Reduced rates of sequence evolution of Y-linked satellite DNA in Rumex (Polygonaceae)

• Published in: Journal of molecular evolution Vol. 60; no. 3; pp. 391 - 399
• Main Authors: Navajas-Pérez, Rafael, la Herrán, Roberto de, Jamilena, Manuel, Lozano, Rafael, Rejón, Carmelo Ruiz, Rejón, Manuel Ruiz, Garrido-Ramos, Manuel A
• Format: Journal Article
• Language: English
• Published: Germany Springer Nature B.V 01.03.2005
• Subjects: Base Sequence; Blotting, Southern; Chromosomes; Chromosomes, Plant - genetics; Cloning, Molecular; Cluster Analysis; Deoxyribonucleic acid; DNA; DNA Primers; DNA, Satellite - genetics; Evolution, Molecular; Genetics; Molecular Sequence Data; Phylogeny; Polygonaceae; Rumex; Rumex - genetics; Rumex acetosa; Rumex papillaris; Sequence Analysis, DNA; Spain; Y Chromosome - genetics; Spain
• ISSN: 0022-2844; 1432-1432
• DOI: 10.1007/s00239-004-0199-0

One characteristic of sex chromosomes is the accumulation of a set of different types of repetitive DNA sequences in the Y chromosomes. However, little is known about how this occurs or about how the absence of recombination affects the subsequent evolutionary fate of the repetitive sequences in the Y chromosome. Here we compare the evolutionary pathways leading to the appearance of three different families of satellite-DNA sequences within the genomes of Rumex acetosa and R. papillaris, two dioecious plant species with a complex XX/XY(1)Y(2) sex-chromosome system. We have found that two of these families, one autosomic (the RAE730 family) and one Y-linked (the RAYSI family), arose independently from the ancestral duplication of the same 120-bp repeat unit. Conversely, a comparative analysis of the three satellite-DNA families reveals no evolutionary relationships between these two and the third, RAE180, also located in the Y chromosomes. However, we have demonstrated that, regardless of the mechanisms that gave rise to these families, satellite-DNA sequences have different evolutionary fates according to their location in different types of chromosomes. Specifically, those in the Y chromosomes have evolved at half the rate of those in the autosomes, our results supporting the hypothesis that satellite DNAs in nonrecombining Y chromosomes undergo lower rates of sequence evolution and homogenization than do satellite DNAs in autosomes.