Sentences with phrase «zona pellucida»
Two reproductive antigens, zona pellucida and GnRH, have been identified as possible targets for fertility control in cats.
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This technology — vectored contraception — utilizes a single intramuscular injection to bring about transgene - mediated expression of proteins that inhibit fertility through action on targets such as GnRH, a master reproductive hormone, the egg zona pellucida, which is an essential binding site for sperm, or sperm.
Four different stages of oocytes, striped of their zona pellucida (ZP), were assayed: 1) GV (germinal vesicle), 2) MI (metaphase I), 3) MII (spontaneously matured metaphase II before IVM) and 4) IVM - MII (in vitro matured metaphase II).
One - step collagenase method for zona pellucida removal in unfertilized eggs: easy and gentle method for large - scale preparation.
Before fertilization can occur, a sperm must fasten to the zona pellucida, a membrane that encases the egg.
The zona pellucida in humans contains four kinds of proteins.
The researchers then used mass spectrometry to identify the carbohydrates in zona pellucida material from the eggs.
Sperm racing to fertilize an egg face numerous hurdles, including burrowing through the zona pellucida, a thick wall surrounding the cell membrane.
As the team reports online today in Science, the sugars from human zona pellucida predominantly carry one kind of carbohydrate branch, a structure known as sialyl - Lewisx.
Their sperm can bind to an egg, the team found, and even burrow through the zona pellucida, but fertilization never occurs.
However, he notes, some sperm can attach to the egg even with distracting sialyl - Lewisx molecules nearby, suggesting that binding to the zona pellucida involves another interaction, probably between a protein on the sperm and a protein on the egg.
When a sperm cell meets an egg cell (the oocyte), it burrows through the thick outer rind surrounding the egg (the zona pellucida), enters the internal cytoplasm of the egg (the ooplasm), and locomotes its male DNA — half of the typical number of chromosomes — to the female half within about three to four hours.
The images depict what might be called embryology in flagrante: micrographs of sperm cells, trailing accordion - like pleats of white zags as they streak across a vast blue ocean of ooplasm; a multihued blastocyst in the process of hatching out of the egg's zona pellucida; and egg cells with a fringe of glowing, fate - determining proteins, looking a bit like a solar eclipse inside a cell.
The zona pellucida protects the egg and the early embryo before implantation.
A study in The Journal of Cell Biology now identifies the protein in the zona pellucida that sperm latch onto.
Human sperm adhered to the mouse zona pellucida if it contained human ZP2 but not if it carried human ZP3, confirming the importance of ZP2.
Hay's team also showed that the same approach could be used to make female mice generate antibodies to the zona pellucida, a layer of proteins that surrounds egg cells.
The most promising contraceptive is porcine zona pellucida (PZP), which causes a mare's immune system to attack fertilised eggs.
Day 20 of pregnancy sees the zona pellucida being replaced by the trophoblast (also known as the trophoderm).
PFC has also developed a method to ease hatching of the embryo, given that vitrification can harden the outer shell surrounding it (the zona pellucida).
Not exact matches
«It's the first time we've had any detailed analysis of the human zona [pellucida],» says Christopher Barratt, a reproductive biologist at the University of Dundee in the United Kingdom.