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Nucleolus size variation during meiosis and NOR activity of a B chromosome in the grasshopper Eyprepocnemis plorans.
Chromosome Res. 2007; 15(6):755-65.CR

Abstract

The number of nucleoli and nucleolar area were measured in meiotic cells from males of the grasshopper Eyprepocnemis plorans collected in three natural populations. Number of nucleoli per cell showed no significant correlation among cells in different meiotic stages, but there was strong positive correlation for nucleolar area between leptotene and interkinesis cells in individuals from distant populations (Salobreña in Spain, and Smir in Morocco). No correlation was, however, observed for both parameters between the meiotic stages analysed in individuals from the population of Torrox (Spain). The number of nucleoli at leptotene was about double the number at interkinesis, as expected from the double ploidy level at leptotene and the corresponding double number of rDNA clusters. Leptotene nucleolar area, however, was about fourfold that in interkinesis, presumably due to higher requirements for ribosome biogenesis in meiosis I than meiosis II. In Torrox, diplotene cells showed a lower number of nucleoli but larger nucleolar area than in leptotene cells, suggesting an increase in nucleolus size during prophase I. Significant differences were found among populations for nucleolar area but not for number of nucleoli, the smallest nucleolar area being observed in Torrox, which is the population harbouring the most parasitic B chromosome variant. No clear effects on nucleolar area or number of nucleoli were associated with the B-chromosome number. However, B-chromosome effects on the nucleolar area were apparent in the Torrox population when data were analysed with respect to a B-chromosome odd-even pattern in leptotene and interkinesis cells. However, in diplotene cells no odd-even pattern was observed for both nucleolar parameters, suggesting that the increase in nucleolar size from leptotene to diplotene dilutes the leptotene odd-even pattern. The rDNA distally located in the B chromosome was associated with a nucleolus in 6.5% out of the 247 diplotene cells analysed. The implications of these findings are discussed in the context of B chromosomes as stress-causing genome parasites and the nucleolus as a sensor of stress.

Authors+Show Affiliations

Departamento de Genética, 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

17609866

Citation

Teruel, María, et al. "Nucleolus Size Variation During Meiosis and nor Activity of a B Chromosome in the Grasshopper Eyprepocnemis Plorans." Chromosome Research : an International Journal On the Molecular, Supramolecular and Evolutionary Aspects of Chromosome Biology, vol. 15, no. 6, 2007, pp. 755-65.
Teruel M, Cabrero J, Perfectti F, et al. Nucleolus size variation during meiosis and NOR activity of a B chromosome in the grasshopper Eyprepocnemis plorans. Chromosome Res. 2007;15(6):755-65.
Teruel, M., Cabrero, J., Perfectti, F., & Camacho, J. P. (2007). Nucleolus size variation during meiosis and NOR activity of a B chromosome in the grasshopper Eyprepocnemis plorans. Chromosome Research : an International Journal On the Molecular, Supramolecular and Evolutionary Aspects of Chromosome Biology, 15(6), 755-65.
Teruel M, et al. Nucleolus Size Variation During Meiosis and nor Activity of a B Chromosome in the Grasshopper Eyprepocnemis Plorans. Chromosome Res. 2007;15(6):755-65. PubMed PMID: 17609866.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Nucleolus size variation during meiosis and NOR activity of a B chromosome in the grasshopper Eyprepocnemis plorans. AU - Teruel,María, AU - Cabrero,Josefa, AU - Perfectti,Francisco, AU - Camacho,Juan Pedro M, Y1 - 2007/07/10/ PY - 2007/04/09/received PY - 2007/05/03/accepted PY - 2007/05/03/revised PY - 2007/7/5/pubmed PY - 2007/12/15/medline PY - 2007/7/5/entrez SP - 755 EP - 65 JF - Chromosome research : an international journal on the molecular, supramolecular and evolutionary aspects of chromosome biology JO - Chromosome Res VL - 15 IS - 6 N2 - The number of nucleoli and nucleolar area were measured in meiotic cells from males of the grasshopper Eyprepocnemis plorans collected in three natural populations. Number of nucleoli per cell showed no significant correlation among cells in different meiotic stages, but there was strong positive correlation for nucleolar area between leptotene and interkinesis cells in individuals from distant populations (Salobreña in Spain, and Smir in Morocco). No correlation was, however, observed for both parameters between the meiotic stages analysed in individuals from the population of Torrox (Spain). The number of nucleoli at leptotene was about double the number at interkinesis, as expected from the double ploidy level at leptotene and the corresponding double number of rDNA clusters. Leptotene nucleolar area, however, was about fourfold that in interkinesis, presumably due to higher requirements for ribosome biogenesis in meiosis I than meiosis II. In Torrox, diplotene cells showed a lower number of nucleoli but larger nucleolar area than in leptotene cells, suggesting an increase in nucleolus size during prophase I. Significant differences were found among populations for nucleolar area but not for number of nucleoli, the smallest nucleolar area being observed in Torrox, which is the population harbouring the most parasitic B chromosome variant. No clear effects on nucleolar area or number of nucleoli were associated with the B-chromosome number. However, B-chromosome effects on the nucleolar area were apparent in the Torrox population when data were analysed with respect to a B-chromosome odd-even pattern in leptotene and interkinesis cells. However, in diplotene cells no odd-even pattern was observed for both nucleolar parameters, suggesting that the increase in nucleolar size from leptotene to diplotene dilutes the leptotene odd-even pattern. The rDNA distally located in the B chromosome was associated with a nucleolus in 6.5% out of the 247 diplotene cells analysed. The implications of these findings are discussed in the context of B chromosomes as stress-causing genome parasites and the nucleolus as a sensor of stress. SN - 0967-3849 UR - https://www.unboundmedicine.com/medline/citation/17609866/Nucleolus_size_variation_during_meiosis_and_NOR_activity_of_a_B_chromosome_in_the_grasshopper_Eyprepocnemis_plorans_ L2 - https://doi.org/10.1007/s10577-007-1159-5 DB - PRIME DP - Unbound Medicine ER -