Further analysis of the duplicated gene sets indicated that a significant portion of duplicated genes in the zebrafish genome were of recent, lineage-specific duplication events.
It has been proposed recently that a large portion of duplicated genes undergo rapid subfunctionalization followed by prolonged and substantial neofunctionalization [4].
Hotspots of gene rearrangement (eg. WANCY) in Amolops and Odorrana have similar portions of duplicated genes yet the positions of silenced genes vary.
Note that this observation may not suggest that the rate of local duplications increases after WGDs but rather confirm the fact that the turnover rate of duplicates following local duplications is much higher than that following WGDs, making a very small portion of local duplicates survive over long evolutionary times (Lynch and Conery 2000; Blanc and Wolfe 2004b).
Using data from Massively Parallel Signature Sequencing, we show that a significant portion of the duplicated genes in rice show divergent expression although a correlation between sequence divergence and correlation of expression could be seen in very young genes.
However, identification of gene conversion events remains a challenging task as the methods commonly employed for detecting such events can have a high false-negative rate, particularly when gene conversion is frequent and covers a large portion of the duplicates [ 50].
A portion of the duplicated sets combined several duplication types (e.g., duplicate set members present in both tandem and inter-chromosomal arrangements; Table 1).
Collection of duplicate portions is known to influence dietary habits [ 29].
The analysis of duplicate portions from lacto-vegetarians (six subjects) and vegans (six subjects) collected between 1978 and 1980 in a health resort showed that the content of 18 : 1 trans isomers contributed about 1·3 and 0·5 E%, respectively.
Thus, rearrangements in animal mt genomes are generally explained by the "duplication and deletion model" (e.g., [ 16, 28]): first, a multi-gene (and CR) portion of the genome is duplicated, and then one duplicate gene copy becomes nonfunctional (a pseudogene) and is subsequently excised from the genome.
