The mitochondrial genomes of sponges provide evidence for multiple invasions by Repetitive Hairpin-forming Elements RHEReportar como inadecuado




The mitochondrial genomes of sponges provide evidence for multiple invasions by Repetitive Hairpin-forming Elements RHE - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

BMC Genomics

, 10:591

First Online: 09 December 2009Received: 12 February 2009Accepted: 09 December 2009

Abstract

BackgroundThe mitochondrial mt genomes of sponges possess a variety of features, which appear to be intermediate between those of Eumetazoa and non-metazoan opisthokonts. Among these features is the presence of long intergenic regions, which are common in other eukaryotes, but generally absent in Eumetazoa. Here we analyse poriferan mitochondrial intergenic regions, paying particular attention to repetitive sequences within them. In this context we introduce the mitochondrial genome of Ircinia strobilina Lamarck, 1816; Demospongiae: Dictyoceratida and compare it with mtDNA of other sponges.

ResultsMt genomes of dictyoceratid sponges are identical in gene order and content but display major differences in size and organization of intergenic regions. An even higher degree of diversity in the structure of intergenic regions was found among different orders of demosponges. One interesting observation made from such comparisons was of what appears to be recurrent invasions of sponge mitochondrial genomes by repetitive hairpin-forming elements, which cause large genome size differences even among closely related taxa. These repetitive hairpin-forming elements are structurally and compositionally divergent and display a scattered distribution throughout various groups of demosponges.

ConclusionLarge intergenic regions of poriferan mt genomes are targets for insertions of repetitive hairpin- forming elements, similar to the ones found in non-metazoan opisthokonts. Such elements were likely present in some lineages early in animal mitochondrial genome evolution but were subsequently lost during the reduction of intergenic regions, which occurred in the Eumetazoa lineage after the split of Porifera. Porifera acquired their elements in several independent events. Patterns of their intra-genomic dispersal can be seen in the mt genome of Vaceletia sp.

List of abbreviationsbpbasepairs

IGRintergenic regions

mtmitochondrial

RHErepetitive hairpin-forming element.

Electronic supplementary materialThe online version of this article doi:10.1186-1471-2164-10-591 contains supplementary material, which is available to authorized users.

Download fulltext PDF



Autor: Dirk Erpenbeck - Oliver Voigt - Gert Wörheide - Dennis V Lavrov

Fuente: https://link.springer.com/article/10.1186/1471-2164-10-591







Documentos relacionados