On the systematic position ofChaetomys subspinosus (Rodentia: Caviomorpha) based on evidence from the incisor enamel microstructure

We have studied the incisor enamel microstructure ofChaetomys subspinosus and other possibly closely related caviomorph rodents.Chaetomys subspinosus lacks the important synapomorphy of the Octodontoidea, reactangular plate-like interprismatic matrix (IPM) in the portio interna (PI) of the incisor Schmelzmuster. Therefore its transfer from the Erethizontidae to the Echimyidae, as proposed by Patterson and Wood (Bull. Mus. Comp. Zool. 149, 371–543, 1982) based on retention of dP4, is contested. The parallel to acute angular IPM in the PI ofChaetomys and the Erethizontidae is a symplesiomorphy and does not indicate close relationship. Contrary to previous claims, a posterior carotid foramen is also retained inChaetomys. Chaetomys is characterized by an unusual thin enamel which is considered primitive after outgroup comparison. Therefore, it is proposed to leaveChaetomys in the monospecific erethizontid subfamily Chaetomyinae, until additional information on the species is available.     

Home range,movements and diurnal roosts of the endangered thin-spined porcupine,Chaetomys subspinosus (Rodentia: Erethizontidae), in the Brazilian Atlantic Forest

Chaetomys subspinosus is the sole species within the Chaetomyinae subfamily of Caviomorph rodents. This poorly studied porcupine is restricted to the Atlantic Forest in eastern Brazil, where deforestation and habitat fragmentation threaten its survival. Data on the ranging and roosting behavior of C. subspinosus is fairly scarce as it is difficult to observe these behaviors in nature and, consequently, it is very rarely detected during field surveys. We monitored the home ranges of three radio-tagged females over the course of 1 year (2005–2006) and collected data on several aspects of their natural history including movement patterns and the use of diurnal roosts and latrines. The animals were monitored at Parque Estadual Paulo Cesar Vinha, a nature reserve dominated by restinga forests, a subtype of Atlantic Forest occurring on sandy soil. The estimated home range varied little between individuals and was relatively small (mean = 2.14 ha/individual and 1.09 ha/individual using minimum convex polygon and kernel methods, respectively). The animals travelled an average of 147 m/night (range: 21–324 m/night) between two consecutive day roosts. The day roosts were mostly located on vine and liana tangles in the canopy which also aid in connecting the canopy to adjacent trees or the forest floor. Latrines were mostly located near the ground in places heavily protected by spiny bromeliads or by other tangled vegetation. Our data suggests that C. subspinosus has the smallest range among all Neotropical Erethizontids which is likely due to its small size and strictly folivorous diet. Our data also helps explain why C. subspinosus is so difficult to observe in nature: researchers should focus on arboreal masses of tangled vegetation where individuals will normally rest during the day.     

Translocation and long-term monitoring of threatened thin-spined porcupines (Chaetomys subspinosus) on the Brazilian coast

With increasing infrastructural development along Brazil’s coast, environmental regulation measures are becoming increasingly necessary in the face of the damage caused by large projects that impact tropical forests. Brazilian legislation supports implementation of translocation programs for impacted fauna, especially threatened species such as the thin-spined porcupine Chaetomys subspinosus (Rodentia, Erethizontidae). Thus, we present a case study of a pioneer translocation program for the thin-spined porcupine in southeastern Brazil. We aimed to analyze the home-range and habitat selection of three translocated porcupines and one resident individual. In addition, we analyzed the success of the translocations. The porcupines were monitored by radiotelemetry for 3–16 months from October 2015 to March 2017 in a mosaic landscape of restinga forests (sandbank forest vegetation) within a eucalyptus matrix. The translocated porcupines had considerably larger home-ranges (14.29–18.36 ha, minimum convex polygon method – MCP) than did the resident animal (1.22 ha – MCP). We observed stabilization in the home-range size curves of the translocated females in the 7th − 9th month of monitoring. All translocated individuals achieved permanence within a preselected area, indicating adaptation to the new area. In addition, individuals showed a clear preference for restinga forests over drained eucalyptus plantations. Thus, our results demonstrate the feasibility of thin-spined porcupine translocations and the importance of maintaining restinga forest remnants outside of protected areas for the conservation and permanence of viable populations of this rodent.     

Relaxin gene family in teleosts: phylogeny, syntenic mapping, selective constraint, andexpression analysis

Background  

In recent years, the relaxin family of signaling molecules has been shown to play diverse roles in mammalian physiology, but little is known about its diversity or physiology in teleosts, an infraclass of the bony fishes comprising ~ 50% of all extant vertebrates. In this paper, 32 relaxin family sequences were obtained by searching genomic and cDNA databases from eight teleost species; phylogenetic, molecular evolutionary, and syntenic data analyses were conducted to understand the relationship and differential patterns of evolution of relaxin family genes in teleosts compared with mammals. Additionally, real-time quantitative PCR was used to confirm and assess the tissues of expression of five relaxin family genes in Danio rerio and in situ hybridization used to assess the site-specific expression of the insulin 3-like gene in D. rerio testis.     

Arsenophonus, an emerging clade of intracellular symbionts with a broad host distribution

Background  

The genus Arsenophonus is a group of symbiotic, mainly insect-associated bacteria with rapidly increasing number of records. It is known from a broad spectrum of hosts and symbiotic relationships varying from parasitic son-killers to coevolving mutualists.     

Characterisation and expression of a PP1 serine/threonine protein phosphatase (PfPP1) from the malaria parasite, <Emphasis Type="Italic">Plasmodium falciparum:</Emphasis> demonstration of its essential role using RNA interference

Background  

Reversible protein phosphorylation is relatively unexplored in the intracellular protozoa of the Apicomplexa family that includes the genus Plasmodium, to which belong the causative agents of malaria. Members of the PP1 family represent the most highly conserved protein phosphatase sequences in phylogeny and play essential regulatory roles in various cellular pathways. Previous evidence suggested a PP1-like activity in Plasmodium falciparum, not yet identified at the molecular level.     

Phylogenetic relationships in genus <Emphasis Type="Italic">Arachis</Emphasis> based on ITS and 5.8S rDNA sequences

Background  

The genus Arachis comprises 80 species and it is subdivided into nine taxonomic sections (Arachis, Caulorrhizae, Erectoides, Extranervosae, Heteranthae, Procumbentes, Rhizomatosae, Trierectoides, and Triseminatae). This genus is naturally confined to South America and most of its species are native to Brazil. In order to provide a better understanding of the evolution of the genus, we reconstructed the phylogeny of 45 species using the variation observed on nucleotide sequences in internal transcribed spacer regions (ITS1 and ITS2) and 5.8 S of nuclear ribosomal DNA.     

Distinct evolutionary histories of the DNA-A and DNA-B components of bipartite begomoviruses

Background  

Viruses of the genus Begomovirus (family Geminiviridae) have genomes consisting of either one or two genomic components. The component of bipartite begomoviruses known as DNA-A is homologous to the genomes of all geminiviruses and encodes proteins required for replication, control of gene expression, overcoming host defenses, encapsidation and insect transmission. The second component, referred to as DNA-B, encodes two proteins with functions in intra- and intercellular movement in host plants. The origin of the DNA-B component remains unclear. The study described here was initiated to investigate the relationship between the DNA-A and DNA-B components of bipartite begomoviruses with a view to unraveling their evolutionary histories and providing information on the possible origin of the DNA-B component.     

Suppression of RNA interference increases alphavirus replication and virus-associated mortality in Aedes aegypti mosquitoes

Background  

Arthropod-borne viruses (arboviruses) can persistently infect and cause limited damage to mosquito vectors. RNA interference (RNAi) is a mosquito antiviral response important in restricting RNA virus replication and has been shown to be active against some arboviruses. The goal of this study was to use a recombinant Sindbis virus (SINV; family Togaviridae; genus Alphavirus) that expresses B2 protein of Flock House virus (FHV; family Nodaviridae; genus Alphanodavirus), a protein that inhibits RNAi, to determine the effects of linking arbovirus infection with RNAi inhibition.     

Characterisation of the genetic diversity of <Emphasis Type="Italic">Brucella</Emphasis> by multilocus sequencing

Background  

Brucella species include economically important zoonotic pathogens that can infect a wide range of animals. There are currently six classically recognised species of Brucella although, as yet unnamed, isolates from various marine mammal species have been reported. In order to investigate genetic relationships within the group and identify potential diagnostic markers we have sequenced multiple genetic loci from a large sample of Brucella isolates representing the known diversity of the genus.     

Frequency and diversity of small cryptic plasmids in the genus <Emphasis Type="Italic">Rahnella</Emphasis>

Background  

Rahnella is a widely distributed genus belonging to the Enterobacteriaceae and frequently present on vegetables. Although Rahnella has interesting agro-economical and industrial properties and several strains possess antibiotic resistances and toxin genes which might spread within microbial communities, little is known about plasmids of this genus. Thus, we isolated a number of Rahnella strains and investigated their complements of small plasmids.     

Evaluation of three commercial bovine ELISA kits for detection of antibodies against Alphaherpesviruses in reindeer (<Emphasis Type="Italic">Rangifer tarandus tarandus</Emphasis>)

Background  

The genus Varicellovirus (family Herpesviridae subfamily Alphaherpesvirinae) includes a group of viruses genetically and antigenically related to bovine herpesvirus 1 (BoHV-1) among which cervid herpesvirus 2 (CvHV-2) can be of importance in reindeer. These viruses are known to be responsible for different diseases in both wild and domestic animals. Reindeer are a keystone in the indigenous Saami culture and previous studies have reported the presence of antibodies against alphaherpesviruses in semi-domesticated reindeer in northern Norway. Mortality rates, especially in calves, can be very high in some herds and the abortion potential of alphaherpesvirus in reindeer, unlike in bovines, remains unknown.     

Heme rescues a two-component system <Emphasis Type="Italic">Leptospira biflexa</Emphasis> mutant

Background  

Heme is typically a major iron source for bacteria, but little is known about how bacteria of the Leptospira genus, composed of both saprophytic and pathogenic species, access heme.     

Evolution and diversity of Rickettsia bacteria

Background  

Rickettsia are intracellular symbionts of eukaryotes that are best known for infecting and causing serious diseases in humans and other mammals. All known vertebrate-associated Rickettsia are vectored by arthropods as part of their life-cycle, and many other Rickettsia are found exclusively in arthropods with no known secondary host. However, little is known about the biology of these latter strains. Here, we have identified 20 new strains of Rickettsia from arthropods, and constructed a multi-gene phylogeny of the entire genus which includes these new strains.     

Evolutionary history of the fish genus <Emphasis Type="Italic">Astyanax</Emphasis> Baird &; Girard (1854) (Actinopterygii,Characidae) in Mesoamerica reveals multiple morphological homoplasies

Background  

Mesoamerica is one of the world's most complex biogeographical regions, mostly due to its complex geological history. This complexity has led to interesting biogeographical processes that have resulted in the current diversity and distribution of fauna in the region. The fish genus Astyanax represents a useful model to assess biogeographical hypotheses due to it being one of the most diverse and widely distributed freshwater fish species in the New World. We used mitochondrial and nuclear DNA to evaluate phylogenetic relationships within the genus in Mesoamerica, and to develop historical biogeographical hypotheses to explain its current distribution.     

Partial characterization of an exopolysaccharide secreted by a marine bacterium,Vibrio neocaledonicus sp. nov., from New Caledonia

Aims

Exopolysaccharides (EPS) are industrially valuable molecules with numerous useful properties. This study describes the techniques used for the identification of a novel Vibrio bacterium and preliminary characterization of its EPS.

Methods and Results

Bioprospection in marine intertidal areas of New Caledonia followed by screening for EPS producing brought to selection of the isolate NC470. Phylogenetic analysis (biochemical tests, gene sequencing and DNA–DNA relatedness) permitted to identify NC470 as a new member of the Vibrio genus. The EPS was produced in batch fermentation, purified using the ultrafiltration process and analysed by colorimetry, Fourier Transform Infrared spectroscopy, gas chromatography, Nuclear Magnetic Resonance and HPLC‐size exclusion chromatography. This EPS exhibits a high N‐acetyl‐hexosamines and uronic acid content with a low amount of neutral sugar. The molecular mass was 672 × 10³ Da. These data are relevant for possible technological exploitation.

Conclusions

We propose the name Vibrio neocaledonicus sp. nov for this isolate NC470, producing an EPS with an unusual sugar composition. Comparison with other known polymers permitted to select applications for this polymer.

Significance and Impact of the Study

This study contributes to evaluate the marine biodiversity of New Caledonia. It also highlights the biotechnological potential of New Caledonia marine bacteria.     

The <Emphasis Type="Italic">WTX/AMER1</Emphasis> gene family: evolution,signature and function

Background  

WTX is a novel gene mutated in a proportion of Wilms' tumors and in patients suffering from sclerosing bone dysplasia. On the molecular level WTX has been shown to act as an antagonist of canonical Wnt/β-catenin signaling in fish and mammals thus linking it to an essential pathway involved in normal development and cancer formation. Interestingly, WTX seems to also localize to an intranuclear component called paraspeckles. In spite of the growing interest of molecular biologists in WTX, little is known about its paralogs and its phylogenetic history.     

Exploring the HME and HAE1 efflux systems in the genus <Emphasis Type="Italic">Burkholderia</Emphasis>

Background  

The genus Burkholderia includes a variety of species with opportunistic human pathogenic strains, whose increasing global resistance to antibiotics has become a public health problem. In this context a major role could be played by multidrug efflux pumps belonging to Resistance Nodulation Cell-Division (RND) family, which allow bacterial cells to extrude a wide range of different substrates, including antibiotics. This study aims to i) identify rnd genes in the 21 available completely sequenced Burkholderia genomes, ii) analyze their phylogenetic distribution, iii) define the putative function(s) that RND proteins perform within the Burkholderia genus and iv) try tracing the evolutionary history of some of these genes in Burkholderia.     

Avidin related protein 2 shows unique structural and functional features among the avidin protein family

Background  

The chicken avidin gene family consists of avidin and several avidin related genes (AVRs). Of these gene products, avidin is the best characterized and is known for its extremely high affinity for D-biotin, a property that is utilized in numerous modern life science applications. Recently, the AVR genes have been expressed as recombinant proteins, which have shown different biotin-binding properties as compared to avidin.