Luis Reginaldo Ribeiro Rodrigues

Chromosome comparison between two species of Phyllostomus (Chiroptera - Phyllostomidae) from Eastern Amazonia, with some phylogenetic insights

Os cariotipos de Phyllostomus discolor e P. hastatus da Amazonia oriental sao estudados por bandeamentos G, C, G/C sequencial e coloracao Ag-NOR. Ambas as especies apresentaram 2n = 32, sendo o complemento autossomico composto por 15 pares bi-armed em P. discolor e 14 bi-armed mais 1 par acrocentrico em P. hastatus. O cromossomo X e um submetacentrico medio e o Y e um pequeno acrocentrico em ambas as especies. O presente estudo encontrou apenas uma diferenca entre os cariotipos de P. discolor e P. hastatus: o menor autossomo (par 15) e metacentrico em discolor e acrocentrico em hastatus. Este resultado e melhor explicado por uma inversao pericentrica. O bandeamento C revelou heterocromatina constitutiva na regiao centromerica de todos os cromossomos, e os sitios NOR foram localizados na regiao distal do par 15, em ambas as especies. O taxon P. discolor e considerado primitivo para o genero Phyllostomus e supoe-se que a forma metacentrica do par 15 seja a condicao primitiva, que foi rearranjada por uma inversao pericentrica, originando a forma acrocentrica encontrada em P. hastatus.

Genetic variation in native and farmed populations of Tambaqui (Colossoma macropomum) in the Brazilian Amazon: regional discrepancies in farming systems

The tambaqui, Colossoma macropomum, is the most popular fish species used for aquaculture in Brazil but there is no study comparing genetic variation among native and farmed populations of this species. In the present study, we analyzed DNA sequences of the mitochondrial DNA to evaluate the genetic diversity among two wild populations, a fry-producing breeding stock, and a sample of fish farm stocks, all from the region of Santarém, in the west of the Brazilian state of Pará. Similar levels of genetic diversity were found in all the samples and surprisingly the breeding stock showed expressive representation of the genetic diversity registered on wild populations. These results contrast considerably with those of the previous study of farmed stocks in the states of Amapá, Pará, Piauí, and Rondônia, which recorded only two haplotypes, indicating a long history of endogamy in the breeding stocks used to produce fry. The results of the two studies show two distinct scenarios of tambaqui farming in the Amazon basin, which must be better evaluated in order to guarantee the successful expansion of this activity in the region, and the rest of Brazil, given that the tambaqui and its hybrids are now farmed throughout the country.

Comparative cytogenetics of two phyllostomids bats. A new hypothesis to the origin of the rearranged X chromosome from Artibeus lituratus (Chiroptera, Phyllostomidae)

Abstract It was carried out a cytogenetic comparison between Phyllostomus hastatus and Artibeus lituratus (Chiroptera, Phyllostomidae), using G-, C- and NOR banding techniques. The P. hastatus specimens presented 2n=32 chromosomes, including 13 biarmed autosome pairs and one acrocentric. The X chromosome is submetacentric and the Y is a minute acrocentric. A. lituratus has 2n=30 chromosomes in females and 31 in males specimens. The autosomes are 14 biarmed pairs and the chromosomal sexual system is XY1Y2 type, being the X chromosome a large submetacentric and both Y1 (real Y) and Y2 acrocentric elements. Several chromosomal homologies are shared between both taxa, including whole chromosomes and chromosomal arms. Based on similarity of G-banding pattern is proposed that the system XY1Y2 from A. lituratus risen by a tandem fusion event involving the stenodermatine original biarmed X chromosome with the autosome acrocentric homologous to Y2.

Phylogenetic Reconstruction by Cross-Species Chromosome Painting and G-Banding in Four Species of Phyllostomini Tribe (Chiroptera, Phyllostomidae) in the Brazilian Amazon: An Independent Evidence for Monophyly

The subfamily Phyllostominae comprises taxa with a variety of feeding strategies. From the cytogenetic point of view, Phyllostominae shows different rates of chromosomal evolution between genera, with Phyllostomus hastatus probably retaining the ancestral karyotype for the subfamily. Since chromosomal rearrangements occur rarely in the genome and have great value as phylogenetic markers and in taxonomic characterization, we analyzed three species: Lophostoma silvicola (LSI), Phyllostomus discolor (PDI) and Tonatia saurophila (TSA), representing the tribe Phyllostomini, collected in the Amazon region, by classic and molecular cytogenetic techniques in order to reconstruct the phylogenetic relationships within this tribe. LSA has a karyotype of 2n=34 and FN=60, PDI has 2n=32 and FN=60 and TSA has 2n=16 and FN=20. Comparative analysis using G-banding and chromosome painting show that the karyotypic complement of TSA is highly rearranged relative to LSI and PHA, while LSI, PHA and PDI have similar karyotypes, differing by only three chromosome pairs. Nearly all chromosomes of PDI and PHA were conserved in toto, except for chromosome 15 that was changed by a pericentric inversion. A strongly supported phylogeny (bootstrap=100 and Bremer=10 steps), confirms the monophyly of Phyllostomini. In agreement with molecular topologies, TSA was in the basal position, while PHA and LSI formed sister taxa. A few ancestral syntenies are conserved without rearrangements and most associations are autapomorphic traits for Tonatia or plesiomorphic for the three genera analyzed here. The karyotype of TSA is highly derived in relation to that of other phyllostomid bats, differing from the supposed ancestral karyotype of Phyllostomidae by multiple rearrangements. Phylogenies based on chromosomal data are independent evidence for the monophyly of tribe Phyllostomini as determined by molecular topologies and provide additional support for the paraphyly of the genus Tonatia by the exclusion of the genus Lophostoma.

Cytogenetic studies in Callicebus personatus nigrifrons (Platyrrhini, Primates)

Abstract This is the first study on the karyotype of a representative of Callicebus from Brazilian Atlantic Forest, which are in the list of threatened species. C. p. nigrifrons has 2n=42, where there are 14 bi-armed and six acrocentric autosome pairs. The X chromosome is submetacentric and the Y is bi-armed and the smallest chromosome of the karyotype. This is a new diploid number for this genus. The sequential G/C-banding shows that the constitutive heterochromatin is located in the centromeric and pericentromeric regions of all the chromosomes, and in the distal part of the short arm of pairs 5, 6, 8, 10, 11, 13 and 14. The sequential G/Ag-NOR as well as fluorescent in situ hybridization showed that rDNA 18S+28S sequences are located in the distal region of the short arm of pair # 4. The chromosomal comparison between Callicebus personatus nigrifrons with the previously published, C. moloch, shows that the karyotype of C. personatus is very different from that of the representatives of the C. moloch group as well as of the other taxa of the genus Callicebus. These results support the classification of C. personatus taxa in a separate taxonomic group isolated from the other Callicebus groups.

Chromosomal phylogeny of Vampyressine bats (Chiroptera, Phyllostomidae) with description of two new sex chromosome systems.

BackgroundThe subtribe Vampyressina (sensu Baker et al. 2003) encompasses approximately 43 species and seven genera and is a recent and diversified group of New World leaf-nosed bats specialized in fruit eating. The systematics of this group continues to be debated mainly because of the lack of congruence between topologies generated by molecular and morphological data. We analyzed seven species of all genera of vampyressine bats by multidirectional chromosome painting, using whole-chromosome-painting probes from Carollia brevicauda and Phyllostomus hastatus. Phylogenetic analyses were performed using shared discrete chromosomal segments as characters and the Phylogenetic Analysis Using Parsimony (PAUP) software package, using Desmodontinae as outgroup. We also used the Tree Analysis Using New Technology (TNT) software.ResultsThe result showed a well-supported phylogeny congruent with molecular topologies regarding the sister taxa relationship of Vampyressa and Mesophylla genera, as well as the close relationship between the genus Chiroderma and Vampyriscus.ConclusionsOur results supported the hypothesis that all genera of this subtribe have compound sex chromosome systems that originated from an X-autosome translocation, an ancestral condition observed in the Stenodermatinae. Additional rearrangements occurred independently in the genus Vampyressa and Mesophylla yielding the X1X1X2X2/X1X2Y sex chromosome system. This work presents additional data supporting the hypothesis based on molecular studies regarding the polyphyly of the genus Vampyressa and its sister relationship to Mesophylla.

Genomic Mapping of Human Chromosome Paints on the Threatened Masked Titi Monkey (Callicebus personatus)

Callicebus is a complex genus of neotropical primates thought to include 29 or more species. Currently, the genus is divided into 5 species groups: donacophilus, cupreus, moloch, torquatus and personatus. However, the phylogenetic relationships among the species are still poorly understood. This genus is karyotypically diverse and shows extensive variation in diploid number (2n = 16 to 50). To foster a better understanding of the chromosomal diversities and phylogenetic relationships among the species of Callicebus, we performed a chromosome-painting analysis on the Callicebus personatus genome using human probes, and compared the resulting hybridization map to those of previously mapped titi species. We detected 38 hybridization signals per haploid autosomal set of C. personatus. Few ancestral syntenies were conserved without rearrangement, but 4 human associations (HSA20/13, 3c/8b, 1b/1c and 21/3a/15a/14) were demonstrated to be apomorphic traits for C. persona tus. G-banding suggested that these associations are shared with C. nigrifrons and C. coimbrai (personatus group), while C. personatus is linked with C. pallescens (donacophilus group) by 2 synapomorphies: HSA10b/11 (submetacentric) and an inversion of HSA1a.

Karyotypic study of Callicebus coimbrai :a rare and threatened primate species from Brazil

Abstract The genus Callicebus comprises 28 species distributed in the Amazonia and Atlantic forest biomes. This paper describes the karyotype of C. coimbrai, a rare and threatened species and compar es it with related species (C. personatus and C. nigrifrons). The karyotype was characterized by G-, C-sequential and NOR banding. C. coimbrai presented 2n=44 chromosomes, with G-banding pattern similar to that observed in C. personatus (2n=44) and C. nigrifrons (2n=42). The karyotypic divergence between C. coimbrai and C. nigrifrons is explained by a single rearrangement of centric fusion/fission. The chromosomal data obtained suggest a closer association between C. coimbrai and C. personatus than with C. nigrifrons.

Cytogenetic variation of repetitive DNA elements in Hoplias malabaricus (Characiformes - Erythrinidae) from white, black and clear water rivers of the Amazon basin

Abstract Hoplias malabaricus is a common fish species occurring in white, black and clear water rivers of the Amazon basin. Its large distribution across distinct aquatic environments can pose stressful conditions for dispersal and creates possibilities for the emergence of local adaptive profiles. We investigated the chromosomal localization of repetitive DNA markers (constitutive heterochromatin, rDNA and the transposable element REX-3) in populations from the Amazonas river (white water), the Negro river (black water) and the Tapajós river (clear water), in order to address the variation/association of cytogenomic features and environmental conditions. We found a conserved karyotypic macrostructure with a diploid number of 40 chromosomes (20 metacentrics + 20 submetacentrics) in all the samples. Heteromorphism in pair 14 was detected as evidence for the initial differentiation of an XX/XY system. Minor differences detected in the amount of repetitive DNA markers are interpreted as possible signatures of local adaptations to distinct aquatic environments.

Estudo da comercialização de peixes ornamentais da família Loricariidae (Siluriformes) em Santarém/PA.

In Brazil, the trade of ornamental fish from freshwater environments still relies on the essentially extractive activity, largely in the Amazon region. The Pará State is one of the major Loricariidae ornamental fish supplier, especially with the Xingu and Tapajós river basins. In the present study, we analyzed the Loricariidae ornamental fish trade from the Tapajós River, marketed by companies operating at Santarém city. The raw data were compiled from the official documents: Animal Transport Guides (GTA) and Fish Transit Guides for Ornamental and Aquarium Fisheries (GTPON), covering a period from January/2013 to December/2016. Were sold 136.705 fish units, which yielded the gross income of R