Evolution of New Genes in Drosophila

这些实验的目的是描述Finnegan基因的基本生物学特性，这是一种在果蝇中从Adh遗传而来的新基因，并在果蝇中找到从Adh遗传而来的新基因的其他例子。这些数据将提供对新功能进化的一般模式和过程的第一次洞察，并为新功能进化的进一步实验提供原材料。尽管它在进化中具有明显的重要性，但在遗传水平上对进化新颖性的起源和阐述却知之甚少。我们对这个关键问题缺乏洞察力，至少可以归结为三个缺口。首先，很少有已知的基因具有最近进化功能的例子，然而，正是在这样的例子中，我们应该有最好的机会了解新基因的起源和功能分化的早期阶段的机制。其次，由于许多例子涉及基本细胞功能基因的古老重组（如外显子洗牌），通常很难想象选择压力是如何驱动分子进化新颖性的。最后，由于没有协调一致的努力来寻找具有最近进化功能的基因，因此没有办法了解这些事件有多普遍，不知道它们的系统发育分布，不了解它们与生态因素的相关性，也不了解决定特定基因或基因类型的进化路径的一般原则。

The goals of these experiments are to describe the basic biology of Finnegan, a novel gene descended from Adh in the repleta group of Drosophila, to find other examples of new genes descended from Adh in Drosophila. These data will provide the first insight into general patterns and processes in the evolution of new function and provide the raw material for further experiments on evolution of novel function.Despite its obvious importance in evolution, the origin and elaboration of evolutionary novelty at the genetic level is only poorly understood. Our lack of insight into this key problem can be attributed to at least three gaps. First there are few known examples of genes having a recently evolved function, yet it is such cases where we should have the best chance of understanding the mechanisms responsible for the origins and early stages of functional divergence of new genes. Second, it is often difficult to imagine how the selective pressures driving molecular evolutionary novelty, might be inferred since many examples involve ancient reorganization (e.g., exon shuffling) of basic cell function genes. Finally, since there has been no concerted effort to search for genes with recently evolved function there is no way to understand how common such events are, no knowledge of their phylogenetic distribution, no understanding of their correlations with ecological factors, and no understanding of the general principles determining the evolutionary paths open to particular genes or types of genes.