Cytotaxonomy of diploid and polyploid Aristolochia (Aristolochiaceae) species based on the distribution of CMA/DAPI bands and 5S and 45S rDNA sites

Berjano, Regina; Roa, Fernando; Lozano, Salvador Talavera; Guerra, Marcelo

doi:10.1007/s00606-009-0184-6

Cited by 32 publications

(24 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Sometimes these sites are closely linked to each other as observed, for example, in different species of Brassica (Hasterok et al 2006;Berjano et al 2009;Sousa et al 2011;Barros e Silva et al 2013). Our results showed that they were located on the same chromosome in 13 species, including 12 of African and 1 of Asian origin.…”

Section: Discussionsupporting

confidence: 76%

Comparative chromosomal localization of 45S and 5S rDNAs and implications for genome evolution inCucumis

Zhang

Yang

et al. 2016

Genome

View full text Add to dashboard Cite

Ribosomal DNAs are useful cytogenetic markers for chromosome analysis. Studies investigating site numbers and distributions of rDNAs have provided important information for elucidating genome organization and chromosomal relationships of many species by fluorescence in situ hybridization. But relevant studies are scarce for species of the genus Cucumis, especially in wild species. In the present study, FISH was conducted to investigate the organization of 45S and 5S rDNA among 20 Cucumis accessions, including cultivars and wild accessions. Our results showed that the number of 45S rDNA sites varied from one to five pairs in different accessions, and most of these sites are located at the terminal regions of chromosomes. Interestingly, up to five pairs of 45S rDNA sites were observed in C. sativus var. sativus, the species which has the lowest chromosome number, i.e., 2n = 14. Only one pair of 5S rDNA sites was detected in all accessions, except for C. heptadactylus, C. sp, and C. spp that had two pairs of 5S rDNA sites. The distributions of 5S rDNA sites showed more variation than 45S rDNA sites. The phylogenetic analysis in this study showed that 45S and 5S rDNA have contrasting evolutionary patterns. We find that 5S rDNA has a polyploidizationrelated tendency towards the terminal location from an interstitial location but maintains a conserved site number, whereas the 45S rDNA showed a trend of increasing site number but a relatively conserved location.

show abstract

Section: Discussionsupporting

confidence: 76%

Comparative chromosomal localization of 45S and 5S rDNAs and implications for genome evolution inCucumis

Zhang

Yang

et al. 2016

Genome

View full text Add to dashboard Cite

show abstract

“…The cytogenetic analysis of this species coincides with the chromosome number that was most frequently reported for the genus (Berjano et al, 2009). A previous chromosomal analysis (Berjano et al, 2009) of material collected in terrestrial environments in the neighboring state of Pernambuco demonstrated essentially the same karyotype as the present sample.…”

Section: Discussionsupporting

confidence: 87%

Is there a relationship between polyploidy and stressful environments? A case study of inselbergs in northeastern Brazil

et al. 2014

View full text Add to dashboard Cite

ABSTRACT. 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. In addition, 13 rupicolous species that grow in the study area, whose chromosome numbers were previously determined, were included in our analysis. Plant chromosome numbers varied between 2n = 12 in Callisia filiformis (Commelinaceae) to 2n = ca. 240 in Epidendrum cinnabarinum (Orchidaceae). The data as a whole do not support the hypothesis that inselberg species have greater levels of ploidy than terrestrial or epiphytic populations of the same or closely related S.R. Pitrez et al. ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 13 (4): 8353-8366 (2014) 8354species because these rupicolous species demonstrate chromosomal evolution patterns that are independent of the stressful environments of inselberg formations.

show abstract

“…In contrast to the 45S rDNA site, the 5S rDNA site can only be located by FISH either in chromosomes or in interphase nuclei so that only after the popularization of this technique, in the last 2 decades, the position of the 5S rDNA sites has become widely known. In most species, the loci for 5S and 45S rRNA genes are located in different chromosomes, whereas in other species the 2 loci are found in the same chromosome pair, sometimes closely linked to each other, as observed for example in different species of Brassica [Hasterok et al, 2006], Aristolochia [Berjano et al, 2009] and Rhynchospora [Sousa et al, 2011]. A completely different kind of association, where a single repeat unit contains both rDNA families, first reported in some members of the daisy family Asteraceae [García et al, 2009;Mazzella et al, 2010] and in the gymnosperm Ginkgo biloba [Galián et al, 2012], may be more common than initially thought.…”

mentioning

confidence: 99%

Linked 5S and 45S rDNA Sites Are Highly Conserved through the Subfamily Aurantioideae (Rutaceae)

Silva

Filho

Guerra

2013

Cytogenet Genome Res

View full text Add to dashboard Cite

Sites of 5S and 45S rDNA are more commonly located on different chromosomes of most angiosperms. Previous investigations have shown that in the subfamily Aurantioideae these sites may appear closely linked (adjacent sites), as in Poncirustrifoliata, or completely isolated, as in some species of Citrus. In the present work, the distribution of rDNA sites was investigated in representatives of 9 genera of Aurantioideae by FISH and CMA banding, aiming to understand the evolution of adjacent sites in the subfamily. A total of 57 rDNA sites were observed, 40 of them being adjacent to each other. All adjacent sites displayed the 45S rDNA array more terminally located. Assuming that the linked 5S-45S rDNA arrangement was the ancestral condition in Aurantioideae, the isolated rDNA sites observed in Clausena excavata,Bergera koenigii, and Fortunella obovata, as well as the complete linkage loss in Citrus maxima and C. medica indicates that unlinked sites arose independently several times in the evolution of the group. The linkage loss may be due to independent dispersion of one or both rDNA sequence families followed by deletion of the corresponding array in the adjacent site. The possible mechanisms behind these events and their occurrence in other groups are discussed.

show abstract

Cytotaxonomy of diploid and polyploid Aristolochia (Aristolochiaceae) species based on the distribution of CMA/DAPI bands and 5S and 45S rDNA sites

Cited by 32 publications

References 31 publications

Comparative chromosomal localization of 45S and 5S rDNAs and implications for genome evolution inCucumis

Comparative chromosomal localization of 45S and 5S rDNAs and implications for genome evolution inCucumis

Is there a relationship between polyploidy and stressful environments? A case study of inselbergs in northeastern Brazil

Linked 5S and 45S rDNA Sites Are Highly Conserved through the Subfamily Aurantioideae (Rutaceae)

Contact Info

Product

Resources

About