tailieunhanh - báo cáo khoa học: " To be or not to be the odd one out - Allelespecific transcription in pentaploid dogroses (Rosa L. sect. Caninae (DC.) Ser)"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: To be or not to be the odd one out - Allelespecific transcription in pentaploid dogroses (Rosa L. sect. Caninae (DC.) Ser) | Ritz et al. BMC Plant Biology 2011 11 37 http 1471-2229 11 37 BMC Plant Biology RESEARCH ARTICLE Open Access To be or not to be the odd one out - Allelespecific transcription in pentaploid dogroses Rosa L. sect. Caninae DC. Ser Christiane M Ritz1 Ines Kohnen2 Marco Groth3 Gunter TheiBen4 Volker Wissemann5 Abstract Background Multiple hybridization events gave rise to pentaploid dogroses which can reproduce sexually despite their uneven ploidy level by the unique canina meiosis. Two homologous chromosome sets are involved in bivalent formation and are transmitted by the haploid pollen grains and the tetraploid egg cells. In addition the egg cells contain three sets of univalent chromosomes which are excluded from recombination. In this study we investigated whether differential behavior of chromosomes as bivalents or univalents is reflected by sequence divergence or transcription intensity between homeologous alleles of two single copy genes LEAFY cGAPDH and one ribosomal DNA locus nrlTS . Results We detected a maximum number of four different alleles of all investigated loci in pentaploid dogroses and identified the respective allele with two copies which is presumably located on bivalent forming chromosomes. For the alleles of the ribosomal DNA locus and cGAPDH only slight if any differential transcription was determined whereas the LEAFY alleles with one copy were found to be significantly stronger expressed than the LEAFY allele with two copies. Moreover we found for the three marker genes that all alleles have been under similar regimes of purifying selection. Conclusions Analyses of both molecular sequence evolution and expression patterns did not support the hypothesis that unique alleles probably located on non-recombining chromosomes are less functional than duplicate alleles presumably located on recombining chromosomes. Background Polyploidisation is considered to be a major creative force in plant evolution since approximately 70 of