engleski

The MEL-172 satellite DNA library in parthenogenetic Meloidogyne species: conserved pattern of nucleotide variability along the monomers

Species-specific profile of satellite DNA sequences is often the result of fluctuation in copy number caused by dynamic amplifications and deletions of satellite sequences. The ancestor of closely related species contained a collection of satellite variants within its genome, and as new species emerge one satellite became predominately amplified. However, this library model does not predict the mechanism that could drive the choice of a satellite variant. Here, we show that high-copy number satellite DNAs from M. arenaria and M. javanica (MARJA) and M. paranaensis (MPA1), together with a new characterized low-copy number satellite MARJA-MPA1 create a library of related satellite sequences in mitotic/meiotic parthenogenic species of Meloidogyne. All these related satellite sequences were characterized as the MEL-172 family. The members of the MEL-172 family have conserved pattern of nucleotide variability along the monomer and show satellite domains with strikingly different rates of nucleotide substitution. The results suggest a sequence-dependent role for this complex satellite family and imply possible selection for specific DNA domains which could make provision for the entry and survival in the satellite library. This is the first evidence for strong constraints in specific regions of satellite sequences which belongs to a satellite library.

root-knot nematodes; repetitive sequences; sequence variability; concerted evolution

Rad je kao poster prezentiran ina skupu Second Congress of Croatian Geneticists with International Participation, održanom od 24.-27.09.2005.g., Supetar, Hrvatska ; objavljen u Knjizi sažetaka / Franekić-Čolić, J. ; Ugarković, Đ. (ur.). - Zagreb : Hrvatsko genetičko društvo , 2005. ; str. 52-52.