THE EARLY HUMAN EMBRYO RESEMBLES A TENNIS BALL ROLLING IN SYRUP
American researchers have discovered how the human embryo attaches itself to the wall of the uterus about a week after fertilisation, in a study that could aid infertility and reduce miscarriages.
The study, published this week in the journal Science, provides a better understanding of the molecular process by which the embryo manages to stop its voyage around the uterine walls and attach itself to begin its nine-month development into a human being.
The findings, according to the researchers, should aid in treating infertility and miscarriages that occur early in pregnancy.
Failure of the embryo to attach itself to the uterus is believed to be the cause of three-quarters of miscarriages, according to researchers at the University of California at San Francisco.
About six days after fertilisation, they found, the molecules on the surface of the embryo, at that stage called the blastocyst, interact with molecules in the uterine wall to create a sticky substance.
”It’s like a tennis ball rolling across a surface covered in syrup,” said professor Susan Fisher, the study’s lead author. ”The embryo’s journey along the uterine wall is arrested by the sticky interaction.”
The study found that at the moment of attachment, the cells on the surface of the blastocyst excrete a protein called L-selectin while the uterine wall becomes rich in carbohydrates, an interaction enabling the wandering embryo to come to a stop. Once at a stop, the embryo is able to attach itself to the uterine wall, where it begins to be nourished by the mother’s blood via the placenta.
The University of California has applied for a patent for use of the protein L-Selectin in diagnostic tests for problems associated with embryonic attachment to the uterus in women suffering from infertility. – Sapa-AFP