Inspired by tests that asked women to choose mates solely by smelling their sweaty T-shirts, scientists from the Weizmann Institute are using yeast to probe how we and other living creatures choose the sexual partners most likely to give us healthy offspring.

More than 30 percent of yeast’s genetic makeup shares ancestry with humans, and like humans, this microscopic fungus needs two to produce offspring.

“You can put billions of yeast cells into a single test tube and allow them to mate like in a huge orgy,” explained Prof. Yitzhak Pilpel, who runs a laboratory in the molecular genetics department of the Weizmann Institute of Science in central Israel. “Within a day, you will have more mating events than it would take the world’s human population to achieve over decades.”

Pilpel’s inspiration came from several small experiments undertaken elsewhere over the years, which asked groups of women to rank different men’s sweaty T-shirts for sexual attractiveness. The results showed that different women preferred different men. DNA sequencing revealed that they tended to choose males who were not too genetically similar.

“Each had the ‘wisdom’ to highly rank a male at an intermediate genetic distance, as if this is an optimal choice,” said Pilpel. “But is it optimal?”

Without knowing the chemical composition of the sweat, he added that he could not say whether the magic ingredient guiding the women was pheromones.

Back in the Pilpel lab, the researchers took some 10 million cells from roughly 100 different strains of common bread yeast (Saccharomyces cerevisiae) and put them in test tubes both with and without oxygen, where they could mingle freely and reproduce over several........

© The Times of Israel