Satellite DNA Derived from 5S rDNA in &lt;i&gt;Physalaemus cuvieri&lt;/i&gt; (Anura, Leiuperidae)

5S and 45S rDNA sites are the best mapped chromosome regions in eukaryotic chromosomes. In this work, a database was built gathering information about the position and number of 5S rDNA sites in 784 plant species, aiming to identify patterns of distribution along the chromosomes and its correlation with the position of 45S rDNA sites. Data revealed that in most karyotypes (54.5%, including polyploids) two 5S rDNA sites (a single pair) are present, with 58.7% of all sites occurring in the short arm, mainly in the proximal region. In karyotypes of angiosperms with only 1 pair of sites (single sites) they are mostly found in the proximal region (52.0%), whereas in karyotypes with multiple sites the location varies according to the average chromosome size. Karyotypes with multiple sites and small chromosomes (<3 µm) often display proximal sites, while medium-sized (between 3 and 6 µm) and large chromosomes (>6 µm) more commonly show terminal or interstitial sites. In species with holokinetic chromosomes, the modal value of sites per karyotype was also 2, but they were found mainly in a terminal position. Adjacent 5S and 45S rDNA sites were often found in the short arm, reflecting the preferential distribution of both sites in this arm. The high frequency of genera with at least 1 species with adjacent 5S and 45S sites reveals that this association appeared several times during angiosperm evolution, but it has been maintained only rarely as the dominant array in plant genera.

Section: Number Of 5s Rdna Sites Per Karyotypementioning

confidence: 89%

Non-Random Distribution of 5S rDNA Sites and Its Association with 45S rDNA in Plant Chromosomes

Roa¹,

Guerra²

2015

“…One of them is localized in chromosome 3 consisting of type I 5S rDNA arrays, and the signals detected in chromosomes 9 and 13 corresponded to arrays of type II 5S rDNA [Martins et al, 2002]. In the anuran species, Engystomops freibergi and P. cuvieri , 2 sites of 5S rDNA were observed in the genomes [Vittorazzi et al, 2011;Rodrigues et al, 2012]. In E. freibergi , arrays in 3p preferentially constituted type I 5S rDNA, and arrays in 6q were related to type II 5S rDNA [Rodrigues et al, 2012].…”

Section: Two Types Of 5s Rdna Array Tandemly Arrangedmentioning

confidence: 99%

“…In the fish Oreochromis niloticus , type I 5S rDNA was found in chromosome 3, while type II 5S rDNA was detected in chromosomes 9 and 13 [Martins et al, 2002]. In the anurans, although studied to date in very limited groups, i.e., P. cuvieri and Engystomops species, it was demonstrated that different classes of 5S rDNA are separately assigned to distinct chromosome loci [Vittorazzi et al, 2011;Rodrigues et al, 2012]. The fact that the 5S rRNA genes are distributed at several chromosomal loci, previously detected in both fishes and amphibians, seems to be associated with the different classes of 5S rDNA.…”

mentioning

confidence: 99%

“…The 120-bp coding sequence is highly conserved, while NTS is variable in length and nucleotide composition. Two types of 5S rDNA array were classified by the differently sized and distinct NTS sequences and were widely documented in vertebrates, including mammals [Hallenberg et al, 1994;Frederiksen et al, 1997;Jensen and Frederiksen, 2000], fish [Martins and Wasko, 2004], chickens [Lazar et al, 1983;Daniels and Delany, 2003], and the anurans Physalaemus cuvieri and Engystomops species [Vittorazzi et al, 2011;Rodrigues et al, 2012]. Another dual system of the 5S rRNA genes, differently expressed in oocytes and somatic cells, was well known in the anurans Xenopus species [Korn and Brown, 1978;Peterson et al, 1980;Harper et al, 1983;Kramer, 1985] and several other animals, e.g., some bony fishes, lamprey, and the tunicate Halocynthia roretzi [Komiya et al, 1986].…”

mentioning

confidence: 99%

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A Tandemly Arranged Pattern of Two 5S rDNA Arrays in Amolops mantzorum (Anura, Ranidae)

Liu¹,

Song²,

Xia³

et al. 2017

In an attempt to extend the knowledge of the 5S rDNA organization in anurans, the 5S rDNA sequences of Amolops mantzorum were isolated, characterized, and mapped by FISH. Two forms of 5S rDNA, type I (209 bp) and type II (about 870 bp), were found in specimens investigated from various populations. Both of them contained a 118-bp coding sequence, readily differentiated by their non-transcribed spacer (NTS) sizes and compositions. Four probes (the 5S rDNA coding sequences, the type I NTS, the type II NTS, and the entire type II 5S rDNA sequences) were respectively labeled with TAMRA or digoxigenin to hybridize with mitotic chromosomes for samples of all localities. It turned out that all probes showed the same signals that appeared in every centromeric region and in the telomeric regions of chromosome 5, without differences within or between populations. Obviously, both type I and type II of the 5S rDNA arrays arranged in tandem, which was contrasting with other frogs or fishes recorded to date. More interestingly, all the probes detected centromeric regions in all karyotypes, suggesting the presence of a satellite DNA family derived from 5S rDNA.

“…Also in animals some cases have been reported, such as the fish Hoplias malabaricus , in which a satellite DNA with high similarity to 5S rDNA was found in the centromeric regions of various chromosomes, suggesting that this satellite DNA originates from the 5S rDNA [Martins et al, 2006]. Similarly, centromeric satellite DNA derived from the 5S rDNA, probably by gene duplication and nucleotide divergence, was reported for the amphibian Physalaemus cuvieri [Vittorazzi et al, 2011].…”

Section: Discussionmentioning

confidence: 91%

Plantago lagopus B Chromosome Is Enriched in 5S rDNA-Derived Satellite DNA

Kumke

Macas²,

Fuchs³

et al. 2016

B chromosomes are supernumerary dispensable parts of the karyotype which appear in some individuals of some populations in some species. Using advanced sequencing technology, we in silico characterized the high-copy DNA composition of Plantago lagopus with and without B chromosomes. The nuclear genome (2.46 pg/2C) was found to be relatively rich in repetitive sequences, with highly and moderately repeated elements making up 68% of the genome. Besides a centromere-specific marker, we identified a B-specific satellite and a repeat enriched in polymorphic A chromosome segments. The B-specific tandem repeat PLsatB originated from sequence amplification including 5S rDNA fragments.