Validation of a microwave energy meter to non-lethally estimate energetic reserves in adult sturgeon.

Whole-body (WB) energetic reserves influence fish survival, growth, and reproduction but are typically quantified using lethal methods (i.e. proximate analyses) or interpreted through body condition indices. Energetic reserves can impact population dynamics through influences on growth rates, age-at-first-reproductive-maturity, and spawning periodicity at the individual-fish level, especially in long-lived sturgeon species. Therefore, a non-lethal tool to track the energetic reserves of endangered sturgeon populations could inform adaptive management and further our understanding of the sturgeon's biology. The Distell Fatmeter is a microwave energy meter that has been validated to non-lethally estimate energetic reserves in some fish species, but never successfully for sturgeon. Here, stepwise linear regressions were applied to test commonly monitored body metrics and Fatmeter measurements at nine different anatomical sites on captive adult pallid sturgeon (Scaphirhynchus albus; total length of 790-1015 mm; WB lipid of 13.9-33.3%) compared with WB lipid and energy content determined by proximate analyses. Fatmeter measurements alone explained approximately 70% of the variation in WB energetic reserves, which outperformed models considering body metrics alone by a margin of approximately 20%. The top-ranked models based on AICc score (second-order Akaike Information Criterion) included a combination of body metrics and Fatmeter measurements and accounted for up to 76% of the variation in WB lipid and energy. We recommend the incorporation of Fatmeter measurements at a single site located dorsally to the lateral scutes at the posterior end of the fish above the pelvic fins (U-P) into conservation monitoring programs for adult pallid sturgeon (total length [TL] ≥ 790 mm; fork length [FL] ≥ 715 mm) and the cautious application of Fatmeter measurements for sturgeon between 435 and 790 mm TL (375-715 mm FL). Measurements at this U-P site combined with body mass explained approximately 75% of the variation in WB lipid and energy.

Uncovering patterns of freshwater positive interactions using meta-analysis: Identifying the roles of common participants, invasive species and environmental context.

Positive interactions are sensitive to human activities, necessitating synthetic approaches to elucidate broad patterns and predict future changes if these interactions are altered or lost. General understanding of freshwater positive interactions has been far outpaced by knowledge of these important relationships in terrestrial and marine ecosystems. We conducted a global meta-analysis to evaluate the magnitude of positive interactions across freshwater habitats. In 340 studies, we found substantial positive effects, with facilitators increasing beneficiaries by, on average, 81% across all taxa and response variables. Mollusks in particular were commonly studied as both facilitators and beneficiaries. Amphibians were one group benefiting the most from positive interactions, yet few studies investigated amphibians. Invasive facilitators had stronger positive effects on beneficiaries than non-invasive facilitators. We compared positive effects between high- and low-stress conditions and found no difference in the magnitude of benefit in the subset of studies that manipulated stressors. Future areas of research include understudied facilitators and beneficiaries, the stress gradient hypothesis, patterns across space or time and the influence of declining taxa whose elimination would jeopardise fragile positive interaction networks. Freshwater positive interactions occur among a wide range of taxa, influence populations, communities and ecosystem processes and deserve further exploration.

Adenylyl cyclase 3/adenylyl cyclase-associated protein 1 (CAP1) complex mediates the anti-migratory effect of forskolin in pancreatic cancer cells.

Pancreatic cancer is one of the most lethal human malignancies. A better understanding of the intracellular mechanism of migration and invasion is urgently needed to develop treatment that will suppress metastases and improve overall survival. Cyclic adenosine monophosphate (cyclic AMP) is a second messenger that has shown to regulate migration and invasion of pancreatic cancer cells. The rise of cyclic AMP suppressed migration and invasion of pancreatic ductal adenocarcinoma cells. Cyclic AMP is formed from cytosolic ATP by the enzyme adenylyl cyclase (AC). There are ten isoforms of ACs; nine are anchored in the plasma membrane and one is soluble. What remains unknown is the extent to which the expression of transmembrane AC isoforms is both modified in pancreatic cancer and mediates the inhibitory effect of forskolin on cell motility. Using real-time PCR analysis, ADCY3 was found to be highly expressed in pancreatic tumor tissues, resulting in a constitutive increase in cyclic AMP levels. On the other hand, ADCY2 was down-regulated. Migration, invasion, and filopodia formation in two different pancreatic adenocarcinoma cell lines, HPAC and PANC-1 deficient in AC1 or AC3, were studied. We found that AC3, upon stimulation with forskolin, enhanced cyclic AMP levels and inhibited cell migration and invasion. Unlikely to be due to a cytotoxic effect, the inhibitory effects of forskolin involved the quick formation of AC3/adenylyl cyclase-associated protein 1 (CAP1)/G-actin complex, which inhibited filopodia formation and cell motility. Using Western blotting analysis, forskolin, through AC3 activation, caused phosphorylation of CREB, but not ERK. The effect of CREB phosphorylation is likely to be associated with long-term signaling changes. © 2016 Wiley Periodicals, Inc.