@misc{SchlenstedtBalfanzBaumannetal.2006,
  author    = {Schlenstedt, Jana and Balfanz, Sabine and Baumann, Arnd and Blenau, Wolfgang},
  title     = {Am5-HT7 : molecular and pharmacological characterization of the first serotonin receptor of the honeybee (Apis mellifera)},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-44423},
  year      = {2006},
  abstract  = {The biogenic amine serotonin (5-HT) plays a key role in the regulation and modulation of many physiological and behavioural processes in both vertebrates and invertebrates. These functions are mediated through the binding of serotonin to its receptors, of which 13 subtypes have been characterized in vertebrates. We have isolated a cDNA from the honeybee Apis mellifera (Am5-ht7) sharing high similarity to members of the 5-HT7 receptor family. Expression of the Am5-HT7 receptor in HEK293 cells results in an increase in basal cAMP levels, suggesting that Am5-HT7 is expressed as a constitutively active receptor. Serotonin application to Am5-ht7-transfected cells elevates cyclic adenosine 3',5'-monophosphate (cAMP) levels in a dose-dependent manner (EC50 = 1.1-1.8 nM). The Am5-HT7 receptor is also activated by 5-carboxamidotryptamine, whereas methiothepin acts as an inverse agonist. Receptor expression has been investigated by RT-PCR, in situ hybridization, and western blotting experiments. Receptor mRNA is expressed in the perikarya of various brain neuropils, including intrinsic mushroom body neurons, and in peripheral organs. This study marks the first comprehensive characterization of a serotonin receptor in the honeybee and should facilitate further analysis of the role(s) of the receptor in mediating the various central and peripheral effects of 5-HT.},
  language  = {en}
}
@article{CleggGaedkeBoehreretal.2012,
  author    = {Clegg, Mark R. and Gaedke, Ursula and B{\"o}hrer, Bertram and Spijkerman, Elly},
  title     = {Complementary ecophysiological strategies combine to facilitate survival in the hostile conditions of a deep chlorophyll maximum},
  series = {Oecologia},
  volume    = {169},
  journal   = {Oecologia},
  number    = {3},
  publisher = {Springer},
  address   = {New York},
  issn      = {0029-8549},
  doi       = {10.1007/s00442-011-2225-4},
  pages     = {609 -- 622},
  year      = {2012},
  abstract  = {In the deep, cooler layers of clear, nutrient-poor, stratified water bodies, phytoplankton often accumulate to form a thin band or "deep chlorophyll maximum" (DCM) of ecological importance. Under such conditions, these photosynthetic microorganisms may be close to their physiological compensation points and to the boundaries of their ecological tolerance. To grow and survive any resulting energy limitation, DCM species are thought to exhibit highly specialised or flexible acclimation strategies. In this study, we investigated several of the adaptable ecophysiological strategies potentially employed by one such species, Chlamydomonas acidophila: a motile, unicellular, phytoplanktonic flagellate that often dominates the DCM in stratified, acidic lakes. Physiological and behavioural responses were measured in laboratory experiments and were subsequently related to field observations. Results showed moderate light compensation points for photosynthesis and growth at 22A degrees C, relatively low maintenance costs, a behavioural preference for low to moderate light, and a decreased compensation point for photosynthesis at 8A degrees C. Even though this flagellated alga exhibited a physiologically mediated diel vertical migration in the field, migrating upwards slightly during the day, the ambient light reaching the DCM was below compensation points, and so calculations of daily net photosynthetic gain showed that survival by purely autotrophic means was not possible. Results suggested that strategies such as low-light acclimation, small-scale directed movements towards light, a capacity for mixotrophic growth, acclimation to low temperature, in situ exposure to low O-2, high CO2 and high P concentrations, and an avoidance of predation, could combine to help overcome this energetic dilemma and explain the occurrence of the DCM. Therefore, corroborating the deceptive ecophysiological complexity of this and similar organisms, only a suite of complementary strategies can facilitate the survival of C. acidophila in this DCM.},
  language  = {en}
}