By considering the recent finding that unequal crossing over and other molecular interactions are contributing to the evolution of multigene families, a model of the origin of repetitive genes was studied by Monte Carlo simulations. Starting from a single gene copy, how genetic systems evolve was examined under unequal crossing over, random drift and natural selection. Both beneficial and deter...

Five independent duplications of the acid-phosphatase (aphtase) structural gene (acpl) were recovered from chemostat populations of S. cerevisiae that were subject to selection for in vivo hyper-aphtase activity. Two of the duplications arose spontaneously. Three of them were induced by UV. All five of the duplication events involved the transpositioning of the aphtase structural gene, acpl, an...

Gene duplication is key to molecular evolution in all three domains of life and may be the first step in the emergence of new gene function. It is a well recognized feature in large DNA viruses, but has not been studied extensively in the largest known virus to date, the recently discovered Acanthamoeba Polyphaga Mimivirus. Here we present a systematic analysis of gene and genome duplication ev...

Gene duplication is key to molecular evolution in all three domains of life and may be the first step in the emergence of new gene function. It is a well-recognized feature in large DNA viruses but has not been studied extensively in the largest known virus to date, the recently discovered Acanthamoeba polyphaga Mimivirus. Here, I present a systematic analysis of gene and genome duplication eve...

All vertebrates possess anatomical features not seen in their closest living relatives, the protochordates (tunicates and amphioxus). Some of these features depend on developmental processes or cellular behaviours that are again unique to vertebrates. We are interested in the genetic changes that may have permitted the origin of these innovations. Gene duplication, followed by functional diverg...

Different models of gene family evolution have been proposed to explain the mechanism whereby gene copies created by gene duplications are maintained and diverge in function. Ohta proposed a model which predicts a burst of nonsynonymous substitutions following gene duplication and the preservation of duplicates through positive selection. An alternative model, the duplication-degeneration-compl...

gastrointestinal duplications are rare congenital malformations and they may vary greatly in presentation, size, location and symptoms. the presence of ectopic gastric mucosa (egm) in them is not common and they are difficult to diagnose prior to surgery. we present the case of a child with long intestinal duplication with ectopic gastric mucosa who presented with just severe anaemia and delaye...

We have performed a large-scale analysis of amino acid sequence evolution after gene duplication by comparing evolution after gene duplication with evolution after speciation in over 1,800 phylogenetic trees constructed from manually curated alignments of protein domains downloaded from the PFAM database. The site-specific rate of evolution is significantly altered by gene duplication. A signif...