The Influence of Genotype on Vertebrate Survivorship

这个项目将解决基因对脊椎动物死亡率的影响。特别是，将考虑两种类型的基因：微卫星和主要组织相容性复合体(MHC)基因。微卫星没有已知的功能，可能是“垃圾”DNA，但在脊椎动物基因组中出现了数千次。相反，MHC基因通常集中在基因组的特定区域，并直接参与免疫反应。老虎火蜥蜴将被研究(繁殖、基因分型和监测)，因为1)它们是免疫学家和对嗅觉感兴趣的神经学家的模型；2)它们是长寿生物，拥有大量的家庭，提供了研究死亡率/存活率所需的样本大小；3)火蜥蜴具有保护价值，一些科学家认为全球两栖动物数量的下降是由于MHC相关病原体。该项目的结果可能会影响我们对包括人类在内的其他脊椎动物胚胎死亡率的看法。在哺乳动物这样的胎生(活产)物种中，由于母婴不相容而导致的自然流产很难研究。然而，在内部受精但外部发育的火蜥蜴身上，这种趋势可能更容易被记录下来。此外，这项研究将确定基于MHC的配偶选择(如在人类、啮齿动物和鱼类中发现的)是否也存在于两栖动物中。

This project will address the influence of genotype on vertebrate mortality. In particular, two types of genes will be considered: microsatellites and major histocompatibility complex (MHC) genes. Microsatellites have no known function and may be "junk" DNA, but occur thousands of times in vertebrate genomes. Conversely, MHC genes are usually consolidated in a particular region of the genome and are directly involved in the immune response. Tiger salamanders will be studied (bred, genotyped, and monitored) because 1) they serve as models for immunologists as well as for neurologists interested in olfaction; 2) they are long-lived creatures that have large families which provide the sample sizes needed to study mortality/survivorship; and 3) salamanders are of conservation interest, and some scientists think the global decline in amphibian populations is due to MHC-related pathogens. The results of this project could influence our thoughts on embryo mortality in other vertebrates, including humans. In viviparous (live-bearing) species like mammals, spontaneous abortion attributable to maternal/fetal incompatibility is difficult to study. However, such trends may be easier to document in salamanders that have internal fertilization but external development. Furthermore, this study will determine if MHC-based mate choice (as found in humans, rodents, and fishes) also exists in amphibians.