First record of the Mediterranean mussel Mytilus galloprovincialis (Bivalvia, Mytilidae) in Brazil

The genus Mytilus comprises a large number of bivalve mollusk species distributed throughout the world and many of these species are considered invasive. In South America, many introductions of species of this genus have already taken place, including reports of hybridization between them. Now, the occurrence of the Mediterranean mussel Mytilus galloprovincialis is reported for the first time from the Brazilian coast. Several specimens of this mytilid were found in a shellfish growing areas in Florianópolis and Palhoça, Santa Catarina State, Brazil. Morphological analysis of the shells and molecular analysis through sequencing of the cytochrome oxidase subunit 1 (COI) confirmed the taxonomic identification. The species is known for its great invasive potential and can become a major environmental problem for seafood business and coastal communities, as it can compete and even hybridize with local species

Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets