Fernie Kim, Bortolotti Gary, Drouillard Ken, Smits Judit, Marchant Tracy
Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B3, Canada.
Environ Toxicol Chem. 2003 Nov;22(11):2688-94. doi: 10.1897/02-551.
The development of second-generation nestling American kestrels (Falco sparverius) was altered by in ovo exposure of only one parent to polychlorinated biphenyls (PCBs). Polychlorinated biphenyls appear to alter nestling development through both maternally and paternally mediated effects. In 1998, F0 parent kestrels consumed approximately 5 to 7 microg total PCBs/g bird/d (Aroclors 1248:1254: 1260) for approximately 100 d prior to eggs hatching; these eggs, containing total PCB concentrations of 34.1 microg/g, produced 13 F1 offspring, which were then paired in 1999 with unexposed kestrels to examine developmental effects of maternal or paternal in ovo PCB exposure. Using a toxicokinetics model, eggs from the maternally exposed group had predicted PCB levels of 0.03 to 0.34 microg/g, with enriched higher chlorinated congeners. Polychlorinated biphenyl concentrations in eggs of all generations have recently been found in eggs and nestlings of free-ranging eagles. Consistent with the first generation, maternally exposed F2 females generally were larger, had altered growth rates, and delayed maximal growth and fledging compared with control females. Maternally exposed F2 males were heavier but had shorter bones, grew more quickly and earlier, and fledged 2 d later than control males. In the maternally exposed group, concentrations of plasma triiodothyronine were elevated in F2 females but suppressed in F2 males. Paternally exposed F2 hatchlings of both sexes were comparable in size to controls with the exception of having longer tarsi bones, but subsequently showed slower, delayed growth (both sexes) and fledging (females) and lower thyroxine concentrations (males). The alterations in thyroid hormones in the F2 generation are discussed in light of the enrichment of higher chlorinated PCB congeners and hydroxylated PCB congeners. The developmental changes in the kestrel nestlings are likely a function of several possible mechanisms involving maternal PCB deposition, parental behavior, and neurobehavioral and endocrine-thyroid function in nestlings.
仅让美洲红隼（Falco sparverius）的一方亲鸟在卵内接触多氯联苯（PCBs），会改变第二代雏鸟的发育情况。多氯联苯似乎通过母体和父体介导的效应来改变雏鸟的发育。1998年，F0代亲鸟在卵孵化前约100天，每天每克鸟体重摄入约5至7微克的总多氯联苯（Aroclors 1248:1254:1260）；这些卵的总多氯联苯浓度为34.1微克/克，产出了13只F1代后代，这些后代在1999年与未接触多氯联苯的红隼配对，以研究母体或父体卵内多氯联苯暴露的发育影响。使用毒代动力学模型，母体暴露组的卵预测多氯联苯水平为0.03至0.34微克/克，且高氯代同系物含量更高。最近在自由放养的鹰的卵和雏鸟中发现了各代卵中的多氯联苯浓度。与第一代一致，与对照雌性相比，母体暴露的F2代雌性通常体型更大，生长速率改变，最大生长和离巢时间延迟。母体暴露的F2代雄性体重更重，但骨骼较短，生长更快且更早，比对照雄性晚2天离巢。在母体暴露组中，F2代雌性的血浆三碘甲状腺原氨酸浓度升高，但F2代雄性则受到抑制。父体暴露的F2代两性雏鸟除跗骨较长外，体型与对照相当，但随后生长（两性）和离巢（雌性）较慢且延迟，雄性甲状腺素浓度较低。根据高氯代多氯联苯同系物和羟基化多氯联苯同系物的富集情况，讨论了F2代甲状腺激素的变化。红隼雏鸟的发育变化可能是多种可能机制的作用结果，这些机制涉及母体多氯联苯沉积、亲代行为以及雏鸟的神经行为和内分泌 - 甲状腺功能。
