Marcelo Santos de Souza

Federal University of Amazonas | UFAM · Institute of Biological Sciences

The genome organization of woodpeckers has several distinctive features e.g., an uncommon accumulation of repetitive sequences, enlarged Z chromosomes, and atypical diploid numbers. Despite the large diversity of species, there is a paucity of detailed cytogenomic studies for this group and we thus aimed to rectify this. Genome organization pattern...

Introduction Passeriformes has the greatest species diversity among Neoaves, and the Tyrannidae is the richest in this order with about 600 valid species. The diploid number of this family remains constant, ranging from 2n = 76 to 84, but the chromosomal morphology varies, indicating the occurrence of different chromosomal rearrangements. Cytogenet...

The Cuculiformes are a family of over 150 species that live in a range of habitats, such as forests, savannas, and deserts. Here, bacterial artificial chromosome (BAC) probes (75 from chicken and 14 from zebra finch macrochromosomes 1–10 +ZW and for microchromosomes 11–28 (except 16)) were used to investigate chromosome homologies between chicken a...

Passeriformes birds are widely recognized for their remarkable diversity, with over 5700 species described so far. Like most bird species, they possess a karyotype characteristic of modern birds, which includes a bimodal karyotype consisting of a few pairs of macrochromosomes and many pairs of microchromosomes. Although the karyotype is typically 2...

Furnariidae (Ovenbirds) is one of the most diversified families in the Passeriformes order and Suboscines suborder. Despite their great diversity of species, cytogenetic research is still in its early stages, restricting our knowledge of their karyotype evolution. We combined traditional and molecular cytogenetic analyses in three representative sp...

Microchromosomes, once considered unimportant elements of the genome, represent fundamental building blocks of bird karyotypes. Shorebirds (Charadriiformes) comprise a wide variety of approximately 390 species and are considered a valuable model group for biological studies. Despite this variety, cytogenetic analysis is still very scarce in this bi...

No Brasil, costuma-se atribuir o conceito de bom às escolas privadas e de ruim às escolas públicas, mas poucos estudos compararam de fato diferenças entre ambas. O presente trabalho estudou o caso de duas escolas, uma pública e uma privada, buscando compreender como o ambiente escolar influencia o aprendizado de alunos do ensino fundamental. Foram...

Avian cell culture is widely applied for cytogenetic studies, the improvement of which increasingly allows for the production of high-quality chromosomes, essential to perform both classical and molecular cytogenetic studies. Among these approaches, there are two main types: fibroblast and bone marrow culture. Despite its high cost and complexity,...

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...

Chromosomal rearrangements are an important process in the evolution of species. It is assumed that these rearrangements occur near repetitive sequences and heterochromatic regions. Avian karyotypes have diverse chromosomal band patterns and have been used as the parameters for phylogenetic studies. Although the group has a high diversity of specie...

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...

Although birds belonging to order Caprimulgiformes show extensive karyotype variation, data concerning their genomic organization is still scarce, as most studies have presented only results obtained from conventional staining analyses. Nevertheless, some interesting findings have been observed, such as the W chromosome of the Common Potoo, Nyctibi...

A utilização de oficinas didáticas em sala de aula é um método eficiente, que pode auxiliar o aluno no processo de aprendizagem, interligando teoria e prática motora. Esta pesquisa teve como principal objetivo avaliar de forma quantitativa e qualitativa os múltiplos conhecimentos disseminados através do uso de oficinas didáticas em sala de aula, te...

The distribution of 45S rDNA cluster in avian karyotypes varies in different aspects, such as position, number of bearer chromosomes, and bearers being macro- or microchromosomes. The present study investigated the patterns of variation in the 45S rDNA-bearer chromosomes of birds in order to understand the evolutionary dynamics of the cluster confi...

Despite the richness of species in the Hirudinidae family, little is known about the genome organization of swallows. The Progne tapera species presents genetic and morphological difference when compared to other members of the same genus. Hence, the aims of this study were to analyze the chromosomal evolution of three species Progne tapera, Progne...

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....

Among birds, species with the ZZ/ZW sex determination system generally show significant differences in morphology and size between the Z and W chromosomes (with the W usually being smaller than the Z). In the present study, we report for the first time the karyotype of the spot-flanked gallinule (Gallinula melanops) by means of classical and molecu...

As in many other bird groups, data on karyotype organization and distribution of repetitive sequences are also lacking in species belonging to the family Hirundinidae. Thus, in the present study, we analyzed the karyotypes of 3 swallow species (Progne tapera, Progne chalybea, and Pygochelidon cyanoleuca) by Giemsa and AgNOR staining, C-banding, and...

Abstract The Passeriformes is the most diverse and cytogenetically well-known clade of birds, comprising approximately 5,000 species. The sooty-fronted spinetail (Synallaxis frontalis Aves: Furnariidae) species, which belongs to the order Passeriformes, is typically found in South America, where it is widely distributed. Polymorphisms provide genet...

In this work we performed comparative chromosome painting using probes from Gallusgallus (GGA) Linnaeus, 1758 and Leucopternisalbicollis (LAL) Latham, 1790 in Synallaxisfrontalis Pelzeln, 1859 (Passeriformes, Furnariidae), an exclusively Neotropical species, in order to analyze whether the complex pattern of intrachromosomal rearrangements (paracen...

Apesar da pequena quantidade de Sequências Repetitivas (SRs) no genoma das aves, estas apresentam uma grande importância para diversidade genética dessa classe. Dentre os SRs destacam-se os microssatélites e clusters de rDNA18s. Assim o objetivo desse trabalho foi identificar os sítios das sequências rDNA18s e o acúmulo de algumas sequências micros...

Dentro da classe Aves a Ordem Passeriformes possui o maior número de espécies com cariótipos descritos, mantendo uma semelhança numérica (2n=80). A espécie Synallaxis frontalis pertence à família Furnariidae, com ampla distribuição na região neotropical. Os rearranjos cromossômicos constituem eventos cromossômicos responsáveis por causar isolamento...

A classe Aves possui distribuição cosmopolita e sua diversidade é de aproximadamente dez mil espécies. As espécies da família Hirundinidae (Passeriformes), são aves Neognatas de hábitos diurnos. Este trabalho objetivou contribuir para o conhecimento citogenético das espécies Pygochelidon cyanoleuca (PCY), Progne chalybea (PCH) e Progne tapera (PTA)...

In this work we performed comparative chromosome painting using probes from Gallus gallus (GGA) Linnaeus, 1758 and Leucopternis albicollis (LAL) Latham, 1790 in Synallaxis frontalis Pelzeln, 1859 (Passeriformes, Furnariidae), an exclusively Neotropical species, in order to analyze whether the complex pattern of intrachromosomal rearrangements (para...