DNA Sequence Variation among Conspecific Accessions of the Legume Coursetia caribaea Reveals Geographically Localized Clades Here Ranked as Species

AbstractNumerous cases of evolutionary trait loss and regain have been reported over the years. Here, we argue that such reverse evolution can also become apparent when trait expression is plastic in response to the environment. We tested this idea for the loss and regain of fat synthesis in parasitic wasps. We first show experimentally that the wasp Leptopilina heterotoma switches lipogenesis on in a fat-poor environment, and completely off in a fat-rich environment. Plasticity suggests that this species did not regain fat synthesis, but that it can be switched off in some environmental settings. We then compared DNA sequence variation and protein domains of several more distantly related parasitoid species thought to have lost lipogenesis, and found no evidence for non-functionality of key lipogenesis genes. This suggests that other parasitoids may also show plasticity of fat synthesis. Last, we used individual-based simulations to show that a switch for plastic expression can remain functional in the genome for thousands of generations, even if it is only used sporadically. The evolution of plasticity could thus also explain other examples of apparent reverse evolution.

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Capturing genomic signatures of DNA sequence variation using a standard anonymous microarray platform

Nucleic Acids Research ◽

10.1093/nar/gkl478 ◽

2006 ◽

Vol 34 (18) ◽

pp. e121-e121 ◽

Cited By ~ 5

Author(s):

C. H. Cannon ◽

C. S. Kua ◽

E. K. Lobenhofer ◽

P. Hurban

Keyword(s):

Dna Sequence ◽

Sequence Variation ◽

Microarray Platform ◽

Genomic Signatures ◽

Dna Sequence Variation

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Sequence variation and evolution of nuclear DNA in man and the primates

Philosophical Transactions of the Royal Society of London Series B Biological Sciences ◽

10.1098/rstb.1981.0021 ◽

1981 ◽

Vol 292 (1057) ◽

pp. 133-142 ◽

Cited By ~ 5

Keyword(s):

Dna Sequence ◽

Sequence Variation ◽

Nuclear Dna ◽

Sequence Divergence ◽

Gene Arrangement ◽

Human Populations ◽

Genetic Changes ◽

Detailed Structural Analysis ◽

Dna Sequence Variation ◽

History Of

Recent advances in nucleic acid technology have facilitated the detection and detailed structural analysis of a wide variety of genes in higher organisms, including those in man. This in turn has opened the way to an examination of the evolution of structural genes and their surrounding and intervening sequences. In a study of the evolution of haemoglobin genes and neighbouring sequences in man and the primates, we have investigated gene arrangement and DNA sequence divergence both within and between species ranging from Old World monkeys to man. This analysis is beginning to reveal the evolutionary constraints that have acted on this region of the genome during primate evolution. Furthermore, DNA sequence variation, both within and between species, provides, in principle, a novel and powerful method for determining inter-specific phylogenetic distances and also for analysing the structure of present-day human populations. Application of this new branch of molecular biology to other areas of the human genome should prove important in unravelling the history of genetic changes that have occurred during the evolution of man.

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