Evolutionary biology and Artemia biodiversity in Chile: how much do we know now? Laboratory of Genetics & Aquaculture, Universidad de Los Lagos, Osorno, Chile. Gonzalo Gajardo
Outline 1. Background (conceptual support: speciation...) 2. Benefits from a concerted international action: previous ideas on the Artemia problem in Chile and adjacent countries expanded/complemented. new tools (genetic markers) available: to complement or check previous results/hypothesis; chance to address new problems. cyst bank: a unique opportunity to compare populations/species from different environments worldwide. formal (workshops) & informal discussions international cooperation (within and outside the project) & public awareness 3. Results & Conclusions
Shifting the baseline, restore old productivity Species diversity (biodiversity)= Origin vs.. extinction Speciation
Speciation process: mystery of the mysteries (Darwin) n n n n An area of evolution not yet well understood. Relevant to understand the origin and maintenance of biodiversity Genetic analysis has produced new generalisations and suggest interesting new research avenues. No longer a mystery, but a box of surprises Required to classify diversity
Speciation: a multi-disciplinary and multi- dimensional problem Geographic distribution, present and past Morphology Ecology (habitat, food, temperature and salinity, preferred substrate Biochemistry and physiology Reproductive cycle, chemical and behavioural isolation mechanisms Genetics (allozymes, nuclear (n) and mitdna), cytogenetics (2n, morphology, karyotype), immunology, hybridization (natural o artificial) White 1978
Artemia: : a significant database at different levels nmorphology nkaryology nallozyme nphysiology nnuclear & extranuclear DNA (mitdna)
From: : Gajardo et al. 2002
Artemia biodiversity: the local (Chile) perspective An island-like biogeographic situation Two species (A. franciscana & A. persimilis), not supposed to be together = new problems! Contrasting environments, and the southern distribution limit for one species a pre-project scientific picture
Chile: a biogeographic island with contrasting environments 18º Iquique A. franciscana 34º A. persimilis 34 31'S; 71 58'W 54º
Testing species boundaries
Pre-project picture: allozymes
3.5 Morphology cr 3 2.5 2 1.5 1 0.5 0-0.5-1 -1.5 ARG-1150 TPA LLA lan RIN pa PCH-2003 la ARG-LHD lat ARG-1393 ARG-1321 CIS PIU SAT PCH YAP sf SFB aa LVI do ARG-1158 lf dmo RIG MAC BAI -3-2 -1 0 1 2 3 axes 2 and 3 ac
A. franciscana A. persimilis 2n=41vs. 42 Chaxas Convento Llamara Pichilemu Salar de Atacama Los Vilos Yape
From local to a global situation A. persimilis close to the ancestral species differentiated in the Mediterranean. Founder/bottle neck event in Argentina. A. franciscana originated from A. persimilis at a later stage. Chilean A. franciscana separated from the rest? e.g., local populations retain peculiar characteristics or markers as compared to the overall Artemia biodiversity? How results relate to geographic factors?
Concerted action Cysts bank = different populations available for comparison (origin, time and pattern of divergence, etc). Formal (workshops) & informal discussions Training: new tools to shed light on old problems
Concerted action = new markers
RFLP,s
SEM observations on the Chilean populations Work done by Professor Graziella Mura, Italy
Iquique Llamara Torres del Paine Buenos Aires
Pichilemu Rinconada Laguna Cisne La Villa, PCH
Pichilemu Pichilemu Convento Cahuil
Contribution from outside the project: DNA sequencing mitdna (cytochrome c oxidase subunit I, CO-I) sequenced using primers pairs LCO1490 and HCO2198 (Folmer et al. 2001). Comparison with a GeneBank sequence (A. franciscana, accession nr. X69067) confirms that we obtained a 658 bp fragment of the CO-I gene n= 195 individuals from 12 populations from six species.
Country Locality Specie Haplotypes Abbreviation or ARC code Chile Salar Llamara A. franciscana 4 LLA El Convento A. franciscana 4 CON Pichilemu unknown 3 PIC Laguna Amarga A. persimilis 4 AMA Laguna de Los Cisnes A. persimilis 2 CIS Argentina A. persimilis 3 PER Brasil Macao A. franciscana 3 MAC United States San Francisco Bay A. franciscana 1 SFB Egypt Qarun Lake A. parthenogenetica 3 QAR 1118 Wadi Narun A. salina 2 WAD 1290 Namibia Vineta Swakopmund A. parthenogenetica 3 VIN 1186 Greece Citros, Pieria A. parthenogenetica 4 CIT 1280 Kalloni A. parthenogenetica 3 KAL 1421 China Aibi Lake, Xinjiang A. parthenogenetica 2 AIB 1236 Tiencsin A. sinica? 2 TIE Russia Kuchuksoe Lake A. parthenogenetica 2 KUC 1389 Turkmenistan Karabogaz-gol A. parthenogenetica 2 KAR 1407 Italy Margherita di Savoia A. parthenogenetica 3 MAR 1436
Diversification of saltwork activity by the semi-intensive culture of Artemia for cysts production in La Villa Pichilemu, VI Region Founded by: FIA (Foundation for Agriculture Innovation) To offer an alternative economic activity to salt-workers. This historical pre- Hispanic activity is virtually disappearing due to low prize and quality of the harvested salt.
The Project step by step Modification of salt-work tanks for Artemia production Algal blooms Characterisation of the strain Laboratory in field Cysts and biomass harvest certificate (ARC, Belgium and CECTA, Chile) Salt quality evaluation Workshop organisation for technology transference and regional diffusion Larviculture network with Chilean enterprises cultivating marine fishes Trip to Salt-works of Brazil (Dr. M. Camara)
How much do we know now? Contribution to a key scientific problem from a key organism (an extremist, or an aquatic Drsophila ). Trend to build up high interpopulation differences, so every location in the world must have a distinctive trait. New tools (genetic markers) to tackle newly discovered problems Emphasis on problems/hypothesis
What basal penis and the spine-like projections have to say? Basal penis similar in all localities except Pichilemu. 3 groups of populations are separated by the spine-like projections: 1) very developed spines (RIN, Cahuil, Chaxa, Llamara); 2) developed spines but long and thin (La Villa, Convento, Los Vilos; 3) spines of intermediate size: Cisnes, Laguna Amarga, Torres del Paine Spine ornamentation and pattern. Some recall the classical pattern observed for most non Mediterranean bisexuals (Convento, Cahuil, Llamara). Pichilemu is a very controversial case : it has multiple or single spines. Possibly mixed populations