Noted

Alex Eben Meyer

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If you think you’re the perennial mosquito magnet among your friends, you probably are. According to Yale researchers, it’s likely you just taste better to the insects.

The researchers observed how neurons in the Asian tiger mosquito’s taste organ responded to 46 different taste compounds—including sugars, salts, bitter compounds, and amino acids. While some compounds stimulated many of the neurons, others inhibited neuron activity. Having these two responses gives mosquitoes an expanded ability to encode and differentiate a variety of tastes. The researchers found that different tastes and taste combinations promoted or suppressed behaviors such as biting, feeding, and egg-laying. Additionally, the bugs showed strong biting preferences for some human sweat samples over others.

A zygote contains genetic information from sperm and an egg, but the cytoplasm—the material that fills cells—only hails from the egg. Once the sperm enters the egg, the male’s cytoplasm disappears.

Yale researchers crossed two mouse species by creating zygotes that had the nuclear material and cytoplasm from both male and female mice. When the males of one species and females of the other breed naturally, no offspring are born. But offspring resulted from the blended zygote technique; the male cytoplasm was able to overcome the reproductive barrier. The offspring did not resemble either parent and showed growth and metabolic patterns different from those of the parental species.

The researchers note that a theoretical instance—in which a species might emerge when male cytoplasm enters the female’s egg during fertilization—could suggest a potential evolutionary mechanism.