Itonaga Keisuke, Jones Susan M, Wapstra Erik
School of Zoology, Private Bag 05, University of Tasmania, Hobart, Tasmania 7001, Australia.
Physiol Biochem Zool. 2012 May-Jun;85(3):231-42. doi: 10.1086/665567. Epub 2012 Apr 3.
Net energy availability depends on plasma corticosterone concentrations, food availability, and their interaction. Limited net energy availability requires energy trade-offs between self-maintenance and reproduction. This is important in matrotrophic viviparous animals because they provide large amounts of energy for embryos, as well as self-maintenance, for the extended period of time during gestation. In addition, gravid females may transmit environmental information to the embryos in order to adjust offspring phenotype. We investigated effects of variation in maternal plasma corticosterone concentration and maternal food availability (2 × 2 factorial design) during gestation on offspring phenotype in a matrotrophic viviparous lizard (Pseudemoia entrecasteauxii). Subsequently, we tested preadaptation of offspring phenotype to their postnatal environment by measuring risk-averse behavior and growth rate using reciprocal transplant experiments. We found that maternal net energy availability affected postpartum maternal body condition, offspring snout-vent length, offspring mass, offspring performance ability, and offspring fat reserves. Females treated with corticosterone allocated large amounts of energy to their own body condition, and their embryos allocated more energy to energy reserves than somatic growth. Further, offspring from females in high plasma corticosterone concentration showed compensatory growth. These findings suggest that while females may be selfish when gestation conditions are stressful, the embryos may adjust their phenotype to cope with the postnatal environment.
净能量可利用性取决于血浆皮质酮浓度、食物可利用性及其相互作用。有限的净能量可利用性要求在自我维持和繁殖之间进行能量权衡。这在母体营养型胎生动物中很重要，因为它们在妊娠期的较长时间内既要为胚胎提供大量能量，也要维持自身。此外，怀孕的雌性可能会向胚胎传递环境信息，以调整后代的表型。我们研究了妊娠期母体血浆皮质酮浓度变化和母体食物可利用性（2×2析因设计）对一种母体营养型胎生蜥蜴（Entrecasteaux氏伪莫氏蜥）后代表型的影响。随后，我们通过使用 reciprocal transplant实验测量规避风险行为和生长速率，测试了后代表型对其产后环境的预适应。我们发现母体净能量可利用性影响产后母体身体状况、后代吻肛长度、后代体重、后代性能能力和后代脂肪储备。用皮质酮处理的雌性将大量能量分配给自身身体状况，而它们的胚胎将更多能量分配给能量储备而非体细胞生长。此外，血浆皮质酮浓度高的雌性所产后代表现出补偿性生长。这些发现表明，虽然在妊娠条件紧张时雌性可能会自私，但胚胎可能会调整其表型以应对产后环境。
