Las Cruces

Achievements for each user project

Estelle Masseret

During my stay,
- DNA extraction,
- PCR and molecules migration and
- measurements using both capillary and acrylamide gels technologies...
were successfully obtained.
The difficulties (which were expected) were the low rate of cross priming and so the necessity to create new well-fit microsatellite markers.

Catherine LEBLANC

The conditions for experimental procedures were set up at Las Cruces Marine Laboratory. Young sporophytes of Lessonia were collected at low tide each day in the nearest local population and kept in running seawater aquarium for 24h hours. The limpet Scuria was also harvested in the front shore of the Marine laboratory.
For grazing kinetics, three independent experiments were conducted in tanks with running seawater. Grazed tissues were freezed 6, 12, 24 and 48 hours after the first contact with Scurria. In paralell, algae placed in the same tank of the grazed algae but without contact with Scurria were also collected (
indirect-grazing) , together with control algae (separated tanks, without grazers). 24 algal samples were freezed in liquid nitrogen for each time (96 samples in total).
For temperature stress experiments, algae were immersed in small vessels with individual bubling at 13°C (control, running seawater), 20°C, 25°C and 30°C seawater for 1, 3 and 24 hours (except for 30°C). Physiological state of algae were monitored using PAM fluorometry. For each temperature condition, 3 to 4 independent experiments were conducted and algal thallus were cut after 15 min, 30 min, 1h, 3h and 24h, either used for DCFH-DA incubation or directly freezed in liquid nitrogen (in total, around 260 freezed samples).
In the end of the stay, preliminary extractions of DCF probe were carried out to monitor oxidative stress in algae in Santiago. We choose to sent algal samples at Roscoff laboratory for subsequent analyses.

Jean-Michel CLAVERIE

The research project went according to plan. Samples were taken at 5 locations: off the coast of Las Cruces, facing the mouth of the Tunquen river, of the Rio Maipo, and of an Algarrobo river. Two samples were also taken from a lake in San Antonio, and the Laguna El Peral (in las Cruces). The samples were filtered on site (ECIM station) and the filters (1.6 micron, and 0.2 micron) brought back to our laboratory in Marseille for EM examination, cultivation and DNA extraction. Contacts with local scientists were taken (Pontifical Catholic University of Chili, Dpt of Ecology, and Molecular Biology), and one seminar was given. We did not encounter any noticeable difficulty.