Kimberling D N, Ferreira A R, Shuster S M, Keim P
Department of Biology, Flagstaff, Arizona 86011, USA.
Mol Ecol. 1996 Aug;5(4):521-9.
Amphibians in the south-western United States are currently experiencing population declines. Causal explanations for these population changes as well as the implementation of sound management practices requires an understanding of the genetic structure of natural amphibian populations. To this end, we estimated genetic differences within and among seven isolated populations of northern leopard frogs, Rana pipiens, from Arizona and southern Utah using random amplified polymorphic DNA (RAPD) analyses. Fourteen arbitrarily designed primers detected 38 polymorphic loci in 85 individual frogs. Three types of population structure were observed in this study. (i) Two populations showed low genetic diversity (D = 0.10 and 0.04) and may have been established by relatively recent events. (ii) Two were not genetically distinct and exhibited a high degree of within-population diversity (D = 0.35). The possibility of gene flow between these populations is high due to their geographical proximity and their shared genetic structure. (iii) Three populations were genetically distinct from each other and the other populations, and exhibited intermediate within-population variation (D = 0.19, 0.17, 0.14). Genetic distances among the seven populations ranged from 0.00 to 0.20, suggesting that some of these leopard frog populations are genetically distinct. Although based on relatively small samples, these data suggest that leopard frog populations in the south-west are likely to represent unique genetic entities worthy of conservation. The management implications of these results are that isolated leopard frog populations should be evaluated on an individual basis to best preserve them.
美国西南部的两栖动物目前正经历种群数量下降。对于这些种群变化的原因解释以及合理管理措施的实施，需要了解自然两栖动物种群的遗传结构。为此，我们使用随机扩增多态性DNA（RAPD）分析，估计了来自亚利桑那州和犹他州南部的七个分离的北美豹蛙种群内部和之间的遗传差异。14个任意设计的引物在85只个体蛙中检测到38个多态位点。本研究观察到三种类型的种群结构。（i）两个种群显示出低遗传多样性（D = 0.10和0.04），可能是由相对近期的事件建立的。（ii）两个种群在遗传上没有差异，并且表现出高度的种群内多样性（D = 0.35）。由于它们地理位置接近且共享遗传结构，这些种群之间基因流动的可能性很高。（iii）三个种群在遗传上彼此不同且与其他种群不同，并且表现出中等的种群内变异（D = 0.19、0.17、0.14）。七个种群之间的遗传距离在0.00至0.20之间，表明其中一些豹蛙种群在遗传上是不同的。尽管基于相对较小的样本，但这些数据表明西南部的豹蛙种群可能代表值得保护的独特遗传实体。这些结果的管理意义在于，应逐个评估孤立的豹蛙种群，以最好地保护它们。
