Chromosome banding patterns and localization of 5S and 45S rDNA sites in three shrub-tree species of Erythrina L. (Leguminosae: Papilionoideae) from Brazil

 Erythrina consists of 112 leguminous trees and shrubs, distributed throughout the tropical regions. Species of Erythrina are of great biological interest because they are pollinated by hummingbirds, which promote a high pollen flow and high chance of homogenization of recombinant forms. The karyotypes of E. speciosa, E. falcata and E. mulungu were cytogenetically analyzed in order to establish relationships among these three species of contrasting strategies. The chromosome count showed 2n = 42, with small chromosomes, prophasic condensation of the proximal type and non-reticulate to semi-reticulate nuclei with evident chromocenters. Chromosome banding showed AT-rich heterochromatic blocks in the pericentromeric region of most chromosomes and GC-rich regions in the terminal region of the largest pairs. In situ hybridization with 45S rDNA probes exhibited ten terminal signals in E. falcata and E. speciosa and eight in E. mulungu, while the 5S rDNA probe showed only two signals, also terminals in three species. The results show quite conserved karyotypes, with small variations in the size and number of 45S rDNA sites, which can be considered the only elements of karyotype differentiation, independent of plant size and strategies.Erythrina consists of 112 species distributed throughout the tropical and temperate regions. Species of Erythrina are of great biological interest because they are pollinated by hummingbirds, which promote a high pollen flow and high chance of homogenization of recombinant forms. The karyotypes of E. speciosa, E. falcata and E. mulungu were cytogenetically analyzed in order to establish relationships among these three species of contrasting habitats. The chromosome count showed 2n = 42, with small chromosomes, prophasic condensation of the proximal type and non-reticulate to semi-reticulate nuclei with evident chromocenters. Chromosome banding showed AT-rich heterochromatic blocks in the pericentromeric region of most chromosomes and GC-rich regions in the terminal portion of the largest pairs. In situ hybridization with 45S rDNA probes exhibited ten terminal signals in E. falcata and E. speciosa and eight in E. mulungu, while the 5S rDNA probe showed only two signals, also terminals in three species. The results show quite conserved karyotypes, with small variations in the size and number of 45S rDNA sites, which can be considered the only elements of karyotype differentiation, independent of plant size and strategies.  

Karyotype differentiation of four Cestrum species (Solanaceae) revealed by fluorescent chromosome banding and FISH

The karyotypes of four South American species of Cestrum (C. capsulare,C. corymbosum,C. laevigatum and C. megalophylum) were studied using conventional staining, C-CMA/DAPI chromosome banding and FISH with 45S and 5S rDNA probes. The karyotypes showed a chromosome number of 2n = 2x = 16, with metacentric chromosomes, except for the eighth submeta- to acrocentric pair. Several types of heterochromatin were detected, which varied in size, number, distribution and base composition. The C-CMA+ bands and 45S rDNA were located predominantly in terminal regions. The C-CMA + /DAPI + bands appeared in interstitial and terminal regions, and the C-DAPI + bands were found in all chromosome regions. The 5S rDNA sites were observed on the long arm of pair 8 in all species except C. capsulare, where they were found in the paracentromeric region of the long arm of pair 4. The differences in band patterns among the species studied here, along with data from other nine species reported in the literature, suggest that the bands are dispersed in an equilocal and non-equilocal manner and that structural rearrangements can be responsible for internal karyotype diversification. However, it is important to point out that the structural changes involving repetitive segments did not culminate in substantial changes in the general karyotype structure concerning chromosome size and morphology

Complete sequence and comparative analysis of the chloroplast genome of Plinia trunciflora

Plinia trunciflora is a Brazilian native fruit tree from the Myrtaceae family, also known as jaboticaba. This species has great potential by its fruit production. Due to the high content of essential oils in their leaves and of anthocyanins in the fruits, there is also an increasing interest by the pharmaceutical industry. Nevertheless, there are few studies focusing on its molecular biology and genetic characterization. We herein report the complete chloroplast (cp) genome of P. trunciflora using high-throughput sequencing and compare it to other previously sequenced Myrtaceae genomes. The cp genome of P. trunciflora is 159,512 bp in size, comprising inverted repeats of 26,414 bp and single-copy regions of 88,097 bp (LSC) and 18,587 bp (SSC). The genome contains 111 single-copy genes (77 protein-coding, 30 tRNA and four rRNA genes). Phylogenetic analysis using 57 cp protein-coding genes demonstrated that P. trunciflora, Eugenia uniflora and Acca sellowiana form a cluster with closer relationship to Syzygium cumini than with Eucalyptus. The complete cp sequence reported here can be used in evolutionary and population genetics studies, contributing to resolve the complex taxonomy of this species and fill the gap in genetic characterization

Chromosome banding patterns and localization of 5S and 45S rDNA sites in three shrub-tree species of Erythrina L. (Leguminosae: Papilionoideae) from Brazil

 Erythrina consists of 112 leguminous trees and shrubs, distributed throughout the tropical regions. Species of Erythrina are of great biological interest because they are pollinated by hummingbirds, which promote a high pollen flow and high chance of homogenization of recombinant forms. The karyotypes of E. speciosa, E. falcata and E. mulungu were cytogenetically analyzed in order to establish relationships among these three species of contrasting strategies. The chromosome count showed 2n = 42, with small chromosomes, prophasic condensation of the proximal type and non-reticulate to semi-reticulate nuclei with evident chromocenters. Chromosome banding showed AT-rich heterochromatic blocks in the pericentromeric region of most chromosomes and GC-rich regions in the terminal region of the largest pairs. In situ hybridization with 45S rDNA probes exhibited ten terminal signals in E. falcata and E. speciosa and eight in E. mulungu, while the 5S rDNA probe showed only two signals, also terminals in three species. The results show quite conserved karyotypes, with small variations in the size and number of 45S rDNA sites, which can be considered the only elements of karyotype differentiation, independent of plant size and strategies.Erythrina consists of 112 species distributed throughout the tropical and temperate regions. Species of Erythrina are of great biological interest because they are pollinated by hummingbirds, which promote a high pollen flow and high chance of homogenization of recombinant forms. The karyotypes of E. speciosa, E. falcata and E. mulungu were cytogenetically analyzed in order to establish relationships among these three species of contrasting habitats. The chromosome count showed 2n = 42, with small chromosomes, prophasic condensation of the proximal type and non-reticulate to semi-reticulate nuclei with evident chromocenters. Chromosome banding showed AT-rich heterochromatic blocks in the pericentromeric region of most chromosomes and GC-rich regions in the terminal portion of the largest pairs. In situ hybridization with 45S rDNA probes exhibited ten terminal signals in E. falcata and E. speciosa and eight in E. mulungu, while the 5S rDNA probe showed only two signals, also terminals in three species. The results show quite conserved karyotypes, with small variations in the size and number of 45S rDNA sites, which can be considered the only elements of karyotype differentiation, independent of plant size and strategies.  

Complete sequence and comparative analysis of the chloroplast genome of Plinia trunciflora

<div><p>Abstract Plinia trunciflora is a Brazilian native fruit tree from the Myrtaceae family, also known as jaboticaba. This species has great potential by its fruit production. Due to the high content of essential oils in their leaves and of anthocyanins in the fruits, there is also an increasing interest by the pharmaceutical industry. Nevertheless, there are few studies focusing on its molecular biology and genetic characterization. We herein report the complete chloroplast (cp) genome of P. trunciflora using high-throughput sequencing and compare it to other previously sequenced Myrtaceae genomes. The cp genome of P. trunciflora is 159,512 bp in size, comprising inverted repeats of 26,414 bp and single-copy regions of 88,097 bp (LSC) and 18,587 bp (SSC). The genome contains 111 single-copy genes (77 protein-coding, 30 tRNA and four rRNA genes). Phylogenetic analysis using 57 cp protein-coding genes demonstrated that P. trunciflora, Eugenia uniflora and Acca sellowiana form a cluster with closer relationship to Syzygium cumini than with Eucalyptus. The complete cp sequence reported here can be used in evolutionary and population genetics studies, contributing to resolve the complex taxonomy of this species and fill the gap in genetic characterization.</p></div

FISH using a gag-like fragment probe reveals a common Ty3-gypsy-like retrotransposon in genome of Coffea species

The genus Coffea possesses about 100 species, and the most economically important are Coffea canephora and Coffea arabica. The latter is predominantly self-compatible with 2n = 4x = 44, while the others of the genus are diploid with 2n = 2x = 22 and mostly self-incompatible. Studies using molecular markers have been useful to detect differences between genomes in Coffea; however, molecular and cytogenetic studies have produced only limited information on the karyotypes organization. We used DOP-PCR to isolate repetitive elements from genome of Coffea arabica var. typica. The pCa06 clone, containing a fragment of 775 bp length, was characterized by sequencing and used as a probe in chromosomes of C. arabica and six other species: C. canephora, Coffea eugenioides, Coffea kapakata, Coffea liberica var. dewevrei, Coffea racemosa, and Coffea stenophylla. This insert shows similarities with a gag protein of the Ty3-gypsy-like super-family. Dot blot and FISH analyses demonstrated that pCa06 is differentially accumulated between species and chromosomes. Signals appeared scattered and clustered on the chromosomes and were also associated with heterochromatic regions. While the literature shows that there is a high karyotype similarity between Coffea species, our results point out differences in the accumulation and dispersion of this Ty3-gypsy-like retrotransposon during karyotype differentiation of Coffea.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq