Unveiling the Mycodrosophila projectans (Diptera, Drosophilidae) species complex: Insights into the evolution of three Neotropical cryptic and syntopic species.

The Zygothrica genus group has been shown to be speciose, with a high number of cryptic species. DNA barcoding approaches have been a valuable tool to uncover cryptic diversity in this lineage, as recently suggested for the Neotropical Mycodrosophila projectans complex, which seems to comprise at least three different species. The aim of this study was to confirm the subdivision of the M. projectans complex while shedding some light on the patterns and processes related to its diversification. In this sense, the use of single and multi-locus datasets under phylogenetic, distance, coalescence, and diagnostic nucleotide approaches confirmed the presence of at least three species under the general morphotype previously described as M. projectans. Only a few subtle morphological differences were found for the three species in terms of aedeagus morphology and abdominal color patterns. Ecologically, sympatry and syntopy seem to be recurrent for these three cryptic species, which present widely overlapping niches, implying niche conservatism. This morphological and ecological similarity has persisted though cladogenesis within the complex, which dates back to the Miocene, providing an interesting example of morphological conservation despite ancient divergence. These results, in addition to contrasting patterns of past demographic fluctuations, allowed us to hypothesize patterns of allopatric or parapatric diversification with secondary contact in Southern Brazil. Nevertheless, genetic diversity was generally high within species, suggesting that migration may encompass an adaptive response to the restrictions imposed by the ephemerality of resources

Induction of phase II enzymes and hsp70 genes by copper sulfate through the electrophile-responsive element (EpRE): insights obtained from a transgenic zebrafish model carrying an orthologous EpRE sequence of mammalian origin.

We have evaluated the homology of the electrophile-responsive element (EpRE) core sequence, a binding site for the Nrf2 transcription factor, in the proximal promoters of the mouse and zebrafish glutathione-S-transferase (gst), glutamate cysteine ligase catalytic subunit (gclc) and heat shock protein 70 (hsp70) genes. The EpRE sites identified for both species in the three analyzed genes showed a high similarity with the putative EpRE core sequence. We also produced a transgenic zebrafish model carrying a transgene comprised of the luciferase (luc) reporter gene under transcriptional control of a mouse EpRE sequence. This transgenic model was exposed to copper sulfate, and the reporter gene was significantly activated. The endogenous gst, gclc and hsp70 zebrafish genes were analyzed in the EpRELuc transgenic zebrafish and showed an expression pattern similar to that of the reporter transgene used. Our results demonstrate that EpRE is conserved between mouse and zebrafish for detoxificationrelated genes and that the development of genetically modified models using this responsive element to drive the expression of reporter genes can be an important tool in understanding the action mechanism of aquatic pollutants

Non-lethal molecular diagnostic for acanthocephalosis in Colossoma macropomum

The tambaqui C. macropomum is intensively produced in aquaculture and is subject to numerous parasitosis, such as acanthocephalosis, a parasitosis caused by Neoechinorhynchus buttnerae infection. The conventional diagnosis of acanthocephalosis is performed through fish euthanasia, which brings economic loss for fish farmers and poor efficiency in managing disease prevention. Thus, in this study, was proposed the use of molecular tools to develop a nonlethal diagnosis method for acanthocephalosis. For this, a partial gene sequence of the 18S ribosomal RNA gene of N. buttnerae was isolated, and specific primers were designed for the detection of parasite DNA presence in the host's blood by quantitative polymerase chain reaction (qPCR). Infected and uninfected fish were submitted to molecular diagnosis by qPCR, which showed 84% efficiency, 100% specificity and 50% sensitivity. The identification of false negatives led to histopathological analysis. These analyses confirmed the impairment of intestinal structures and the presence of inflammatory response, specific features of acanthocephalosis lesions. Also, gene expression analysis of RAG2 (Recombination Activating Gene) and MALT1 (Mucosa-associated Lymphoid Tissue Lymphoma Translocation) showed a decrease in parasitized fish, demonstrating that the host immune system was compromised. Thus, evidence that it is possible to diagnose non-lethally, by qPCR, the presence of the parasite N. buttnerae from blood samples taken from its host C. macropomum were generated. Experimental alternatives, however, should be improved to increase the sensitivity of the method. © 2019 Elsevier B.V

Natural occurrence of white spot syndrome virus and infectious hypodermal and hematopoietic necrosis virus in neohelice granulata crab

White spot syndrome virus (WSSV) and Infectious hypodermal and hematopoietic necrosis virus (IHHNV) are two infectious agents associated to economic losses in shrimp aquaculture. As virus spread occurs through vectors and hosts, this study sought to verify the presence of WSSV and IHHNV in Neohelice granulata crab from Lagoa dos Patos estuary in Brazil and nearby shrimp farms. DNA extractions were performed with phenol/chloroform protocol. Molecular diagnosis was carried out by nested PCR for WSSV and one-step PCR for IHHNV. Results showed the presence of WSSV on crabs of both Lagoa dos Patos and farms, while IHHNV was found only on crabs collected in estuary. This is the first study to report IHHNV presence in N. granulata. Moreover, as analyzed crabs had no clinical symptoms or showed in situ mortality, we suggest its use as a bioindicator for virus occurrence in aquatic environments