Translational Machinery of Senegalese Sole (Solea senegalensis Kaup) and Atlantic Halibut (Hippoglossus hippoglossus L.): Comparative Sequence Analysis of the Complete Set of 60S Ribosomal Proteins and their Expression
MARINE BIOTECHNOLOGY
Authors: Matsuoka, Makoto P.; Infante, Carlos; Reith, Michael; Pedro Canavate, Jose; Douglas, Susan E.; Manchado, Manuel
Abstract
Ribosomal proteins (RPs) comprise a large set of highly evolutionarily conserved proteins that are often over-represented in complementary DNA libraries. They have become very useful markers in comparative genomics, genome evolution, and phylogenetic studies across taxa. In this study, we report the sequences of the complete set of 60S RPs in Senegalese sole (Solea senegalensis) and Atlantic halibut (Hippoglossus hippoglossus), two commercially important flatfish species. Amino-acid sequence comparisons of the encoded proteins showed a high similarity both between these two flatfish species and with respect to other fish and human counterparts. Expressed sequence tag analysis revealed the existence of paralogous genes for RPL3, RPL7, RPL41, and RPLP2 in Atlantic halibut and RPL13a in Senegalese sole as well as RPL19 and RPL22 in both species. Phylogenetic analysis of paralogs revealed distinct evolutionary histories for each RP in agreement with three rounds of genome duplications and lineage-specific duplications during flatfish evolution. Steady-state transcript levels for RPL19 and RPL22 RPs were quantitated during larval development and in different tissues of sole and halibut using a real-time polymerase chain reaction approach. All paralogs were expressed ubiquitously although at different levels in different tissues. Most RP transcripts increased coordinately after larval first-feeding in both species but decreased progressively during the metamorphic process. In all cases, expression profiles and transcript levels of orthologous genes in Senegalese sole and Atlantic halibut were highly congruent. The genomic resources and knowledge developed in this survey will be useful for the study of Pleuronectiformes evolution.
A severe disease induced by 'Candidatus Phytoplasma asteris' in Digitalis lanata
BULLETIN OF INSECTOLOGY
Authors: Bellardi, Maria Grazia; Benni, Alessandro; Paltrinieri, Samanta; Bertaccini, Assunta
Abstract
In spring of 2007, a severe disease was observed in Digitalis lanata plants cultivated in an herb garden. Stunting of the whole plants, size reduction and reddish colour of leaf lamina, axillary bud proliferation (witches' broom), virescence and rosetting of flower spikes were observed. 'Candidatus Phytoplasma asteris'-related phytoplasmas were identified by direct and nested PCR assays followed by RFLP analyses on 16S ribosomal gene. RFLP analyses on rpL22, elongation factor EF-Tu, aminoacid kinase plus ribosome recycling factors and Amp genes showed that phytoplasmas infecting D. lanata are undistinguishable from representative phytoplasmas enclosed in ribosomal subgroup 16SrI-B. This is the first report of phytoplasma presence in this species.