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Asexuality and polyploidy in Daphnia from the tropical Andes
Author(s) -
Aguilera Ximena,
Mergeay Joachim,
Wollebrants An,
Declerck Steven,
Meester Luc De
Publication year - 2007
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.2007.52.5.2079
Subject(s) - biology , daphnia pulex , polyploid , asexuality , daphnia , ecology , lineage (genetic) , genetic diversity , arctic , zoology , crustacean , ploidy , population , genetics , gene , gender studies , sociology , human sexuality , demography
We assessed genetic variation at microsatellite loci within and among populations of the planktonic crustacean Daphnia pulex in 12 Bolivian Andean lakes, located above 4,000 m above sea level. Genetic analyses show that all populations consisted of obligately asexual lineages, a fact that was confirmed by observations from laboratory cultures. Moreover, microsatellite phenotypes indicate that these tropical lineages are polyploid. Levels of genetic diversity were comparable to those found in polyploid Daphnia from arctic regions, indicating a local origin rather than an accidental colonization from arctic regions. This is the first record of polyploid cladocerans in a tropical region. We suggest that their origination and abundance have probably been facilitated by the extreme environmental conditions in Andean lakes. Our analysis of multilocus genotype frequencies in relation to variation in environmental conditions indicates lineage sorting along a food availability and fish predation gradient.