how and why chromosome inversions evolve如何以及为什么染色体倒置进化.pdfVIP

Primer 1 How and Why Chromosome Inversions Evolve Mark Kirkpatrick* Section of Integrative Biology, University of Texas, Austin, Texas, United States of America Alfred Sturtevant, who invented genetic mapping while still an pair of coexisting biological species on the other. Within each of undergraduate, published the first evidence of a chromosomal the two species, the normal rules of Mendelian inheritance apply. inversion in 1921 [1]. He suggested then, and later proved, that Between them, though, there is little genetic exchange, save for an they have a dramatic effect on transmission: when heterozygous, occasional hybridization event (like the rare recombination inversions suppress recombination. Over the next half century, between inverted and uninverted chromosomes). Ecological inspired largely by Dobzhansky and his coworkers, much of competition between the two species (like the fitness differences empirical population genetics devoted itself to studying the between the two chromosome forms) can either result in abundant polymorphisms within and fixed differences of inver- coexistence of the two species (like a stable polymorphism) or sions between species of Drosophila [2]. Starting in the 1970s, this the replacement of one species by the other (like fixation of the rich literature largely sank from view with the rise of biochemical ancestral or inverted chromosomal form). and then molecular genetics. But inversions are ascendant again. Comparative genomics is now revealing that chromosomes are far How Do Inversions Evolve? more structurally fluid than even Dobzhansky dared to suppose. Where class