1. The document discusses the recognition and interaction between eggs and sperm in various species. It describes the key steps in fertilization, including chemoattraction of sperm to eggs, the acrosomal reaction, binding to the egg's extracellular envelope, and fusion of the plasma membranes.
2. In sea urchins, a peptide called resact attracts sperm to eggs and activates them. Bindin, a protein in the acrosomal process, mediates species-specific binding to the egg.
3. In mice, the zona pellucida protein ZP3 specifically binds sperm and initiates the acrosomal reaction, allowing enzymes to penetrate the zona for fertilization.
INTRODUCTION
DEFINATION
GAMETES
STRUCTURE OF GAMETES
SPERM
OVUM
RECOGNITION OF EGG AND SPERM
CAPACITATION
ACROSOME REACTION
SPECIES-SPECIFIC RECOGNITION
GAMETE BINDING AND RECOGNITION
GAMETE FUSION
PREVENTION OF POLYSPERMY
ACTIVATION OF GAMETE METABOLISM
FUSION OF THE GENETIC MATERIAL
SIGNIFICANCE OF FERTILIZATION
CONCLUSIONS
REFERENCES
Polyspermy describes an egg that has been fertilized by more than one sperm. Diploid organisms normally contain two copies of each chromosome, one from each parent. The cell resulting from polyspermy
The first issue that an egg and a sperm of any organism type face in successfully producing an embryo is the possibility of polyspermy. Polyspermy is the fertilization of an egg by multiple sperm, and the results of such unions are lethal.
If multiple sperm fertilize an egg, the embryo inherits multiple paternal centrioles. This causes competition for extra chromosomes and results in the disruption of the creation of the cleavage furrow, thus causing the zygote to die. As an important model organism in the study of fertilization and embryonic development, polyspermy in sea urchins has been studied in detail. The sea urchin’s methods of polyspermy prevention have been broken down into two main pathways. These two primary pathways are known as the fast block and the slow block to polyspermy
After the sperm’s receptors come into contact with the egg’s jelly layer and the acrosomal enzymes are released and break down the jelly layer, the sperm head comes into contact with the vitelline and plasma membranes of the egg. When the two plasma membranes contact one another, signals in the egg are initiated.
First, Na+ channels in the egg open, allowing Na+ to flood into the egg. This causes a depolarization of the egg from it’s normal resting potential of -70 mV.
While depolarization is occurring, the remainder of the jelly layer is dissolving. With the dissolution of the jelly layer and the depolarization of the plasma membrane, the first block to preventing fertilization by multiple sperm is put into place.
These two simple changes are part of the first block to polyspermy, known as the fast block. Within 1/10th of a second of contact, the fast block t
INTRODUCTION
The jaw (Upper and lower) is any opposable articulated structure at the entrance of the mouth.
It is typically used for grasping and manipulating food.
Jaw suspension means the fusion of upper jaw and lower jaw or skull for efficient biting.
There are different ways in which these attachments are attained depending upon the modifications in visceral arches in vertebrates.
In most vertebrates, the jaws are bony or cartilaginous and oppose vertically.
The vertebrate jaw is derived from the most anterior two pharyngeal arches supporting the gills, and usually bears numerous teeth.
The vertebrate jaw probably originally evolved in the Silurian period and appeared in the Placoderm fish which further diversified in the Devonian.
It is believed that the hyoid system suspends the jaw from the brain case of the skull, permitting great mobility of the jaws.
The original selective advantage offered by the jaw may not be related to feeding, but rather to increased respiration efficiency.
The jaws were used in the buccal pump (observable in modern fish and amphibians) that pumps water across the gills of fish or air into the lungs in the case of amphibians.
Over evolutionary time the more familiar use of jaws (to humans), in feeding, was selected for and became a very important function in vertebrates. Many teleost fish have substantially modified jaws for suction feeding and jaw protrusion, resulting in highly complex jaws with dozens of bones involved.
Jaw Suspension or Suspensoria:
The method by which the upper and lower jaws are suspended or attached from the chondrocranium is known as jaw suspension or suspensorium.
Amongst the visceral arches, the first (mandibular) arch consists of
= a dorsal palato pterygoquadrate bar forming the upper jaw,
= and ventral Meckel’s cartilage forms the lower jaw.
The second (hyoid) arch consists of = a dorsal hyomandibular supporting and suspending the jaws with the cranium, and a ventral hyoid.
The remaining visceral arches support the gills and are, hence, called branchial arches. Thus, splanchnocranium forms the jaws and suspends them with the chondrocranium.
Vittelogenesis is a word developed from Latin vitellus-yolk, and genero-produce
Vitellogenesis (also known as yolk deposition) is the process of yolk formation via nutrients being deposited in the oocyte, or female germ cell involved in reproduction of lecithotrophic organisms. In insects, it starts when the fat body stimulates the release of juvenile hormones and produces vitellogenin protein.
Yolks is the most usual form of food storage in the egg.
Yolks appear in the oocyte in the secondary period of their growth called vittelogenesis.
Thus,the formation and deposition of yolks is known as vittelogenesis
Characteristic
Yolks is a complex variable assembled component.
The principle component are protein,phospholipid and fats in different combination.
Depending upon these component yolks is distinguished into protein yolks and fatty acid
For eg- the avian contain 48.19% water , 16.6 % protein, 32.6% phospholipids and fats and 1% carbohydrates.
INTRODUCTION
DEFINATION
GAMETES
STRUCTURE OF GAMETES
SPERM
OVUM
RECOGNITION OF EGG AND SPERM
CAPACITATION
ACROSOME REACTION
SPECIES-SPECIFIC RECOGNITION
GAMETE BINDING AND RECOGNITION
GAMETE FUSION
PREVENTION OF POLYSPERMY
ACTIVATION OF GAMETE METABOLISM
FUSION OF THE GENETIC MATERIAL
SIGNIFICANCE OF FERTILIZATION
CONCLUSIONS
REFERENCES
Polyspermy describes an egg that has been fertilized by more than one sperm. Diploid organisms normally contain two copies of each chromosome, one from each parent. The cell resulting from polyspermy
The first issue that an egg and a sperm of any organism type face in successfully producing an embryo is the possibility of polyspermy. Polyspermy is the fertilization of an egg by multiple sperm, and the results of such unions are lethal.
If multiple sperm fertilize an egg, the embryo inherits multiple paternal centrioles. This causes competition for extra chromosomes and results in the disruption of the creation of the cleavage furrow, thus causing the zygote to die. As an important model organism in the study of fertilization and embryonic development, polyspermy in sea urchins has been studied in detail. The sea urchin’s methods of polyspermy prevention have been broken down into two main pathways. These two primary pathways are known as the fast block and the slow block to polyspermy
After the sperm’s receptors come into contact with the egg’s jelly layer and the acrosomal enzymes are released and break down the jelly layer, the sperm head comes into contact with the vitelline and plasma membranes of the egg. When the two plasma membranes contact one another, signals in the egg are initiated.
First, Na+ channels in the egg open, allowing Na+ to flood into the egg. This causes a depolarization of the egg from it’s normal resting potential of -70 mV.
While depolarization is occurring, the remainder of the jelly layer is dissolving. With the dissolution of the jelly layer and the depolarization of the plasma membrane, the first block to preventing fertilization by multiple sperm is put into place.
These two simple changes are part of the first block to polyspermy, known as the fast block. Within 1/10th of a second of contact, the fast block t
INTRODUCTION
The jaw (Upper and lower) is any opposable articulated structure at the entrance of the mouth.
It is typically used for grasping and manipulating food.
Jaw suspension means the fusion of upper jaw and lower jaw or skull for efficient biting.
There are different ways in which these attachments are attained depending upon the modifications in visceral arches in vertebrates.
In most vertebrates, the jaws are bony or cartilaginous and oppose vertically.
The vertebrate jaw is derived from the most anterior two pharyngeal arches supporting the gills, and usually bears numerous teeth.
The vertebrate jaw probably originally evolved in the Silurian period and appeared in the Placoderm fish which further diversified in the Devonian.
It is believed that the hyoid system suspends the jaw from the brain case of the skull, permitting great mobility of the jaws.
The original selective advantage offered by the jaw may not be related to feeding, but rather to increased respiration efficiency.
The jaws were used in the buccal pump (observable in modern fish and amphibians) that pumps water across the gills of fish or air into the lungs in the case of amphibians.
Over evolutionary time the more familiar use of jaws (to humans), in feeding, was selected for and became a very important function in vertebrates. Many teleost fish have substantially modified jaws for suction feeding and jaw protrusion, resulting in highly complex jaws with dozens of bones involved.
Jaw Suspension or Suspensoria:
The method by which the upper and lower jaws are suspended or attached from the chondrocranium is known as jaw suspension or suspensorium.
Amongst the visceral arches, the first (mandibular) arch consists of
= a dorsal palato pterygoquadrate bar forming the upper jaw,
= and ventral Meckel’s cartilage forms the lower jaw.
The second (hyoid) arch consists of = a dorsal hyomandibular supporting and suspending the jaws with the cranium, and a ventral hyoid.
The remaining visceral arches support the gills and are, hence, called branchial arches. Thus, splanchnocranium forms the jaws and suspends them with the chondrocranium.
Vittelogenesis is a word developed from Latin vitellus-yolk, and genero-produce
Vitellogenesis (also known as yolk deposition) is the process of yolk formation via nutrients being deposited in the oocyte, or female germ cell involved in reproduction of lecithotrophic organisms. In insects, it starts when the fat body stimulates the release of juvenile hormones and produces vitellogenin protein.
Yolks is the most usual form of food storage in the egg.
Yolks appear in the oocyte in the secondary period of their growth called vittelogenesis.
Thus,the formation and deposition of yolks is known as vittelogenesis
Characteristic
Yolks is a complex variable assembled component.
The principle component are protein,phospholipid and fats in different combination.
Depending upon these component yolks is distinguished into protein yolks and fatty acid
For eg- the avian contain 48.19% water , 16.6 % protein, 32.6% phospholipids and fats and 1% carbohydrates.
Here provided contents for learning that what are the male and female gametes. How to they form? And described how to both gametes fused (fertilization)on the molecular basis.
Evolutionary Biology: Based on CBCS (2019 Credit Pattern); Savitribai Phule P...Shoeb Ahmad
The Presentation contains following chapters with adequate contents based on CBCS (2019 Credit Pattern); Savitribai Phule Pune University Syllabus-
1.1 Concept of Evolution.
1.2 Origin of life.
1.3 Origin of eukaryotic cell (Origin of mitochondria, plastids & symbionts).
Evidences of Evolution:
2.1 Analogy and Homology.
2.2 Embryological Evidences of Evolution.
2.3 Evolutionary & Paleontological Evidences.
Historical Review of Evolutionary Concept:
3.1 Theories of Evolution. 3.2 Lamarckism.
3.3 Darwinism and Neo Darwinism.
3.4 Mutation Theory.
3.5 Modern Synthetic theory.
4. Sources of Variations:
4.1 Variation and Mutations.
5. Isolation
6. Speciation:
6.1 Types of speciation (Allopatric & Sympatric).
6.2 Mechanism of speciation.
6.3 Patterns of speciation.
6.4 Factors influencing speciation.
7 Population Genetics:
7.1 Hardy-Weinberg Law & Genetic Drift.
7.2 Types of Natural Selection.
Origin of Man:
8.1 Evolution of Man (Evolution of anthropoids including man) - Kenyapithecus to Homo sapiens.
9. Zoogeographical Realms With reference to fauna
10. Extinctions:
10.1 Extinction - An Overview.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
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How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
1. Dr. Shoeb Ahmad, Assistant Professor, Department of Zoology, AKI’s Poona College of Arts, Science & Commerce, Camp, Pune -01
e-mail: shoeb.zoology@gmail.com Mobile no 9919509673 Page 1
Recognition of Egg and Sperm
The interaction of sperm and egg generally proceeds according to five basic steps
Fig 1. Summary of events leading to the fusion of egg and sperm plasma membranes in the sea urchin (A) and
the mouse (B). (A) Sea urchin fertilization is external. (1) The sperm is activated by and chemotactically
attracted to the egg. (2, 3) The egg jelly causes the acrosomal reaction to occur, allowing the acrosomal process
to form and release proteolytic enzymes. (4) The sperm adheres to the vitelline envelope and lyses a hole in it.
(5) The sperm adheres to the egg plasma membrane and fuses with it. The sperm pronucleus can now enter the
egg cytoplasm. (B) Mammalian fertilization is internal. (1) The contents of the female reproductive tract
capacitate, attract, and activate the sperm. (2) The acrosome-intact sperm binds to the zona pellucida, which
constitutes a thicker envelope than that of sea urchins. (3) The acrosomal reaction occurs on the zona pellucida.
(4) The sperm digests a hole in the zona pellucida. (5) The sperm adheres to the egg, and their plasma
membranes fuse.
1. The chemoattraction of the sperm to the egg by soluble molecules (fertilizin) secreted by the egg.
2. The exocytosis of the acrosomal vesicle to release its enzymes.
3. The binding of the sperm to the extracellular envelope (vitelline layer or zona pellucida) sof the
egg.
4. The passing of the sperm through this extracellular envelope.
5. Fusion of egg and sperm cell plasma membranes
2. Dr. Shoeb Ahmad, Assistant Professor, Department of Zoology, AKI’s Poona College of Arts, Science & Commerce, Camp, Pune -01
e-mail: shoeb.zoology@gmail.com Mobile no 9919509673 Page 2
Sometimes steps 2 and 3 are reversed (as in mammalian fertilization) and the sperm binds to
the egg before releasing the contents of the acrosome. After these five steps are
accomplished, the haploid sperm and egg nuclei can meet, and the reactions that initiate
development can begin.
In many species, the meeting of sperm and egg is not a simple matter. Many marine
organisms release their gametes into the environment. That environment may be as small as a
tide pool or as large as an ocean. Moreover, it is shared with other species that may shed their
sex cells at the same time. These organisms are faced with two problems: How can sperm and
eggs meet in such a dilute concentration, and how can sperm be prevented from trying to
fertilize eggs of another species? Two major mechanisms have evolved to solve these
problems: species-specific attraction of sperm and species-specific sperm activation.
Sperm attraction: Action at a distance
Species-specific sperm attraction has been documented in numerous species, including
cnidarians, molluscs, echinoderms, and urochordates. In many species, sperm are attracted
toward eggs of their species by chemotaxis, that is, by following a gradient of a chemical
secreted by the egg.
The mechanisms of chemotaxis differ among species. One chemotactic molecule, a 14-amino
acid peptide called resact, has been isolated from the egg jelly of the sea urchin (Arbacia
punctulata). Resact diffuses readily in seawater and has a profound effect at very low
concentrations when added to a suspension of Arbacia sperm. When a drop of seawater
containing Arbacia sperm is placed on a microscope slide, the sperm generally swim in
circles about 50 μm in diameter. Within seconds after a minute amount of resact is injected
into the drop, sperm migrate into the region of the injection and congregate there. As resact
continues to diffuse from the area of injection, more sperm are recruited into the growing
cluster. Resact is specific for A. punctulata and does not attract sperm of other species. A.
punctulata sperm have receptors in their plasma membranes that bind resact and can swim up
a concentration gradient of this compound until they reach the egg.
Resact also acts as a sperm-activating peptide. Sperm-activating peptides cause dramatic and
immediate increases in mitochondrial respiration and sperm motility. The sperm receptor for
resact is a transmembrane protein, and when it binds resact on the extracellular side, a
conformational change on the cytoplasmic side activates the receptor’s enzymatic activity.
This activates the mitochondrial ATP-generating apparatus as well as the dynein ATPase that
stimulates flagellar movement in the sperm
The acrosomal reaction in sea urchins
A second interaction between sperm and egg is the acrosomal reaction. In most marine
invertebrates, the acrosomal reaction has two components: the fusion of the acrosomal vesicle
with the sperm plasma membrane (an exocytosis that results in the release of the contents of
the acrosomal vesicle) and the extension of the acrosomal process. The acrosomal reaction in
sea urchins is initiated by contact of the sperm with the egg jelly. Contact with egg jelly
3. Dr. Shoeb Ahmad, Assistant Professor, Department of Zoology, AKI’s Poona College of Arts, Science & Commerce, Camp, Pune -01
e-mail: shoeb.zoology@gmail.com Mobile no 9919509673 Page 3
causes the exocytosis of the sperm’s acrosomal vesicle and the release of proteolytic enzymes
that can digest a path through the jelly coat to the egg surface. The sequence of these events
is outlined in Fig. 2
Fig. 2 Acrosomal reaction in sea urchin sperm. (A–C) The portion of the acrosomal membrane lying
directly beneath the sperm plasma membrane fuses with the plasma membrane to release the contents
of the acrosomal vesicle. (D) The actin molecules assemble to produce microfilaments, extending the
acrosomal process outward. Actual photographs of the acrosomal reaction in sea urchin sperm are
shown below the diagrams.
The exocytosis of the acrosomal vesicle is caused by the calcium-mediated fusion of the
acrosomal membrane with the adjacent sperm plasma membrane. The egg jelly factors that
initiate the acrosomal reaction in sea urchins are often highly specific to each species.
The second part of the acrosomal reaction involves the extension of the acrosomal process
(see Fig. 2). This protrusion arises through the polymerization of globular actin molecules
into actin filaments.
Species-specific recognition in sea urchins
Once the sea urchin sperm has penetrated the egg jelly, the acrosomal process of the sperm
contacts the surface of the egg (Fig. 3). A major species-specific recognition step occurs at
this point. The acrosomal protein mediating this recognition is called bindin. Further, its
interaction with eggs is relatively species-specific. Bindin isolated from the acrosomes of a
species will bind to eggs of same species.
4. Dr. Shoeb Ahmad, Assistant Professor, Department of Zoology, AKI’s Poona College of Arts, Science & Commerce, Camp, Pune -01
e-mail: shoeb.zoology@gmail.com Mobile no 9919509673 Page 4
Fig. 4 Species-specific binding of acrosomal process to egg cell surface in sea urchins. (A) Actual
contact of a sea urchin sperm acrosomal process with an egg microvillus. (B) In vitro model of
species-specific binding. The agglutination of dejellied eggs by bindin was measured by adding
bindin aggregates to a plastic well containing a suspension of eggs. After 2–5 minutes of gentle
shaking, the wells were photographed. Each bindin bound to and agglutinated only eggs from its own
species.
Biochemical studies have shown that the bindins of closely related sea urchin species are
indeed different. This finding implies the existence of species-specific bindin receptors on the
egg, vitelline envelope, or plasma membrane. The bindin receptors are thought to be
aggregated into complexes on the egg cell surface, and hundreds of these complexes may be
needed to tether the sperm to the egg. Thus, species-specific recognition of sea urchin
gametes occurs at the levels of sperm attraction, sperm activation, and sperm adhesion to the
egg surface.
Gamete binding and recognition in mammals
ZP3: the sperm-binding protein of the mouse zona pellucida
The zona pellucida in mammals plays a role analogous to that of the vitelline envelope in
invertebrates. This glycoprotein matrix, which is synthesized and secreted by the growing
oocyte, plays two major roles during fertilization: it binds the sperm, and it initiates the
acrosomal reaction after the sperm is bound. The binding of sperm to the zona is relatively,
but not absolutely, species-specific. (Species-specific gamete recognition is not a major
problem when fertilization occurs internally.)
5. Dr. Shoeb Ahmad, Assistant Professor, Department of Zoology, AKI’s Poona College of Arts, Science & Commerce, Camp, Pune -01
e-mail: shoeb.zoology@gmail.com Mobile no 9919509673 Page 5
The binding of mouse sperm to the mouse zona pellucida can be inhibited by first incubating
the sperm with zona glycoproteins. Bleil and Wassarman (1980, 1986 1988) isolated an 83-
kDa glycoprotein, ZP3, from the mouse zona that was the active competitor for binding in
this inhibition assay. The other two zona glycoproteins they found, ZP1 and ZP2, failed to
compete for sperm binding (Fig.5). Moreover, they found that radiolabeled ZP3 bound to the
heads of mouse sperm with intact acrosomes. Thus, ZP3 is the specific glycoprotein in the
mouse zona pellucida to which the sperm bind. ZP3 also initiates the acrosomal reaction after
sperm have bound to it. The mouse sperm can thereby concentrate its proteolytic enzymes
directly at the point of attachment at the zona pellucida.
Fig. 5. Mouse ZP3 as the zona protein that binds sperm. (A) Diagram of the fibrillar structure of the
mouse zona pellucida. The major strands of the zona are composed of repeating dimers of proteins
ZP2 and ZP3. These strands are occasionally crosslinked together by ZP1, forming a meshlike
network. (B) Inhibition assay showing the specific decrease of mouse sperm binding to zonae
pellucidae when sperm and zonae were first incubated with increasingly large amounts of the
glycoprotein ZP3. The importance of the carbohydrate portion of ZP3 is also indicated by this graph