RT Journal
A1 Betrán, Esther
A1 Thornton, Kevin
A1 Long, Manyuan
T1 Retroposed New Genes Out of the X in Drosophila

JF Genome Research 
JO Genome Research 
YR 2002 
FD December 01 
VO 12 
IS 12 
SP 1854 
OP 1859 
DO 10.1101/gr.604902 
UL http://genome.cshlp.org/content/12/12/1854.abstract 
AB New genes that originated by various molecular mechanisms are an essential component in understanding the evolution of genetic systems. We investigated the pattern of origin of the genes created by retroposition in Drosophila. We surveyed the wholeDrosophila melanogaster genome for such new retrogenes and experimentally analyzed their functionality and evolutionary process. These retrogenes, functional as revealed by the analysis of expression, substitution, and population genetics, show a surprisingly asymmetric pattern in their origin. There is a significant excess of retrogenes that originate from the X chromosome and retropose to autosomes; new genes retroposed from autosomes are scarce. Further, we found that most of these X-derived autosomal retrogenes had evolved a testis expression pattern. These observations may be explained by natural selection favoring those new retrogenes that moved to autosomes and avoided the spermatogenesis X inactivation, and suggest the important role of genome position for the origin of new genes.[The sequence data from this study have been submitted to GenBank under accession nos. AY150701–AY150797. The following individuals kindly provided reagents, samples, or unpublished information as indicated in the paper: M.-L. Wu, F. Lemeunier, and P. Gibert.]