Papers by Leonardo Pessoa Felix
Revista Brasileira de Farmacognosia, 2018
bioRxiv (Cold Spring Harbor Laboratory), Nov 1, 2023
Holocentric karyotypes are assumed to rapidly evolve through chromosome fusions and fissions due ... more Holocentric karyotypes are assumed to rapidly evolve through chromosome fusions and fissions due to the diffuse nature of their centromeres. Here, we took advantage of the recent availability of a chromosome-scale reference genome for Rhynchospora breviuscula, a model species of this holocentric genus, and developed the first set of oligo-based barcode probes for a holocentric plant. These probes were applied to 13 additional species of the genus, aiming to investigate the evolutionary dynamics driving the karyotype evolution in Rhynchospora. The two sets of probes were composed of 27,392 (green) and 23,968 (magenta) oligonucleotides, and generated 15 distinct FISH signals as a unique barcode pattern for the identification of all five chromosome pairs of the R. breviuscula karyotype. Oligo-FISH comparative analyzes revealed different types of rearrangements, such as fusions, fissions, putative inversions and translocations, as well as genomic duplications among the analyzed species. Two rounds of whole genome duplication (WGD) were demonstrated in R. pubera, but both analyzed accessions differed in the complex chain of events that gave rise to its large, structurally diploidized karyotypes with 2n = 10 or 12. Considering the phylogenetic relationships and divergence time of the species, the specificity and synteny of the probes were maintained up to species with a divergence time of ~25 My. However, karyotype divergence in more distant species hindered chromosome mapping and the inference of specific events. This barcoding system is a powerful tool to study chromosomal variations and genomic evolution in holocentric chromosomes of Rhynchospora species.
Revista Brasileira de Biociências, Oct 2, 2007
Iheringia, Série Botânica
Baixas (FEDTB) na Paraíba apresentam relações florísticas complexas, ora sendo consideradas mais ... more Baixas (FEDTB) na Paraíba apresentam relações florísticas complexas, ora sendo consideradas mais relacionadas à Mata Atlântica, ora sendo entendidas como mais próximas à Caatinga, ou mesmo como áreas transicionais (ecótonos). Desta forma, tem-se como objetivo analisar as relações florísticas do componente lenhoso ocorrente nas FEDTB do Agreste Pré-Litorâneo da Paraíba com a Mata Atlântica litorânea e a Caatinga interiorana. Foram selecionados 22 levantamentos florísticos e realizadas análises de Similaridade Florística e Análise de Parcimônia de Endemismo (PAE). Ambas as análises revelaram que as FEDTB formam um grupo mais relacionado à Caatinga s.l., não constituindo um ecótono. A presença de elementos da Mata Atlântica nas FEDTB é marcada especialmente por espécies amplamente distribuídas em ecossistemas florestais do Brasil. Maiores precipitações e sazonalidade menos acentuada em relação à Caatinga podem explicar a ocorrência de espécies típicas das matas úmidas nas FEDTB.
Annals of Botany, 2022
Background and Aims The entangled relationship of chromosome number and genome size with species ... more Background and Aims The entangled relationship of chromosome number and genome size with species distribution has been the subject of study for almost a century, but remains an open question due to previous ecological and phylogenetic knowledge constraints. To better address this subject, we used the clade Maxillariinae, a widely distributed and karyotypically known orchid group, as a model system to infer such relationships in a robust methodological framework. Methods Based on the literature and new data, we gathered the chromosome number and genome size for 93 and 64 species, respectively. We built a phylogenetic hypothesis and assessed the best macroevolutionary model for both genomic traits. Additionally, we collected together ecological data (preferences for bioclimatic variables, elevation and habit) used as explanatory variables in multivariate phylogenetic models explaining genomic traits. Finally, the impact of polyploidy was estimated by running the analyses with and with...
Botanical Journal of the Linnean Society, 2021
To contribute to what is known about involvement of vegetation dynamics in Neotropical speciation... more To contribute to what is known about involvement of vegetation dynamics in Neotropical speciation, we used the Epidendrum latilabre complex, a taxonomically well-defined species group, to investigate past connections between Amazonian (AM) and Atlantic (AF) forests and address the following topics: (1) divergence times between sister species currently distributed in AM and AF; (2) distribution patterns of ancestral species of the E. latilabre complex and (3) potential routes connecting ancestral ranges between AM and AF. We developed a robust phylogenetic estimate for species of the E. latilabre complex by sequencing two nuclear and six plastid loci. Then, we combined divergence time estimation, ancestral range reconstruction and ecological niche modelling. Our biogeographic reconstruction exhibits a complex pattern of connections among tropical forests east of the Andes in South America. The AM and AF species of the E. latilabre complex are intermixed in the results, and climatic s...
Genome, 2021
Alstroemeria (Alstroemeriaceae) displays a conserved and highly asymmetric karyotype, where most ... more Alstroemeria (Alstroemeriaceae) displays a conserved and highly asymmetric karyotype, where most rDNA sites can be properly recognized by the size and morphology of the chromosomes. We analyzed the intraspecific variation of rDNA sites in A. longistaminea and compared with their distribution in other species (A. caryophyllaea and A. piauhyensis) and a representative of a sister genus, Bomarea edulis. All three species of Alstroemeria presented 2n = 16, and one to six B chromosomes were found in some individuals of A. longistaminea. There was a set of 12 conserved rDNA sites (four 5S and eight 35S) and up to 11 variable sites. B chromosomes were almost entirely covered by 35S signals, coupled with tiny 5S sites. Noteworthy, most rDNA sites found in A. caryophyllaea and A. piauhyensis were localized in chromosome positions similar to those in A. longistaminea, suggesting the existence of conserved hotspots for rDNA accumulation. Some of these hotspots were absent in Chilean Alstromeri...
Protoplasma, 2021
Alstroemeria species present a well-conserved and asymmetric karyotype. The genus is divided into... more Alstroemeria species present a well-conserved and asymmetric karyotype. The genus is divided into a Chilean clade, rich in heterochromatin, and a Brazilian clade, poor in heterochromatin. We investigated the distribution of the main repetitive sequences in the chromosomes of the Brazilian species A. longistaminea (2 n = 16 + 0-6B) aiming to evaluate the role played by these sequences on the structural organization of the karyotype. In situ hybridization of the three most abundant retrotransposons, corresponding to ~ 45% of the genome, was uniformly distributed. Three satellite DNA sequences, representing near half of the whole satellite fraction (1.93% of the genome), were mainly concentrated on the heterochromatin and one of them painted the whole B chromosome. Noteworthy, some satellites were located on euchromatin, either dispersed or concentrated in clusters along the chromosomes, revealing a G-band-like pattern. The two satellites that presented more C-band- and G-band-like labeling were also hybridized in situ in two other Alstroemeria species. They revealed astonishing similar patterns of distribution, indicating an unusually structural karyotype conservation among Brazilian species.
Botanical Journal of the Linnean Society, 2020
In this study, we analyse a species complex in Epidendrum, a mega-diverse Neotropical orchid genu... more In this study, we analyse a species complex in Epidendrum, a mega-diverse Neotropical orchid genus, that is formed by the 11 Brazilian species of the E. difforme group. Although this group (c. 100 taxa) exhibits relatively high levels of floral variation, the Brazilian species are similar, making delimitation problematic. Here we combine molecular (phylogenetics), morphological (geometric morphometrics), genome size and cytogenetic (chromosome counts and CMA/DAPI staining) data to investigate circumscription of these species. Our results were interpreted by looking for congruence of the results as a means to delimit species. The studied taxa appear to be monophyletic, and karyotypically all analysed accessions were 2n = 40. Their 1C values vary from 1.99 ± 07 pg to 2.84 ± 0.12 pg. We did not find evidence for recent polyploidy or dysploidy and, apparently, these phenomena have not been important in the evolution of this species complex. On the other hand, we found high levels of pol...
TAXON, 2019
The chromosome numbers ascertained here are different from those reported by other authors Chukr ... more The chromosome numbers ascertained here are different from those reported by other authors Chukr & Giulietti, 2008). ** Species with intra-specific cytotype variation. * Band position: i, interstitial; p, proximal; t, terminal; (st), satellite (the number of satellited chromosomes is indicated in parentheses)
Plant Systematics and Evolution, 2020
The subtribe Laeliinae (Orchidaceae) comprises approximately 2000 species and 38 genera, with num... more The subtribe Laeliinae (Orchidaceae) comprises approximately 2000 species and 38 genera, with numerically stable karyotypes of 2n = 40 (x = 20) in most species. Cytomolecular and chromosome banding analyses have not yet been combined with phylogenetic studies, making the understanding of chromosomal evolution in the group more difficult. The present work sought to perform comparative cytogenetic analyses of representatives of the subtribe Laeliinae, followed by the interpretation of that data within an evolutive context. We analyzed 23 species from seven genera for their chromosome numbers and morphology, the distribution of CMA and DAPI bands, fluorescent in situ hybridization (FISH) with 5S and 35S rDNA and DNA quantification by flow cytometry. All of the species showed 2n = 40, suggesting an apparent macrostructural karyotypic stability, except the polyploids Encyclia alboxanthina, E. jenischiana, E. seidelii, Laelia gouldiana and Prosthechea faresiana (2n = 80). At least two CMA + /DAPI -terminal bands were observed in all analyzed species. Additionally, CMA + / DAPI -blocks were observed in the pericentromeric region of species of the genera Brassavola, Cattleya (except C. trianae) and Laelia. Terminal CMA -/DAPI + bands were observed in representatives of Brassavola, Laelia and Guarianthe. The clade Brassavola + Cattleya + Laelia, that presented high number of heterochromatic bands, also showed expansions of the numbers of 5S rDNA sites. DNA contents varied from 2C = 2.85 pg (Prosthechea fragrans) to 2C = 5.76 pg (Laelia gouldiana) without relation with number of CMA/DAPI bands or 5S rDNA sites. The relationship between the amplification of repetitive DNAs (viewed here as rDNA sites or heterochromatic bands) and genome size variation is discussed and compared with other plant groups.
Acta Botanica Brasilica, 2019
Cactaceae species are karyotypically well-known with x = 11 and chromosome number variation due m... more Cactaceae species are karyotypically well-known with x = 11 and chromosome number variation due mainly to polyploidization. However, both assumptions are based on descriptive observations without taking an evolutionary framework of Cactaceae into account. Aiming to confirm these hypotheses in an evolutionary context, we obtained chromosome numbers for 20 species of Cactoideae, performed an extensive review of chromosome number for the family, and analyzed these data using a phylogenetic approach. The karyotypes presented here were characterized by CMA/DAPI banding, and for six species 5S and 45S rDNA sites were located. Our data, along with a survey of the literature, reinforce the long-standing hypothesis of a x = 11 as the base chromosome number for Cactaceae. They also reinforce the relevance of polyploidy in karyotype evolution of cacti, although polyploidy was important just after the diversification of subfamilies Maihuenioideae and Pereskioideae. Despite the homogeneous chromosome complements observed among cacti, chromosome banding and FISH techniques revealed informative characteristics, allowing the identification of chromosome synapomorphies, such as proximal CMA + bands in Melocactus and proximal 5S rDNA in Pilosocereus, indicating the taxonomic potential of chromosome characterization in cacti.
Revista Brasileira de Ciências Agrárias - Brazilian Journal of Agricultural Sciences, 2007
Objetivou-se estudar a vegetação sucessional em um campo de sisal abandonado há 30 anos, no munic... more Objetivou-se estudar a vegetação sucessional em um campo de sisal abandonado há 30 anos, no município de Pocinhos, Paraíba. Foram plotadas 20 parcelas de 10 x 20 m e tomados o DNS (Diâmetro a Nível do Solo) e a altura total de todos os indivíduos. A diferença entre adultos e regenerantes foi estabelecida a partir do DNS sendo que, para esses últimos, foram estabelecidas quatro classes de tamanho: Classe I (0,3 a 1,49 m); Classe II (1,5 a 2,49 m); Classe III (2,5 a 3 m) e Classe IV (altura > 3 m e DNS < 3 cm). Identificaram-se 1569 indivíduos pertencentes a 19 Famílias, 33 Gêneros e 45 Espécies. O valor do índice de diverssidade de Shannon foi de 2,16 e a área basal total foi de 23,85 m 2 .ha -1 . As espécies adultas de maior VI foram: Pilosocereus glaucescens (Labour.) Byles, Pithecellobium diversifolium G.P. Lewis, Caesalpinia pyramidalis Tul. e Schinopsis brasiliensis Engl., sendo que a primeira espécie contribuiu com 27% do VI total. As Classes I e II detiveram 45 e 41% dos regenerantes, respectivamente. Conclui-se que o período de 30 anos após o abandono da cultura, foi suficiente para a recuperação da vegetação nativa, cujas diversidade e estrutura estão compatíveis com as da caatinga, no contexto regional.
Curtis's Botanical Magazine, 2018
This special issue highlights some of the wonderful species of native Australian tobacco (Nicotia... more This special issue highlights some of the wonderful species of native Australian tobacco (Nicotiana sect. Suaveolentes). We here present twelve species of this genus, four of which are new to science. Many Nicotiana species have a high ornamental value, and we hope that particularly the rarer Australian species will find a way into horticulture to prevent them from becoming threatened. This would allow maintenance of ex-situ populations, mitigating the effects of changing climate and introduction of invasive species. Tobaccos dispersed into the Australian outback around two million years ago and are now radiating there. It has been clear that they have interesting cytological evolution as well as morphological differences. They appear to have peculiar drought adaptations, which are needed for thin-leaved herbs growing in some of the driest places on the planet.
Phytotaxa, 2018
We describe a new species of Gomesa (Oncidiinae, Orchidaceae), Gomesa caatingana, with restricted... more We describe a new species of Gomesa (Oncidiinae, Orchidaceae), Gomesa caatingana, with restricted distribution on caatinga inselbergs in Paraíba and Pernambuco States, Brazil. Morphological and karyological characters of the new species were compared with those of Gomesa flexuosa, which is morphologically the most closely related species. Differences in geographical distribution, habit, flower morphology and chromosome number support description of this new species.
Plant Biology, 2017
1) Orchidaceae is a widely distributed plant family with a very diverse vegetative and floral mor... more 1) Orchidaceae is a widely distributed plant family with a very diverse vegetative and floral morphology and such variability is also reflected in their karyotypes. However, since only a low proportion of Orchidaceae has been analysed for chromosome data, a greater diversity may await to be unveiled. Here we analyse both genome size (GS) and karyotype in two subtribes recently included in the broadened Maxillariineae to detect how much chromosome and GS variation there are in these groups and to evaluate which genome rearrangements were involved in the species evolution. (2) To do so, the GS (14 species), the karyotype -based on chromosome number, heterochromatic banding and 5S and 45S rDNA localisation (18 species) -was characterized and analysed along with published data using phylogenetic approaches. (3) The GS presented a high phylogenetic correlation and it was related to morphological groups in Bifrenaria (larger plantshigher GS). The two largest GS found among genera were caused by different mechanisms: by polyploidy in
Revista Brasileira de Farmacognosia, 2017
Pilosocereus pachycladus F. Ritter, Cactaceae, popularly known as "facheiro", is used as food and... more Pilosocereus pachycladus F. Ritter, Cactaceae, popularly known as "facheiro", is used as food and traditional medicine in Brazilian caatinga ecoregion. The plant is used to treat prostate inflammation and urinary infection. The present work reports the first secondary metabolites isolated from P. pachycladus. Therefore, the isolated compound 4-hydroxy-3,5-dimethoxy benzaldehyde (syringaldehyde) was evaluated as modulator of Staphylococcus aureus pump efflux-mediated antibiotic resistance. The isolation of compounds was performed using chromatographic techniques and the structural elucidation was carried out by spectroscopic methods. In order to evaluate syringaldehyde ability to modulate S. aureus antibiotic resistance, its minimum inhibitory concentrations (g/ml) was first determinate, then, the tested antibiotics minimum inhibitory concentrations were determined in the presence of the syringaldehyde in a sub-inhibitory concentration. The chromatographic procedures led to isolation of twelve compounds from P. pachycladus including fatty acids, steroids, chlorophyll derivatives, phenolics and a lignan. The syringaldehyde did not show any antibacterial activity at 256 g/ml against S. aureus. On the other hand the compound was able to reduce the antibiotic concentration (tetracycline, norfloxacin, ethidium bromide) required to inhibit the growth of drug-resistant bacteria, showing the ability of syringaldehyde of inhibiting the efflux pump on these bacteria.
Genetics and molecular research : GMR, Jan 17, 2016
Most taxa in the Bignoniaceae have 2n = 40, but the basal clade Jacarandeae has 2n = 36, suggesti... more Most taxa in the Bignoniaceae have 2n = 40, but the basal clade Jacarandeae has 2n = 36, suggesting that x = 18 is the ancestral basic number for the family. Variations in heterochromatin band patterns in genera that are numerically stable, such as Jacaranda, could facilitate our understanding of the chromosomal and karyotypic evolution of the family. We characterized heterochromatin distributions in six Jacaranda species using chromomycin A3 (CMA) and 4'6-diamidino-2-phenylindole (DAPI). All of them had 2n = 36, including first counts for Jacaranda bracteata Bureau & K. Schum., Jacaranda irwinii A.H. Gentry, Jacaranda jasminoides (Thunb.) Sandwith, and Jacaranda rugosa A.H. Gentry. Their karyotypes had four to eight terminal CMA(+)/DAPI(-) bands per monoploid set. In the section Monolobos, Jacaranda brasiliana (Lam.) Pers. had eight terminal bands and Jacaranda mimosifolia D. Don had four; in the section Dilobos, J. bracteata had six bands per monoploid set, with the other spec...
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Papers by Leonardo Pessoa Felix