Thales Freitas

Thales Freitas
Universidade Federal do Rio Grande do Sul | UFRGS · Departamento de Genética

PhD

About

475
Publications
72,098
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
4,201
Citations
Additional affiliations
August 2013 - February 2014
University Joseph Fourier - Grenoble 1
Position
  • Visitor
February 1996 - March 1997
University of California, Berkeley
Position
  • Visitor
August 1985 - present
Universidade Federal do Rio Grande do Sul
Position
  • Professor Titular

Publications

Publications (475)
Article
Full-text available
In order to monitor the effects of anthropogenic pressures in ecosystems, molecular techniques can be used to characterize species composition. Among molecular markers capable of identifying species, the cytochrome c oxidase I (COI) is the most used. However, new possibilities of biodiversity profiling have become possible, in which molecular fragm...
Preprint
Full-text available
Human impacts have been eroding marine ecosystems in such a way that biodiversity patterns are changing. Therefore, policies and science-based solutions are indispensable for monitoring threats to the most impacted species. In such effort, the analysis of elasmobranchs' environmental traces via eDNA metabarcoding represent a candidate tool for effe...
Article
Full-text available
The Neotropical underground rodents of the genus Ctenomys (Rodentia: Ctenomyidae) comprise about 65 species, which harbor the most significant chromosomal variation among mammals (2n = 10 to 2n = 70). Among them, C. minutus stands out with 45 different cytotypes already identified, among which, seven parental ones, named A to G, are parapatrically...
Book
Full-text available
Sinopse: Encadernada com capa dura e composta de 214 páginas, impressas em papel couché, a obra contem diversas ilustrações e fotografias, todas em cores (inclusive as tabelas). Tem como base dados morfológicos coletados de animais que participaram ao longo de vinte anos na Expointer, uma das exposições agropecuárias mais importantes da América Lat...
Preprint
The genus Ctenomys has been widely used in karyotype evolution studies due to the variation in their diploid numbers (2n), which range from 2n = 10 to 2n = 70. Ctenomys minutus is characterized by intraspecific variation in diploid number (2n = 42, 46, 48, and 50), which makes it an interesting model to investigate the genomic instability mechanism...
Article
Full-text available
Karyotypic analyses have several applications in studies of chromosome organization, evolution, and cytotaxonomy. They are also essential to genome assembly projects. Here, we present for the first time the karyotype description of the endangered species yellow cardinal, Gubernatrix cristata (Passeriformes, Thraupidae), using conventional staining...
Article
Full-text available
The phylogenetic position and taxonomic status of Rhynchocyclidae (Aves: Passeriformes) have been the subject of debate since their first description. In most models, Rhynchocyclidae represents a subfamily-level taxon placed within the Tyrant Flycatchers (Tyrannidae). Considering that this classification does not include cytotaxonomic characters, w...
Article
Full-text available
• Elasmobranchs are apex predators that play a crucial role in marine ecosystems by regulating the dynamics of food webs, as well as connecting different trophic levels across habitats. • The large-scale removal of elasmobranchs impacts the energy transfer in trophic interactions. The pressure of unsustainable fisheries is considerable, as most ela...
Preprint
Full-text available
Anthropogenic pressures have been depleting the global biodiversity. In order to monitor the changes in ecosystems, molecular techniques can be used to characterize species composition. Among molecular markers capable of identifying species, the COI is the most used, and its sequencing is the standard procedure of how taxonomic information can be s...
Preprint
Full-text available
Sound signals can travel through long distances, becoming an important communication channel between animals that need to establish contact beyond the visual form. They can then be considered a relevant form of communication between species living in the underground environment. Ctenomys torquatus and Ctenomys lami are solitary subterranean rodents...
Article
Full-text available
Interchromosomal rearrangements involving microchromosomes are rare events in birds. To date, they have been found mostly in Psittaciformes, Falconiformes, and Cuculiformes, although only a few orders have been analyzed. Hence, cytogenomic studies focusing on microchromosomes in species belonging to different bird orders are essential to shed more...
Chapter
The vast mammal diversity of the Neotropics is the result of a long evolutionary history. Among mammals, rodents comprise more than half of all Neotropical mammal species, and South America is home to about a quarter of the entire world’s rodent species. However, the economic growth of the region still depends strongly on natural resource exploitat...
Chapter
The genus Ctenomys is comprised of more than 70 valid living species. It is the largest collection of fossorial mammals that occupy underground habitats, mainly in the grasslands of South America. We investigated different aspects of morphological evolution in the genus Ctenomys, with special attention to the skull. We analyzed 1359 craniums and 83...
Article
Yellow Cardinal is an Endangered Species. Its populations are in constant decline due to habitat reduction and loss and illegal capture. There are approximately 50 free-living animals in the south of Brazil (state of Rio Grande do Sul), but estimates indicate more than 1000 in captivity. Our goals were to investigate the genetic variability of capt...
Chapter
The genus Ctenomys is one of the most specious among the subterraneous rodent genera. The most recent revision lists 65 species. Regarding speciation models, it has always been accepted that the genus Ctenomys would have diversified due to allopatric processes. However, no reports have discussed the speciation models that might have generated this...
Article
Identifying factors that create and maintain a hybrid zone is of great interest to ecology, evolution and, more recently, conservation biology. Here, we investigated the role of environmental features in shaping the spatial dynamics of a hybrid zone between the southern tigrina, Leopardus guttulus, and Geoffroy’s cat, L. geoffroyi, testing for exog...
Book
This book examines the biology of tuco-tucos (Ctenomys) from an evolutionary perspective. Historically, these subterranean rodents have long attracted the attention of scientists due to its remarkable chromosomes variability and rapid diversification. A wealth of knowledge on physiology, ecology, genetics, morphology, paleontology, and taxonomy has...
Article
Full-text available
Although cytogenetics studies in cuckoos (Aves, Cuculiformes) have demonstrated an interesting karyotype variation, such as variations in the chromosome morphology and diploid number, their chromosome organization and evolution, and relation with other birds are poorly understood. Hence, we combined conventional and molecular cytogenetic approaches...
Article
Full-text available
Biodiversity loss is currently one of the most important societal concerns worldwide, and it is caused mainly by habitat loss and fragmentation, biological invasion, and climate change (Vitousek et al. 1996, Newbold et al. 2015, Bellard et al. 2016). Introduced species can have positive effects on human well‐being, especially when used for liveliho...
Article
Full-text available
Endemic, small range species are susceptible to environmental changes and landscape modification. Understanding genetic diversity and distributional patterns is important for implementation of effective conservation measures. In this context, genetic diversity was evaluated to update the conservation status of an endemic tuco-tuco, Ctenomys ibicuie...
Article
We present a new assessment of the genetic and morphological variation within Oxymycterus quaestor Thomas, 1903, which currently includes the junior synonyms O. judex Thomas, 1909 and O. misionalis Sanborn, 1931. We integrate distinct lines of evidence, including variation of mitochondrial (Cytochrome b [Cytb]) and nuclear (intron 7 of beta fibrino...
Article
Full-text available
Knowledge of how animal species use food resources available in the environment increases our understanding of ecological processes. However, obtaining this information using traditional methods is a hard task for species feeding on a large variety of food items in highly diverse environments. We amplified the DNA of plants for 306 scat and 40 soil...
Article
In contrast to the ‘avian-like’ diploid number (2n = 80), most toucans and aracaris (Piciformes: Ramphastidae) have divergent karyotypes, exhibiting a higher 2n. To identify the chromosomal rearrangements that shaped the karyotype of these species, we applied chicken macrochromosome paints 1–10 and 11 microsatellite sequences to the chromosomes of...
Article
Full-text available
The Columbidae species (Aves, Columbiformes) show considerable variation in their diploid numbers (2n = 68-86), but there is limited understanding of the events that shaped the extant karyotypes. Hence, we performed whole chromosome painting (wcp) for paints GGA1-10 and bacterial artificial chromosome (BAC) probes for chromosomes GGA11-28 for Colum...
Article
Full-text available
As species recover from exploitation, continued assessments of connectivity and population structure are warranted to provide information for conservation and management. This is particularly true in species with high dispersal capacity, such as migratory whales, where patterns of connectivity could change rapidly. Here we build on a previous long-...
Article
Full-text available
The genus Ctenomys comprises approximately 70 recognized living species of subterranean rodents endemic to South America. Phylogenetic studies to date, based on mitochondrial DNA data, place 44 recognized species in eight species groups and provide evidence for a burst of speciation early in the history of the genus. Species from Argentina, Uruguay...
Article
Full-text available
The order Charadriiformes comprises three major clades: Lari and Scolopaci as sister group to Charadrii. Until now, only three Charadriiformes species have been studied by chromosome painting: Larus argentatus (Lari), Burhinus oedicnemus and Vanellus chilensis (Charadrii). Hence, there is a lack of information concerning the third clade, Scolapaci....
Article
Full-text available
Reproductive compatibility usually decreases according to increasing genetic difference and the time of divergence between species. However, the amount of modification required to influence hybridization may vary in different species. Thus, it is extremely important to conduct studies that seek to understand what and how variables influence the rep...
Article
Full-text available
After 50 years without any formal record of Ephemeridae from the South Brazil, we present the rediscover of the family from the region, recorded Hexagenia (Pseudeatonica) albivitta (Walker, 1853) for the first time in Rio Grande do Sul State, including notes on its morphology and ecology.
Article
We describe a new species of the cricetid rodent Oxymycterus (Sigmodontinae), which inhabits a transitional area between the southern Cerrado and the Atlantic Forest in south-southeastern Brazil. Compared to other Oxymycterus, the new species is large-sized with a tawny-brown pelage coloration. The new species could be differentiated from other Oxy...
Article
Full-text available
The Candiota coal mine in Rio Grande do Sul (RS) is one of the largest in Brazil. Coal is a fossil fuel that causes environmental impacts from its extraction to combustion due to the release of different agents, such as polycyclic aromatic hydrocarbons (PAH) and heavy metals. Ctenomys torquatus are herbivorous and subterranean rodents that dig tunn...
Article
Full-text available
Road-barrier effects can lead to population isolation, with consequent negative outcomes for individuals and populations. Small mammals have been identified as particularly vulnerable to barrier effects, yet few studies have focused on subterranean species. Given the burrowing habit of these species, we hypothesized that roads block their movement...
Article
Full-text available
We studied the population ecology of the South American subterranean rodent Ctenomys flamarioni at the Taim Ecological Station, Rio Grande do Sul, Brazil. A capture-mark-release program was conducted in two different time periods: (A) from February 2004 to November 2005 and (B) from December 2011 to March 2013; as a result, a total of131 individual...
Article
Accurate identification of predator species is a critical requirement to investigate their diet using faecal samples. We used non-invasive sampling and two methods of predator identification to investigate the diets of sympatric carnivores in a highly deforested region of the Brazilian Amazon. Of 108 scats, 81 could be identified at the species lev...
Article
Full-text available
A major interest of evolutionary biologists is to understand which environmental features are associated with morphological and behavioural characteristics of species. Intraspecific studies addressing this question provide the best evidence for ecology-driven evolution over short time scales. Here, we evaluated whether two adjacent habitats differ...
Article
Full-text available
Mesenchymal stem/stromal cells (MSCs) are multipotent cells distributed in all tissues and characterized by adherence, morphology, immunophenotype and trilineage differentiation potential. The present study aimed to isolate and characterize adherent MSC-like populations from different tissues of Ctenomys minutus, a threatened wildlife rodent popula...
Article
Full-text available
Zonotrichia capensis is widely distributed in the Neotropics. Previous cytogenetic studies demonstrated the presence of polymorphisms in two chromosome pairs (ZCA2 and ZCA4). Here, we report results based on comparative chromosome painting, using probes derived from Gallus gallus and Leucopternis albicollis, focused on characterizing the chromosome...
Book
Full-text available
O Brasil possui uma das maiores riquezas de mamíferos do mundo, com mais de 700 espécies reconhecidas, pertencentes a 12 ordens. O processo de avaliação do estado de conservação dos mamíferos brasileiros contou com a participação de quatro Centros de Pesquisa e Conservação do Instituto Chico Mendes: Centro Nacional de Pesquisa e Conservação de Mamí...
Article
Full-text available
Pigeons and doves (Columbiformes) are one of the oldest and most diverse extant lineages of birds. However, the karyotype evolution within Columbiformes remains unclear. To delineate the synteny-conserved segments and karyotypic differences among four Columbidae species, we used chromosome painting from Gallus gallus (GGA, 2n = 78) and Leucopternis...
Article
Full-text available
Spines, or modified hairs, have evolved multiple times in mammals, particularly in rodents. In this study, we investigated the evolution of spines in six rodent families. We first measured and compared the morphology and physical properties of hairs between paired spiny and non-spiny sister lineages. We found two distinct hair morphologies had evol...
Data
Deformation curves in relation to tension (A, C, E) and force (B, D, F) for hairs of eleven rodent species, clustered according to the cross-section shape of the hair. (TIF)
Data
Young’s modulus for the linear portion of hair deformation curves (Fig 5A) for eleven rodent species. The modulus was calculated as E = σ/ε for the initial portion of each deformation curve (at 3% of deformation). (TIF)
Preprint
Full-text available
Spines, or modified hairs, have evolved multiple times in mammals, particularly in rodents. In this study, we investigated the evolution of spines in six rodent families. We first measured and compared the morphology and physical properties of hairs between paired spiny and non-spiny sister lineages. We found two distinct hair morphologies had repe...
Article
Full-text available
An extensive karyotype variation is found among species belonging to the Columbidae family of birds (Columbiformes), both in diploid number and chromosomal morphology. Although clusters of repetitive DNA sequences play an important role in chromosomal instability, and therefore in chromosomal rearrangements, little is known about their distribution...
Article
Full-text available
The Neotropical region currently harbors 8 recognized species of small cats, including the margay (Leopardus wiedii) and jaguarundi (Puma yagouaroundi). These similar-sized species have broad geographic distributions and commonly occur in sympatry. We constructed species occurrence databases and used the maximum entropy (Maxent) modeling approach t...
Article
Full-text available
Patterns of univariate trait variation across metacommunities are widely explored, as are searches for their underlying causes. Surprisingly, patterns of multivariate shape remain unknown, and the search for drivers of functional traits of communities often neglect the biogeographical distribution of phylogenetic clades. Our aim was to investigate...
Article
Full-text available
We tested the association between chromosomal polymorphism and skull shape and size variation in two groups of the subterranean rodent Ctenomys. The hypothesis is based on the premise that chromosomal rearrangements in small populations, as it occurs in Ctenomys, produce reproductive isolation and allow the independent diversification of population...
Data
- Definition of landmarks.
Article
Full-text available
A major interest of evolutionary biologists is to understand which environmental features are associated with morphological and behavioural characteristics of species. Intraspecific studies addressing this question provide the best evidence for ecology-driven evolution over short time scales. Here, we evaluated whether two adjacent habitats differ...
Article
Full-text available
Pleistocene climatic oscillations favoured the expansion of grassland ecosystems and open vegetation landscapes throughout the Neotropics, and influenced the evolutionary history of species adapted to such environments. In this study, we sampled populations of the rodent Oxymycterus nasutus endemic to open areas in the Pampas and Atlantic Forest bi...
Data
Scatter plot of the first Canonical Variate axis for the skull of O. nasutus in the lateral view, with groups following the genetic haplogroups (A, B) and the physiognomies (C). Changes in the shape for each axis are given. Solid lines indicate positive scores and dashed lines indicate negative ones. (TIF)
Data
Additional localities retrieved from the literature for the spatial distribution modelling analysis. (DOCX)
Data
Position of the landmarks (circles) digitized on the dorsal, ventral, and lateral views of the O. nasutus skull. A description of each landmark is presented in S1 Appendix. (TIF)