Premium
Transgenerational retention and maternal transfer of selenium in Daphnia magna
Author(s) -
Lam Isaac K.S.,
Wang WenXiong
Publication year - 2006
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1897/05-631r.1
Subject(s) - selenium , daphnia magna , offspring , daphnia , transgenerational epigenetics , zoology , reproduction , biology , algae , cladocera , dry weight , scenedesmus obliquus , chemistry , botany , toxicity , ecology , pregnancy , zooplankton , organic chemistry , genetics
We examined transgenerational retention and maternal transfer of selenium (Se) in three consecutive generations (F 0 , F 1 , and F 2 ) of Daphnia magna. The F 0 generation was exposed to dietary selenium (as selenite) only, and the F 1 and F 2 generations received only the maternally derived selenium from F 0 and F 1 , respectively. Algal food Scenedesmus obilquus was radiolabeled with 0.56 μM Se, and the finial Se concentration in the algae was 115.6 μg Se/g dry weight. After 10 d feeding, the initial Se concentration in the F 0 prior to depuration was 0.72 μg Se/g wet weight. The Se retention within the same generation was comparable at different food concentrations, but it increased across the consecutive generations regardless of the food concentration, suggesting that Se elimination was dependent on the source of Se accumulation (dietary vs maternally derived). Retention was also comparable among different batches of offspring within the same generation. Reproduction rate increased with increasing food concentration but decreased across the successive batches in F 1 . The 10‐d overall maternal transfer efficiency increased with increasing food concentration in all generations. Approximately 19 to 24% of Se in F 0 was transferred maternally to F 1 during reproductive events, but the efficiency decreased considerably from F 1 to F 2 . Maternal transfer also decreased in the later batches of F 1 . The transfer efficiency to each neonate showed a negative relationship with food concentration in both F 0 and F 1 , suggesting that the Se transfer to the offspring was compromised by the reproduction rate. We concluded that dietary‐derived Se (from F 0 ) was more efficiently transferred to the offspring (F 1 ) than the maternally derived Se (from F 1 ) transferred to F 2 ; thus it is necessary to separate the dietary and maternal contributions to the overall Se accumulation in Daphnia .