The centromeric satellite of the wedge sole (Dicologoglossa cuneata, Pleuronectiformes) is composed mainly of a sequence motif conserved in other vertebrate centromeric DNAs.
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, pJalpha) 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.
de la Herrán
R
R
Departamento de Genética, Facultad de Ciencias, Universidad de Granada, Granada, Spain. rherran@ugr.es
Robles
F
F
Navas
J I
JI
López-Flores
I
I
Herrera
M
M
Hachero
I
I
Garrido-Ramos
M A
MA
Ruiz Rejón
C
C
Ruiz Rejón
M
M