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At many vertebrate synapses, presynaptic functions are tuned by expression of different Ca v 2 channels. Most invertebrate genomes contain only one Ca v 2 gene. The Drosophila Ca v 2 homolog, cacophony (cac), induces synaptic vesicle release at presynaptic active zones (AZs). We hypothesize that Drosophila cac functional diversity is enhanced by two mutually exclusive exon pairs that are not conserved in vertebrates, one in the voltage sensor and one in the loop binding Ca β and G βγ subunits. We find that alternative splicing in the voltage sensor affects channel activation voltage. Only the isoform with the higher activation voltage localizes to AZs at the glutamatergic Drosophila larval neuromuscular junction and is imperative for normal synapse function. By contrast, alternative splicing at the other alternative exon pair tunes multiple aspects of presynaptic function. While expression of one exon yields normal transmission, expression of the other reduces channel number in the AZ and thus release probability. This also abolishes presynaptic homeostatic plasticity. Moreover, reduced channel number affects short-term plasticity, which is rescued by increasing the external calcium concentration to match release probability to control. In sum, in Drosophila alternative splicing provides a mechanism to regulate different aspects of presynaptic functions with only one Ca v 2 gene.

Behavioural patterns and distributions of crustaceans, fish and mammals can be inferred from acoustic recordings of the extremely noisy marine acoustic environment. In this study, we determined the soundscape of protected and non-protected marine areas between January and April 2016. Sonobuoy (a device for sound monitoring) recordings began at sunset and lasted approximately 12 hours per day. The results show a complex soundscape dominated by biological sounds produced by crustaceans and fish. Six fish chorus-dominant frequencies between 200 and 1000 Hz occurred at a similar time each day, except for chorus I. The choruses consisted of high-energy callings after the last reef line within the protected area. However, fish choruses showed low energy levels in unprotected areas. The results show the importance of protected areas for fish populations and the usefulness of passive acoustics to monitor biodiversity of sounds of commercial fish in Brazilian tropical costal reefs.

Background Different methods have been used to preserve phlebotomine sand flies for research purposes, including for taxonomic studies and detection of Leishmania spp. Here, we evaluated the effect of various preservation methods at different storage times on phlebotomine sand fly DNA concentration and purity. Methods Field-collected phlebotomine sand flies were individually stored in 70% ethanol (G1) and 95% ethanol (G2) at room temperature, 70% ethanol (G3) and 95% ethanol (G4) at 8 °C or frozen dry (i.e. no preservation solution) at − 20 °C (G5). DNA concentration and purity were assessed at various storage times (T1, ≤ 12 h; T2, 3 months; T3, 6 months; T4, 9 months; and T5, 12 months). Fragments of the cytochrome c oxidase subunit 1 ( cox 1) and cacophony ( CAC ) genes of phlebotomine sand flies were also amplified. Results Mean DNA concentration ( P  = 0.178) and 260/280 purity ratios ( P  = 0.584) did not vary significantly among various preservation methods and storage times. Within each group, DNA concentration varied in G1 (Kruskal-Wallis H-test, P  = 0.009) for T3 vs T4 (Dunn’s post-hoc , P  < 0.05), and in G2 (Kruskal-Wallis H-test, P  = 0.004) for T1 vs T2 and T1 vs T4 (Dunn’s post-hoc , P  < 0.05). For 260/280 purity ratios, the only statistically significant difference was found for G5 (Kruskal-Wallis H-test, P  = 0.020) between T1 vs T4 (Dunn’s post-hoc test, P  < 0.05). The cox 1 and CAC genes were successfully amplified, regardless of the preservation method and storage time; except in one sample from G2 at T1, for which the CAC gene failed to amplify. Conclusions The preservation methods and storage times herein evaluated did not affect the concentration and purity of DNA samples obtained from field-collected phlebotomine sand flies, for up to 12 months. Furthermore, these preservation methods did not interfere with PCR amplification of CAC and cox 1 genes, being suitable for molecular analyses under the conditions studied herein.

Unlike architecture, music is mostly a marginal or infrequent aspect of utopian literature, though usually invested with solely positive connotations. It is however particularly prominent in Samuel Butler’s Erewhon but it is only described negatively, as unpleasant, discordant and even cacophonous. This is where Butler’s radical originality lies: firstly in this diversion of the laudatory, spiritualized conception of music and of its utopian associations; and secondly in the (re)appropriation of music for satiric and anti-utopian purposes. After a brief survey of the usual role and connotations of music in utopias, this paper will focus on its value and symbolism before the narrator’s stay in Erewhon. It will then address its representation in the unknown land that collapses the literal (acoustic) and social meanings of discordance with unpleasant or cacophonous music as the index to a dysfunctional world and its ethical flaws. Lastly, the article will deal with the narrator’s unstable stance and views, which, together with the generic and tonal hybridity of the text and its ironic logic, alternating between satire and (anti)utopia, make the novel go through a series of perplexing ideological fluctuations. Like the cacophonous music of Erewhon, the message conveyed is ultimately ambiguous and at times discordant.

Genes involved in the reproductive isolation are particularly useful as molecular markers in speciation studies. Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae), a putative species complex, is a vector of visceral leishmaniasis in Latin America. We isolated from this species a fragment homologous to cacophony, a Drosophila gene that encodes features of the lovesong, an acoustic signal that is important in the sexual isolation of closely related species and known to vary considerably among L. longipalpis putative siblings species. Using an intron of the sandfly cacophony as a marker, we analyzed the molecular variation and sequence divergence among five populations of L. longipalpis from Brazil, three allopatric (Jacobina, Lapinha and Natal) and two putative sympatric sibling species from the locality of Sobral. A high level of polymorphism was found and analysis of the data indicates that very little gene flow is occurring among the populations of Jacobina, Lapinha, and Natal. A high level of differentiation was also observed between the two putative sympatric species of Sobral, one of which seems to be the same sibling species found in Natal, while the other is somewhat more related to Jacobina and Lapinha. However, the amount of estimated gene flow among the Sobral siblings is about seven times higher than the previously estimated for period, another lovesong gene, perhaps indicating that introgression might be affecting cacophony more than period. The results suggest that L. longipalpis is not a single species in Brazil, but it is yet not clear whether the different populations studied deserve species status rather than representing an incipient speciation process.