Science | The benefits of Escherichia coli
Infection and intestinal damage can trigger severe muscle wasting and loss of fat in mice. How this happens is poorly understood. Palaferri Schieber et al. discovered a protective Escherichia coli strain in their mouse colony. Mice intestinally colonized with the E. coli and infected with the food-poisoning bug Salmonella or with the lung pathogen Burkholderia did not waste away. Without the E. coli, similarly infected mice became fatally ill. The protective E. coli stimulated an innate immune mechanism that ensured that muscle-signaling pathways were not damaged by infection. Thus, the friendly E. coli allowed its host to tolerate and survive the pathogens.
Science | Live birth has evolved repeatedly across the major taxonomic groups, but in the vast majority it is the female that does the brooding. The most developed case of gender reversal in brooding occurs among seahorses. In some seahorse species, males not only incubate the eggs internally but develop a pouch structure that is strikingly similar to a uterus in terms of form and function. Whittington et al. produced a detailed transcriptome of the genes up-regulated during pregnancy in male Hippocampus abdominalis and found that those involved in embryo growth and support functions, such as nutrient transport and waste removal, were generally homologous to those seen in pregnant female mammals and reptiles. Thus, it seems that the pregnancy pathway is much the same whether fish or mammal, female or male