What happens after the acrosomal reaction?
Fertilization. After the acrosome reaction, the exposed acrosome becomes the head of the spermatozoon. This is covered in the acrosome reaction by proteolytic enzymes. These digest a path through the zona pellucida through which the spermatozoon passes.
What is the function of the acrosomal reaction that is what does it accomplish in the process of fertilization?
The function of the acrosome reaction is to help the sperm get through the egg’s protective coat and to allow the plasma membranes of the sperm and egg to fuse. This places both haploid nuclei (one from the sperm and one from the egg) into the same cell, where they form the diploid genome of the new organism.
Which event triggers the acrosomal reaction?
Zona pellucida is the natural inducer of the acrosome reaction. Binding of the sperm receptor to ZP3, a zona glycoprotein acting as ligand, triggers the molecular events leading to acrosomal exocytosis.
Which event triggers the acrosomal reaction in mammals?
The sperm acrosome reaction (AR), an essential event for mammalian fertilization, involves Ca2+ permeability changes leading to exocytosis of the acrosomal vesicle. The acrosome, an intracellular Ca2+ store whose luminal pH is acidic, contains hydrolytic enzymes.
What are the steps in the acrosome reaction?
The acrosome reaction must occur before the sperm cell reaches the zona pellucida. Acrosin digests the zona pellucida and membrane of the oocyte. Part of the sperm’s cell membrane then fuses with the egg cell’s membrane, and the contents of the head sink into the egg.
What are the phases of fertilization?
The stages of fertilization can be divided into four processes: 1) sperm preparation, 2) sperm-egg recognition and binding, 3) sperm-egg fusion and 4) fusion of sperm and egg pronuclei and activation of the zygote.
What is the acrosomal reaction describe it and why it’s important?
The acrosome reaction allows the sperm by exocytotic release of acrosomal enzymes to penetrate the zona pellucida of the egg. The species-specific zona pellucida protein that serves as a sperm receptor also stimulates a series of events that lead to fusion between the plasma membrane and outer acrosomal membrane.
How do acrosomal reactions occur?
The acrosomal reaction usually takes place in the ampulla of the fallopian tube (site of fertilization) when the sperm penetrates the secondary oocyte. The acrosome reaction must occur before the sperm cell reaches the zona pellucida. Acrosin digests the zona pellucida and membrane of the oocyte.
What is important of the acrosomal reaction?
The acrosome reaction is a crucial step during gamete interaction in all species, including man. It allows spermatozoa to penetrate the zona pellucida and fuse with the oocyte membrane. Spermatozoa unable to undergo the acrosome reaction will not fertilize intact oocytes.
How is acrosomal cap formed?
The inner acrosomal membrane is in juxtaposition to the nuclear membrane and the acrosome spreads over the anterior pole of the nucleus to cover it like a cap. The inception of its formation from the Golgi apparatus of the spermatid ushers in the last phase of spermatogenesis-spermiogenesis.
What step of fertilization is species specific?
The zona pellucida is the species specific barrier to fertilization as shown by the hamster experiment. Human sperm are incapable of fertilizing intact hamster eggs, but can fertilize hamster eggs stripped of their zona pellucida. This is used clinically to assess the fertilizing capacity of sperm.