Bueno, Danilo [UNESP]Palacios-Gimenez, Octavio Manuel [UNESP]Cabral-de-Mello, Diogo Cavalcanti [UNESP]2014-05-272014-05-272013-06-27PLoS ONE, v. 8, n. 6, 2013.1932-6203http://hdl.handle.net/11449/75719Supernumerary chromosomes (B chromosomes) occur in approximately 15% of eukaryote species. Although these chromosomes have been extensively studied, knowledge concerning their specific molecular composition is lacking in most cases. The accumulation of repetitive DNAs is one remarkable characteristic of B chromosomes, and the occurrence of distinct types of multigene families, satellite DNAs and some transposable elements have been reported. Here, we describe the organization of repetitive DNAs in the A complement and B chromosome system in the grasshopper species Abracris flavolineata using classical cytogenetic techniques and FISH analysis using probes for five multigene families, telomeric repeats and repetitive C0t-1 DNA fractions. The 18S rRNA and H3 histone multigene families are highly variable and well distributed in A. flavolineata chromosomes, which contrasts with the conservation of U snRNA genes and less variable distribution of 5S rDNA sequences. The H3 histone gene was an extensively distributed with clusters occurring in all chromosomes. Repetitive DNAs were concentrated in C-positive regions, including the pericentromeric region and small chromosomal arms, with some occurrence in C-negative regions, but abundance was low in the B chromosome. Finally, the first demonstration of the U2 snRNA gene in B chromosomes in A. flavolineata may shed light on its possible origin. These results provide new information regarding chromosomal variability for repetitive DNAs in grasshoppers and the specific molecular composition of B chromosomes. © 2013 Bueno et al.engDNA fragmenthistone H3repetitive DNARNA 18SRNA 5Ssatellite DNAAbracris flavolineataanimal cellanimal tissueautosomebioaccumulationCaeliferacentromerechromosome analysischromosome mapchromosome variantDNA sequencefemalefluorescence in situ hybridizationgenetic conservationkaryotypemalenonhumannucleotide sequenceplesiomorphyRNA genetelomereArtigo10.1371/journal.pone.0066532WOS:000321150000005Acesso aberto2-s2.0-848795408152-s2.0-84879540815.pdf