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Ribosomal DNA is active in different B chromosome variants of the grasshopper Eyprepocnemis plorans.
Genetica. 2013 Sep; 141(7-9):337-45.G

Abstract

B chromosomes are considered to be genetically inert elements. However, some of them are able to show nucleolus organizer region (NOR) activity, as detected by both cytological and molecular means. The grasshopper Eyprepocnemis plorans shows a B chromosome polymorphism characterized by the existence of many B variants. One of them, B24, shows NOR activity in about half of B-carrying males in the Torrox population. Molecular data have suggested the recent origin for B chromosomes in this species, and on this basis it would be expected that NOR activity was widespread among the different B variants. Here we test this hypothesis in four different B chromosome variants (B1, B2, B5, and B24) from 11 natural populations of the grasshopper E. plorans covering the south and east of the Iberian Peninsula plus the Balearic Islands. We used two different approaches: (1) the cytological observation of nucleoli attached to the distal region of the B chromosome (where the rDNA is located), and (2) the molecular detection of the rDNA transcripts carrying an adenine insertion characteristic of B chromosome ITS2 sequences. The results showed NOR expression not only for B24 but also for the B1 and B2 variants. However, the level of B-NOR expression in these latter variants, measured by the proportion of cells showing nucleoli attached to the B chromosomes, was much lower than that previously reported for B24. This suggests the possibility that structural or genetic background conditions are enhancing the expressivity of the rDNA in the B24 variant.

Authors+Show Affiliations

Departamento de Genética, Facultad de Ciencias, Universidad de Granada, 18071, Granada, Spain.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

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

Language

eng

PubMed ID

24008810

Citation

Ruíz-Estévez, Mercedes, et al. "Ribosomal DNA Is Active in Different B Chromosome Variants of the Grasshopper Eyprepocnemis Plorans." Genetica, vol. 141, no. 7-9, 2013, pp. 337-45.
Ruíz-Estévez M, López-León MD, Cabrero J, et al. Ribosomal DNA is active in different B chromosome variants of the grasshopper Eyprepocnemis plorans. Genetica. 2013;141(7-9):337-45.
Ruíz-Estévez, M., López-León, M. D., Cabrero, J., & Camacho, J. P. (2013). Ribosomal DNA is active in different B chromosome variants of the grasshopper Eyprepocnemis plorans. Genetica, 141(7-9), 337-45. https://doi.org/10.1007/s10709-013-9733-6
Ruíz-Estévez M, et al. Ribosomal DNA Is Active in Different B Chromosome Variants of the Grasshopper Eyprepocnemis Plorans. Genetica. 2013;141(7-9):337-45. PubMed PMID: 24008810.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Ribosomal DNA is active in different B chromosome variants of the grasshopper Eyprepocnemis plorans. AU - Ruíz-Estévez,Mercedes, AU - López-León,M Dolores, AU - Cabrero,Josefa, AU - Camacho,Juan Pedro M, Y1 - 2013/09/06/ PY - 2013/06/16/received PY - 2013/08/31/accepted PY - 2013/9/7/entrez PY - 2013/9/7/pubmed PY - 2014/5/3/medline SP - 337 EP - 45 JF - Genetica JO - Genetica VL - 141 IS - 7-9 N2 - B chromosomes are considered to be genetically inert elements. However, some of them are able to show nucleolus organizer region (NOR) activity, as detected by both cytological and molecular means. The grasshopper Eyprepocnemis plorans shows a B chromosome polymorphism characterized by the existence of many B variants. One of them, B24, shows NOR activity in about half of B-carrying males in the Torrox population. Molecular data have suggested the recent origin for B chromosomes in this species, and on this basis it would be expected that NOR activity was widespread among the different B variants. Here we test this hypothesis in four different B chromosome variants (B1, B2, B5, and B24) from 11 natural populations of the grasshopper E. plorans covering the south and east of the Iberian Peninsula plus the Balearic Islands. We used two different approaches: (1) the cytological observation of nucleoli attached to the distal region of the B chromosome (where the rDNA is located), and (2) the molecular detection of the rDNA transcripts carrying an adenine insertion characteristic of B chromosome ITS2 sequences. The results showed NOR expression not only for B24 but also for the B1 and B2 variants. However, the level of B-NOR expression in these latter variants, measured by the proportion of cells showing nucleoli attached to the B chromosomes, was much lower than that previously reported for B24. This suggests the possibility that structural or genetic background conditions are enhancing the expressivity of the rDNA in the B24 variant. SN - 1573-6857 UR - https://www.unboundmedicine.com/medline/citation/24008810/Ribosomal_DNA_is_active_in_different_B_chromosome_variants_of_the_grasshopper_Eyprepocnemis_plorans_ L2 - https://doi.org/10.1007/s10709-013-9733-6 DB - PRIME DP - Unbound Medicine ER -