Juliano Tomazzoni Boldo

Shifts in soil bacterial community after eight years of land-use change.

The interaction between plants, soil and microorganisms is considered to be the major driver of ecosystem functions and any modification of plant cover and/or soil properties might affect the microbial structure, which, in turn, will influence ecological processes. Assuming that soil properties are the major drivers of soil bacterial diversity and structure within the same soil type, it can be postulated whether plant cover causes significant shifts in soil bacterial community composition. To address this question, this study used 16S rRNA pyrosequencing to detect differences in diversity, composition and/or relative abundance of bacterial taxa from an area covered by pristine forest, as well as eight-year-old grassland surrounded by the same forest. It was shown that a total of 69% of the operational taxonomic units (OTUs) were shared between environments. Overall, forest and grassland samples presented the same diversity and the clustering analysis did not show the occurrence of very distinctive bacterial communities between environments. However, 11 OTUs were detected in statistically significant higher abundance in the forest samples but in lower abundance in the grassland samples, whereas 12 OTUs occurred in statistically significant higher abundance in the grassland samples but in lower abundance in the forest samples. The results suggested the prevalence of a resilient core microbial community that did not suffer any change related to land use, soil type or edaphic conditions. The results illustrated that the history of land use might influence present-day community structure.

Draft Plastid and Mitochondrial Genome Sequences from Antarctic Alga Prasiola crispa.

ABSTRACT The organelle genomes of the Antarctic alga Prasiola crispa (Lightfoot) Kützing have been sequenced. The plastid and mitochondrial genomes have a total length of 196,502 bp and 89,819 bp, respectively. These genomes have 19 putative photosynthesis-related genes and 17 oxidative metabolism-related genes, respectively.

Phylogenetic positioning of the Antarctic alga Prasiola crispa (Trebouxiophyceae) using organellar genomes and their structural analysis

Antarctica is one of the most difficult habitats for sustaining life on earth; organisms that live there have developed different strategies for survival. Among these organisms is the green alga Prasiola crispa, belonging to the class Trebouxiophyceae. The literature on P. crispa taxonomy is scarce, and many gaps in the evolutionary relationship with its closest relatives remain. The goal of this study was to analyze the evolutionary relationships between P. crispa and other green algae using plastid and mitochondrial genomes. In addition, we analyzed the synteny conservation of these genomes of P. crispa with those of closely related species. Based on the plastid genome, P. crispa grouped with Prasiolopsis sp. SAG 84.81, another Trebouxiophyceaen species from the Prasiola clade. Based on the mitochondrial genome analysis, P. crispa grouped with other Trebouxiophyceaen species but had a basal position. The structure of the P. crispa chloroplast genome had low synteny with Prasiolopsis sp. SAG 84.81, despite some conserved gene blocks. The same was observed in the mitochondrial genome compared with Coccomyxa subellipsoidea C‐169. We were able to establish the phylogenetic position of P. crispa with other species of Trebouxiophyceae using its genomes. In addition, we described the plasticity of these genomes using a structural analysis. The plastid and mitochondrial genomes of P. crispa will be useful for further genetic studies, phylogenetic analysis and resource protection of P. crispa as well as for further phylogenetic analysis of Trebouxiophyceaen green algae.

A scientific note on genetic profile of the mite Varroa destructor infesting apiaries in Rio Grande do Sul state, Brazil

mite / Africanized bees / haplotype / genetic characterization / CO-I gene The Varroa destructor mite is a hematophagous ecto-parasite widely known as the most important Apis mellifera parasite; it causes severe economic impact on beekeeping, since in most regions of the world colonies infested with V. destructor eventually collapse (Strapazzon et al. 2009; Rosenkranz et al. 2010). Different mite haplotypes present distinct reproductive capacity and virulence factors (Anderson and Trueman 2000; Garrido et al. 2003; Strapazzon et al. 2009), which contribute to infestation rates and consequent damage to honey bee colonies. We examined the prevalence of Japan (J) and Korean (K) mitochondrial haplotypes of the mites infesting A. mellifera from southwestern Rio Grande do Sul state, an important Brazilian honey-producing region that borders Argentina (to the west) and Uruguay (to the south), both of which have severe problems with V. destructor infestations. Given the higher infestation levels in cold regions of Brazil (Moretto et al. 1991) and the tendency for beekeepers in this southernmost region of the country to copy management practices used in the neighboring countries, there is a considerable concern about Varroa infestations. This study was carried out between May 2013 and November 2015 and sampled phoretic adult females of V. destructor , 47 in total, from adult workers from arbitrarily selected beehives. One known V. destructor hap-lotype J mite sample from Fernando de Noronha Island (Pernambuco State) was collected and used for comparison. The molecular analysis of the CO-I mito-chondrial gene using PCR-restriction enzyme, as described in Anderson and Fuchs (1998), and sequencing and alignment experiments indicated all 47 mite samples of the southwestern region of Rio Grande do Sul state belong to the Korean (K) haplotype pattern. Only the Fernando de Noronha Island sample showed the haplotype J pattern, although the Japan (J) haplotype was formerly reported in the region (Strapazzon et al. 2009). All PCR amplicons presented the expected 458 base pairs and had 100% identity to previously reported sequences. The sequences obtained from our southwestern samples (GenBank accession numbers: KX458254.1 and KY380010-KY380055) were identical to one another and to the previously reported V. destructor Korean (K) haplotype, with the same genetic pattern that was found in Argentina (Guerra et al. 2010). As expected, only the Xho I restriction site was observed. The sequence obtained from the Fernando de Noronha Island sample (GenBank accession number: KX458253.1) were identical to the previously reported V. destructor …