defence

Mothers can teach their children much about the world, but some mothers can do it without ever meeting their young. Take the field cricket Gryllus pennsylvanicus. A female cricket isn't exactly a caring mother. Once she lays her eggs, she abandons them to their fate. But amazingly, she can also forewarn her young of the dangers they might face. If a pregnant female is exposed to a wolf spider, her experiences affect her unborn young. When they hatch, the baby crickets are more likely to freeze when they smell wolf spiders nearby. If mothers sense a threat in their environment, there are…
Bats view the world in echoes, timing the reflections of their own ultrasonic calls to navigate and hunt. This biological sonar, or echolocation, has made them masters of the night sky; it's so sensitive that some species take moths and other insects on the wing, while others pluck spiders from their webs without entangling themselves in silk. But with such an efficient technology, it was only a matter of time before their quarry developed countermeasures. Some insects gained ears; others simply rely on outmanoeuvring their attackers. But one group, the tiger moths, play bats at their own…
HIV is an elusive adversary. The virus is so good at fooling the immune system that the quest for an HIV vaccine, or even a countermeasure to resist infections, has spanned two fruitless decades. But maybe a defence has been lurking in our genomes all this time. Nitya Venkataraman from the University of Central Florida has managed to reawaken a guardian gene that has been lying dormant in our genomes for 7 million years. These genes, known as retrocyclins, protect monkeys from HIV-like viruses. The hope is that by rousing them from their slumber, they could do the same for us. The technique…