US EditionStudy finds heat-activated switch in sperm is crucial for fertility
- Researchers from Washington University in St. Louis published on April 17, 2025, that a temperature-sensitive protein called CatSper triggers sperm hyperactivity during fertilization in mice and mammals.
- This discovery follows the unresolved question of how sperm activate their hyperactive movement, with previous theories focusing on pH and progesterone but failing, leading researchers to identify temperature as the key trigger.
- CatSper is a calcium channel embedded in sperm that flips on at temperatures above 33.5°C, initiating vigorous tail motions needed for sperm to penetrate the egg, while cooler testicles prevent premature activation.
- Polina Lishko, lead author and professor at WashU, suggested that rather than blocking the CatSper channel, it could be triggered early by temperature to exhaust the sperm’s energy reserves, rendering it incapable of fertilizing the egg.
- The findings explain why mammals have external testicles to maintain cooler temperatures for sperm, highlight new possibilities for male contraception, and offer promising avenues to address infertility by regulating the timing of sperm activation.
14 Articles
14 Articles
Turning up the heat drives sperm into ‘hyperactive mode’ key to fertility
A study in mice has found that warm temperatures in the reproductive tract trigger a “switch” that sends sperm into a hyperactive mode. This changes their motions from the smooth swimming necessary for navigation to the thrashing, twisting motions necessary to make it through the tough outer layer of the egg. “That hyperactive state in sperm is key for successful fertilization, and no one knew exactly how temperature triggers it,” says Polina Li…
Expert explains the hidden reasons for increasing infertility in men; know causes
People often blame women for not having children, but if you talk about reports, men are as much responsible for this as women. The cause of infertility in women can be hormonal imbalance, obesity, disorganised lifestyle, old age, etc. The cause of male infertility can be the consumption of intoxicants like alcohol or cigarettes, stress, or any kind of genetic problem. Before making any decision, you have to be aware; only then can the root of t…
Study finds heat-activated switch in sperm is crucial for fertility
In mammals—including us humans—sperm are surprisingly picky about temperature, thriving best in conditions a few degrees cooler than normal body temperature. But, given that the female reproductive tract is warmer than normal body temperature, how do these heat-sensitive swimmers manage to fertilize an egg in such a toasty environment?
Why Testicles Hang Outside The Body: Scientists Discover Sperm's Temperature Switch
Men's testicles hang outside the body for a good reason – and scientists have finally figured out why they need to stay cool. The post Why Testicles Hang Outside The Body: Scientists Discover Sperm’s Temperature Switch appeared first on Study Finds.
Coverage Details
Bias Distribution
- 80% of the sources are Center
Factuality
To view factuality data please Upgrade to Premium
