Heterocromatina – cu localizare la periferia nucleului, condensată și cu Poate fi de două tipuri: heterocromatină constitutivă (heterocromatină ce nu este. Na maioría dos organismos, a heterocromatina constitutiva aparece arredor do centrómero dos cromosomas e. HETEROCROMATINA Definición: Desde el punto de vista de un alumno: ” Hetero” significa mezcla, es decir, es ADN más histonas. Según un.
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The genus Trigona contains at least 31 species, but there have been few cytogenetic studies of this group. In this work, four species of Trigona T.
The C-banding patterns showed that the karyotypes of these species consisted mainly of acrocentric and pseudoacrocentric chromosomes. These cytogenetic findings should useful hetfrocromatina future phylogenetic studies of this group.
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However, there is very little information on the apifauna of Mato Grosso and still no list of the bee species heterocromattina occur in this state. The tribe Meliponini stingless bees is highly diversified in the Neotropics, with 52 genera and more that species found in the Americas Velthuis, Some species of Trigona are important in the pollination of certain palm species of the Brazilian Cerrado Oliveira, and may have an hetedocromatina role in nutrient dispersal since they are frequently seen collecting animal feces.
To date, only five species of Trigona have been studied cytogenetically and include T. These investigations have been limited to a description of chromosome numbers based on acetic-orcein staining, which does not allow efficient visualization of the contitutiva morphology. The aim of this study was to cytogenetically characterize four species of Trigona in order to obtain data that could be useful for future phylogenetic studies of this group.
The four species of Trigona studied T. Adult specimens were identified to the species level by Dr. Jesus Santiago Moure, Dr. The cytogenetic mounts were prepared from the cerebral ganglia of post-defecating larvae as described by Imai et al.
On average, 20 metaphases were analyzed per slide in a total of consgitutiva slides per species.
Hererocromatina pairing, the chromosomes were classified as acrocentric Atotally euchromatic acrocentric A epseudoacrocentric A M or totally heterochromatic metacentricbased on the location of the constitutive heterochromatin and on the nomenclature proposed by Imai The karyotypic formulas based on the C-banding patterns Imai, are shown in Table 1.
These findings differed from those obtained for T. Homologies were observed among the euchromatic acrocentric A e chromosomal pairs of T.
Homologies were also noted for the totally heterochromatic metacentric pair of Trigona branneriT. In the other chromosomes of T. The positive reactions seen were probably associated with nucleolus organizing regions NORsas observed in other insects such as Orthoptera Camacho et al.
Some authors have suggested that the number of NORs revealed by impregnation with silver nitrate or by CMA 3 staining is an important taxonomic character.
Studies of the genus Trigona in other biomes should contribute to our knowledge of the karyotypic diversity among these bees. The authors thank Dr.
Gabriel Rodrigues de Melo for identifying the bees and Dra. Banding analysis Cytobios Genet Heterkcromatina Biol Braz J Genet Jpn J Genet Exp Cell Res Correspondence to Carlos S. January 6, ; Accepted: All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License.
HETEROCROMATINA by Fernando Medina Conde on Prezi
Services on Demand Journal. Material and Methods The four species of Trigona studied T. Acknowledgements The authors thank Dr.
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