Dr Edson Sandoval-Castellanos

Postdoctoral Researcher

Department of Bioinformatics and Genetics
Swedish Museum of Natural History
Box 50007, SE-104 05 Stockholm
SWEDEN

Email: edsonsandovalc@outlook.com

 

Scholar: [Papers in Google Scholar]

 

Research

My general research interests focus on the broader discipline of evolutionary genetics and genomics. Both my past and current research aims to elucidate the main evolutionary forces and the ecological factors that govern the evolutionary dynamic of the genetic diversity of several types of organisms.

 

CLIMIGRATE

The main goal of this project is to enhance conservation efforts for European wild mammals by establishing the tempo and mode of population response to climate change. We are using ancient DNA from nine mammal species to try to understand whether certain species are more likely than others to move with their habitat as the geographical range of that habitat changes.
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My participation in the CLIMIGRATE program involves the analysis of molecular data and testing evolutionary hypotheses related to molecular patterns associated with climate change. This will be carried out using computer-simulation based methods, specifically, Approximate Bayesian Computation (ABC). The analysis of real datasets will be used as a feedback for improving existing mathematical and computational analysis.

My work will additionally employ the main climate predictors, species distribution and migration patterns for designing simulation programs that integrate the ecological modelling output with the molecular analyses. These can then be used to forecast how climate change can alter species distributions.

Collaborators

Dr Ian Barnes (Royal Holloway, University of London)
Prof Nigel Yoccoz (University of Tromsø)
Dr Love Dalén (University of Stockholm)

Population Genetics of the Humboldt Squid (Dosidicus gigas)

 

Humboldt, or Jumbo, squid sustains one of the largest invertebrates’ fisheries in the world. However despite their economical importance, very little is known about the population genetics of this taxa. Our study was one of the first studies tackling the genetic structure and demographic history of this organism. We showed that D. gigas, whose distribution is constrained to the Eastern Pacific, has two well defined genetic stocks: separated into southern and the northern populations. The study showed that fine scale genetic structure could be explained by the effect of a post-glacial expansion and ocean currents acting as barriers or enhancers of/to the gene flow.

Supervisor (PhD): Dr. Manuel Uribe Alcocer.

Plant-herbivores coevolution

Plants have two different defence systems against herbivores: the resistance and the tolerance. Both are present in many natural populations contradicting some theoretical results that argument that having two defence systems duplicates costs. My research explored the possible interaction of mating system (which refers to the type of reproduction present in a population: by selfing, outcrossing or a mix) with the defence systems by means of computer simulations. The results indicated that, under the proposed model, not only the costs determine the expectation of mixed mating systems but the type of selfing in the populations and the specific interaction of genotypes between plats and herbivores. Also, selfing alleles presented behaviour proper of “selfish genes”.

Supervisor (Postdoctoral fellow): Dr. Juán Núñez Farfán.

Temporal Tests of Allele Frequencies

All microevolutionary processes produce changes in allele frequencies; understanding how allele frequencies change through time is important. However, researchers rarely analyse the observed temporal changes in allele frequencies in a statistical framework. In this work I presented a MonteCarlo approach for contrasting a null hypothesis of changes due purely to stochastic forces (sampling error and genetic drift) against an alternate hypothesis of the action of evolutionary or external factors impacting the allele frequencies. The test proved to be useful under a variety of situations especially for a large number of alleles and samples.

Leopard spotting in ancient horses

The genetic basis of the coat colour in horses has been well described by many studies. In this collaboration study with people from many institutions across Europe, I complemented a wide archaeological work of recovering samples from ages ranging from the Pleistocene (> 20 000 years bp) up to medieval times, and the laboratory work of pyrosequencing and genotyping 96 specimens sampled along 31 Eurasian localities. An ABC analysis was performed with the genetic data, showing that the allele associated to a polymorphism responsible of the coat pattern known as “leopard” spotting, which is also responsible of a congenital stationary night blindness (CSNB), presented changes congruent with changes in the selection regimes operating in the Pleistocene, Copper age and Early Bronze age.

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Brief CV

2011-present……Postdoctoral researcher, Swedish Museum of Natural History
2008-2010………Postdoctoral researcher, Ecology Institute, National Autonomous University of Mexico
2001-2007………Ph.D. in Biological Sciences, Faculty of Sciences, National Autonomous University of Mexico
1995-2001………B.Sc. (Biology), Faculty of Sciences, National Autonomous University of Mexico

Publications

Pruvosta, M., Bellonec, R., Benecke, N., Sandoval-Castellanos, E., Cieslak, M., Kuznetsova, T., Morales-Muñiz, A., O'Connor, T., Reissmann, M., Hofreiter, M and Ludwig, A. ( 2011). Genotypes of predomestic horses match phenotypes painted in Paleolithic works of cave art. Proc. Natl. Acad. Sci. USA. 108(46): 18626-18630.

Sandoval-Castellanos E. (2010) Testing temporal changes in allele frequencies: a simulation approach. Genetics Research 92: 309-320.

Sandoval-Castellanos E.
, Uribe-Alcocer M, Díaz-Jaimes P (2010) Population genetic structure of the Humboldt squid (Dosidicus gigas d’Orbigny, 1835) inferred by mitochondrial DNA analysis. Journal of Experimental Marine Biology and Ecology 385: 73-78.

Sandoval-Castellanos E.
, Uribe-Alcocer M, Díaz-Jaimes P (2009) Lack of genetic differentiation among size groups of jumbo squid (Dosidicus gigas). Ciencias Marinas 35: 419-428.

Sandoval-Castellanos E.
, Uribe-Alcocer M, Díaz-Jaimes P (2007) Population genetic structure of jumbo squid (Dosidicus gigas) evaluated by RAPD analysis. Fisheries Research 83: 113-118.

Díaz-Jaimes P, Sandoval-Castellanos E., Uribe-Alcocer M (2007) Comparative population structure of three snook species (Teleostei: Centropomidae) from the eastern central Pacific. Ichthyological Research 54:380-387.

Software

Sandoval-Castellanos E. TAFT version 2.3: Temporal Allele Frequencies Test. Available at: http://sites.google.com/site/egenevol/home/programas.

Sandoval-Castellanos E.
HerbSim version 0.76: A program for simulation of genetic coevolving systems of plants and herbivores. Available at: http://sites.google.com/site/egenevol/home/programas.

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