all lectins, but penetration rates (40~49%) were simililar in group treated with lectins. The incidence of monospermy was similar in oocytes untreated and UEA-I, but it was higher in oocytes treated with BS-II, Con A, RCA-I and LCA. The porcine oocytes cultured for 48 h in TC-199 medium were freed from cumulus cells and treated for 30 min with fluorescein isothiocyanate-labelled lectins. When examined under fluorescein illumination, higher (p<0.001) proportions of oocytes showed fluorescein of zona pellucida after treatment with Con A (93%), LCA (93%) and RCA-I (100%) than BS-II (37%) and UEA-I (50%). All of the oocytes treated with RCA-I exhibited strong fluorescein in the outer region of the zona pellucida while those treated with LCA exhibited strong fluorescein throughout the zona pellucida. BS-II bounded mainly to the outer region and UEA-I bounded mainly to the inner region of the zona pellucida, with either strong or weak fluorescein. At 120 min after insemination in vitro, fewer spermatozoa were bound to the zona pellucida of the oocytes treated with BS-II, Con-A and RCA-I. Of the lectins, Con A most inhibited sperm binding. CONCLUSIONS: These results suggest that beta-D-Galactose residues in the porcine zona pellucida may act as primary sperm receptors and inducers of the sperm acrosome reaction and these sugar residues may be involved in the block to polyspermy.

Intactness of zona pellucida does not affect the secretion of a trypsin-like protease from mouse blastocyst

Assisted hatching (AH), which is known to improve the hatching potential of mammalian embryos, has been used to increase the pregnancy rate in in vitro fertilization cycles. However, the effect of AH on a trypsin-like protease, which is known to be associated with the hatching process, has not been studied. In this study, we evaluate whether the intactness of zona pellucida affects the secretion of a trypsin-like protease from mouse blastocyst. Four- to 8-cell stage mouse embryos were collected at 66- to 68 hr after hCG injection and divided into 3 groups according to the manipulation of zona pellucida. The groups are no treatment (control), drilling of zona pellucida (ZD) and thinning of zona pellucida (ZT). The activity of a trypsin-like protease, blastocyst development and hatching rate were compared among the three groups at 110 and 135 hr after hCG injection, respectively. The protease activity and blastocyst development were not significantly different among control, ZD and ZT groups at 110 and 135 hr after hCG injection, respectively. However, the hatching rate of ZD and ZT groups was significantly higher than that of control group at each time, respectively (p>0.001). Even in the zona pellucida removed embryos, the protease activity did not differ from the control group. In conclusion, the secretion of a trypsin-like protease from mouse blastocyst does not seem to be affected by the intactness of zona pellucida.

A Study of Clinical Parameters Influencing Human Zona Pellucida Thickness / 대한산부인과학회잡지

The purpose of present study was to assess which parameters influence human oocyte zona pellucida(ZP). Zone pellucida thickness was evaluated in 124 oocytes of 16 cycles IVF-ET with intracytoplasmic sperm injection(ICSI) between July 1995 and October 1995 at the department of obstetrics and Gynecology, Yonsei university, Wonju Christian Hospital. The zone pullucida thickness was 17.7+/-2.0micronm(mean+/-SD) for 107 metaphase II oocy- tes. The zona pullucida thickness was singinficantly different according to maximum estr- adiol(E2) value ; The mean thickness of Zona pellucida was thinner below 2000 pg/ml of E2 value than that above 2001 pg/ml of E2 value(p0.05).

Immunogenicity of recombinant Lugurus zone pellucida-3 expressed in E.coli and efficacy of its antiserum to affect in vitro mouse sperm-egg binding in vitro / 中国免疫学杂志

Objective:Present study was aimed to analyze the immunogenicity of recombinant Lugurus zona pellucida-3 protein (r-LZP3) expressed in E.coli,and to evaluate the efficacy of its antiserum to affect in vitro mouse sperm-egg binding.Methods:Female mouse were immunized using LZP3 DNA vaccine for priming,and boosted with r-LZP3 protein.The antibody response level of LZP3 antisera was determined by ELISA.The immunoreactivity and specificity of the anti-LZP3 antisera were tested by immunoblot, indirect immunofluorescence and immunohistochemistry using native mouse ZP.A sperm-zone pellucida binding assay was used to evaluate the efficacy of anti-LZP3 antisera to inhibit mouse sperm-egg binding in vitro.Results: The result of ELISA showed that LZP3 DNA vaccine was able to induce higher antibody titers in mouse.Antiserum could specifically recognize or bind to r-LZP3 protein expressed in E.coli and native mouse ZP in vitro.The LZP3 antisera and r-LZP3 protein also inhibited sperm-egg binding in vitro.Condusion:These results show that r-LZP3 protein is of strong immunogenicity.