Adolescence is a period of high vulnerability for alcohol use and abuse. Early alcohol use has been shown to increase the risk for alcohol-related problems later in life; therefore effective preventive treatments targeted toward adolescents would be very valuable. Many epidemiological and longitudinal studies in humans have revealed the beneficial effects of exercise for prevention and treatment of alcohol addiction. Pre-clinical studies have demonstrated that access to a running wheel leads to decreased voluntary alcohol consumption in adult mice, hamsters, and rats. However, age and sex may also influence the effects of exercise on alcohol use. Herein, we studied male and female C57BL/6 adolescent mice using a 24-h two bottle choice paradigm to evaluate 21 days of concurrent voluntary exercise on alcohol consumption and preference. Given previously known effects of exercise in increasing the expression of brain-derived neurotrophic factor (BDNF) in the hippocampus and its role in regulating the reward system, BDNF mRNA and protein levels were measured at the end of the behavioral experiment. Our results demonstrate sex differences in the efficacy of voluntary exercise and its effects on decreasing alcohol consumption and preference. We also report increased BDNF expression after 21 days of voluntary exercise in both male and female mice. Interestingly, the distance travelled played an important role in alcohol consumption and preference in female mice but not in male mice. Overall, this study demonstrates sex differences in the effects of voluntary exercise on alcohol consumption in adolescent mice and points out the importance of distance travelled as a limiting factor to the beneficial effects of wheel running in female mice.

The genetic architecture of a phenotype can have considerable effects on the evolution of a trait or species. Characterizing genetic architecture provides insight into the complexity of a given phenotype and, potentially, the role of the phenotype in evolutionary processes like speciation. We use genome sequences to investigate the genetic basis of phenotypic variation in redpoll finches (Acanthis spp.). We demonstrate that variation in redpoll phenotype is broadly controlled by a ~55-Mb chromosomal inversion. Within this inversion, we find multiple candidate genes related to melanogenesis, carotenoid coloration, and bill shape, suggesting the inversion acts as a supergene controlling multiple linked traits. A latitudinal gradient in ecotype distribution suggests supergene driven variation in color and bill morphology are likely under environmental selection, maintaining supergene haplotypes as a balanced polymorphism. Our results provide a mechanism for the maintenance of ecotype variation in redpolls despite a genome largely homogenized by gene flow.

Avian evolution has generated an impressive array of patterns and colors in the ~10,000 bird species that exist on Earth. Recently, a number of exciting studies have utilized whole-genome sequencing to reveal new details on the genetics of avian plumage color. These findings provide compelling evidence for genes that underlie plumage variation across a wide variety of bird species (e.g., juncos, warblers, seedeaters, and estrildid finches). While much is known about large, body-wide color changes, these species exhibit discrete color differences across small plumage patches. Many genetic differences appear to be located in regulatory regions of genes rather than in protein-coding regions, suggesting gene expression is playing a large role in the control of these color patches. Taken together, these studies have the potential to broadly facilitate further research of sexual selection and evolution in these charismatic taxa.

Known colloquially as ‘Old Man’s Beard’, Usnea is a genus of lichenized Ascomycete fungi characterized by having a fruticose growth form and cartilaginous central axis. The complete mitochondrial genomes of Usnea halei , U. mutabilis , U. subfusca , U. subgracilis , and U. subscabrosa were sequenced using Illumina data and then assembled de novo . These mitogenomes ranged in size from 52,486 bp ( U. subfusca ) to 94,464 bp ( U. subgracilis ). All were characterized by having high levels of intronic and intergenic variation, such as ORFs that encode proteins with homology to two homing endonuclease types, LAGLIDADG and GIY-YIG. Genes annotated within these mitogenomes include 14 protein-coding genes, the large and small ribosomal subunits (LSU and SSU), and 23–26 tRNAs. Notably, the atp9 gene was absent from each genome. Genomic synteny was highly conserved across the five species. Five conserved mitochondrial genes ( nad2 , nad4 , cox1 , cox2 , and cox3 ) were used to infer a best estimate maximum likelihood phylogeny among these five Usnea and other relatives, which yielded relationships consistent with prior published phylogenies.

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