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摘要
En 中文
We use the pattern of intron conservation in 684 groups of orthologs from seven fully sequenced eukaryotic genomes to provide maximum likelihood estimates of the number of introns present in the same orthologs in various eukaryotic ancestors. We find: (i) intron density in the plant-animal ancestor was high, perhaps two-thirds that of humans and three times that of Drosophila; and (ii) intron density in the ancestral bilateran was also high, equaling that of humans and four times that of Drosophila. We further find that modern introns are generally very old, with two-thirds of modern bilateran introns dating to the ancestral bilateran and two-fifths of modern plant, animal, and fungus introns dating to the plant-animal ancestor. Intron losses outnumber gains over a large range of eukaryotic lineages. These results show that early eukaryotic gene structures were very complex, and that simplification, not embellishment, has dominated subsequent evolution.
Keyword:
INTRON POSITIONS
SPLICEOSOMAL INTRONS
CHEMORECEPTOR GENES
GENOME EVOLUTION
ISOMERASE GENE
EXON THEORY
PHYLOGENY
SEQUENCE
ORIGINS
NEMATODES
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期刊
P
IF:
9.1
论文数:
10.8W
被引数:
73.5W
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引用论文
Two large families of chemoreceptor genes in the nematodes Caenorhabditis elegans and Caenorhabditis briggsae reveal extensive gene duplication, diversification, movement, and intron loss
GENOME RESEARCH
IF5.5

