Karyotypic analyses of 366 specimens of the solitary wasp Trypoxylon (Trypargilum) albitarse coll... more Karyotypic analyses of 366 specimens of the solitary wasp Trypoxylon (Trypargilum) albitarse collected from ten populations in the municipalities of Viçosa and Porto Firme (Minas Gerais, Southeastern Brazil), revealed the presence of two morphological types of supernumerary (B) chromosomes. C-banding and fluorochrome banding suggest that the B chromosomes of T. albitarse may have originated from heterochromatin breaks within the standard (A) chromosome complement.
AimThe aim of this study was to test the hypothesis that the Brazilian coastal populations of Hop... more AimThe aim of this study was to test the hypothesis that the Brazilian coastal populations of Hoplias malabaricus were subject to the same geomorphological and palaeohydrological factors that resulted in endemic fish regions, by characterizing the mitochondrial DNA, nuclear sequences and cytogenetic data of these populations.LocationSeventeen coastal basins in north‐eastern, eastern and south‐eastern Brazil, plus the São Francisco Basin.MethodsForty‐two specimens were analysed. Mitochondrial ATP synthase 6 (ATPase‐6) and nuclear recombination activating gene 2 (RAG2) gene sequences were used for Bayesian inference and maximum parsimony analyses. Molecular models were selected using MrModeltest.ResultsMolecular analyses indicated four haplogroups (Northeastern, Eastern A, Eastern B and Southeastern) for ATPase‐6 and three clades for RAG2. All topologies were congruent with Hoplias malabaricus diploid numbers, with most regions of proposed endemism and coastal geomorphological units.Main conclusionsDeep genetic divergence between the Northeastern and the other haplogroups was interpreted as evidence of the vicariant effect of the Abrolhos Formation, which effectively isolates 2n = 40 and 2n = 42 coastal populations. To the south, the Cabo Frio Magmatic Lineament also isolates the Eastern and Southeastern 2n = 42 populations. In the Northeastern haplogroup, stream piracy was probably involved in chronologically varied dispersal events between coastal and continental basins. All haplogroups also included haplotypes that dispersed in recent times. Results show an older vicariant pattern and recent dispersal events congruent with the occurrence of temporary connections along the coast caused by eustatic sea level variations and the occurrence of stream piracy involving either continental or coastal basins, and suggest these processes contributed to the current distribution patterns of Brazilian coastal freshwater fish.
The monotypic Astroblepidae fish family includes 81 species distributed along Central and Norther... more The monotypic Astroblepidae fish family includes 81 species distributed along Central and Northern Andes in South America and Panamá in Central America; most aspects regarding its biology, taxonomy, and chromosomal features remain largely unknown. This study reports the karyotype of two sympatric Astroblepus species from the Colombian Andes, aiming to provide novel information on karyotype organization and reveal possible chromosomal rearrangements occurred on these species, through mapping of different repetitive DNA classes, including microsatellites and ribosomal DNA multigene families. The results showed differences in the chromosome number and karyotypic formula: Astroblepus grixalvii had 2n = 52 (28m+8sm +12st +4a) with the metacentric pair number 1 as the largest chromosome pair, whereas Astroblepus homodon had 2n = 54 (30m+8sm +8st +8a) and less evident chromosome size differences. Microsatellite probes marked the tips of all chromosomes in both species except the short arms of acrocentric pair numbers 24 and 25 in A. homodon. Each ribosomal probe marked different chromosome pairs in both species. Microsatellite patterns suggest that the 2n increase probably involved a centric fission event that occurred during the evolutionary history of these species. This is the first karyotype description of an Astroblepus species and it contributes to the theoretical framework about the karyoevolutionary trends within Loricarioidei.
Astyanax bimaculatus, a ubiquitous species in many Neotropical basins, is characterized by a comp... more Astyanax bimaculatus, a ubiquitous species in many Neotropical basins, is characterized by a complex taxonomy and are currently considered a species complex. The goal of this study was to analyze 31 populations (N = 136) of this species from southeastern Brazil using cytogenetic techniques: conventional staining, nucleolar organizer region (Ag-NOR), C-banding, and 18S and 5S recombinant DNA fluorescent in situ hybridization (FISH) probes; and molecular techniques: S72, RAG2, and COI. All populations were 2n = 50 (6m + 20sm +18st +6a); Ag-NORs were predominantly simple, C-banding revealed high variation levels within and among basins, and the FISH probes 18S and 5S were restricted to chromosome pairs 14 and 7, respectively. The S72 was uninformative for phylogenetic analyses, and RAG2 showed no variation among populations. The COI gene revealed three haplogroups. The most basal was composed of Pandeiros population (São Francisco Basin) that diverged in the Middle Miocene. The second was composed of A. altiparanae from the Upper Paraná Basin and Espírito Santo Stream (Paraíba do Sul Basin), whereas the third was composed of Astyanax lacustris from São Francisco and coastal basins. The second and third haplogroups diverged in the Pleistocene, indicating that diversification of the bimaculatus complex was driven by tectonic activity and sea-level fluctuations.
The genus Enyalius is composed of 10 described species inhabiting forest areas in Amozônia, Cerra... more The genus Enyalius is composed of 10 described species inhabiting forest areas in Amozônia, Cerrado and Atlantic forest biomes. Currently, eight species with high levels of chromosome variation have been karyotyped. The study aims to characterize the karyotype of Enyalius boulengeri, with classical and molecular techniques, and improve knowledge about the karyotype evolution of the lizard genus Enyalius. The species has 2n = 36 chromosomes (8m + 4sm + 24mc), FN = 24; NORs and 18S rDNA were subtelomeric and located on chromosome pair 2. Repetitive DNA probes (CAT)10 accumulated on centromeric and terminal regions of some macrochromosomes. (GA)15 probe showed conspicuous accumulation on the pericentromeric region of chromosome pairs 1 and 6. Repetitive FISH patterns obtained with (GC)15 probe marked the pericentromeric region of the first chromosome pair. All probes showed accumulation in the microchromosomes. The chromosomal formula found on E. boulengeri has been considered the ance...
Zachaenus carvalhoi is an endemic frog from the Atlantic Forest of southeastern Brazil. It is con... more Zachaenus carvalhoi is an endemic frog from the Atlantic Forest of southeastern Brazil. It is considered a rare species, being currently classified as Data Deficient by the IUCN due to the shortage of information about its natural history and ecological requirements. In the present study, we aim to fill gaps into the current knowledge of this species by: updating its altitudinal distribution range; describing its release call; providing new natural history data; and describing its karyotype. During fieldwork in the municipality of Cataguases, Minas Gerais State, we recorded individuals Z. carvalhoi in three small forest fragments, one of them at only 230 m a.s.l., which now represents the lowest known altitudinal record for this species. In all occasions, we only recorded this frog in vocalization activity during rainy days, suggesting an opportunistic breeding strategy. Moreover, the karyotype of Z. carvalhoi (2n=26) is similar to other species of the family Cycloramphidade, but it...
Lizards of the Ophiodes genus, popularly known as glass snakes, are exclusively Neotropical. Desp... more Lizards of the Ophiodes genus, popularly known as glass snakes, are exclusively Neotropical. Despite their wide geographic distribution, glass snakes are poorly studied and there are many knowledge gaps in their biology and ecology to be filled. In this context, the objective of this study was to analyze possible sexual and population morphological differences of Ophiodes striatus specimens collected from different municipalities in the state of Minas Gerais, Brazil. A total of 63 specimens belonging to the Herpetological Collection of the Federal University of Juiz de Fora - Reptiles (CHUFJF-Reptiles), collected between 1995 and 2015 were analyzed. All the specimens were necropsied and morphometric measures related to body and head were measured. The males and females analyzed showed similar morphometric measures, and there was no size-related sexual dimorphism. Principal component analysis did not group the analyzed specimens by sex or locality. A positive correlation was observed...
The tree frog Aplastodiscus is a Neotropical taxon that encompasses 15 species in the Atlantic fo... more The tree frog Aplastodiscus is a Neotropical taxon that encompasses 15 species in the Atlantic forest biome, with one isolated species in the Central Brazilian Cerrado. To date, only 8 species have been karyotyped, showing high levels of diploid number variation, which allowed clustering species in chromosome number groups: 2n = 24 (Aplastodiscus perviridis group), 2n = 22 (Aplastodiscus albofrenatus group), 2n = 20, and 2n = 18 (both within Aplastodiscus albosignatus group). This study aims to report karyotypic information on 4 species from the last 2 groups using classical and molecular cytogenetic techniques and hypothesize chromosomal evolutionary trends within the species groups. Aplastodiscus weygoldti showed 2n = 22; Ag-NOR and FISH 18S rDNA signals were located in the interstitial region of the short arms of chromosome pair 6. Aplastodiscus cavicola, Aplastodiscus sp. 4, and Aplastodiscus sp. 6 showed 2n = 18; Ag-NOR and FISH 18S rDNA bands were located in the terminal regio...
The Brazilian buffy-tufted-ear marmoset (Callithrix aurita), one of the world’s most endangered p... more The Brazilian buffy-tufted-ear marmoset (Callithrix aurita), one of the world’s most endangered primates, is threatened by anthropogenic hybridization with exotic, invasive marmoset species. As there are few genetic data available for C. aurita, we developed a PCR-free protocol with minimal technical requirements to rapidly generate genomic data with genomic skimming and portable nanopore sequencing. With this direct DNA sequencing approach, we successfully determined the complete mitogenome of a marmoset that we initially identified as C. aurita. The obtained nanopore-assembled sequence was highly concordant with a Sanger sequenced version of the same mitogenome. Phylogenetic analyses unexpectedly revealed that our specimen was a cryptic hybrid, with a C. aurita phenotype and C. penicillata mitogenome lineage. We also used publicly available mitogenome data to determine diversity estimates for C. aurita and three other marmoset species. Mitogenomics holds great potential to address...
A new species of Pimelodella is described from northern coastal drainages of the Sierra Nevada de... more A new species of Pimelodella is described from northern coastal drainages of the Sierra Nevada de Santa Marta (SNSM), Colombia. The new species is diagnosed from all trans-Andean congeners by the following unique combination of characters: head length 22.2–23.7% SL, bony interorbital width 17.6–21.6% HL, maxillary barbels length 53.0–68.3% SL, inner mental-barbels length 14.4–20.0% SL, body width 17.6–21.1% SL, dorsal-fin spine length 8.3–13.7% SL, dorsal-fin base 12.3–14.9% SL, pectoral-fin spine length 12.9-14.5% SL, pectoral-fin spine length without dentations on the distal posterior margin 21.6–29.8% in pectoral-fin spine length, maximum depth of dentations in posterior margin of pectoral-fin spine 1.40–1.68 times in the width of the spine at its base, adipose-fin base length 22.8–26.4% SL, caudal-peduncle depth 9.2–10.5% SL, 40 vertebrae, having a conspicuous paired dark brown stripe on the dorsal surface of body, extending from posterior margin of head to caudal-fin insertion ...
Stingless bees of the genus Melipona are subdivided into 4 subgenera called Eomelipona, Melikerri... more Stingless bees of the genus Melipona are subdivided into 4 subgenera called Eomelipona, Melikerria, Melipona sensu stricto, and Michmelia according to species morphology. Cytogenetically, the species of the genus Melipona show variation in the amount and distribution of heterochromatin along their chromosomes and can be separated into 2 groups: the first with low content of heterochromatin and the second with high content of heterochromatin. These heterochromatin patterns and the number of chromosomes are characteristics exclusive to Melipona karyotypes that distinguish them from the other genera of the Meliponini. To better understand the karyotype organization in Melipona and the relationship among the subgenera, we mapped repetitive sequences and analyzed previously reported cytogenetic data with the aim to identify cytogenetic markers to be used for investigating the phylogenetic relationships and chromosome evolution in the genus. In general, Melipona species have 2n = 18 chrom...
Karyotypic analyses of 366 specimens of the solitary wasp Trypoxylon (Trypargilum) albitarse coll... more Karyotypic analyses of 366 specimens of the solitary wasp Trypoxylon (Trypargilum) albitarse collected from ten populations in the municipalities of Viçosa and Porto Firme (Minas Gerais, Southeastern Brazil), revealed the presence of two morphological types of supernumerary (B) chromosomes. C-banding and fluorochrome banding suggest that the B chromosomes of T. albitarse may have originated from heterochromatin breaks within the standard (A) chromosome complement.
AimThe aim of this study was to test the hypothesis that the Brazilian coastal populations of Hop... more AimThe aim of this study was to test the hypothesis that the Brazilian coastal populations of Hoplias malabaricus were subject to the same geomorphological and palaeohydrological factors that resulted in endemic fish regions, by characterizing the mitochondrial DNA, nuclear sequences and cytogenetic data of these populations.LocationSeventeen coastal basins in north‐eastern, eastern and south‐eastern Brazil, plus the São Francisco Basin.MethodsForty‐two specimens were analysed. Mitochondrial ATP synthase 6 (ATPase‐6) and nuclear recombination activating gene 2 (RAG2) gene sequences were used for Bayesian inference and maximum parsimony analyses. Molecular models were selected using MrModeltest.ResultsMolecular analyses indicated four haplogroups (Northeastern, Eastern A, Eastern B and Southeastern) for ATPase‐6 and three clades for RAG2. All topologies were congruent with Hoplias malabaricus diploid numbers, with most regions of proposed endemism and coastal geomorphological units.Main conclusionsDeep genetic divergence between the Northeastern and the other haplogroups was interpreted as evidence of the vicariant effect of the Abrolhos Formation, which effectively isolates 2n = 40 and 2n = 42 coastal populations. To the south, the Cabo Frio Magmatic Lineament also isolates the Eastern and Southeastern 2n = 42 populations. In the Northeastern haplogroup, stream piracy was probably involved in chronologically varied dispersal events between coastal and continental basins. All haplogroups also included haplotypes that dispersed in recent times. Results show an older vicariant pattern and recent dispersal events congruent with the occurrence of temporary connections along the coast caused by eustatic sea level variations and the occurrence of stream piracy involving either continental or coastal basins, and suggest these processes contributed to the current distribution patterns of Brazilian coastal freshwater fish.
The monotypic Astroblepidae fish family includes 81 species distributed along Central and Norther... more The monotypic Astroblepidae fish family includes 81 species distributed along Central and Northern Andes in South America and Panamá in Central America; most aspects regarding its biology, taxonomy, and chromosomal features remain largely unknown. This study reports the karyotype of two sympatric Astroblepus species from the Colombian Andes, aiming to provide novel information on karyotype organization and reveal possible chromosomal rearrangements occurred on these species, through mapping of different repetitive DNA classes, including microsatellites and ribosomal DNA multigene families. The results showed differences in the chromosome number and karyotypic formula: Astroblepus grixalvii had 2n = 52 (28m+8sm +12st +4a) with the metacentric pair number 1 as the largest chromosome pair, whereas Astroblepus homodon had 2n = 54 (30m+8sm +8st +8a) and less evident chromosome size differences. Microsatellite probes marked the tips of all chromosomes in both species except the short arms of acrocentric pair numbers 24 and 25 in A. homodon. Each ribosomal probe marked different chromosome pairs in both species. Microsatellite patterns suggest that the 2n increase probably involved a centric fission event that occurred during the evolutionary history of these species. This is the first karyotype description of an Astroblepus species and it contributes to the theoretical framework about the karyoevolutionary trends within Loricarioidei.
Astyanax bimaculatus, a ubiquitous species in many Neotropical basins, is characterized by a comp... more Astyanax bimaculatus, a ubiquitous species in many Neotropical basins, is characterized by a complex taxonomy and are currently considered a species complex. The goal of this study was to analyze 31 populations (N = 136) of this species from southeastern Brazil using cytogenetic techniques: conventional staining, nucleolar organizer region (Ag-NOR), C-banding, and 18S and 5S recombinant DNA fluorescent in situ hybridization (FISH) probes; and molecular techniques: S72, RAG2, and COI. All populations were 2n = 50 (6m + 20sm +18st +6a); Ag-NORs were predominantly simple, C-banding revealed high variation levels within and among basins, and the FISH probes 18S and 5S were restricted to chromosome pairs 14 and 7, respectively. The S72 was uninformative for phylogenetic analyses, and RAG2 showed no variation among populations. The COI gene revealed three haplogroups. The most basal was composed of Pandeiros population (São Francisco Basin) that diverged in the Middle Miocene. The second was composed of A. altiparanae from the Upper Paraná Basin and Espírito Santo Stream (Paraíba do Sul Basin), whereas the third was composed of Astyanax lacustris from São Francisco and coastal basins. The second and third haplogroups diverged in the Pleistocene, indicating that diversification of the bimaculatus complex was driven by tectonic activity and sea-level fluctuations.
The genus Enyalius is composed of 10 described species inhabiting forest areas in Amozônia, Cerra... more The genus Enyalius is composed of 10 described species inhabiting forest areas in Amozônia, Cerrado and Atlantic forest biomes. Currently, eight species with high levels of chromosome variation have been karyotyped. The study aims to characterize the karyotype of Enyalius boulengeri, with classical and molecular techniques, and improve knowledge about the karyotype evolution of the lizard genus Enyalius. The species has 2n = 36 chromosomes (8m + 4sm + 24mc), FN = 24; NORs and 18S rDNA were subtelomeric and located on chromosome pair 2. Repetitive DNA probes (CAT)10 accumulated on centromeric and terminal regions of some macrochromosomes. (GA)15 probe showed conspicuous accumulation on the pericentromeric region of chromosome pairs 1 and 6. Repetitive FISH patterns obtained with (GC)15 probe marked the pericentromeric region of the first chromosome pair. All probes showed accumulation in the microchromosomes. The chromosomal formula found on E. boulengeri has been considered the ance...
Zachaenus carvalhoi is an endemic frog from the Atlantic Forest of southeastern Brazil. It is con... more Zachaenus carvalhoi is an endemic frog from the Atlantic Forest of southeastern Brazil. It is considered a rare species, being currently classified as Data Deficient by the IUCN due to the shortage of information about its natural history and ecological requirements. In the present study, we aim to fill gaps into the current knowledge of this species by: updating its altitudinal distribution range; describing its release call; providing new natural history data; and describing its karyotype. During fieldwork in the municipality of Cataguases, Minas Gerais State, we recorded individuals Z. carvalhoi in three small forest fragments, one of them at only 230 m a.s.l., which now represents the lowest known altitudinal record for this species. In all occasions, we only recorded this frog in vocalization activity during rainy days, suggesting an opportunistic breeding strategy. Moreover, the karyotype of Z. carvalhoi (2n=26) is similar to other species of the family Cycloramphidade, but it...
Lizards of the Ophiodes genus, popularly known as glass snakes, are exclusively Neotropical. Desp... more Lizards of the Ophiodes genus, popularly known as glass snakes, are exclusively Neotropical. Despite their wide geographic distribution, glass snakes are poorly studied and there are many knowledge gaps in their biology and ecology to be filled. In this context, the objective of this study was to analyze possible sexual and population morphological differences of Ophiodes striatus specimens collected from different municipalities in the state of Minas Gerais, Brazil. A total of 63 specimens belonging to the Herpetological Collection of the Federal University of Juiz de Fora - Reptiles (CHUFJF-Reptiles), collected between 1995 and 2015 were analyzed. All the specimens were necropsied and morphometric measures related to body and head were measured. The males and females analyzed showed similar morphometric measures, and there was no size-related sexual dimorphism. Principal component analysis did not group the analyzed specimens by sex or locality. A positive correlation was observed...
The tree frog Aplastodiscus is a Neotropical taxon that encompasses 15 species in the Atlantic fo... more The tree frog Aplastodiscus is a Neotropical taxon that encompasses 15 species in the Atlantic forest biome, with one isolated species in the Central Brazilian Cerrado. To date, only 8 species have been karyotyped, showing high levels of diploid number variation, which allowed clustering species in chromosome number groups: 2n = 24 (Aplastodiscus perviridis group), 2n = 22 (Aplastodiscus albofrenatus group), 2n = 20, and 2n = 18 (both within Aplastodiscus albosignatus group). This study aims to report karyotypic information on 4 species from the last 2 groups using classical and molecular cytogenetic techniques and hypothesize chromosomal evolutionary trends within the species groups. Aplastodiscus weygoldti showed 2n = 22; Ag-NOR and FISH 18S rDNA signals were located in the interstitial region of the short arms of chromosome pair 6. Aplastodiscus cavicola, Aplastodiscus sp. 4, and Aplastodiscus sp. 6 showed 2n = 18; Ag-NOR and FISH 18S rDNA bands were located in the terminal regio...
The Brazilian buffy-tufted-ear marmoset (Callithrix aurita), one of the world’s most endangered p... more The Brazilian buffy-tufted-ear marmoset (Callithrix aurita), one of the world’s most endangered primates, is threatened by anthropogenic hybridization with exotic, invasive marmoset species. As there are few genetic data available for C. aurita, we developed a PCR-free protocol with minimal technical requirements to rapidly generate genomic data with genomic skimming and portable nanopore sequencing. With this direct DNA sequencing approach, we successfully determined the complete mitogenome of a marmoset that we initially identified as C. aurita. The obtained nanopore-assembled sequence was highly concordant with a Sanger sequenced version of the same mitogenome. Phylogenetic analyses unexpectedly revealed that our specimen was a cryptic hybrid, with a C. aurita phenotype and C. penicillata mitogenome lineage. We also used publicly available mitogenome data to determine diversity estimates for C. aurita and three other marmoset species. Mitogenomics holds great potential to address...
A new species of Pimelodella is described from northern coastal drainages of the Sierra Nevada de... more A new species of Pimelodella is described from northern coastal drainages of the Sierra Nevada de Santa Marta (SNSM), Colombia. The new species is diagnosed from all trans-Andean congeners by the following unique combination of characters: head length 22.2–23.7% SL, bony interorbital width 17.6–21.6% HL, maxillary barbels length 53.0–68.3% SL, inner mental-barbels length 14.4–20.0% SL, body width 17.6–21.1% SL, dorsal-fin spine length 8.3–13.7% SL, dorsal-fin base 12.3–14.9% SL, pectoral-fin spine length 12.9-14.5% SL, pectoral-fin spine length without dentations on the distal posterior margin 21.6–29.8% in pectoral-fin spine length, maximum depth of dentations in posterior margin of pectoral-fin spine 1.40–1.68 times in the width of the spine at its base, adipose-fin base length 22.8–26.4% SL, caudal-peduncle depth 9.2–10.5% SL, 40 vertebrae, having a conspicuous paired dark brown stripe on the dorsal surface of body, extending from posterior margin of head to caudal-fin insertion ...
Stingless bees of the genus Melipona are subdivided into 4 subgenera called Eomelipona, Melikerri... more Stingless bees of the genus Melipona are subdivided into 4 subgenera called Eomelipona, Melikerria, Melipona sensu stricto, and Michmelia according to species morphology. Cytogenetically, the species of the genus Melipona show variation in the amount and distribution of heterochromatin along their chromosomes and can be separated into 2 groups: the first with low content of heterochromatin and the second with high content of heterochromatin. These heterochromatin patterns and the number of chromosomes are characteristics exclusive to Melipona karyotypes that distinguish them from the other genera of the Meliponini. To better understand the karyotype organization in Melipona and the relationship among the subgenera, we mapped repetitive sequences and analyzed previously reported cytogenetic data with the aim to identify cytogenetic markers to be used for investigating the phylogenetic relationships and chromosome evolution in the genus. In general, Melipona species have 2n = 18 chrom...
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