Differential resistance to copper and mine drainage in Daphnia longispina: Relationship with allozyme genotypes

Abstract

Differential resistance to metal pollution in Daphnia longispina populations was reported in previous studies. In this work, we tried to determine if variation in polymorphic enzymes, often referred as being under metal selection, were related with differences in resistance to acute single- and mixed-metal exposure. Allozyme genotype of 20 putatively polymorphic enzymes, 48-h median lethal concentration (LC50) for copper, and median lethal time (LT50) for a 3% dilution of acid mine drainage (AMD) were determined for 24 lineages of D. longispina. The copper LC50s ranged from 29.3 to 226 microg/L, and the AMD LT50s ranged from 48 min to 25 h and 29 min, with a strong correlation between both end points. Five distinct multilocus genotypes were identified based on polymorphisms in glucose-6-phosphate isomerase, lactate dehydrogenase, malate dehydrogenase, nicotinamide adenine dinucleotide phosphate (NADP+), phosphoglucomutase, and peroxidase. No differences were found in average genotype sensitivity for both toxicity end points or in genotype frequencies between the resistant- and sensitive-lineage groups. The results obtained indicate that allozyme genotype is not associated with increased resistance to acute metal stress in D. longispina.

Life-history consequences of adaptation to pollution. “Daphnia longispina clones historically exposed to copper”

“…Hereafter, increasing fitness costs will be defined in terms of reduced reproductive output, growth rates and population growth and physiological costs in terms of increasing energy demand according to Shirley and Sibly (1999). Previous studies have reported that long term adaptation to acid main drainage did not affect genetic diversity of neutral markers in these D. longispina populations (Martins et al 2007;Martins et al 2009). In a quantitative genetic study testing up to 40 different clones for resistance to copper and zinc, Agra et al (2010) found only high degrees of resistance to copper in D. longispina clones from populations affected by S. Domingos acid drainage.…”

Testing hypotheses on the resistance to metals by Daphnia longispina: Differential acclimation, endpoints association, and fitness costs

“…Toxicity endpoints used in these correlations were those determined in the present study (reproduction EDil50 and EDil20 and growth EDil50 and EDil20 of AMD) and those already mentioned from previous studies [14,28,29] (Table 1). Toxicity endpoints used in these correlations were those determined in the present study (reproduction EDil50 and EDil20 and growth EDil50 and EDil20 of AMD) and those already mentioned from previous studies [14,28,29] (Table 1).…”

“…These lineages derived from two field populations, one inhabiting a reference site (pH 7.35, 236 mS/cm, dissolved oxygen 9.7 mg/L) and the other inhabiting an acid mine drainage (AMD) historically impacted site (pH 6.37, 295 mS/cm, dissolved oxygen 9.2 mg/L), located at the aquatic system of an abandoned cupric-pyrite mine (Mina de São Domingos, Southeast Portugal, 37840 0 N, 7830 0 W). In addition, their allozyme and microsatellite genotypes were characterized by Martins et al [28] and Silva et al [30], respectively. The clonal lineages for the present study were selected from a pool of 265 field-collected females [6], to cover a wide range of genetically determined resistance to lethal levels of AMD and Cu, which was previously characterized [28] using 6-to 24-h-old neonates at 19 to 218C, through the estimation of median lethal time values after exposure to a 3% dilution of AMD, and median lethal Cu concentrations after a 48-h exposure (Table 1).…”

Tolerance to Copper and to Salinity in Daphnia longispina: Implications within a Climate Change Scenario

“…Müller were selected to conduct this work: N91, N116, N31, E99 and E89 (Table 1 shows the allozyme and microsatellite profiles, determined by [23], [24], of these five clonal lineages). These lineages were derived from two field populations: one inhabiting a reference site, and the other inhabiting an acid mine drainage (AMD) historically impacted site; both located at the aquatic system of an abandoned cupric-pyrite mine (São Domingos mine, Southeast Portugal) [25].…”