Torque teno viruses are an enigma, since contradictory data have defined them as both harmless and opportunistic. Dogs also have their own Torque tenovirus (TTCaV), which has been detected in various countries. The purpose of this study was to find TTCaV, for the first time in Italy, in the feces of seemingly healthy dogs and to assess risk variables associated with greater prevalences. In total, 18 of 171 animals (10.5%) tested positive for nested end-point PCR. No individual component (sex, age, etc.) was related with greater prevalences, although there were substantial disparities between kennels and mixed-breed animals. TTCaV was more frequently identified in dogs with an altered fecal score, although it did not appear to co-infect CPV-2-positive animals (only one of the 18 animals was also positive for CPV-2). A total of six amplicons were sequenced, yielding two distinct sequences that, when deposited in international databases and compared with those published in other studies, allowed the homology between the many strains to be detected globally (mostly in Asia). Although many questions about TTVs (such as their true pathogenicity) remain unanswered, our work described the presence of this virus in the dog population of southern Italy, providing valuable information for the study of this virus in Europe.

Raw donkey milk, a lesser-known but nutritionally valuable resource, has gained recognition for its unique composition and potential health benefits. It is within this context that the diversity, technological attributes, safety considerations, and probiotic potential of enterococci from raw donkey milk are explored. This study aimed to determine whether these isolates could be potential probiotics in donkey milk. A total of 25 Gram-positive, catalase-negative bacteria were obtained from twenty raw milk samples collected from a donkey species from Southern-Western Haryana, utilizing selective microbiological media. All isolates underwent identification through both phenotypic and molecular techniques and were subjected to a comprehensive assessment of their technological and probiotic properties. To assess their viability as starter or adjunct cultures, the isolates were evaluated for their susceptibility to antibiotics, absence of virulence factors, and absence of hemolytic activity, and the safety analysis of these isolates revealed that the majority exhibited susceptibility to clinically important antibiotics, such as vancomycin. Overall, the findings of this study suggest that the Enterococci strains that are present in raw donkey milk are unlikely to pose a significant risk to human health. Additionally, they display noteworthy technological characteristics such as high antibacterial efficacy against Staphylococcus aureus, Pseudomonas, Escherichia coli, etc. It was possible to enhance the antibacterial activities against these pathogenic strains by using various induction techniques and use them as potential probiotics in fermented food products.

The Andes are among the world's most significant hotspots of species richness and have acted both as a barrier and a conduit for biota with diverse geographic origins. The grasshopper genus Orotettix, with its ten species endemic to the Central Andes, offers a compelling opportunity to study diversification mechanisms. Previous studies have suggested that speciation in Orotettix was primarily allopatric, driven by glacial–interglacial cycles during the late and mid-Pleistocene. However, it has also been suggested that some species, which are distributed almost sympatrically, may have differentiated through sympatric or parapatric speciation due to adaptation along elevation gradients. In this study, we performed the first genomic approach to analyze the phylogenetic relationships and the population structure of Orotettix species, to ultimately have an insight into the strength of species limits and the role of altitude in speciation and adaptation. We conducted a RAD-Seq procedure to analyze 95 samples representing seven Orotettix species. We obtained a final matrix of 1239 RAD-loci (one SNP per locus), and performed a Maximum Likelihood phylogenetic analysis using IQ-TREE and a population analysis using STRUCTURE. We identified a total of five clusters, which differentiate samples at the species level. Notably, the sister species O. andeanus and O. carrascoi were found within a single cluster, suggesting ongoing gene flow between them. Additionally, two individuals were found to have mixed ancestry, with 50% genetic contribution from both O. andeanus and O. dichrous, indicative of hybridization between these deeply diverged species (2 Ma). The results presented herein, together with the fact that they share significant geographic and ecological niche overlap, underline the need for revising the taxonomic status of O. andeanus and O. carrascoi. It is also remarkable that O. dichrous displays significant niche overlap with these two species. These results confirm the critical role of ecological niche in hybridization.

Parotocinclus includes 27 species of small armored catfish that occur in coastal river basins of Brazil, and also in the São Francisco river basin (SF). Four species occur exclusively in the SF: P. cearensis, P. jumbo, P. prata and P. robustus. Recent sampling in a tributary on the right bank of the São Francisco river revealed a population distinct morphologically from the congeners known to the basin. An integrative taxonomic study, using morphological and molecular data, revealed it as a new species. Parotocinclus sp. n. differs from its congeners, except P. bidentatus, P. cabessadecuia, P. jacumirim, P. muriaensis, P. pukuixe, P. seridoensis and P. spilurus, by its vestigial or rudimentary adipose fin (vs. developed adipose fin). The new species differs from P. bidentatus and P. muriaensis by the absence of accessory unicuspid teeth (vs. presence), from P. jacumirim and P. seridoensis by the abdomen being completely covered with large plates (vs. an abdomen with small plates and naked areas in P. jacumirim and P. seridoensis, and an abdomen with small plates without naked areas in P. pukuixe), from P. spilurus by the pectoral girdle being completely covered by odontodes (vs. the pectoral girdle being covered solely laterally by odontodes), and from P. cabessadecuia by having rounded white spots on the head (vs. an absence of white spots). The phylogenetic results based on molecular data indicate that Parotocinclus sp. n. is a sister taxa of P. jacumirim and both are closely related to a clade that includes P. bahiensis and P. minutus, but distant from P. maculicauda, the type species of the genus. The molecular results showed a clear structuring of Parotocinclus sp. n., supporting the hypothesis of a new species indicated by the morphological analyses.

Compsura is a genus of freshwater fish belonging to the order Characiformes and the family Characidae, subfamily Cheirodontinae. The type species, Compsura heterura, was described based on specimens from the Itapicuru River, which is part of the North Group (GN) within the Northeast Mata Atlântica ecoregion (NMAF). Although the original description focused on the Itapicuru River, C. heterura has also been found in the São Francisco (São Francisco ecoregion, SF) and Parnaíba (Parnaíba ecoregion, PB) river basins. Recent studies have suggested a broader distribution in the GN of the NMAF, including the Sergipe, Vaza-Barris, and Pojuca river basins, which indicated possible historical connections between these basins and the SF, influencing species distribution. The present study aimed to investigate, describe, and analyze the phylogeographic pattern of C. heterura in the NMAF and SF ecoregions. To this end, mitochondrial COI gene sequences from samples of the species in these ecoregions were obtained and analyzed. A haplotype network was constructed and comparatively analyzed with a distribution map also developed in this study. Five haplotypes were found, all of which are exclusive to the basins where they occur. The absence of shared haplotypes indicates structuring within the species, corroborated by the number of mutational steps that separate them. This structuring is evident both between distinct ecoregions (NMAF and SF) and within the same ecoregion (NMAF). Considering that freshwater fishes tend to have their biogeographic history related to the history of the basins where they occur, the results found are as expected, since these drainages are isolated from each other.

The genus Hemigrammus is one of the most representative of the Characidae family. It includes about 60 valid species, distributed mainly in the Amazon basin, but species also occur in the São Francisco River basin and in coastal drainages of the Northeast region of Brazil. This study focused on two species within this genus, Hemigrammus brevis and H. marginatus, which coexist in the Itapicuru (Northeastern Mata Atlântica ecoregion, NMAF), São Francisco (São Francisco ecoregion, SF), and potentially the Vaza-Barris (NMAF) River basins. The sharing of these species among these basins partly supports the hypothesis that the Itapicuru and Vaza-Barris rivers may have once been tributaries of a basin that included the main course of São Francisco River. Although the sharing of fish species among these ecoregions provides a starting point for understanding the biogeographic history of the rivers draining them, no comprehensive population-level study has been conducted until now. In this context, the present study aimed to investigate, describe, and analyze the phylogeographic pattern of H. brevis and H. marginatus within the NMAF and SF ecoregions. Mitochondrial COI gene sequences were obtained and analyzed from samples collected across all basins where they occur, including their type localities. The results revealed haplotype sharing among some populations of H. marginatus from different localities and ecoregions, along with subtle structuring within the NMAF. In contrast, H. brevis exhibited no haplotype sharing, indicating subtle structuring between the Itapicuru and São Francisco River basins, with only a few mutational steps separating the distinct haplotypes. These findings suggest that the two congeneric species share a similar phylogeographic history, supporting the idea of past connectivity between the SF and NMAF ecoregions, particularly through tributaries of the right bank of the São Francisco River and the Itapicuru river basin.

Comparative phylogeographic analyses provide a means to examine the influence of past abiotic changes on species distributions, as drastic or rapid landscape changes are expected to produce congruent phylogeographic patterns across multiple taxa. Despite the unparalleled biodiversity of the Neotropical Region, phylogeographic studies in this domain remain limited, particularly concerning the aquatic biota of Atlantic Forest rivers. The species Mimagoniates microlepis and M. sylvicola were selected as models for this study because they are co-distributed in the Northeastern Mata Atlântica Ecoregion (NMAF). The aim of this study was to investigate, describe, and analyze the phylogeographic pattern of these species in the NMAF. For this purpose, we analyzed mitochondrial DNA from samples collected across the known distribution of the species within the area of interest. Haplotype networks were constructed and comparatively analyzed based on a distribution map of the species, which was also created in this study. The results indicate that, for M. microlepis, five distinct haplotypes were identified, distributed across five different drainages, with only one shared between different localities. For M. sylvicola, 12 distinct haplotypes were identified across seven drainages. The absence of shared haplotypes suggests significant phylogeographic structuring in M. sylvicola, further supported by the high number of mutational steps separating the haplotypes. Interestingly, this study found intraspecific structuring in M. sylvicola but no significant structuring in M. microlepis. According to the fundamental principles of comparative phylogeography, congruent genetic structuring among co-distributed species typically occurs due to a shared biogeographic history. However, although such a pattern was expected within the same genus, the results of this study reveal that the Mimagoniates species in the NMAF display incongruent genetic distribution patterns. This discrepancy may reflect distinct biogeographical or evolutionary histories that require further investigation.

The Trimerotropis pallidipennis complex, comprising species such as Trimerotropis andeana, Trimerotropis ochraceipennis, and Trimerotropis sp., is a group of Andean grasshoppers that presents challenges in species delimitation and shows signs of hybridization events. Climate change and Andean landscape fluctuations may have facilitated hybridization between phylogenetically related species.

The difficulty in clearly defining species within this group and the absence of clear morphological differentiation suggest the possibility of hybridization among closely related species. Using RAD-seq loci markers, individuals from various lineages in southern South America were analyzed. The PhyloNetworks, Treemix, and fastsimcoal programs were employed to detect hybridization events and estimate the proportion of genes inherited by hybrid nodes.

The analysis revealed the presence of more than one hybrid event within this complex. One hybrid event occurred from Trimerotropis andeana to Trimerotropis ochraceipennis, and another was detected between populations from Mendoza, San Luis, and La Rioja with the Uspallata population of Trimerotropis sp. This study provides insights into the interactions between related species in the context of climate and geological changes in the Andes and it will contribute to understanding the mechanisms of speciation and adaptation in mountainous environments, with implications for conservation and biogeography in the Andean region.

Oecomys is a taxonomically complex and cytogenetically diverse genus with a controversial intraspecific phylogenetic relationship. Karyotypic analyses, using whole chromosome probes from Hylaeamys megacephalus (HME, Sigmodontinae, Oryzomyini) in some taxonomic lineages of this genus have been detecting the rearrangements that shaped their karyotypes, in addition to revealing relevant insights into the taxonomic status of these taxa. Thus, intending to investigate the chromosomal evolution of the genus, we characterized the karyotype of Oecomys rutilus (ORU) with HME probes, establishing chromosomal homology maps with the karyotypes of other congeners that already mapped with the same set of probes. The chromosomal phylogeny obtained by Maximum Parsimony analysis recovered the genus Oecomys as monophyletic, with moderate bootstrap support (68%). This clade branches into two large groups, the first including O. rutilus followed by O. catherinae - Rio de Janeiro and O. catherinae – Pará; the other group includes O. auyantepui followed by O. paricola cytotype C and O. paricola cytotype A + cytotype B. We detected that these taxa underwent intensive reorganization in their karyotypes, and the rearrangements that produced this diversity were 15 pericentric inversions, 12 centric fusions, 11 fissions, 5 in tandem fusions, 8 simple translocations, 1 neo-centromere and addition/deletion of constitutive heterochromatin on two autosomes and the X chromosomes. However, despite the high number of chromosomal rearrangements found, we identified some entirely conserved syntenic blocks shared among all species analyzed. From these data, we hypothesized a putative ancestral karyotype (2n=60/FN= 62) for the species analyzed. We also detected exclusive characteristics for ORU, the syntenic blocks HME 1/20/4, HME (16,17)/3, HME 2/1, HME 2/7, HME 5/(9,10)/8, HME 19/12. Here we provide an overview of the chromosomal reorganization of the genus that points to a high chromosomal diversity, and demonstrates that chromosomal rearrangements play a significant role in the radiation of these species.

Chromosomal studies in birds have shown that this group has an extremely conserved karyotype compared to other lineages of vertebrates. Passeriformes is the most species-rich order within this class and is the most cytogenetically studied, presenting a karyotype similar to the ancestral avian karyotype (2n=80). The Antbirds (Thamnophilidae) comprise a Neotropical passeriform family, which includes many insectivorous bird species. Different species occur in all Neotropical biomes, though the local species richness of this family is far higher in tropical forest sites. Thamnophilus palliatus is a species native to the Amazon region, also found on the northeast and southeast coasts of Brazil. The objective of this study was to determine the karyotype of T. palliatus. Field collection was carried out in Belém/Pará using mist nets. A male and a female were caught. After euthanization, chromosomal preparation was obtained according to Ford and Hamerton (1956), then the metaphasic chromosomes were stained with Giemsa for analysis. Chromosome painting was performed using whole chromosome probes from Gallus gallus (GGA, 2n=78) and Burhinus oedicnemus (BOE, 2n=42). As a result, we observed a 2n=80 and fundamental number (FN) of 84 chromosomes, with 10 pairs of macrochromosomes and 70 micro chromosomes. The BOE-1 and BOE-2 probes marked in two pairs each, which is consistent with the results of other studies in this family, though BOE-2 marked only the long arm of pair THP-1; the remaining probes marked one chromosome each or micro-chromosomes. GGA-Z marked the same pair as BOE-2, but on the short arm, it marked an unusual pattern for the first time described for this order. A similar rearrangement has been described for the order Psittaciformes. More experiments are needed in other populations of this species for a better understanding of this new Z chromosome and how it is impacting the species.