Researches have been focused almost either on recent duplication events occurring in humans or other mammals involved in human diseases [ 19, 20] or on the duplication and adaptive evolution of single gene families, such as chalcone synthase genes and MADS-box genes in plants [ 21, 22], fatty acid biosynthesis genes in bacteria [ 23], or Toll-like receptor genes in Drosophila[ 24].
This implies large number of recent duplications in chicken.
It has also been previously observed [ 26] that 30% of the sorghum genome showed correspondence to two or more unlinked intervals which the authors postulated could either be due to very localised colinearity or which may reflect more recent duplications superimposed on more ancient ones.
The first report that the HB3 genome sequencing project detected two var2csa-type genes indicated that these genes are very similar and closely linked on chromosome 12 and thus potentially recent duplications.
Based on the current Btau_4.0 assembly, bovine recent duplications are distributed in a nonuniform fashion across the genome.
Here we focus on genes that have evolved after recent duplications and, therefore, have relatively small dS values: only genes with individual dS values between 0.005 and 0.6 were used for the individual dN and dS analyses.
On the other hand, leaf clustering can also reveal recent duplications of T6SS gene clusters.
The two most recent duplications occurred less than 7 mya, one after the M. sativa speciation event (time estimate based on matK substitution rates) (Lavin et al. 2005) and one after the much more recent A17 R108 split.
In this study, we use a recent adaptive radiation so that, whilst strong positive selection on duplicates might be overlooked by the aCGH technique, the majority of very recent duplications are likely to be identified.
Recent duplications of chromosomal segments are particularly found on rice chromosomes 11 and 12, and corresponding regions on chromosome 5 and 8 in sorghum.
