The inferred ancestral number of gene families, according to DOLLOP, is shown in green boxes.. We discovered that known gene families implicated in digestion, detoxification and transport of xenobiotics had a unique spider mite composition, and were often expanded when compared to insects (Supplementary Note 6.1). The mean number of exons per gene was low and similar to that found in D. The size distribution of introns was typically skewed with a mean intron size of 400 (the absence of centromeres and the diffuse nature of the kinetochores) is correlated with a lack of large tracts of gene-poor heterochromatin. pulex, the chordate Homo sapiens, and the cnidarian Nematostella vectensis (Fig. RNA-seq data is available under Gene Expression Omnibus (GEO) super series number GSE32342.
As the first completed chelicerate genome, the comparison of the T.
urticae genome with the genomes of insects and the crustacean Daphnia pulex expands the arthropod genetic toolkit. urticae genome has unique attributes among arthropod genomes with remarkable instances of gene gains and losses. urticae genome sequence opens new avenues for understanding the fundamentals of plant–herbivore interactions, developing novel pest-management strategies and producing new biomaterials on the nanometre scale. urticae genome (strain London) was sequenced (Sanger) to 8.05× coverage and assembled into 640 scaffolds covering 89.6 megabases (Mb) (Supplementary Notes 1, 2.1 and 2.2).
Tetranychus urticae is known for its ability to develop rapid resistance to pesticides.
Among arthropods it has the highest incidence of pesticide resistanceyears.
Many aspects of the biology of the spider mite, including rapid development, high fecundity and haplo-diploid sex determination, seem to facilitate rapid evolution of pesticide resistance.
Control of multi-resistant mites has become increasingly difficult and the genetic basis of such resistance remains poorly understood.
Compared with other arthropods, the spider mite genome shows unique changes in the hormonal environment and organization of the Hox complex, and also reveals evolutionary innovation of silk production.
We find strong signatures of polyphagy and detoxification in gene families associated with feeding on different hosts and in new gene families acquired by lateral gene transfer.
Chelicerates represent a basal branch of arthropods.
Subsequent to their origin in the Cambrian period, arthropods radiated into two lineages: the Chelicerata and the Mandibulata (comprising the Myriapoda and the Pancrustacea (which includes both crustaceans and insects))million years ago).
3.2.1) contrasts with the human body louse (Pediculus humanus, Phthiraptera, a hemimetabolous insect with a small genome), where 95% of the genes are concentrated in only 55 As the first completely sequenced and annotated chelicerate genome, the T. Almost 3,000 gene families are common to the arthropods sampled, whereas 5,038 gene families (8,329 genes) are unique to T. Homologues of 74 gene families (93 genes) were found in the unfinished genomes of tick and are probably chelicerate, rather than specific to T. Therefore, 4,416 gene families (6,609 genes) were found to be unique to T. urticae, plus almost 4,300 genes that are single copy (orphans).