Chromosomal Mapping of Repetitive DNAs in the Grasshopper Abracris flavolineata Reveal Possible Ancestry of the B Chromosome and H3 Histone Spreading

Author(s)

Bueno, Danilo ^[1] ; Palacios-Gimenez, Octavio Manuel ^[1] ; Cabral-de-Mello, Diogo Cavalcanti ^[1]

Affiliation

^[1] Univ Estadual Paulista, UNESP, Inst Biociencias, Dept Biol, Rio Claro, SP - Brazil

• Document type: Journal article
• Source: PLoS One; v. 8, n. 6 JUN 27 2013.
• Web of Science Citations: 55

Abstract

Supernumerary 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 C(0)t-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. (AU)

• FAPESP's process: 11/19481-3 - Contributions to elucidation of B chromosome biological roles using as model Rhammatocerus brasiliensis (Orthoptera) and Haplochromis obliquidens (Teleostei): structure, evolution and histone proteins modification patterns
• Grantee: Diogo Cavalcanti Cabral de Mello
• Support Opportunities: Regular Research Grants
• FAPESP's process: 11/18028-3 - Isolation, characterization and chromosomal mapping of repeated DNA sequences in Abracris flavolineata (Acrididae, Ommatolampinae), with enphasis in the B chromosome analysis
• Grantee: Danilo Bueno
• Support Opportunities: Scholarships in Brazil - Scientific Initiation