Tandemly repeated satellite DNA ofDolichopoda schiavazzii: A test for models on the evolution of highly repetitive DNA

Abstract

Three specific satellite DNA families can be detected in the genome of the cave cricket Dolichopoda schiavazzii. The pDoP102 and the pDsPv400 families are species specific for D. schiavazzii; the pDoP500 family is probably present in all Dolichopoda species. The three satellite DNA families were characterized from individuals of three isolated populations of D. schiavazzii with respect to nucleotide sequence, sequence complexity, sequence variability, and copy number. This unique data set on satellite DNAs of D. schiavazzii seems to allow one to test the significance of theoretical approaches to the mode of evolution of noncoding, tandemly arranged satellite DNA. At least for satellite DNAs of D. schiavazzii two clear trends were observed: (1) sequence variability increases with copy number and (2) the repeat length decreases with copy number. The first trend is in good agreement with the theory but the second is not. Thus, a revision of the models is proposed.

Cytogenetic and molecular characterization of a highly repeated DNA sequence in the peach potato aphid Myzus persicae

“…This high sequence homology could be due either to a strong functional constraint or to a process of "concerted evolution" determined by molecular drive (Dover et al 1982;Dover and Tautz 1986). According to current opinion on the evolution of satellite DNA (Charlesworth et al 1994), the degree of sequence homogeneity we observed among the six HindIII repeats could be related to the frequency of recombination events (Charlesworth et al 1994;Bachmann et al 1996). Such recombination could also act on the sequence length of the repeats, but the absence of internal repeats within HindIII fragments, by preventing sequence length variation, strongly diminishes the significance of this hypothesis.…”

Conservation of pBuM–2 satellite DNA sequences among geographically isolated Drosophila gouveai populations from Brazil

“…The pDo500 sequences are transcribe and were sug- Table 2. Analysis of molecular variance (AMOVA) of pBuM satellite DNA sequences among the D. gouveai (present work), D. seriema (Kuhn & Sene, 2004) and D. buzzatii populations (Kuhn et al, 2003) gesting that the high nucleotide similarity of pDo500 among the Dolichopoda species, even in geographically isolated populations from Dolichopoda schiavazzi species (Bachmann et al, 1996), is related to some biological role of hammerhead motifs present in these transcripts (Rojas et al, 2000). An alternative explanation for the maintenance of the primary structure of pBuM-2 sequences in D. gouveai could be related to selective pressure under this sequences, due to a functional role (although not discovered yet) of this satellite DNA.…”

“…Furthermore, in particular cases, was discovered satellite sequences transcribed in RNA, which biological role is unclear (Renaut et al, 1999). Rojas et al (2000), found hammerhead motifs with autocatalytic activity within of monomers of the pDo500 satellite DNA, isolated from Dolichopoda crave cricket species (Bachmann et al, 1996). The pDo500 sequences are transcribe and were sug- Table 2.…”

Low rates of homogenization of the DBC-150 satellite DNA family restricted to a single pair of microchromosomes in species from the Drosophila buzzatii cluster

“…The origin of satDNAs might be a consequence of unequal crossing over between short stretches of homology appearing by chance in regions of the chromosomes not maintained by natural selection (Smith 1976). Several satellite DNA families with independent origin may be present in the genome of a species (Bachmann et al 1996).…”