Dear colleagues, My co-authors and I are pleased to announce the publication of a new paper: „Establishment of the first humpback whale fibroblast cell lines and their application in chemical risk assessment" Abstract: This paper reports the first successful derivation and characterization of humpback whale fibroblast cell lines. Primary fibroblasts were isolated from the dermal connective tissue of skin biopsies, cultured at 37◦C and 5% CO2 in the standard mammalian medium DMEM/F12 supplemented with 10% fetal bovine serum (FBS). Of nine initial biopsies, two cell lines were established from two different animals and designated HuWa1 and HuWa2. The cells have a stable karyotype with 2n = 44, which has commonly been observed in other baleen whale species. Cells were verified as being fibroblasts based on their spindle-shaped morphology, adherence to plastic and positive immunoreaction to vimentin. Population doubling time was determined to be ∼41 h and cells were successfully cryopreserved and thawed. To date, HuWa1 cells have been propagated 30 times. Cells proliferate at the tested temper- atures, 30, 33.5 and 37 ◦ C, but show the highest rate of proliferation at 37◦ C. Short-term exposure to para,para′ -dichlorodiphenyldichloroethylene (p,p′ -DDE), a priority compound accumulating in southern hemisphere humpback whales, resulted in a concentration-dependent loss of cell viability. The effective concentration which caused a 50% reduction in HuWa1 cell viability (EC50 value) was approximately six times greater than the EC50 value for the same chemical measured with human dermal fibroblasts. HuWa1 exposed to a natural, p,p′-DDE-containing, chemical mixture extracted from whale blubber showed dis- tinctively higher sensitivity than to p,p′-DDE alone. Thus, we provide the first cytotoxicological data for humpback whales and with establishment of the HuWa cell lines, a unique in vitro model for the study of the whales’ sensitivity and cellular response to chemicals and other environmental stressors. A PDF version of the paper is available online at: http://authors.elsevier.com/a/1Rgvp_,OE92iql or https://www.researchgate.net/publication/281641631_Establishment_of_the_firs... or via e-mail request to michael.burkard@eawag.ch<mailto:michael.burkard@eawag.ch> Cheers, Michael Burkard [cid:61A2A85B-F56E-4AB5-85C9-260FAD2F1118@guests.emp-eaw.ch]