Inherited hemoglobin disorders in an Afro-Amazonian community: Saracura

ABSTRACT: The most common hemoglobinopathies, viz, hemoglobins S and C, and α-and β-thalassemias, were investigated through the molecular screening of 116 subjects from the community of Saracura, comprising fugitive African slaves from farms of the municipality of Santarém, in the west of Pará State, Brazilian Amazon. The observed frequency of the HBB*S gene (0.9%) was significantly lower than that encountered in other Afro-derived communities in the region. Concomitantly, the absence of the HBB*C allele has been reported for most of the Afro-Amazonian communities thus far studied. As remnant populations of quilombos are generally small, the heterogeneous distribution of HBB*S and HBB*C alleles among them is probably due to genetic drift and/or founder effect. The observed frequency of 3.7 kb deletion in Saracura (8.5%) was consistent with the African origin of the population, with a certain degree of local differentiation and admixture with individuals of Caucasian ancestry, placed in evidence by the occurrence of - -(MED) deletion (1.2%), a common mutation in Mediterranean regions. As regards f-thalassemia, among the seven different mutations found in Saracura, three βºand two β+ mutations were of Mediterranean origin, and two β+ of African. Thus, only 28% of the local β-thalassemia mutations found in Saracura were of African origin.

Genetic identification of bucktooth parrotfish Sparisoma radians (Valenciennes, 1840) (Labridae, Scarinae) by chromosomal and molecular markers

Parrotfishes (Labridae, Scarinae) comprise a large marine fish group of difficult identification, particularly during juvenile phase when the typical morphology and coloration of adults are absent. Therefore, the goal of this study was to test cytogenetic markers and DNA barcoding in the identification of bucktooth parrtotfish Sparisoma radians from the northeastern coast of Brazil. Sequencing of cytochrome c oxidase subunit I (COI) confirmed all studied samples as S. radians, and all showed high similarity (99-100%) with Caribbean populations. The karyotype of this species was divergent from most marine Perciformes, being composed of 2n = 46 chromosomes. These consisted of a large number of metacentric and submetacentric pairs with small amounts of heterochromatin and GC-rich single nucleolar organizer regions (NORs) not syntenic to 5S rDNA clusters. These are the first data about DNA barcoding in parrotfish from the Brazilian province and the first refined chromosomal analysis in Scarinae, providing useful data to a reliable genetic identification of S. radians.

Chromosomal diversity in three species of electric fish (Apteronotidae, Gymnotiformes) from the Amazon Basin

Cytogenetic studies were carried out on samples of Parapteronotus hasemani, Sternarchogiton preto and Sternarchorhamphus muelleri (Apteronotidae, Gymnotiformes) from the Amazon basin. The first two species exhibited both a 2n = 52 karyotype, but differed in their karyotypic formulae, distribution of constitutive heterochromatin, and chromosomal location of the NOR. The third species, Sternarchorhamphus muelleri, was found to have a 2n = 32 karyotype. In all three species the DAPI and chromomycin A3 staining results were consistent with the C-banding results and nucleolar organizer region (NOR) localization. The 18S rDNA probe confirmed that there was only one pair of ribosomal DNA cistron bearers per species. The telomeric probe did not reveal interstitial telomeric sequences (ITS). The karyotypic differences among these species can be used for taxonomic identification. These data will be useful in future studies of these fishes and help understanding the phylogenetic relationships and chromosomal evolution of the Apteronotidae.

Radiographic study of dental anomalies in brazilian patients with neuropsychomotor disorders

The purposes of this study were to investigate radiographically the dental and maxillomandibular in patients with neuropsychomotor disorders and determine the role of panoramic radiographs for quantitative and qualitative analyses of dental alterations. A total of 322 panoramic radiographs from 190 males and 132 females aged 4 to 57 years were obtained from the files of the Center for Care to Patients with Special Needs (CAPE; Dental School, University of São Paulo) and subdivided into syndromes, special needs, neurological, neuromuscular or cerebral disorders, and sequels of diseases. 32% of dental alterations were in tooth position, with 69% of this group associated with tooth rotation. The mandible accounted for 54.62% of alterations. The male gender (55.85%) and the permanent dentition (78.7%) were most affected. Panoramic radiographs were proved to be well suited for quantitative evaluation of dental anomalies of epidemiological nature. Panoramic radiographs are important diagnostic resources when applied to patients with special needs because of the difficulty to place intraoral films and held them correctly positioned during the radiographic technique.