EFFECT OF MORPHOLOGICAL ABNORMALITIES OF PROTRUDING AND STRATIFIED ZONA PELLUCIDA ON FERTILIZATION RATE

AbstractHuman spermatozoa can fertilize an oocyte only after post-testicular maturation and capacitation. These processes involve dynamic modification and reorganization of the sperm plasma membrane, which allow them to bind to the zona pellucida (ZP) of the oocyte. Defective sperm-ZP binding is one of the major causes of male subfertility. Galectin-3 is a secretory lectin in human seminal plasma well known for its action on cell adhesion. The aim of this study was to determine the role of galectin-3 in spermatozoa-ZP interaction and its association with fertilization rate in clinical assisted reproduction. Our studies revealed that the acrosomal region of ejaculated and capacitated spermatozoa possess strong galectin-3 immunoreactivity, which is much stronger than that of epididymal spermatozoa. Expression of galectin-3 can also be detected on seminal plasma-derived extracellular vesicles (EVs) and can be transferred to the sperm surface. Blocking of sperm surface galectin-3 function by antibody or carbohydrate substrate reduced the ZP-binding capacity of spermatozoa. Purified galectin-3 is capable of binding to ZP, indicating that galectin-3 may serve as a cross-linking bridge between ZP glycans and sperm surface glycoproteins. Galectin-3 levels in seminal plasma-derived EVs were positively associated with fertilization rates. These results suggest that galectin-3 in EVs is transferred to the sperm surface during post-testicular maturation and plays a crucial role in spermatozoa-ZP binding after capacitation. Reduced galectin-3 expression in seminal plasma-derived EVs may be a cause behind a low fertilization rate. Further studies with more clinical samples are required to confirm the relationship between galectin-3 levels and IVF outcomes.

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Effect of immunization of hamsters against recombinant P26h on fertility rates

Reproduction ◽

10.1530/rep.0.1230307 ◽

2002 ◽

pp. 307-313 ◽

Cited By ~ 18

Author(s):

C Gaudreault ◽

L Montfort ◽

R Sullivan

Keyword(s):

Zona Pellucida ◽

Binding Protein ◽

Maltose Binding Protein ◽

Fertilization Rate ◽

Active Immunization ◽

Antigenic Determinants ◽

Binding Assays ◽

Contraceptive Vaccine

Despite the various contraceptive methods available, an effective and inexpensive method remains to be established. Immunocontraception may help to achieve this goal. P26h has been proposed as a candidate for the development of a male contraceptive vaccine. P26h, a hamster sperm protein, interacts with the zona pellucida. Furthermore, in vivo fertilization can be blocked completely by active immunization of male hamsters against P26h. Maltose binding protein (MBP)-P26 shares antigenic determinants with the native P26h present on cauda epididymal spermatozoa. The aim of the present study was to reproduce the immunocontraceptive properties of native P26h by immunizing male hamsters against a recombinant P26h fused with a maltose binding protein (MBP). Active immunization of male hamsters with the MBP-P26h showed that specific anti-P26h circulating IgGs could be generated. Mating of immunized male hamsters with superovulated females resulted in a significant decrease, 20-25%, in the fertilization rate. This result is in agreement with results from in vitro sperm-zona pellucida binding assays. Indeed, the anti-recombinant P26h IgGs showed lower inhibitory properties when compared with anti-native P26h IgG. Despite the high anti-P26h IgG titres generated in hamsters, histological studies showed that active immunization has no pathological sequelae to the reproductive tissues. The potential of P26h as a candidate for a contraceptive vaccine is discussed.

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Mutation of rat Zp2 causes ROS-mediated oocyte apoptosis

Reproduction ◽

10.1530/rep-20-0037 ◽

2020 ◽

Vol 160 (3) ◽

pp. 353-365

Author(s):

Yan Wang ◽

Hualin Huang ◽

Minghua Zeng ◽

Ru-Ping Quan ◽

Jun-Ting Yang ◽

...

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Granulosa Cells ◽

Rat Model ◽

Zona Pellucida ◽

Reactive Oxygen ◽

Fertilization Rate ◽

Oocyte Development ◽

Oxygen Species ◽

Bidirectional Signaling

In this study, we investigated a gene-edited (Zp2MT/MT) rat model of infertility caused by the failure to express the zona pellucida glycoprotein 2 (ZP2) due to the significant reduction of mRNA amount. We examined the defects in the zona pellucida (ZP) caused by ZP2 nullification and the influence of these defects on aspects of oocyte development, including apoptosis and fertilization ability. To investigate the cause of the influence to the oocytes’ development, we evaluated the morphology of follicular transzonal projections (TZPs), known as ‘bridges’, which mediate the bidirectional signaling between the oocyte and surrounding granulosa cells and the level of reactive oxygen species (ROS) in ovulated eggs. Our results showed that two types of ZP defects were generated in the Zp2MT/MT rat,that is, ZP intact but thinned and ZP cracked (or even absent). The fertilization rate of the ovulated eggs reduced in both types, while increased oocyte apoptosis was observed only in the latter type. Moreover, the increased oocyte apoptosis rate correlated closely with the reduction in follicular TZPs and increased ROS levels in ovulated egg. In conclusion, nullification of rat ZP2 destroyed the integrity of the ZP, impaired the bidirectional signaling between the oocyte and surrounding granulosa cells. Therefore, the resulting infertility likely occurs via elevation of oxidative stress and oocytes apoptosis.

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Fertilization and early embryology: Does zona pellucida thickness influence the fertilization rate?

Human Reproduction ◽

10.1093/oxfordjournals.humrep.a136116 ◽

1995 ◽

Vol 10 (5) ◽

pp. 1189-1193 ◽

Cited By ~ 51

Author(s):

E. Bertrand ◽

M. Van Den Bergh ◽

Y. Englert

Keyword(s):

Zona Pellucida ◽

Fertilization Rate

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The serum protein fetuin-b increases in vitro fertilization rate in mice by inhibiting premature zona pellucida hardening

Geburtshilfe und Frauenheilkunde ◽

10.1055/s-0036-1592757 ◽

2016 ◽

Vol 76 (10) ◽

Author(s):

E Dietzel ◽

J Floehr ◽

E Van de Leur ◽

R Weiskirchen ◽

W Jahnen-Dechent

Keyword(s):

In Vitro Fertilization ◽

Serum Protein ◽

Zona Pellucida ◽

Fertilization Rate ◽

Vitro Fertilization

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Fertilization and Development of Conjoined Human Oocyte from a Binovular Follicle Containing Two Individual Oocytes Surrounded by a Zona Pellucida

10.21203/rs.3.rs-646284/v1 ◽

2021 ◽

Author(s):

Guangzhong Jiao ◽

Jianhua Wang ◽

Lili Chen ◽

Yinghua Shan ◽

Hua Xing ◽

...

Keyword(s):

Zona Pellucida ◽

Clinical Characteristics ◽

Fertilization Rate ◽

Human Oocyte ◽

Laboratory Setting ◽

High Quality ◽

Significant Difference ◽

Maturation Rate ◽

The Mean ◽

Definition Of

Abstract The most reliable definition of conjoined oocytes is the inclusion of two oocytes within a common zona pellucida(ZP) or their fusion in the zonal region. Because the available data are extremely limited, the significance of conjoined oocytes in IVF laboratory setting has been questionable. We analyzed the characteristics of 18 patients with conjoined oocytes in our center. The maturation of conjoined oocytes were asynchronous. Most of the cases were that one oocyte in each pair of conjoined oocytes was in the MII stage and the other was in the GV stage. The maturation rate and fertilization rate of conjoined oocytes were significantly lower than that of normal oocytes. There was no significant difference in the rate of cleavage and D3 High-quality embryo, but the rate of blastocyst formation of conjoined oocytes decreased significantly. The area of larger oocytes in conjoined oocytes was not different from that of normal oocytes, and its companion was significantly smaller than that of normal oocytes. The mean ZP thickness of all oocytes, larger or smaller, was significantly thinner than that of normal oocytes. After analyzing the clinical characteristics of the patients, it was suggested that the higher estrogen level or the more number of maturation follicles on HCG day were more likely to promote the emergence of conjoined oocytes.

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Fertilization of Pronase-Treated Mouse Ova in Vitro

Australian Journal of Biological Sciences ◽

10.1071/bi9810245 ◽

1981 ◽

Vol 34 (2) ◽

pp. 245 ◽

Cited By ~ 6

Author(s):

P Quinn ◽

JD Stanger

Keyword(s):

Zona Pellucida ◽

Binding Sites ◽

Relative Effectiveness ◽

Fertilization Rate ◽

Enzyme Treatment ◽

Perivitelline Space ◽

Sperm Binding ◽

Mechanical Removal ◽

Better Than

In order to obtain consistently a large number of zona-free mouse ova for studies of sperm-egg interactions, a study was made of the relative effectiveness of removing the zona pellucida from ova by mechanical or enzymatic treatments. Ova exposed to pronase before mechanical removal of the zona pellucida in medium devoid of pronase had similar fertilization rates in vitro compared with ova mechanically denuded in the absence of pronase. Ova with pronase-weakened zonae were easier to denude and survived the mechanical manipulations better than the ova denuded by vigorous aspiration in narrow-bore pipettes. However, exposure to pronase did significantly lower the incidence of polyspermy in the naked ova, indicating that some of the enzyme may have diffused across the perivitelline space and damaged sperm-binding sites on the vitelline plasma membrane. The enzyme treatment also reduced the fertilization rate of zona-intact ova.

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Biology of eggs, embryos and larvae of Rhinelepis aspera (Spix & Agassiz, 1829) (Pisces: Siluriformes)

Zygote ◽

10.1017/s0967199409990165 ◽

2009 ◽

Vol 18 (2) ◽

pp. 159-171 ◽

Cited By ~ 31

Author(s):

Violeta da Rocha Perini ◽

Yoshimi Sato ◽

Elizete Rizzo ◽

Nilo Bazzoli

Keyword(s):

Zona Pellucida ◽

Positive Response ◽

Fertilization Rate ◽

Essential Information ◽

Jelly Coat ◽

Hormone Injection ◽

Commercial Species ◽

First Time ◽

Time Information ◽

Armoured Catfish

SummaryThe black armoured catfish Rhinelepis aspera is an important commercial species found in the São Francisco River (Brazil) that has great potential for pisciculture. This paper presents, for the first time, information on the embryogenesis and larval development of this species. The breeder fish were subjected to spawning induction with crude carp pituitary extract. Eggs were kept in incubators at 24°C and embryogenesis was observed with a stereomicroscope until hatching. Ovary fragments, samples of recently extruded oocytes and larvae were fixed in Bouin's solution and subjected to routine histology techniques. Recently extruded oocytes were also analyzed with a scanning electron microscope (SEM). Females (80%) had a positive response to hypophysation. Oocyte extrusion was performed at 8 h and 30 min after the second hormone injection and the fertilization rate achieved 72.4 ± 8.8%. Recently extruded oocytes had a mean diameter of 1360.80 ± 40.87 μm and presented a conspicuous jelly coat covering the zona pellucida. Histochemical reactions indicated the presence of neutral glycoproteins in the yolk globules and in the zona pellucida. These reactions also indicated the presence of neutral glycoproteins and carboxylated acid glycoconjugates in the follicular cells and the jelly coat. These compounds form mucosubstances that can be related to the adhesiveness of the eggs. Under the SEM the oocytes presented a micropyle disc and a thick jelly coat over their surface. The closure of the blastopore occurred 9 h and 40 min after fertilization and embryogenesis was completed at 45 h and 50 min after fertilization, when the embryos were incubated at 24°C. The total absorption of the yolk sac occurred during the fifth day indicating the need for an exogenous food supply. These results provide essential information for the successful breeding and management of the promising R. aspera.

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Complexin-I-deficient sperm are subfertile due to a defect in zona pellucida penetration

Reproduction ◽

10.1530/rep-07-0569 ◽

2008 ◽

Vol 136 (3) ◽

pp. 323-334 ◽

Cited By ~ 7

Author(s):

Longmei Zhao ◽

Kerstin Reim ◽

David J Miller

Keyword(s):

Zona Pellucida ◽

Semen Analysis ◽

Fertilization Rate ◽

Computer Assisted ◽

Cell Fractionation ◽

Synaptic Vesicle Exocytosis ◽

Protein Receptor ◽

Vesicle Exocytosis ◽

Deficient Mice

Upon adhesion to the zona pellucida, sperm undergo regulated exocytosis of the acrosome. Although it is necessary for sperm to penetrate the zona pellucida and fertilize an egg, the acrosomal membrane fusion process is poorly understood. Complexins I and II are small, cytosolic proteins that bind to a complex of proteins termed the solubleN-ethylmaleimide-sensitive factor attachment protein receptor complex to regulate synaptic vesicle exocytosis. Complexin-II-deficient mice are fertile but the fertility of sperm from complexin-I-deficient male mice is unclear because the mice have ataxia and cannot mate. Here, we show that the genes encoding complexins I and II are expressed in primary spermatocytes and spermatids. Complexin proteins were found in/near the developing acrosome in spermatids and in or around the acrosome of mature sperm. Cell fractionation demonstrated that complexins I and II were predominantly found in the cytosolic fraction. Furthermore, sperm from complexin-I-deficient mice had normal morphology, number, and only small differences in motility, as assessed by computer-assisted semen analysis. Complexin-I-deficient sperm capacitated normally and bound to the zona pellucida. But when sperm from complexin-I-deficient mice were inseminated into females, a defect in fertility was observed, in concordance with previous data showing thatin vitrofertilization rate was also reduced. If the zona pellucida was removed prior toin vitrofertilization, fertility was normal, demonstrating that zona pellucida penetration was defective, a step requiring acrosomal exocytosis. Therefore, complexin-I-deficient sperm are subfertile due to faulty zona pellucida penetration.

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