Chromosomal characteristics of a Brazilian whip spider (Amblypygi) and evolutionary relationships with other arachnid orders

We analyzed mitotic and meiotic cells of a Brazilian amblypygid, Heterophrynus longicornis, using conventional and molecular cytogenetic techniques (Giemsa staining, C-banding, Ag-NOR, and FISH with rDNA probe). This is the first study that focuses solely on amblypygid chromosomes; it was undertaken to add data on cytogenetic knowledge of this group and contribute to the understanding of chromosome evolution in the Arachnida. We found 2n = 66 for male and female individuals, monocentric chromosomes, and absence of morphologically differentiated sex chromosomes. C-banding showed heterochromatin in the pericentromeric region of most chromosomes. Mitotic and meiotic nuclei submitted to silver impregnation and FISH revealed, respectively, Ag-NORs and ribosomal genes in the terminal region of two chromosome pairs. Most chromosome features that we observed in H. longicornis are shared with species of other arachnid orders; however, the absence of morphologically differentiated sex chromosomes in amblypygid contrasts with the remarkable variety of sex chromosome systems recorded for the Araneae. Consequently, we conclude that analysis of species of the Tetrapulmonata clade is useful for understanding the trends of sex chromosome evolution in this arachnid group. © FUNPEC-RP.

Informe de la Tercera Conferencia Regional sobre la Pobreza en América Latina y el Caribe = Report of the Third Regional Conference on Poverty in Latin America and the Caribbean

Incluye Bibliografía

Third Meeting of the Expert Group on Poverty Statistics (Rio Group)

Includes bibliography

Infant and child mortality in the Third World: background information and proposals for cooperative studies among demographic centers

Includes bibliography

Is it too early to study the elderly in the Third World?

Includes bibliography

Provisional agenda. Third Regional Intergovernmental Conference on Ageing in Latin America and the Caribbean

Spanish version available at the Library

Annotated Provisional Agenda. Third Regional Intergovernmental Conference on Ageing in Latin America and the Caribbean

Spanish version availanle at the Library

Ageing, solidarity and social protection: time for progress towards equality. Third Regional Intergovernmental Conference on Ageing in Latin America and the Caribbean, San José, 8-11 May 2012

This publication summarizes the "Report on application of the Brasilia Declaration and the Regional Strategy for the Implementation in Latin America and the Caribbean of the Madrid International Plan of Action on Ageing", which will be presented at the Third Regional Intergovernmental Conference on Ageing in Latin America and the Caribbean, to be held in San José from 8 to 11 May 2012.