Widespread Intron Loss Suggests Retrotransposon Activity in Ancient Apicomplexans

Widespread intron loss suggests retrotransposon activity in ancient apicomplexans.

Several facets of spliceosomal intron in apicomplexans remain mysterious. First, intron numbers vary across species by 2 orders of magnitude, indicating massive intron loss and/or gain. Second, previous studies have shown very different evolutionary patterns over different timescales, with 100-fold higher rates of intron loss/gain between genera than within genera. Third, the timing and dynamic...

Intron distribution difference for 276 ancient and 131 modern genes suggests the existence of ancient introns.

o introns delineate elements of protein tertiary structure? This issue is crucial to the debate about the role and origin of introns. We present an analysis of the full set of proteins with known three-dimensional structures that have homologs with intron positions recorded in GenBank. A computer program was generated that maps on a reference sequence the positions of all introns in homologous ...

Detection of Polymorphism in Ancient Tempranillo Clones (Vitis vinifera L.) Using Microsatellite and Retrotransposon Markers

Tempranillo is one of the most widely cultivated grapevine varieties in Spain. After several years of clone selection, some highly recommended old clones have been identified in terms of both their qualitative and production characteristics. This study was designed to discriminate among 28 ancient clones of the cultivar Tempranillo (Vitis vinifera). DNA samples from clones were analysed using t...

Conservation of Selection on matK in Ferns Following an Ancient Loss its Flanking Intron

Evolution of yeast noncoding RNAs reveals an alternative mechanism for widespread intron loss.

The evolutionary forces responsible for intron loss are unresolved. Whereas research has focused on protein-coding genes, here we analyze noncoding small nucleolar RNA (snoRNA) genes in which introns, rather than exons, are typically the functional elements. Within the yeast lineage exemplified by the human pathogen Candida albicans, we find--through deep RNA sequencing and genome-wide annotati...