Naya Daniel E, Veloso Claudio, Sabat Pablo, Bozinovic Francisco
Center for Advanced Studies in Ecology and Biodiversity, and Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
J Exp Zool A Ecol Genet Physiol. 2009 Apr 1;311(4):270-7. doi: 10.1002/jez.525.
One of the most fundamental questions in organismal ecology is how animals work in a continuously changing environment. In order to contribute to the current understanding of this question, this study evaluated seasonal changes in digestive enzymes activities, organs size, and energy reserves in Liolaemus nigroviridis, a medium-size lizard that inhabit extreme environments in the Andes range. We found that digestive enzymes (trehalase, maltase, and aminopeptidase-N) hydrolytic activities, dry masses of digestive organs and liver, and energy reserve (dry mass of fat bodies and tail energy density) were greater during summer than during winter months. By contrast, dry mass of the kidneys, lungs, heart, and gonads were greater during winter (though significance was reach only for the last two organs). In summary, obtained results reinforce the idea that hibernation is connected with phenotypic adjustments at different organizational levels, which in turn, potentially affects rates of energy acquisition and expenditure, organisms' fitness, and, ultimately, ecological and evolutionary success of species living in highly seasonal environments. We suggest that, owing to the pressing need to explain and predict the impact of climatic change on the biota, more studies destined to determine the levels and limits of physiological flexibility are necessary.
个体生态学中最基本的问题之一是动物如何在不断变化的环境中生存。为了有助于当前对这个问题的理解，本研究评估了绿黑安乐蜥（Liolaemus nigroviridis）消化酶活性、器官大小和能量储备的季节性变化，绿黑安乐蜥是一种栖息在安第斯山脉极端环境中的中型蜥蜴。我们发现，消化酶（海藻糖酶、麦芽糖酶和氨肽酶 - N）的水解活性、消化器官和肝脏的干质量以及能量储备（脂肪体干质量和尾部能量密度）在夏季比冬季月份更高。相比之下，肾脏、肺、心脏和性腺的干质量在冬季更大（尽管仅后两个器官达到显著水平）。总之，获得的结果强化了这样一种观点，即冬眠与不同组织水平的表型调整有关，这反过来又可能影响能量获取和消耗的速率、生物体的适应性，并最终影响生活在高度季节性环境中的物种的生态和进化成功。我们建议，由于迫切需要解释和预测气候变化对生物群的影响，有必要进行更多旨在确定生理灵活性水平和限度的研究。
