Successful compensation for dystrophin deficiency by a helper-dependent adenovirus expressing full-length utrophin

Helper-dependent adenovirus vector (AdV)\u2013mediated full-length dystrophin expression leads to significant mitigation of the dystrophic phenotype of the mdx mouse. However, dystrophin, as a neoantigen, elicits antibody formation. As an alternative approach, we evaluated gene transfer of full-length murine utrophin, a functional homologue of dystrophin that is normally present only at the neuromuscular junction. A single injection in the tibialis anterior (TA) muscle of the helper-dependent adenovirus vector encoding utrophin provided very good transduction, with 58% of fibers demonstrating sarcolemmal utrophin expression in the neonates, and 35% utrophin-positive (Utr\u207a) fibers in adults. The presence of utrophin prevented extensive necrosis in the neonates, halted further necrosis in the adults, and led to restoration of sarcolemmal expression of dystrophin-associated proteins up to 1 year after injection. Marked physiological improvement was observed in both neonates and adults. Neither increased humoral responses nor cellular immune responses were evident. However, there was a time-related decline of the initial high utrophin expression. Although viral DNA persisted in animals that were injected in the neonatal stage, viral DNA levels decreased in muscles of adult mice. These results demonstrate that although utrophin gene transfer leads to amelioration of the dystrophic phenotype, the effects are not sustained upon loss of utrophin expression.NRC publication: Ye

Artificial ornaments manipulate intrinsic male quality in wild-caught zebra finches (Taeniopygia guttata)

The addition of red and green color bands is a commonly used method for manipulating male attractiveness in the zebra finch (Taeniopygia guttata), providing insight into the study of maternal investment and sexual selection. The addition of artificial ornaments has been assumed to manipulate a females’ perception of the male, rather than affecting intrinsic qualities of the male himself. Here, however, we reveal that the artificial band color worn by a male changes his body mass, condition, and courtship display rate. Males wearing red color bands in aviaries prior to mate-choice trials had a significantly higher song rate during trials than those wearing green color bands, alongside a significant increase in mass change and condition. Male song rate was found to significantly correlate with female preference alongside a female preference for red-banded males. However, male song rate in turn increased when female response was positive, suggesting a social feedback between the interacting birds. Our data suggest the presence of socially mediated feedback mechanisms whereby the artificial increase in attractiveness or dominance of a male directly affects other aspects of his attractiveness. Therefore, housing birds in social groups while manipulating attractiveness can directly influence other male qualities and should be accounted for by future studies