|By Neil Raymond | 2 years ago|
Scientists who are working with the Marine Biological Laboratory (MBL) discovered a molecule that guides the sperm to the egg. The study was published in Nature Communicatuons, according to Science Daily.
MBL Director F.R. Lillie of the University of Chicago discovered that eggs from marine invertebrates release a chemical factor that attracts sperm, a process that is called chemotaxis. Sperm then swim up a chemical gradient to reach the egg, and are further assisted by a pulsatile rise in calcium ion (Ca2+) concentration in the sperm tail that controls its beating.
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. Kaupp spent 18 summers at the MBL conducting research on this subject.
The molecule that Kaupp and colleagues have discovered, allows sodium ions to flow into the sperm cell and in exchange, transports protons out of the cell. This sodium/proton exchange in the sperm cell, like in the pacemaker channels, is activated by a stretch of positively charged amino acids that are called the voltage sensor.
When sperm capture chemoattractant molecules, the voltage becomes more negative, because potassium channels open and potassium ions leave the cell. The voltage-sensor The. 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 Ca2+ pulses in the sperm tail are suppressed and sperm are lost on their way to the egg. This discovery helps us understand the more about this complicated process.