Russell Anthony P, Lynn Sabrina E, Powell G Lawrence, Cottle Andrew
Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4.
Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4.
Zoology (Jena). 2015 Jun;118(3):183-91. doi: 10.1016/j.zool.2014.12.003. Epub 2015 Feb 24.
The tail of many species of lizard is used as a site of fat storage, and caudal autotomy is a widespread phenomenon among lizards. This means that caudal fat stores are at risk of being lost if the tail is autotomized. For fat-tailed species, such as the leopard gecko, this may be particularly costly. Previous work has shown that tail regeneration in juveniles of this species is rapid and that it receives priority for energy allocation, even when dietary resources are markedly reduced. We found that the regenerated tails of juvenile leopard geckos are more massive than their original counterparts, regardless of dietary intake, and that they exhibit greater amounts of skeleton, inner fat, muscle and subcutaneous fat than original tails (as assessed through cross-sectional area measurements of positionally equivalent stations along the tail). Autotomy and regeneration result in changes in tail shape, mass and the pattern of tissue distribution within the tail. The regenerated tail exhibits enhanced fat storage capacity, even in the face of a diet that results in significant slowing of body growth. Body growth is thus sacrificed at the expense of rapid tail growth. Fat stores laid down rapidly in the regenerating tail may later be used to fuel body growth or reproductive investment. The regenerated tail thus seems to have adaptive roles of its own, and provides a potential vehicle for studying trade-offs that relate to life history strategy.
许多蜥蜴物种的尾巴被用作脂肪储存部位，尾部自割在蜥蜴中是一种普遍现象。这意味着如果尾巴自割，尾部脂肪储存就有丢失的风险。对于肥尾物种，如豹纹守宫，这可能代价尤为高昂。先前的研究表明，该物种幼体的尾巴再生迅速，并且即使在饮食资源显著减少时，它在能量分配上也享有优先权。我们发现，无论饮食摄入量如何，幼年豹纹守宫再生后的尾巴都比原来的尾巴更粗壮，而且与原来的尾巴相比，它们在骨骼、内部脂肪、肌肉和皮下脂肪方面都表现出更多（通过沿尾巴位置相当的部位的横截面积测量来评估）。自割和再生会导致尾巴形状、质量以及尾巴内部组织分布模式的变化。即使在导致身体生长显著减缓的饮食条件下，再生后的尾巴仍表现出增强的脂肪储存能力。因此，身体生长是以快速的尾巴生长为代价的。在再生尾巴中迅速积累的脂肪储存随后可能用于促进身体生长或生殖投资。因此，再生后的尾巴似乎有其自身的适应性作用，并为研究与生活史策略相关的权衡取舍提供了一个潜在的载体。
