SGER: Isolation and Characterization of Rapidly-Evolving Human Genes

近年来出现的一个令人惊讶的事实是，人类和黑猩猩在基因上有很大的相似性。98%的人类单拷贝DNA（遗传的遗传物质）与黑猩猩的DNA非常相似，当在试管中适当的条件下混合在一起时，它们形成了人类-黑猩猩的杂交DNA分子。Ruvolo博士将研究人类DNA中2%的不与黑猩猩DNA形成杂交分子的部分。因为所有DNA中只有一小部分是由基因（蛋白质编码单位）组成的，所以要回答的第一个问题是，在这2%的“人类特异性”DNA部分中是否存在任何基因。如果有，它们将通过DNA测序来表征。如果没有，那么人类和黑猩猩之间最不同的基因仍然可以从其他98%的人类DNA中分离出来，并通过DNA测序来类似地表征。无论哪种情况，鲁沃罗博士都将分离出人类和黑猩猩之间最大差异的基因。这些DNA序列将通过计算机搜索技术与所有已知的DNA序列进行比较，以测试它们是否与任何已知基因相似，以及以何种方式相似。这项研究是重要的，因为它发展了一个通用的方法来鉴定基因之间的最大差异密切相关的物种。这类基因在种群生物学和系统生物学中很有用，可以用来确定种群和物种之间的关系。该方法的扩展可允许分离生物体群共有的基因，例如“灵长类特异性”或“哺乳动物特异性”基因。分离人类进化最快的基因有助于将人类基因组划分为古代和现代两个部分。

A surprising fact that has emerged in recent years is the great degree of genetic similarity between humans and chimpanzees. Ninety-eight percent of human single-copy DNA (the inherited genetic material) is so similar to chimpanzee DNA that it forms hybrid human-chimpanzee DNA molecules when mixed together under appropriate conditions in a test tube. Dr. Ruvolo will study the 2% of human DNA which does not form hybrid molecules with chimpanzee DNA. Because only a fraction of all DNA consists of genes (protein-coding units), the first question to answer is whether there are any genes in this 2% "human- specific" DNA fraction. If there are, they will be characterized by DNA sequencing. If not, then the genes most different between humans and chimpanzees can still be isolated from the other 98% of human DNA and similarly characterized by DNA sequencing. In either case, Dr. Ruvolo will isolate those genes maximally different between humans and chimpanzees. These DNA sequences will be compared with all known DNA sequences by computer search techniques to test whether, and in what way, they resemble any known genes. This research is important because it develops a general method for identifying genes maximally different between closely- related species. Such genes are useful in population biology and in systematics for determining how groups and species are related to one another. Extension of this method may allow isolation of genes common to groups of organisms, such as "primate-specific" or "mammal-specific" genes. Isolation of the most rapidly- evolving genes in humans can help partition the human genome into ancient and modern segments.