Male, female and immature stages of Phyllocnistis tethys Moreira & Vargas sp. nov. (Lepidoptera; Gracillariidae) from the Atlantic Rain Forest, coastal mountains of southern Brazil, are described and illustrated, using both optical and scanning electron microscopy. A preliminary analysis of mitochondrial (COI) DNA sequences including putative members of congeneric species is also provided. The immature stages are associated with the passion vine Passiflora organensis (Passifloraceae). The hypermetamorphic, endophyllous larva has four instars; the first, second and third instars are sap-feeders, associated primarily with the spongy parenchyma, and construct a blotch mine in the lower surface of the lamina; the fourth, non-feeding (spinning) instar constructs a flimsy endophyllous cocoon at the end of the mine, where pupation occurs. This is the first species of Phyllocnistis Zeller described from Brazil, and the first leaf-mining gracillariid associated with Passifloraceae.
The neurohormone oxytocin is a key player in the modulation of reproductive and social behavioral traits, such as parental care. Recently, a correlation between different forms of oxytocin and behavioral phenotypes has been described in the New World Monkeys (NWMs). Here, we demonstrate that, compared with the LeuOXT found in most placental mammals, the Cebidae ProOXT and ValProOXT taxon-specific variants act as equi-efficacious agonists for the G-dependent pathway but are weaker agonists for the β-arrestin engagement and subsequent endocytosis toward the oxytocin receptor (OXTR). Upon interaction with the AVPR1a, ProOXT and the common LeuOXT yielded similar signaling profiles, being equally efficacious on G and β-arrestin, while ValProOXT showed reduced relative efficacy toward β-arrestin. Intranasal treatment with either of the variants increased maternal behavior and also promoted unusual paternal care in rats, as measured by pup-retrieval tests. We therefore suggest that ValProOXT and ProOXT are functional variants, which might have been evolutionarily co-opted as an essential part of the adaptive genetic repertoire that allowed the emergence of taxon-specific complex social behaviors, such as intense parental care in the Cebidae and the genus .
The melanocortin 1 receptor (MC1R) is involved in the control of melanogenesis. Polymorphisms in this gene have been associated with variation in skin and hair color and with elevated risk for the development of melanoma. Here we used 11 computational tools based on different approaches to predict the damage-associated non-synonymous single nucleotide polymorphisms (nsSNPs) in the coding region of the human MC1R gene. Among the 92 nsSNPs arranged according to the predictions 62% were classified as damaging in more than five tools. The classification was significantly correlated with the scores of two consensus programs. Alleles associated with the red hair color (RHC) phenotype and with the risk of melanoma were examined. The R variants D84E, R142H, R151C, I155T, R160W and D294H were classified as damaging by the majority of the tools while the r variants V60L, V92M and R163Q have been predicted as neutral in most of the programs The combination of the prediction tools results in 14 nsSNPs indicated as the most damaging mutations in MC1R (L48P, R67W, H70Y, P72L, S83P, R151H, S172I, L206P, T242I, G255R, P256S, C273Y, C289R and R306H); C273Y showed to be highly damaging in SIFT, Polyphen-2, MutPred, PANTHER and PROVEAN scores. The computational analysis proved capable of identifying the potentially damaging nsSNPs in MC1R, which are candidates for further laboratory studies of the functional and pharmacological significance of the alterations in the receptor and the phenotypic outcomes.
The rodent genus Ctenomys (tuco-tucos) comprises more than 60 described species, and shows extraordinary inter- and intraspecific karyotypic variation. The most widely distributed species of Ctenomys in Brazil is C. torquatus. Although several cytogenetic studies have been done, the karyotypic variability of this species is still poorly known. In this paper we report two new diploid numbers for C. torquatus: 2n = 40 and 2n = 42, both showing AN = 72. The new distribution limits of C. torquatus here reported include localities in the southern, central and western parts of Rio Grande do Sul (RS) State in southern Brazil. The phylogenetic relationship between C. torquatus from Alegrete, RS, and Ctenomys sp. from Corrientes, Argentina, is described by means of mtDNA cytochrome b analysis. Although both entities share similar karyotypes and sperm morphology, these two species are not phylogenetically close.
Aim We describe patterns of skull size and shape variation in an Atlantic forest endemic rodent to test the influence of genetic structure, historical and environmental variables upon intraspecific morphological variability. Location South America, Brazil, Atlantic forest. Methods We analyse subtle differences in skull morphology of Akodon cursor through geometric morphometrics applied to 324 individuals from 12 localities distributed throughout the species range. Using cytochrome‐b gene (cyt‐b) sequences from 125 individuals (38 localities), we describe underlying patterns of genetic structure and transform them into distance measures that are included in our morphological analyses. We estimate the relative importance of genetic structure, historical variables and environmental variables on skull size and shape through mixed model selection and Akaike's information criterion. Results Geographical patterns in skull size are mainly explained by non‐random factors related to primary productivity and precipitation, whereas spatial shifts in shape correlate with mitochondrial divergence. Cytochrome‐b data revealed a phylogeographic break around the Jequitinhonha River, yet striking morphological shifts were observed further south. Differences in palaeostability between regions, and the configuration of rivers, appear as secondary sources of explanation for observed patterns. Main conclusions Multiple forces explain morphological variation within A. cursor. Teasing apart the effects of local adaptation and gene flow may be difficult, but is a key to improve our understanding of the drivers of intraspecific morphological variation. Our findings support the view that size is a more labile feature than shape, and that it may more easily break away from constraints imposed by gene flow. The combination of random and non‐random factors, together with documented breaks in the distribution of the Atlantic forest over the Late Quaternary, accounts for the majority of morphological differences observed in A. cursor.
Three new species of Phyllocnistis Zeller (Phyllocnistinae) from the Atlantic Forest, Rio Grande do Sul (RS) state of Brazil, are described. Phyllocnistis ourea sp. nov. is a leaf miner of Baccharis anomala DC. (Asteraceae) in the municipality of Montenegro. The other two species, P. phoebus sp. nov. and P. selene sp. nov. were found mining Begonia fruticosa (Klotzsch) A.DC. (Begoniaceae) and Drimys angustifolia Miers (Winteraceae) leaves, respectively, in the municipality of São Francisco de Paula. Information regarding the natural history of each species is provided. The specific status and phylogenetic relationships, including other members of Phyllocnistis, are inferred from DNA barcode (COI) sequences. Immature stages of the three species are typical sap-feeding instars, followed by a final spinning instar. Differences found in pupal characters and the colour pattern of the fasciae of adult fore wings were stable and thus used to delimit these new species. Thus, five species of Phyllocnistis are now known from Brazil, four of them from the Atlantic Forest. For the first time, we recorded Begoniaceae as a host plant family for Gracillariidae.
ABSTRACT. The melanocortin 1 receptor (MC1R) gene has been described as responsible for the black color in some breeds of sheep, but little is known about its function in many colored breeds, particularly those with a wide range of pigmentation phenotypes. The Brazilian Creole is a local breed of sheep from southern Brazil that has a wide variety of wool colors. We examined the MC1R gene (Extension locus) to search for the e allele and determine its role in controlling wool color variation in this breed. One hundred and twenty-five animals, covering the most common Creole sheep phenotypes (black, brown, dark gray, light gray, and white), were sequenced to detect the mutations p.M73K and p.D121N. Besides these two mutations, three other synonymous sites (429, 600, and 725) were found. The dominant allele (E
Species identification through DNA barcoding is a tool to be added to taxonomic procedures, once it has been validated. Applying barcoding techniques in public health would aid in the identification and correct delimitation of the distribution of rodents from the subfamily Sigmodontinae. These rodents are reservoirs of etiological agents of zoonoses including arenaviruses, hantaviruses, Chagas disease and leishmaniasis. In this study we compared distance-based and probabilistic phylogenetic inference methods to evaluate the performance of cytochrome c oxidase subunit I (COI) in sigmodontine identification. A total of 130 sequences from 21 field-trapped species (13 genera), mainly from southern Brazil, were generated and analyzed, together with 58 GenBank sequences (24 species; 10 genera). Preliminary analysis revealed a 9.5% rate of misidentifications in the field, mainly of juveniles, which were reclassified after examination of external morphological characters and chromosome numbers. Distance and model-based methods of tree reconstruction retrieved similar topologies and monophyly for most species. Kernel density estimation of the distance distribution showed a clear barcoding gap with overlapping of intraspecific and interspecific densities < 1% and 21 species with mean intraspecific distance < 2%. Five species that are reservoirs of hantaviruses could be identified through DNA barcodes. Additionally, we provide information for the description of a putative new species, as well as the first COI sequence of the recently described genus Drymoreomys. The data also indicated an expansion of the distribution of Calomys tener. We emphasize that DNA barcoding should be used in combination with other taxonomic and systematic procedures in an integrative framework and based on properly identified museum collections, to improve identification procedures, especially in epidemiological surveillance and ecological assessments.
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