This Molecule Could Help Sperm Find Egg Cells Easily
Sperm swims up a chemical gradient to reach the egg, assisted by a pulsatile rise in calcium ion concentration in the sperm tail that controls its beating.
Sperm swims up a chemical gradient to reach the egg
- Sperm swims up a chemical gradient to reach the egg
- Scientists have identified a key molecule that drives chemo attraction
- This crucial molecule remained unidentified for quite long
In a recent discovery, scientists have identified a key molecule that drives chemo attraction between sperm and egg cells in marine invertebrates, animals that don't have a vertebral column. More than 100 years ago, MBL Director F.R. Lillie of the University of Chicago discovered that eggs from marine invertebrates release a chemical factor that attracts sperm by a process called chemotaxis. Sperm swims up a chemical gradient to reach the egg, assisted by a pulsatile rise in calcium ion concentration in the sperm tail that controls its beating.
In past years, many of the cellular components that translate chemo-attractant stimulation into a calcium response have been revealed, but a crucial ingredient has been missing. A prerequisite for calcium ions from the sperm's environment being able to enter the tail is that the sperm cell's pH becomes more alkaline. The molecule that brings about this change in pH has been hard to pin down.
In this new report, U. Benjamin Kaupp, a MBL Whitman Center Scientist from the Center of Advanced European Studies (Caesar) in Bonn, Germany, identifies this molecule.
This sodium/proton exchange in the sperm cell is activated by a stretch of positively charged amino acids called the voltage sensor. When sperm capture chemo-attractant molecules, the voltage becomes more negative, because potassium channels open and potassium ions leave the cell.
The voltage-sensor registers this voltage change and the exchanger begins exporting protons from the cell, the cell's interior becomes more alkaline. When this mechanism is disabled, the calcium pulses in the sperm tail are suppressed, and sperm are lost on their voyage to the egg.
DoctorNDTV is the one stop site for all your health needs providing the most credible health information, health news and tips with expert advice on healthy living, diet plans, informative videos etc. You can get the most relevant and accurate info you need about health problems like diabetes, cancer, pregnancy, HIV and AIDS, weight loss and many other lifestyle diseases. We have a panel of over 350 experts who help us develop content by giving their valuable inputs and bringing to us the latest in the world of healthcare.