The centromeric satellite of the wedge sole (<i>Dicologoglossa cuneata</i>, Pleuronectiformes) is composed mainly of a sequence motif conserved in other vertebrate centromeric DNAs

Abstract

Here, a new satellite-DNA family is isolated and characterized from wedge sole, Dicologoglossa cuneata Moreau, 1881 (Pleuronectiformes), a fish having a small genome. This satellite-DNA family of sequences was isolated by conventional cloning after digestion of genomic DNA with the DraI restriction enzyme. Repeat units are 171 bp in length with a high AT content (63%). Several runs of consecutive adenines and thymines were found, and concomitantly computer analyses revealed that these regions are prone to acquire stable sequence-directed curvature. Especially remarkable is that the DraI sequences are composed almost entirely of the repetition of up to fourteen 9-bp motifs (T/C)GTC(A/C)AAAA similar to other vertebrate centromeric satellite-DNA sequences. In fact, we demonstrate the origin of this satellite through duplication of this motif plus the addition of a stretch of cytosines. The centromeric location and the presence in this satellite-DNA sequence of not only different vertebrate motifs (CENP-B box, pJα) but also others such as the CDEIII motif of Saccharomyces cerevisiae reveal a possible role in centromere function. All these characteristics provide important information on the origin, function, and the evolution of the centromeric satellite DNAs in wedge sole.

The Molecular Cytogenetic Characterization of Pistachio (Pistacia vera L.) Suggests the Arrest of Recombination in the Largest Heteropycnotic Pair HC1

“…the satellite DNAs of Mus musculus [ 51 ], Sparus aurata [ 52 ], Oreochromis mossambicus , O . hornorum [ 53 ], Dicologlossa cuneata [ 54 ] and Drosophila buzzatii group [ 55 ], but also in plants, Rumex acetosa [ 33 ].…”

Satellite DNA: An Evolving Topic

“…Thus, for example, the centromeric satDNAs of tilapias, sparids, or mice are the result of several cycles of duplication and sequence divergence of a basic shorter monomer composed of nine nucleotides [ 30 ]. A complex scenario of duplications and expansions was observed in the formation of the HindIII satDNA of sturgeons [ 89 ] or in the case of the centromeric satDNA of the wedge sole [ 90 ]. Current repeats originated from shorter repeat units were also found in several plant species [ 25 , 47 , 91 , 92 ].…”

“…On the basis of this model, tandem repeats of 15 bp or less may appear by chance in many places in the genome in such a way that both microsatellites and shorter minisatellites can begin their life cycle in the second stage. These shorter repeat units can in turn give rise to longer repeat units through several consecutive cycles of duplication and divergence [ 25 , 30 , 89 , 90 ]. Similarly, HORs are evolutionary units of amplification and homogenization of smaller monomers [ 70 ].…”

Bread wheat satellitome: a complex scenario in a huge genome

“…In bread wheat we have not found a relationship between abundance and organization There is no correlation either in the bread wheat satellitome between repeat-unit length and AT-richness as found previously in some satellitomes, in which longer satellites are older and, in turn, they are richer in AT (Ruiz-Ruano et al 2016 , 2019 ). Notwithstanding, it can be assumed that the longer satellites in bread wheat are older than the shorter ones because the repeat units of all satDNAs are composed of smaller subunits, suggesting an origin of these repeats from shorter sequences, as in other satDNAs (Garrido-Ramos et al 1995 ; de la Herrán et al 2001 , 2008 ; Navajas-Pérez et al 2005 ; Macas et al 2006 ; Emadzade et al 2014 ) which would also explain the common origin of the different members of the different superfamilies from the diversification of pre-existing sequences of shorter size (Navajas-Pérez et al 2005 ; Ruiz-Ruano et al 2019 ).…”