Triatomines are insects that are taxonomically included in the Hemiptera order and Triatominae subfamily. Based on phenotypic similarity, capacity hybridization, and genetic and ecological aspects, the triatomine species can be grouped into specific complexes and subcomplexes. However, these groupings have not been confirmed. Cytogenetic analyses are important cytotaxonomic tools for improving the taxonomic knowledge of triatomines.
We describe the first postnatal diagnosis of a child from Central Brazil with de novo cytogenetic alterations in 13q showing malformations of the brain, eyes, distal limbs, and genitourinary tract, and severe intellectual disability. The karyotype was a constitutive 46,XX,r(13)/45,XX,-13/46,XX,idic r(13).
The aim of this study was to examine the hypothesis that plants with higher ploidy levels are selected by environments under more extremely stressful conditions than the same (or closely related) species from less rigorous terrestrial or epiphytic habitats. Therefore, we analyzed the chromosome numbers of 26 species belonging to 21 genera and 13 families of angiosperms that were collected on 4 inselbergs in Paraiba State, northeastern Brazil.
Rheum palmatum, one of the source plants of the traditional Chinese medicine rhubarb, is anendemic and endangered species. To our knowledge, this is the first report on the chromosome number and karyotype of this species. Sectioning combined with micrography was used to analyze the karyotype. The following results were obtained: R. palmatum had a stable chromosome number 2n = 22; the basic number of chromosomes was 11; karyotype formula is 2n = 22 = 20 metacentric + 2 submetacentric, belonging to Stebbins’ 1A type; and karyotype asymmetry index was 55.39%.
We examined the cytogenetics of mithun (Bos frontalis), a domesticated version of the Asian gaur, and hybrids (F1 generation) produced by artificial insemination of Brahman cows (Bos indicus) with mithun semen. Reproductive potential was also examined in the F1 generation and a backcrossed heifer for utilization of heterosis. Metaphase chromosome spreads were examined by conventional staining and fluorescence in situ hybridization hybridized with the entire chromosome 1 of mithun as a specific probe.
Males of Zophobas aff. confusus and Nyctobates gigas (Tenebrionidae) collected in the State of Pernambuco, Brazil, were studied through conventional staining, C-banding, silver nitrate impregnation (AgNO3), and the base specific fluorochromes CMA3 and DAPI. Z. aff. confusus was found to have 2n = 20 (9+Xyp) while N. gigas exhibited 2n = 18 (8+neoXY).
Aegilops biuncialis can be hybridized with wheat (Triticum spp) and has been used for wheat breeding and genetic studies. The A. biuncialis karyotype (Ub Ub Mb Mb) was investigated based on three A. biuncialis accessions grown in China. Two pairs of SAT chromosomes were identified as 1Ub and 5Ub, with a karyotype formula of 2n = 4x = 28 = 14m + 10sm + 4st. Fluorescence in situ hybridization (FISH) and C-banding approaches were used to analyze the A.
The genus Smilax (Smilacaceae) includes species of medicinal interest; consequently, their identification is important for the control of raw material used in the manufacture of phytotherapeutic products. We investigated the karyotype of Smilax rufescens in order to look for patterns that would be useful for comparative studies of this genus. To accomplish this, we developed procedures to grow plants and optimize root pretreatment with mitotic fuse inhibitors to obtain metaphase spreads showing clear chromosome morphology.
Chromosome abnormalities, Y-chromosome microdeletions, and androgen receptor gene CAG and GGN repeat polymorphisms in infertile Chinese men featuring severe oligospermia and azoospermia were analyzed. Ninety-six fertile men and 189 non-obstructive infertile men, including 125 patients with azoospermia and 64 with severe oligozoospermia, were studied. Seventeen infertile men (9.0%) carried a chromosome abnormality. Twenty (10.6%) carried a Y-chromosome microdeletion. In the remainder of the patients and controls, GGN and CAG repeats were sequenced.
In order to provide the first cytogenetic data of naturalized and threatened goat breeds from northeastern Brazil, cytogenetic analyses were carried out in individuals of Repartida and Moxotó breeds raised in Bahia and Ceará States. Males and females of both breeds had 2n = 60, with 29 autosomal acrocentric pairs plus the sex chromosome pair. The number of nucleolar organizer region (NOR)-bearing chromosomes ranged from 6 to 8 per metaphase in Moxotó and Repartida goats, respectively.