Science with the GTC 10-m Telescope (Granada, España, 5-8 febrero 2002) GALAXY EVOLUTION STUDIES OBSERVING EMISSION LINE GALAXIES WITH THE GTC

RESUMEN Las galaxias con líneas de emisión son los objetos más fáciles de detectar y estudiar en el Universo a alto desplazamieno al rojo. Están siendo usadas para trazar la evolución de observables críticos del Universo, tales como densidades de tasa de formación estelar, propiedades de los procesos de formación estelar y abundancias. GTC constituirá una herramienta muy potente para el estudio de la evolución de las poblaciones de galaxias con líneas de emisión a diferentes desplazamientos al rojo. Grandes exploraciones como OTELO, llevada a cabo con OSIRIS y extendida mediante espectroscopía infrarroja con EMIR, permitirán a GTC contribuir con un gran impacto en el campo de la Astronomía Extragaláctica. ABSTRACT Emission line galaxies are the most easily detected and studied objects in the high redshift Universe. They are being used to trace the evolution of the critical observables of the Universe such as star formation rate densities, starburst properties, and abundances. The GTC will be a very powerful tool for studying the evolution of emission line galaxy populations at different redshifts. Large surveys, such as OTELO, carried out with OSIRIS and extended by follow-up spectroscopic studies in the near infrared using EMIR will enable the GTC to make a major impact in extragalactic astronomy

Karyotype characterization and nucleolar organizer regions of marsupial species (Didelphidae) from areas of Cerrado and Atlantic Forest in Brazil

The karyotypes of 23 specimens belonging to 16 species from nine genera of Brazilian marsupials (family Didelphidae) were studied. The animals were collected in eight localities of Cerrado or Atlantic Forest biomes in the states of Goiás, Tocantins and São Paulo. The karyotypes were analyzed after conventional Giemsa staining and silver staining of the nucleolus organizer regions (Ag-NORs). New karyotypic data were obtained for Gracilinanus microtarsus (2n = 14, FN = 24), Marmosops paulensis (2n = 14, FN = 24) , Micoreus paraguayanus (2n = 14, FN = 20) and Monodelphis rubida (2n = 18, FN = 32) and are discussed in detail. The karyotypes of G. microtarsus , M. paulensis and M. paraguayanus include three large pairs of submetacentrics (pairs 1, 2 and 3) and a medium-sized metacentric or submetacentric pair 4. Pairs 5 and 6 are small submetacentrics in G. microtarsus and M. paulensis and acrocentrics in M. paraguayanus . M. paulensis presented a single Ag-NOR in pair 6 (6p6p), while M. paraguayanus exhibited multiple Ag-NORs in pairs 5 and 6 (5pq5pq6p6p). There was variation in size and morphology of the sex chromosomes among these species. Monodelphis rubida presented a karyotype with 2n = 18 and FN = 32 composed of a large submetacentric pair 1, a medium-sized metacentric pair 2 and six pairs of submetacentrics (pairs 3 through 8). The X was a small acrocentric and the Y was dot-like. A single Ag-NOR bearing pair (5p5p) characterized M. rubida. Relevant karyotypic information was obtained for 19 specimens belonging to 12 species collected in areas sampled for the first time [ Caluromys lanatus and C. philander (2n = 14, FN = 20), Gracilinanus emiliae (2n = 14, FN = 24), Marmosa murina , Metachirus nudicaudatus and Micoureus demerarae (2n = 14, FN = 20), Monodelphis americana (2n = 18, FN = 32) and M. domestica (2n = 18, FN = 20), and Didelphis marsupialis, Philander frenata, P. opossum and P. sp (2n = 22, FN = 20)]. Although the karyotypes were relatively conserved with respect to the morphology of the autosomes among species with the same diploid number, some differences regarding FN, sex chromosomes morphology and Ag-NORs patterns were detected