Sentences with word «pellucida»

The zona pellucida in humans contains four kinds of proteins.

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.

The team also tested the binding of human sperm to mouse eggs surrounded by a zona pellucida harboring human glycoproteins.

To find out more, Jurrien Dean and colleagues from the National Institute of Diabetes and Digestive and Kidney Diseases engineered mice to produce various combinations of human and mouse zona pellucida glycoproteins.

The zona pellucida protects the egg and the early embryo before implantation.

Last summer, patchy outbreaks of clear - winged grasshoppers (Camnulla pellucida) in Colorado attained densities of 200 per square yard; a tenth of thisnumber is considered a danger to crops.

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.

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.

The researchers then used mass spectrometry to identify the carbohydrates in zona pellucida material from the eggs.

Although scientists have identified mouse carbohydrates that sperm bind to, they haven't been able to do the same for people, largely because of a scarcity of zona pellucida samples to test.

«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.

Mouse sperm didn't bind to the zona pellucida if it was missing ZP2, and female mice lacking the protein were sterile.

The most promising contraceptive is porcine zona pellucida (PZP), which causes a mare's immune system to attack fertilised eggs.

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).

Day 20 of pregnancy sees the zona pellucida being replaced by the trophoblast (also known as the trophoderm).

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.

This result jibes with a previous finding that fertilization triggers the release of an enzyme that severs ZP2 in this region, thus preventing additional sperm from attaching to the zona pellucida.

Before it can fertilize an egg, a sperm has to bind to and bore through an outer egg layer known as the zona pellucida.

A study in The Journal of Cell Biology now identifies the protein in the zona pellucida that sperm latch onto.

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.

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 intricacy with which an early embryo divides, compacts, hatches out of the zona pellucida, ingeniously secretes molecules that penetrate the cells lining the uterine wall in order to implant in the womb, and then recruits blood vessels to nourish the placenta and the developing fetus marks one of the most awe - inspiring metamorphoses in all of nature.

Their sperm can bind to an egg, the team found, and even burrow through the zona pellucida, but fertilization never occurs.

Human fertilization begins when spermatozoa bind to the extracellular matrix coating of the oocyte, known as the zona pellucida (ZP).

Sperm racing to fertilize an egg face numerous hurdles, including burrowing through the zona pellucida, a thick wall surrounding the cell membrane.

One of these sperm will penetrate the egg after binding to carbohydrates on the zona pellucida.

Before fertilization can occur, a sperm must fasten to the zona pellucida, a membrane that encases the egg.

«Influence of cholesterol sulfate and carbohydrate moieties on rabbit sperm penetration of zonae pellucidae»; The University of Georgia; 1987.

Two reproductive antigens, zona pellucida and GnRH, have been identified as possible targets for fertility control in cats.