Kyle M. Judkins

We report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus purpuratus, a model for developmental and systems biology. The sequencing strategy combined whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones, aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome. The genome encodes about 23,300 genes, including many previously thought to be vertebrate innovations or known only outside the deuterostomes. This echinoderm genome provides an evolutionary outgroup for the chordates and yields insights into the evolution of deuterostomes.

BACKGROUND: Interventions for T2DM have in part aimed to mimic exercise. Here, we have compared the independent and combined effects of a PPARdelta agonist and endurance training mimetic (GW501516) and a myostatin antibody and resistance training mimetic (PF-879) on metabolic and performance outcomes in obese insulin resistant mice. METHODOLOGY/PRINCIPAL FINDINGS: Male ob/ob mice were treated for 6 weeks with vehicle, GW501516, PF-879, or GW501516 in combination with PF-879. The effects of the interventions on body composition, glucose homeostasis, glucose tolerance, energy expenditure, exercise capacity and metabolic gene expression were compared at the end of study. GW501516 attenuated body weight and fat mass accumulation and increased the expression of genes of oxidative metabolism. In contrast, PF-879 increased body weight by driving muscle growth and altered the expression of genes involved in insulin signaling and glucose metabolism. Despite their differences, both interventions alone improved glucose homeostasis. Moreover, GW501516 more effectively improved serum lipids, and PF-879 uniquely increased energy expenditure, exercise capacity and adiponectin levels. When combined the robust effects of GW501516 and/or PF-879 on body weight, adiposity, muscle mass, glycemia, serum lipids, energy expenditure and exercise capacity were highly conserved. CONCLUSIONS/SIGNIFICANCE: The data, for the first time, demonstrate postnatal inhibition of myostatin not only promotes gains in muscle mass similar to resistance training,but improves metabolic homeostasis. In several instances, these effects were either distinct from or complimentary to those of GW501516. The data further suggest that strategies to increase muscle mass, and not necessarily oxidative capacity, may effectively counter insulin resistance and T2DM.

Existing methods to quantify angiogenesis range from image analysis of photographs to fluorescent microscopy. These methods are often time consuming and costly; they also may not detect capillaries if they are indistinct from the background of the image. We have developed a simple method based on the motion of blood to create an image that reveals the entire angiogenic vasculature. Two image analysis software programs were used separately to demonstrate the method. Using either ImageJ or Environment for Visualizing Images, we analyzed a video clip of regenerated tissue from the partially amputated caudal fin of a zebrafish (Danio rerio). The deviations among the frames in the video stack were calculated to reveal pixels where motion has occurred. The resulting image highlighted all vessels through which blood flowed and allowed for automatic quantification of the newly developed vasculature. Using this method, we quantified the angiogenic action of basic fibroblast growth factor and vascular endothelial growth factor, as well as suppression of angiogenesis by an inhibitor. In a preliminary study, we also found that it could be used to trace the developing vasculature in zebrafish embryos. Thus, motion-based angiogenesis analysis may provide an easy and accurate quantification of angiogenesis.

Tadalafil, better known as Cialis, is a phosphodiesterase E2 inhibitor which causes vasodilation. Many vasodilators have been shown to stimulate blood vessel growth. We used a zebrafish caudal fin regeneration model to investigate the angiogenic action of tadalafil. The three most ventral caudal fin bones of the zebrafish, Danio rerio, were amputated above the first branching point after being anesthetized with 0.2% Tricaine. After submerging five groups of zebrafish for 6o minutes in five increasing concentrations of taladifil (100 nM to 800 nM), they were placed in tanks containing regular water. Six days post amputation, each fish was anesthetized and its newly developed vascular bed in the regenerated tail fin region was examined under a microscope at 40X magnification. A 15 second video clip was also recorded. The area of each vascular bed was then quantified using our newly developed motion‐based angiogenesis analysis. As compared to the controls, zebrafish exposed to tadalafil showed significantly greater blood vessel growth. Statistically significant dose‐related responses were also demonstrated. In conclusion, tadalafil stimulates angiogenesis during caudal fin regeneration in zebrafish.