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The satellite DNA AflaSAT-1 in the A and B chromosomes of the grasshopper Abracris flavolineata.
BMC Genet. 2017 08 29; 18(1):81.BG

Abstract

BACKGROUND

Satellite DNAs (satDNAs) are organized in repetitions directly contiguous to one another, forming long arrays and composing a large portion of eukaryote genomes. These sequences evolve according to the concerted evolution model, and homogenization of repeats is observed at the intragenomic level. Satellite DNAs are the primary component of heterochromatin, located primarily in centromeres and telomeres. Moreover, satDNA enrichment in specific chromosomes has been observed, such as in B chromosomes, that can provide clues about composition, origin and evolution of this chromosome. In this study, we isolated and characterized a satDNA in A and B chromosomes of Abracris flavolineata by integrating cytogenetic, molecular and genomics approaches at intra- and inter-population levels, with the aim to understand the evolution of satDNA and composition of B chromosomes.

RESULTS

AflaSAT-1 satDNA was shared with other species and in A. flavolineata, was associated with another satDNA, AflaSAT-2. Chromosomal mapping revealed centromeric blocks variable in size in almost all chromosomes (except pair 11) of A complement for both satDNAs, whereas for B chromosome, only a small centromeric signal occurred. In distinct populations, variable number of AflaSAT-1 chromosomal sites correlated with variability in copy number. Instead of such variability, low sequence diversity was observed in A complement, but monomers from B chromosome were more variable, presenting also exclusive mutations. AflaSAT-1 was transcribed in five tissues of adults in distinct life cycle phases.

CONCLUSIONS

The sharing of AflaSAT-1 with other species is consistent with the library hypothesis and indicates common origin in a common ancestor; however, AflaSAT-1 was highly amplified in the genome of A. flavolineata. At the population level, homogenization of repeats in distinct populations was documented, but dynamic expansion or elimination of repeats was also observed. Concerning the B chromosome, our data provided new information on the composition in A. flavolineata. Together with previous results, the sequences of heterochromatic nature were not likely highly amplified in the entire B chromosome. Finally, the constitutive transcriptional activity suggests a possible unknown functional role, which should be further investigated.

Authors+Show Affiliations

Departamento de Biologia, UNESP - Univ Estadual Paulista, Instituto de Biociências/IB, Rio Claro, São Paulo, CEP 13506-900, Brazil.Departamento de Morfologia, UNESP - Univ Estadual Paulista, Instituto de Biociências/IB, Botucatu, São Paulo, Brazil.Departamento de Genética, UFPE - Univ Federal de Pernambuco, Centro de Biociências/CB, Recife, Pernambuco, Brazil.IBS - UNaM - CONICET, Posadas, Misiones, Argentina.Departamento de Morfologia, UNESP - Univ Estadual Paulista, Instituto de Biociências/IB, Botucatu, São Paulo, Brazil.Departamento de Biologia, UNESP - Univ Estadual Paulista, Instituto de Biociências/IB, Rio Claro, São Paulo, CEP 13506-900, Brazil.Departamento de Morfologia, UNESP - Univ Estadual Paulista, Instituto de Biociências/IB, Botucatu, São Paulo, Brazil.Departamento de Biologia, UNESP - Univ Estadual Paulista, Instituto de Biociências/IB, Rio Claro, São Paulo, CEP 13506-900, Brazil. mellodc@rc.unesp.br.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

28851268

Citation

Milani, Diogo, et al. "The Satellite DNA AflaSAT-1 in the a and B Chromosomes of the Grasshopper Abracris Flavolineata." BMC Genetics, vol. 18, no. 1, 2017, p. 81.
Milani D, Ramos É, Loreto V, et al. The satellite DNA AflaSAT-1 in the A and B chromosomes of the grasshopper Abracris flavolineata. BMC Genet. 2017;18(1):81.
Milani, D., Ramos, É., Loreto, V., Martí, D. A., Cardoso, A. L., de Moraes, K. C. M., Martins, C., & Cabral-de-Mello, D. C. (2017). The satellite DNA AflaSAT-1 in the A and B chromosomes of the grasshopper Abracris flavolineata. BMC Genetics, 18(1), 81. https://doi.org/10.1186/s12863-017-0548-9
Milani D, et al. The Satellite DNA AflaSAT-1 in the a and B Chromosomes of the Grasshopper Abracris Flavolineata. BMC Genet. 2017 08 29;18(1):81. PubMed PMID: 28851268.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The satellite DNA AflaSAT-1 in the A and B chromosomes of the grasshopper Abracris flavolineata. AU - Milani,Diogo, AU - Ramos,Érica, AU - Loreto,Vilma, AU - Martí,Dardo Andrea, AU - Cardoso,Adauto Lima, AU - de Moraes,Karen Cristiane Martinez, AU - Martins,Cesar, AU - Cabral-de-Mello,Diogo Cavalcanti, Y1 - 2017/08/29/ PY - 2017/04/21/received PY - 2017/08/22/accepted PY - 2017/8/31/entrez PY - 2017/8/31/pubmed PY - 2017/11/4/medline KW - B chromosome KW - Repetitive DNA KW - Tandem repeat KW - Transcription SP - 81 EP - 81 JF - BMC genetics JO - BMC Genet VL - 18 IS - 1 N2 - BACKGROUND: Satellite DNAs (satDNAs) are organized in repetitions directly contiguous to one another, forming long arrays and composing a large portion of eukaryote genomes. These sequences evolve according to the concerted evolution model, and homogenization of repeats is observed at the intragenomic level. Satellite DNAs are the primary component of heterochromatin, located primarily in centromeres and telomeres. Moreover, satDNA enrichment in specific chromosomes has been observed, such as in B chromosomes, that can provide clues about composition, origin and evolution of this chromosome. In this study, we isolated and characterized a satDNA in A and B chromosomes of Abracris flavolineata by integrating cytogenetic, molecular and genomics approaches at intra- and inter-population levels, with the aim to understand the evolution of satDNA and composition of B chromosomes. RESULTS: AflaSAT-1 satDNA was shared with other species and in A. flavolineata, was associated with another satDNA, AflaSAT-2. Chromosomal mapping revealed centromeric blocks variable in size in almost all chromosomes (except pair 11) of A complement for both satDNAs, whereas for B chromosome, only a small centromeric signal occurred. In distinct populations, variable number of AflaSAT-1 chromosomal sites correlated with variability in copy number. Instead of such variability, low sequence diversity was observed in A complement, but monomers from B chromosome were more variable, presenting also exclusive mutations. AflaSAT-1 was transcribed in five tissues of adults in distinct life cycle phases. CONCLUSIONS: The sharing of AflaSAT-1 with other species is consistent with the library hypothesis and indicates common origin in a common ancestor; however, AflaSAT-1 was highly amplified in the genome of A. flavolineata. At the population level, homogenization of repeats in distinct populations was documented, but dynamic expansion or elimination of repeats was also observed. Concerning the B chromosome, our data provided new information on the composition in A. flavolineata. Together with previous results, the sequences of heterochromatic nature were not likely highly amplified in the entire B chromosome. Finally, the constitutive transcriptional activity suggests a possible unknown functional role, which should be further investigated. SN - 1471-2156 UR - https://www.unboundmedicine.com/medline/citation/28851268/The_satellite_DNA_AflaSAT_1_in_the_A_and_B_chromosomes_of_the_grasshopper_Abracris_flavolineata_ L2 - https://bmcgenet.biomedcentral.com/articles/10.1186/s12863-017-0548-9 DB - PRIME DP - Unbound Medicine ER -