Genome evolution in plethodontid salamanders: molecular and modeling-based analyses of genomic gigantism

不同的动物物种有不同数量的DNA（也称为DNA）。不同的基因组大小）。虽然更复杂的动物会有更多的DNA似乎是合乎逻辑的，但这不是真的;事实上，阿米巴比人类有更多的DNA。在脊椎动物中，鸟类的DNA最少，蝾螈的DNA最多;蝾螈的DNA是人类的25倍，是鸟类的50倍。令人惊讶的是，大多数物种（包括人类和蝾螈）的DNA并不存在于构成生物体发育或功能的基因中。相反，它是高度重复的DNA序列，在生物体的基因组中繁殖和传播，有时甚至会伤害生物体。因此，这些重复序列被称为“寄生”或“自私”的DNA。这个项目将确定蝾螈自私的DNA，并研究为什么蝾螈比其他脊椎动物有更多的DNA。这些目标将通过对几种蝾螈物种的部分基因组进行测序来实现，这些物种的总DNA含量不同。了解塑造基因组的力量，包括人类基因组，是生物学的一个主要目标。由于蝾螈在基因组大小和自私DNA的数量方面是如此的离群，将它们的基因组与包括人类在内的已被充分研究的物种的基因组进行比较，将澄清为什么不同动物的基因组如此不同。该项目还包括对科罗拉多的小学和中学的推广部分。学生们总是非常有兴趣了解他们自己的大部分DNA都有“自己的生命”，而且它的功能（如果有的话）在很大程度上是未知的。

Different animal species have different amounts of DNA (a.k.a. different genome sizes). Although it seems logical that more complex animals would have more DNA, this is not true; in fact, amoebas have more DNA than humans. Within vertebrates, birds have the least DNA and salamanders have the most; salamanders have 25 times as much DNA as humans and 50 times as much as birds. Surprisingly, most species' DNA (including humans and salamanders) is not in genes that underlie development or function of the organism. Rather, it is highly repetitive DNA sequences that multiply and spread throughout an organism's genome, sometimes even harming the organism. Because of this, these repetitive sequences are nicknamed "parasitic" or "selfish" DNA. This project will identify the selfish DNA in salamanders and examine why salamanders have so much more DNA than other vertebrates. These goals will be met by sequencing part of the genome of several salamander species that differ in total DNA content.Understanding the forces that shape genomes, including the human genome, is a major goal of biology. Because salamanders are such outliers in terms of genome size and amount of selfish DNA, comparing their genomes to those of well-studied species, including humans, will clarify why genomes of different animals are so different. The project also includes an outreach component to elementary and high schools in Colorado. Students are always extremely interested to learn that most of their own DNA has a "life of its own" and that its function, if any, is largely unknown.