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In reptiles, dorsal body darkness often varies with substrate color or temperature environment, and is generally presumed to be an adaptation for crypsis or thermoregulation. However, the genetic basis of pigmentation is poorly known in this group. In this study we analyzed the coding region of the melanocortin-1-receptor (MC1R) gene, and therefore its role underlying the dorsal color variation in two sympatric species of sand lizards (Liolaemus) that inhabit the southeastern coast of South America: L. occipitalis and L. arambarensis. The first is light-colored and occupies aeolic pale sand dunes, while the second is brownish and lives in a darker sandy habitat. We sequenced 630 base pairs of MC1R in both species. In total, 12 nucleotide polymorphisms were observed, and four amino acid replacement sites, but none of them could be associated with a color pattern. Comparative analysis indicated that these taxa are monomorphic for amino acid sites that were previously identified as functionally important in other reptiles. Thus, our results indicate that MC1R is not involved in the pigmentation pattern observed in Liolaemus lizards. Therefore, structural differences in other genes, such as ASIP, or variation in regulatory regions of MC1R may be responsible for this variation. Alternatively, the phenotypic differences observed might be a consequence of non-genetic factors, such as thermoregulatory mechanisms. 相似文献
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Male, female, pupa, larva and egg of a new genus and species of Gracillariidae (Gracillariinae), Spinivalva gaucha Moreira and Vargas from southern Brazil are described and illustrated with the aid of optical and scanning electron microscopy. A preliminary analysis of mitochondrial DNA sequences including members of related lineages is also provided. The immature stages are associated with Passiflora actinia, Passiflora misera and Passiflora suberosa (Passifloraceae), and build mines on the adaxial leaf surface. Initially the mines are serpentine in shape, but later in larval ontogeny become a blotch type. Although the larvae are hypermetamorphic as in other Gracillariidae, there is no sap-feeding instar in Spinivalva gaucha; the larva feeds on the palisade parenchyma, thus producing granular frass during all instars. Pupation occurs outside the mine; prior to pupating, the larva excretes numerous bubbles that are placed in rows on the lateral margins of the cocoon external surface. This is the second genus of gracillariid moth described for the Atlantic Rain Forest, and the second gracillariid species known to be associated with Passifloraceae. 相似文献
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The yeast centrosome translates the positional information of the anaphase spindle into a cell cycle signal 总被引:3,自引:0,他引:3 下载免费PDF全文
The spindle orientation checkpoint (SPOC) of budding yeast delays mitotic exit when cytoplasmic microtubules (MTs) are defective, causing the spindle to become misaligned. Delay is achieved by maintaining the activity of the Bfa1-Bub2 guanosine triphosphatase-activating protein complex, an inhibitor of mitotic exit. In this study, we show that the spindle pole body (SPB) component Spc72, a transforming acidic coiled coil-like molecule that interacts with the gamma-tubulin complex, recruits Kin4 kinase to both SPBs when cytoplasmic MTs are defective. This allows Kin4 to phosphorylate the SPB-associated Bfa1, rendering it resistant to inactivation by Cdc5 polo kinase. Consistently, forced targeting of Kin4 to both SPBs delays mitotic exit even when the anaphase spindle is correctly aligned. Moreover, we present evidence that Spc72 has an additional function in SPOC regulation that is independent of the recruitment of Kin4. Thus, Spc72 provides a missing link between cytoplasmic MT function and components of the SPOC. 相似文献
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Saraiva DG Fournier GF Martins TF Leal KP Vieira FN Câmara EM Costa CG Onofrio VC Barros-Battesti DM Guglielmone AA Labruna MB 《Experimental & applied acarology》2012,58(2):159-166
From June 2005 to November 2010, 43 small mammals encompassing 6 species of Didelphimorphia, 8 species of Rodentia, and 1 species of Lagomorpha were found parasitized by ticks in the state of Minas Gerais, southeastern Brazil. Nine tick species, in total 186 specimens, were identified as follows: Amblyomma cajennense (larvae and nymphs) on opossums and rodents; Amblyomma ovale (nymphs) on rodents; Amblyomma parvum (nymphs) on rodents; Amblyomma coelebs (nymphs) on opossums; Amblyomma dubitatum (nymph) on opossums; Ixodes amarali (females, nymphs, and larvae) on opossums and rodents; Ixodes loricatus (male, females, nymph) on opossums; Ixodes schulzei (female) on rodents; and Haemaphysalis leporispalustris (female) on rabbits. Most of the tick-host associations found in the present study have never been recorded in the literature; those include three new host records for I. amarali, four for A. cajennense, one for A. dubitatum, two for A. ovale, and one for A. coelebs. In addition, we provide the first record of A. coelebs in the state of Minas Gerais. 相似文献
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The Araucaria forest is Brazil's highly threatened subtropical forest ecosystem that has been disappearing in recent decades. Restoration programs involving this forest type are scarce, and there is a lack of scientific information on how ecological processes such as competition, facilitation, and seed dispersal influence natural forest restoration. This work aims to investigate how use of perches to attract seed dispersers and the influence of pioneer vegetation and soil fertilization could affect the colonization of woody species in a degraded area. An experiment was conducted in an abandoned field where the natural establishment of seeds and seedlings of woody species was monitored under factorial combinations of the following treatments: (1) pioneer vegetation (presence and absence); (2) soil fertility (addition of NPK and control); and (3) perches (presence and absence). Seed and seedling abundance, seed and seedling species richness, and seedling mortality were recorded monthly during 12 months. Seed abundance and species richness were significantly greater in places with perches than in control plots. These results were consistent over the year and more pronounced when the surrounding forest produced a higher amount of fruit. Species richness and abundance of seedlings were significantly greater in places with perches than in control plots, and in places with vegetation than without. Soil fertility did not influence seedling establishment. Facilitation and seed dispersal are important factors affecting the colonization of woody species in this subtropical area. Nutrient availability neither regulates the facilitation process nor influences species replacement during the early stages of Araucaria forest succession. 相似文献
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Gabriela B. Cybis Gislene L. Gonçalves Alcides Pissinatti Francisco M. Salzano Maria Cátira Bortolini 《Journal of evolutionary biology》2018,31(8):1180-1192
Traits that undergo massive natural selection pressure, with multiple events of positive selection, are hard to find. Social behaviour, in social animals, is crucial for survival, and genetic networks involved in behaviour, such as those of serotonin (5‐HT) and other neurotransmitters, must be the target of natural selection. Here, we used molecular analyses to search for signals of positive selection in the 5‐HT system and found such signals in the M3‐M4 intracellular domain of the 5‐HT3A serotonin receptor subunit (HTR3A) in primates. We detected four amino acid sites with signs of putatively positive selection (398, 403, 432 and 416); the first three showed indications of being selected in New World monkeys (NWM, Platyrrhini), specifically in the Callitrichinae branch. Additionally, we searched for associations of these amino acid variants with social behavioural traits (i.e. sex‐biased dispersal, dominance and social monogamy) using classical and Bayesian methods, and found statistically significant associations for unbiased sex dispersal (398L and 416S), unbiased sex dominance (416S) and social monogamy (416S), as well as significant positive correlation between female dispersal and 403G. Furthermore, we found putatively functional protein motifs determined by three selected sites, of which we highlight a ligand motif to GSK3 in the 416S variant, appearing only in Platyrrhini. 5‐HT, 5‐HT3A receptor and GSK3 are part of a network that participates in neurodevelopment and regulates behaviour, among other functions. We suggest that these genetic variations, together with those found in other neurotransmitter systems, must contribute to adaptive behaviours and consequently to fitness in NWMs. 相似文献
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In Vitro Susceptibility of Environmental Isolates of Exophiala dermatitidis to Five Antifungal Drugs
Ana Paula Miranda Duarte Fernando Carlos Pagnocca Noemi Carla Baron Marcia de Souza Carvalho Melhem Gislene Aparecida Palmeira Dejanira de Franceschi de Angelis Derlene Attili-Angelis 《Mycopathologia》2013,175(5-6):455-461
Several dematiaceous fungi frequently isolated from nature are involved in cases of superficial lesions to lethal cerebral infections. Antifungal susceptibility data on environmental and clinical isolates are still sparse despite the advances in testing methods. The objective of this study was to examine the activities of 5-flucytosine, amphotericin B, itraconazole, voriconazole and terbinafine against environmental isolates of Exophiala strains by minimum inhibition concentration (MIC) determination. The strains were obtained from hydrocarbon-contaminated soil, ant cuticle and fungal pellets from the infrabuccal pocket of attine gynes. Broth microdilution assay using M38-A2 reference methodology for the five antifungal drugs and DNA sequencing for fungal identification were applied. Terbinafine was the most active drug against the tested strains. It was observed that amphotericin B was less effective, notably against Exophiala spinifera, also studied. High MICs of 5-flucytosine against Exophiala dermatitidis occurred. This finding highlights the relevance of studies on the antifungal resistance of these potential opportunistic species. Our results also contribute to a future improvement of the standard methods to access the drug efficacy currently applied to black fungi. 相似文献
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Iliane Freitas de Souza Alexandre F. Souza Marco Aurélio Pizo Gislene Ganade 《Biodiversity and Conservation》2010,19(6):1683-1698
To evaluate the effects of distinct management of the matrix in which forest fragments are found upon plant populations thriving
in forest remnants in south Brazil, we assessed the conservation status of populations of four woody species (Campomanesia rhombea, Diospyros incontans, Myrciaria cuspidata and Sebastiania commersoniana) through analyses of size structure. Analyzes were carried out at two scales. At a local scale, we consider populations in
fragments surrounded by pastures or eucalypts forest plantations, and at a regional scale we also consider larger forest tracts
taken as reference areas (Rio Grande do Sul Forest Inventory databank). Population size structures were summarized using the
symmetry of height distributions. Small individual size classes prevailed at the local scale in fragments surrounded by eucalypts
plantations, whereas in areas exposed to cattle ranching, populations of the same species consistently lack small individuals.
At the regional scale, populations in fragments surrounded by pastures presented greater skewness (prevalence of small plants)
than populations in reference areas, while populations surrounded by eucalypts plantations presented intermediate skewness.
These results reinforce the notion that plantations have a higher conservation value for forest ecosystems than other commercial
land uses, like cattle ranching. 相似文献