Getting an evolutionary handle on life after reproduction
Since many animals live beyond their fertile years, biologists have searched for evolutionary clues to this extended lifespan. What role, if any, does natural selection play in the evolution of the postreproductive lifespan? For natural selection to shape the twilight years, postreproductive females should contribute to the fitness of their offspring or relatives, a hypothesis called the...Olfactory system detects pheromones that control reproduction
Howard Hughes Medical Institute researchers have discovered that pheromones essential for mating behavior in mice are recognized by the nose and not by the vomeronasal system, as researchers had long suspected.The new studies demonstrate that the main olfactory epithelium, which was presumed to be mostly involved with the sense of smell, plays a critical role in pheromone detection. Howar...The brain is broadly wired for reproduction
Howard Hughes Medical Institute researchers have discovered a vast network of neurons in the brain of mice that governs reproduction and controls the effects of reproductive status on other brain functions. In their studies, the researchers found neural circuits that coordinate a complex interplay between neurons that control reproduction and brain areas that carry the neural signals trigg...Sexual reproduction delays aging in a mammalian species
Past research on aging and the life histories of diverse species has shown that sexual reproduction is biologically costly for individuals and tends to decrease lifespan rather than increase it. But a new study by Philip Dammann and Hynek Burda from the University of Duisburg-Essen shows that, in a vertebrate species, the opposite can be true as well. The authors, studying captive Zambian...New brain hormone puts brakes on reproduction
University of California, Berkeley, researchers have discovered a new actor in the mammalian reproductive system, a hormone that fills a role long suspected, but until now undetected. The hormone, a small protein, or peptide, called gonadotropin-inhibitory hormone (GnIH), puts the brakes on reproduction by directly inhibiting the action of the central hormone of the reproductive system - g...Tissue Engineered Scaffolding Allows Reproduction of Cartilage Tissue
A new study examines the use of tissue-engineered scaffolding made of cartilage cells, which have a limited ability to heal naturally, to replace defective cartilage tissue. Cartilage cells are extracted and seeded to the scaffold which is implanted into the body, where new cartilage tissue is grown along the structure. The study appears in the journal Artificial Organs....