Occurrence and chromosome distribution of retroelements and NUPT sequences in Copaifera langsdorffii Desf. (Caesalpinioideae).
Copaifera langsdorffii possesses 2n = 24 large meta- and submetacentric chromosomes (5.97-2.60 microm) in comparison with other Caesalpinioideae trees. Chromosome banding revealed an abundance of GC-rich blocks with a few differences in the size and location of bands between different populations. Polymerase chain reaction and digestion with restriction enzyme RsaI were carried out in order to isolate repetitive DNAs, yielding three fragments of different size: (1) cp-rDNA-like, 109 bp (pCl03 clone); (2) Ty1-copia-like retroelement, 185 bp (pCl23 clone); and (3) Ty3-gypsy-like retroelement, 269 bp (pCl08 clone). The first clone produced unmistakable hybridization signals at subterminal and intercalary positions, coinciding with or adjacent to most of the GC-rich bands. The second clone (pCl23 clone) showed dispersed signals distributed throughout several chromosomes, while the pCl08 clone exhibited hybridization signals scattered and organized in blocks in all chromosomes of the complement. Fluorescent in situ hybridization and chromosome banding results allowed the detection of translocation events and unequal crossing-over involving 45S rDNA regions (pairs 7, 8, and 11). However, the most intriguing result was the insertion and subsequent overamplification of a cp-rDNA-like fragment and its distribution over the chromosomes of C. langsdorffii. Additionally, the results suggest that this segment behaves like satellite DNA. These different chromosome markers produced by cytomolecular techniques show that samples from different locations, although isolated, retain more karyotypic similarities than differences.
Gaeta
Marcos Letaif
ML
Laboratório de Biodiversidade e Restauração de Ecossistemas, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Caixa Postal 6001, CEP 86051-990, Londrina, PR, Brazil. andrevanzela@uel.br
Yuyama
Priscila Mary
PM
Sartori
Daniele
D
Fungaro
Maria Helena Pelegrinelli
MH
Vanzela
André Luís Laforga
AL
D001483:Base Sequence; D032461:Chromosomes, Plant / Q000235:genetics*; D003001:Cloning, Molecular; D007887:Fabaceae / Q000235:genetics*; D005819:Genetic Markers; D017404:In Situ Hybridization, Fluorescence; D012091:Repetitive Sequences, Nucleic Acid; D018626:Retroelements
D005819:Genetic Markers; D018626:Retroelements