Thermal tolerance in the lugworm Arenicola marina: Measures of climate dependent organismal performance

The lugworm Arenicola marina is distributed over a wide latitudinal range and exposed to highly fluctuating temperature conditions within seasonal as well as tidal cycles. Animals are specialized to adjust to ambient climate conditions as well as climate variability as evidenced from patterns of latitudinal adaptation and seasonal acclimatisation of thermal tolerance windows. These and associated temperature dependent performance optima were elaborated from in vivo measurements of protein synthesis in artificial burrows and from the quantification of digging activity in natural sediments. The respective results in fact revealed differences in location, width and height of performance curves on the temperature scale between populations from the French Atlantic coast, the German North Sea and the Russian White Sea in accordance with temperature dependent latitudinal adaptation and seasonal acclimatisation. Quantification of the organismal performance range is thus relevant in the light of global warming and climate change, because long-term exposure to temperatures beyond the respective performance window leads to, for example, restrictions of digging activity with the consequence of extended exposure to predators or restrictions of growth. Both phenomena would result in decreased local abundances and eventually in a shift in geographical distribution. This study is part of a joined research project with Münster University (Animal Physiology) within the DFG priority programme AQUASHIFT

Physiological measures of climate dependent organismal performance investigated in populations of the lugworm Arenicola marina in a latitudinal cline

The lugworm Arenicola marina is a key organism from the intertidal zone, which is very abundant and shapes the ecosystem by bioturbation. The lugworm is distributed over a wide latitudinal range and exposed to widely fluctuating temperature conditions during seasonal as well as diurnal (tidal) cycles. Animals are specialized to adjust to ambient climate conditions as well as climate variability as evidenced from patterns of latitudinal adaptation and seasonal acclimatisation of thermal tolerance windows. While thermal responses can be found at various levels of organisation we expect climate sensitivity to be highest at the organismal level, the animals balance of oxygen demand and supply. Quantification of the resulting organismal performance range is relevant in the light of global warming and climate change, as exposure to temperatures beyond the performance window likely leads to fitness losses with the consequence of decreased local abundances and eventually a shift in geographical distribution. Performance optima, the width of thermal tolerance windows and their location on the temperature scale were quantified by investigating basic metabolism, growth and muscular exercise on the demand side and ventilation, haemoglobin concentration and oxygen affinity on the supply side in populations of Arenicola marina from the French Atlantic coast, the German North Sea and the Russian White Sea. Performance optima shift to higher temperatures at decreasing latitudes. Seasonal shifts to higher temperatures occur during summer acclimatisation emphasizing a close relationship between the local climate regime and the degree of thermal specialisation of the respective population

Multicenter assessment of animal-free collagenase AF-1 for human islet isolation

Animal-free (AF) SERVA Collagenase AF-1 and Neutral Protease (NP) AF GMP Grade have recently become available for human islet isolation. This report describes the initial experiences of 3 different islet transplant centers. Thirty-four human pancreases were digested using 1 vial of the 6 different lots of Collagenase AF-1 (2,000-2,583 PZ-U/vial) supplemented with 4 different lots of NP AF in a range of 50 to 160 DMC-U per pancreas. Isolation, culture, and quality assessment were performed using standard techniques as previously described. All data are presented as mean ± standard error of the mean (SEM). Variability of pancreas weight was associated with a wide range of collagenase and NP activities, ranging from 12.7 to 46.6 PZ-U/g (26.0 ± 1.5 PZ-U/g) and 0.4 to 3.0 DMC-U/g (1.5 ± 0.1 DMC-U/g), respectively. Postpurification islet yield was 296,494 ± 33,620 islet equivalents (IEQ) equivalent to 3,274 ± 450 IEQ/g with a purity of 55.9% ± 3.2%. Quality assessment performed after 2 to 4 d of culture demonstrated a viability of 88.1% ± 1.5% and a stimulation index of 3.7 ± 0.7. Eighteen of the 34 preparations were transplanted into type 1 diabetic patients equivalent to a transplantation rate of 52.9%. Six preparations, which were infused into patients as first transplant, could be analyzed and increased the fasting C-peptide level from 0.11 ± 0.08 pretransplant to 1.23 ± 0.24 and 2.27 ± 0.31 ng/mL 3 and 6 mo posttransplant ( P < 0.05), respectively. Insulin requirements were simultaneously reduced at the same time from 39.2 ± 3.8 IU/d before transplantation to 10.8 ± 4.1 and 4.0 ± 2.3 IU/d, after 3 and 6 mo posttransplant ( P < 0.05), respectively. This study demonstrates the efficiency of AF SERVA Collagenase AF-1 and NP AF for clinical islet isolation and transplantation. The new plant-based production process makes these products a safe new option for the islet field

Seawater carbonate chemistry and Mytilus edulis biological processes during experiments, 2010

CO2 emissions are leading to an acidification of the oceans. Predicting marine community vulnerability towards acidification is difficult, as adaptation processes cannot be accounted for in most experimental studies. Naturally CO2 enriched sites thus can serve as valuable proxies for future changes in community structure. Here we describe a natural analogue site in the Western Baltic Sea. Seawater pCO2 in Kiel Fjord is elevated for large parts of the year due to upwelling of CO2 rich waters. Peak pCO2 values of >230 Pa (>2300 µatm) and pHNBS values of 400 Pa (>4000 µatm). These changes will most likely affect calcification and recruitment, and increase external shell dissolution