Characteristics of the nuclear (18S, 5.8S, 28S and 5S) and mitochondrial (12S and 16S) rRNA genes of Apis mellifera (Insecta: Hymenoptera): structure, organization, and retrotransposable elements

As an accompanying manuscript to the release of the honey bee genome, we report the entire sequence of the nuclear (18S, 5.8S, 28S and 5S) and mitochondrial (12S and 16S) ribosomal RNA (rRNA)-encoding gene sequences (rDNA) and related internally and externally transcribed spacer regions of Apis mellifera (Insecta: Hymenoptera: Apocrita). Additionally, we predict secondary structures for the mature rRNA molecules based on comparative sequence analyses with other arthropod taxa and reference to recently published crystal structures of the ribosome. In general, the structures of honey bee rRNAs are in agreement with previously predicted rRNA models from other arthropods in core regions of the rRNA, with little additional expansion in non-conserved regions. Our multiple sequence alignments are made available on several public databases and provide a preliminary establishment of a global structural model of all rRNAs from the insects. Additionally, we provide conserved stretches of sequences flanking the rDNA cistrons that comprise the externally transcribed spacer regions (ETS) and part of the intergenic spacer region (IGS), including several repetitive motifs. Finally, we report the occurrence of retrotransposition in the nuclear large subunit rDNA, as R2 elements are present in the usual insertion points found in other arthropods. Interestingly, functional R1 elements usually present in the genomes of insects were not detected in the honey bee rRNA genes. The reverse transcriptase products of the R2 elements are deduced from their putative open reading frames and structurally aligned with those from another hymenopteran insect, the jewel wasp Nasonia (Pteromalidae). Stretches of conserved amino acids shared between Apis and Nasonia are illustrated and serve as potential sites for primer design, as target amplicons within these R2 elements may serve as novel phylogenetic markers for Hymenoptera. Given the impending completion of the sequencing of the Nasonia genome, we expect our report eventually to shed light on the evolution of the hymenopteran genome within higher insects, particularly regarding the relative maintenance of conserved rDNA genes, related variable spacer regions and retrotransposable elements

Growth in atopic eczema.

Growth was studied in 68 children aged 2-12 years with atopic eczema. Height SD scores were significantly correlated with the surface area of skin affected by eczema. The mean height of 41 patients with less than 50% of their skin surface affected (group I) was normal (mean SD score -0.11). The 27 children with more than 50% of their skin affected (group II) were significantly shorter (SD score -0.83) and were also short allowing for their parental target height. The predicted heights were also normal in group I but were lower than expected in group II. Regression analysis suggested that height was most dependent on parental height. The extent of the disease had a significant additional effect, whereas dietary treatment and treatment with topical steroids had only marginal additional effects. The growth of children with eczema affecting less than 50% of the skin surface area appears to be normal, and impaired growth is confined to those with more extensive disease

Author Correction: Widespread long-range cis-regulatory elements in the maize genome.

An amendment to this paper has been published and can be accessed via a link at the top of the paper