Search

The IUCN Red List of Threatened Species contains 175 Brazilian bat species that are threatened by extinction in some degree. From this perspective, it is essential to expand the knowledge about the genetic diversity of vulnerable bats. Genomic sequencing can be useful to generate robust and informative genetic references, increasing resolution when analyzing relationships among populations, species, or higher taxonomic levels. In this study, we sequenced and characterized in detail the first complete mitochondrial genomes of Furipterus horrens, Lonchorhina aurita, and Natalus macrourus, and investigated their phylogenetic position based on amino acid sequences of protein-coding genes (PCGs). The mitogenomes of these species are 16,516, 16,697, and 16,668 bp in length, respectively, and each comprises 13 PCGs, 22 tRNA genes, two rRNA genes, and a putative control region (CR). In the three species, genes were arranged similarly to all other previously described bat mitogenomes, and nucleotide composition was also consistent with the reported range. The length and arrangement of rrnS and rrnL were also consistent with those of other bat species, showing a positive AT-skew and a negative GC-skew. Except for trnS1, for which we did not observe the DHU arm, all other tRNAs showed the cloverleaf secondary structure in the three species. In addition, the mitogenomes showed minor differences in start and stop codons, and in all PCGs, codons ending in adenine were more common compared to those ending in guanine. We found that PCGs of the three species use multiple codons to encode each amino acid, following the previously documented pattern. Furthermore, all PCGs are under purifying selection, with atp8 experiencing the most relaxed purifying selection. Considering the phylogenetic reconstruction, F. horrens was recovered as sister to Noctilio leporinus, L. aurita and Tonatia bidens shared a node within Phyllostomidae, and N. macrourus appeared as sister to Molossidae and Vespertilionidae. [ABSTRACT FROM AUTHOR]

Here we present a taxonomic treatment for the Brazilian species of Syrbatus (Reitter, 1882), including the description of three new species (Syrbatus moustache Asenjo & Valois sp. nov., Syrbatus obsidian Asenjo & Valois sp. nov. and Syrbatus superciliata Asenjo & Valois sp. nov.) from the Quadrilátero Ferrífero (Minas Gerais, Brazil). In addition, we designated lectotypes for the Brazilian species of species-group 2, Syrbatus centralis (Raffray, 1898), Syrbatus hetschkoi (Reitter, 1888), Syrbatus hiatusus (Reitter, 1888), Syrbatus transversalis (Raffray, 1898), and Syrbatus trinodulus (Schaufuss, 1887), besides recognizing the holotype for Syrbatus brevispinus (Reitter, 1882), Syrbatus bubalus (Raffray, 1898), and Syrbatus grouvellei (Raffray, 1898). The mitochondrial genomes (mitogenomes) of the three new species are presented, for which we present the phylogenetic placement among Staphylinidae with previously published data. [ABSTRACT FROM AUTHOR]

RNA editing is a post-transcriptional process that challenges the central dogma of molecular biology by modifying RNA sequences, introducing nucleotide changes at specific sites, and generating functional diversity beyond the genomic code, especially when it concerns organellar transcripts. In plants, this phenomenon is widespread, but its extent varies significantly among species and organellar genomes. Among land plants, the heterosporous lycophytes (i.e., Isoetes and Selaginella) stand out for their exceptionally high numbers of RNA-editing sites, despite their morphological stasis and ancient lineage. In this study, we explore the complete set of organellar protein-coding genes in the aquatic plant group Isoetes, providing a detailed analysis of RNA editing in both the mitochondrial and plastid genomes. Our findings reveal a remarkable abundance of RNA editing, particularly in the mitochondrial genome, with thousands of editing sites identified. Interestingly, the majority of these edits result in non-silent substitutions, suggesting a role in finetuning protein structure and function. Furthermore, we observe a consistent trend of increased hydrophobicity in membrane-bound proteins, supporting the notion that RNA editing may confer a selective advantage by preserving gene functionality in Isoetes. The conservation of highly edited RNA sequences over millions of years underscores the evolutionary significance of RNA editing. Additionally, the study sheds light on the dynamic nature of RNA editing, with shared editing sites reflecting common ancestry whereas exclusive edits matching more recent radiation events within the genus. This work advances our understanding of the intricate interplay between RNA editing, adaptation, and evolution in land plants and highlights the unique genomic features of Isoetes, providing a foundation for further investigations into the functional consequences of RNA editing in this enigmatic plant lineage. [ABSTRACT FROM AUTHOR]

Despite the huge difference in land coverage between mountains and lowlands, most species are indeed found in mountains and foothills. The causes of this pattern have challenged biogeographers and evolutionary biologists. The Espinhaço and Mantiqueira Ranges are large mountain ranges from eastern Brazil that are global biodiversity hotspots located between the Brazilian Atlantic Forest (AF) and the Cerrado. However, Espinhaço and Mantiqueira species diversity may still be underestimated, either due taxonomic complexity or morphological cryptic species complexes. Two hylid frogs, Bokermannohyla nanuzae and Bokermannohyla feioi, are endemic, respectively, distributed in these two mountain ranges. These species were recently synonymized based on traditional taxonomy. We used data from the mitochondrial DNA (mtDNA) gene 16S and two nuclear genes to undertake phylogenetic and network, distance-based, and multispecies coalescent analyses on B. nanuzae, B. feioi, and an extensive outgroup dataset. We tested the monophyly of B. nanuzae, as well as the presence of candidate new species. Based on 16S phylogenetic analysis, We recovered B. nanuzae as paraphyletic, with B. sagarana nested within it. We recovered two main groups, with the geographic distribution generally corresponding to the Cerrado and AF boundaries. Probably due to ancestral polymorphism, both nuclear haplotype genealogies failed to distinguish B. nanuzae from the former B. feioi and/or from B. sagarana. The time-calibrated mtDNA tree revealed that B. martinsi, B. sagarana, and B. nanuzae have diverged during the Late Miocene, subsequently splitting into the remaining species/lineages during the Plio-Pleistocene. Taken together, our distance-based barcode and nuclear Bayesian analyses identified the former B. feioi, referred to as the AF group, as a distinct evolutionary lineage from B. nanuzae (Cerrado group). We provide the first insights into how different evolutionary lineages speciated in the highlands of southeastern Brazil and revalidated B. feioi for the AF group. [ABSTRACT FROM AUTHOR]

Geonoma maxima (Poit.) Kunth is an example of a species complex, among many others restricted to Neotropical rain forests, which contribute to their high species diversity. Using environmental, morphological, karyological, and molecular data, we aim to test the taxonomic circumscription of 3 of the 11 G. maxima subspecies defined in the latest taxonomic treatment. We evaluated 217 samples of G. maxima complex from Ducke Reserve in the state of Amazonas, Brazil. Environmental preferences were significant at the 0.1% level. Subspecies maxima occurred in the slope, subsp. chelidonura in the floodplain, and subsp. spixiana in the plateau. Leaf morphology and height were different for each subspecies, but not leaf anatomy. The karyotypes of subspp. chelidonura and maxima were symmetrical with 2n = 28 chromosomes, 16 metacentric and 12 submetacentric. Molecular analysis revealed two groups, one comprised subspp. maxima and chelidonura, and the other formed exclusively by subsp. spixiana. At Ducke Reserve, it is clear that the three subspecies are easily recognizable morphologically and ecologically, and it is likely that they do not interbreed locally. However, if these subspecies are analyzed on a larger geographic scale, it may not be possible to separate them. [ABSTRACT FROM AUTHOR]

Background: Biribá (Annona mucosa Jacq.) is a fruit tree domesticated in Amazonia and has polyploid populations. The species presents ample phenotypic variation in fruit characteristics, including weight (100-4,000 g) and differences in carpel protrusions. Two cytotypes are recorded in the literature (2n = 28, 42) and genome size records are divergent (2C = 4.77, 5.42 and 6.00 pg). To decipher the role of polyploidy in the domestication of A. mucosa, we examined the relationships among phenotypic variation, chromosome number and genome size, and which came first, polyploidization or domestication. Methodology: We performed chromosome counts of A. mucosa from central and western Brazilian Amazonia, and estimated genome size by flow cytometry. We performed phylogenetic reconstruction with publicly available data using a Bayesian framework, time divergence analysis and reconstructed the ancestral chromosome number for the genus Annona and for A. mucosa. Results: We observed that variation in fruit phenotypes is not associated with variation in chromosome number and genome size. The most recent common ancestor of A. mucosa is inferred to be polyploid and diverged before domestication. Conclusions: We conclude that, when domesticated, A. mucosa was already polyploid and we suggest that human selection is the main evolutionary force behind fruit size and fruit morphological variation in Annona mucosa. [ABSTRACT FROM AUTHOR]

Although phylogenetic studies have revealed major clades, the deepest relationships in Isoetes remain unresolved. The use of next‐generation sequencing provides enormous amounts of gene sequences, which allows not only clarification of the basal relationships but also rapid radiations. Plastomes of six key Isoetes species were annotated, revealing a total of 129 or 130 genes, depending on the species. Our phylogenomic analyses comprising representatives of all major clades yielded well‐supported nodes and identical topologies using maximum likelihood and Bayesian inference. The phylogenetic reconstructions detangled the deep relationships in Isoetes and illuminated the more recent radiations in the genus. A basal dichotomy was found that grouped Isoetes spp. from Brazil and South Africa into a clade sister to the remaining Isoetes groups. Interestingly, I. andicola was found to be sister to the North American species complex. Genomic trait mapping analysis showed that the missing introns in the atpF and clpP genes were well conserved in two major clades. The absence of trnK‐UUU was observed in the Brazilian tropical species and in I. velata. Among lycophytes, the gene trnR‐CCG was missing only in I. eludens. In general, genomic traits such as the presence or absence of internal stop codons, a tRNA, and an intron were revealed to be conserved within groups, suggesting that these genomic traits might reveal vital information about the evolution of the genus. This study will contribute to understanding the diversification of Isoetes and the establishment of a better framework to address the evolutionary history of the genus. [ABSTRACT FROM AUTHOR]

We describe the chromosome numbers and genome sizes of species of the cryptanthoid complex of Bromeliaceae in a phylogenetic framework and their relationship with habitat preferences. The 2C DNA contents varied 2.13-fold among species, ranging from 0.76 to 1.66 pg. A significant difference in DNA content was found among Cryptanthus , Hoplocryptanthus and Rokautskyia. Moreover, species from campos rupestres and the Atlantic Forest had lower and higher genome size values, respectively. The smaller genome sizes of Hoplocryptanthus spp. from campos rupestres may be related with the large genome constraint. The species show a highly conserved ploidy (with 2 n = 32 and 34), although the genome sizes varied considerably. The observed variation in chromosome numbers seems to be influenced by dysploidy, but additional investigations are needed. Our study demonstrates that the genome size variation in the cryptanthoid complex species is not strictly related to the phylogenetic relationships and has probably been influenced by different evolutionary processes. [ABSTRACT FROM AUTHOR]

Plant evolution may be triggered by significant chromosome changes. In some plant groups, karyoevolution played an important role, influencing speciation processes. Hohenbergia comprises 48 species distributed through eastern Brazil. Previous cytological information includes few species and only chromosome counts, lacking information about genome size and more accurate karyomorphological investigation. Here, we compare cytomolecular features and genome sizes of 12 Hohenbergia spp. Besides, new measurements of genome sizes of 32 species are reported. All studied species presented 2 n = 50, a number prevalent in Bromelioideae. The genome sizes (2C) varied from 0.74 to 1.52 pg. Despite the apparent homogeneity in chromosome number and genome size in Hohenbergia , significant polymorphism was observed in regard to the distribution of CMA+/DAPI0 bands and sites of 35S and 5S rDNA in metaphase chromosomes. Seven out of 12 analysed species presented heteromorphic pairs regarding 35S rDNA and/or 5S rDNA. Hohenbergia thus shows karyotypic diversity despite the conservation in chromosome number. [ABSTRACT FROM AUTHOR]