Abstract
Advances in sequencing technologies have accelerated the sequencing of new genomes, far outpacing the generation of gene and protein resources needed to annotate them. Direct comparison and alignment of existing cDNA sequences from a related species is an effective and readily available means to determine genes in the new genomes. Current spliced alignment programs are inadequate for comparing sequences between different species, owing to their low sensitivity and splice junction accuracy. A new spliced alignment tool, sim4cc, overcomes problems in the earlier tools by incorporating three new features: universal spaced seeds, to increase sensitivity and allow comparisons between species at various evolutionary distances, and powerful splice signal models and evolutionarily-aware alignment techniques, to improve the accuracy of gene models. When tested on vertebrate comparisons at diverse evolutionary distances, sim4cc had significantly higher sensitivity compared to existing alignment programs, more than 10% higher than the closest competitor for some comparisons, while being comparable in speed to its predecessor, sim4. Sim4cc can be used in one-to-one or one-to-many comparisons of genomic and cDNA sequences, and can also be effectively incorporated into a high-throughput annotation engine, as demonstrated by the mapping of 64,000 Fagus grandifolia 454 ESTs and unigenes to the poplar genome.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by-nc. Read at the source ↗
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Claims 3
Claim · model-written summary
Sim4cc had significantly higher sensitivity than existing alignment programs in vertebrate tests, by more than 10% for some comparisons.
Verbatim
e0“When tested on vertebrate comparisons at diverse evolutionary distances, sim4cc had significantly higher sensitivity compared to existing alignment programs, more than 10% higher than the closest competitor for some comparisons”
Claim · model-written summary
Sim4cc speed was comparable to sim4.
Verbatim
e0“while being comparable in speed to its predecessor, sim4.”
Claim · model-written summary
Sim4cc mapped 64,000 Fagus grandifolia ESTs and unigenes to the poplar genome.
- Taxon
- Fagus grandifolia
Fagus grandifoliae0 - Outcome
- mappinge0
- Value
- 64,000e0
- Comparator
- poplar genomee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Verbatim
e0“mapping of 64,000 Fagus grandifolia 454 ESTs and unigenes to the poplar genome”