Stages of plumage maturation of the Tawny-bellied Seedeater: Evidence of delayed plumage maturation and cryptic differentiation between juveniles and females

In some sexually dichromatic passerines, juvenile males retain a plumage similar to that of adult females through their first year or longer (delayed plumage maturation). The Tawny-bellied Seedeater (Sporophila hypoxantha) is a sexually dichromatic species in which, to the human eye, the juveniles look like females. We analyzed the species' stages of plumage maturation by reflectance spectrometry and a visual model of color discrimination on captive individuals of known ages. We found that males retain a plumage different from that of adult males through their first breeding season. By the time males passed the age of 1 year, their color did not differ from that of adult males in any region of the body except the crown. Spectrophotometry also revealed differences between the plumage color of juvenile males and females, and the color-discrimination model implies that the birds should be able to detect these differences. Thus juvenile males of the Tawny-bellied Seedeater acquire adult plumage after their first breeding season but are already dichromatic during the first year. How this pattern of plumage development affects the species' reproductive or other social behavior deserves further study.Fil: Facchinetti, Carolina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mahler, Bettina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Di Giacomo, Alejandro G.. Aves Argentinas / Asociación Ornitológica del Plata; ArgentinaFil: Reboreda, Juan Carlos. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Vitamin D receptor expression is associated with improved overall survival in human glioblastoma multiforme

Vitamin D and its analogs have been shown to display anti-proliferative effects in a wide variety of cancer types including glioblastoma multiforme (GBM). These anticancer effects are mediated by its active metabolite, 1α, 25-dihydroxyvitamin D3 (calcitriol) acting mainly through vitamin D receptor (VDR) signaling. In addition to its involvement in calcitriol action, VDR has also been demonstrated to be useful as a prognostic factor for some types of cancer. However, to our knowledge, there are no studies evaluating the expression of VDR protein and its association with outcome in gliomas. Therefore, we investigated VDR expression by using immunohistochemical analysis in human glioma tissue microarrays, and analyzed the association between VDR expression and clinico-pathological parameters. We further investigated the effects of genetic and pharmacologic modulation of VDR on survival and migration of glioma cell lines. Our data demonstrate that VDR is increased in tumor tissues when compared with VDR in non-malignant brains, and that VDR expression is associated with an improved outcome in patients with GBM. We also show that both genetic and pharmacologic modulation of VDR modulates GBM cellular migration and survival and that VDR is necessary for calcitriol-mediated effects on migration. Altogether these results provide some limited evidence supporting a role for VDR in glioma progression.Fil: Salomón, Débora Gisele. Consejo Nacional de Investigaciones Cienti­ficas y Tecnicas. Centro Cientifico Tecnologico Bahi­a Blanca. Instituto de Investigaciones Bioquimicas Bahi­a Blanca (i); ArgentinaFil: Fermento, María Eugenia. Consejo Nacional de Investigaciones Cienti­ficas y Tecnicas. Centro Cientifico Tecnologico Bahi­a Blanca. Instituto de Investigaciones Bioquimicas Bahi­a Blanca (i); ArgentinaFil: Gandini, Norberto Ariel. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Bahi­a Blanca. Instituto de Investigaciones Bioquimicas Bahi­a Blanca (i); ArgentinaFil: Ferronato, María Julia. Consejo Nacional de Investigaciones Cienti­ficas y Tecnicas. Centro Cientifico Tecnologico Bahi­a Blanca. Instituto de Investigaciones Bioquimicas Bahi­a Blanca (i); ArgentinaFil: Arevalo, Julian. Hospital Municipal General de Agudos Doctor José Penna; ArgentinaFil: Blasco, J.. Hospital Int. Gral. de Agudos Dr. Jose Penna. Servicio de Patologia; ArgentinaFil: Andrés, Nancy Carolina. Consejo Nacional de Investigaciones Cienti­ficas y Tecnicas. Centro Cientifico Tecnologico Bahi­a Blanca. Instituto de Investigaciones Bioquimicas Bahi­a Blanca (i); ArgentinaFil: Zenklusen, Jean C.. National Institutes of Health. National Cancer Institute; Estados UnidosFil: Curino, Alejandro Carlos. Consejo Nacional de Investigaciones Cienti­ficas y Tecnicas. Centro Cientifico Tecnologico Bahi­a Blanca. Instituto de Investigaciones Bioquimicas Bahi­a Blanca (i); ArgentinaFil: Facchinetti, Maria Marta. Consejo Nacional de Investigaciones Cienti­ficas y Tecnicas. Centro Cientifico Tecnologico Bahi­a Blanca. Instituto de Investigaciones Bioquimicas Bahi­a Blanca (i); Argentin

The PDE4 Inhibitor Tanimilast Restrains the Tissue-Damaging Properties of Human Neutrophils

: Neutrophils, the most abundant subset of leukocytes in the blood, play a pivotal role in host response against invading pathogens. However, in respiratory diseases, excessive infiltration and activation of neutrophils can lead to tissue damage. Tanimilast-international non-proprietary name of CHF6001-is a novel inhaled phosphodiesterase 4 (PDE4) inhibitor in advanced clinical development for the treatment of chronic obstructive pulmonary disease (COPD), a chronic inflammatory lung disease where neutrophilic inflammation plays a key pathological role. Human neutrophils from healthy donors were exposed to pro-inflammatory stimuli in the presence or absence of tanimilast and budesonide-a typical inhaled corticosteroid drug-to investigate the modulation of effector functions including adherence to endothelial cells, granule protein exocytosis, release of extracellular DNA traps, cytokine secretion, and cell survival. Tanimilast significantly decreased neutrophil-endothelium adhesion, degranulation, extracellular DNA traps casting, and cytokine secretion. In contrast, it promoted neutrophil survival by decreasing both spontaneous apoptosis and cell death in the presence of pro-survival factors. The present work suggests that tanimilast can alleviate the severe tissue damage caused by massive recruitment and activation of neutrophils in inflammatory diseases such as COPD

Female tawny-bellied seedeaters do not prefer more colorful males in choice experiments

Plumage coloration has long been studied as a sexually selected character. The tawny-bellied seedeater, Sporophila hypoxantha, is a sexually dichromatic species, with adult males the more colorful sex and juvenile males indistinguishable from females. We did choice experiments to evaluate female preferences for males that differ in age or plumage coloration. Females were evaluated in three experiments: (1) choice between males with similar breast brightness that differed in age, (2) choice between males of 2 years of age that differed in breast brightness, and (3) choice between males of 3 or more years of age that differed in breast brightness. We also repeated the latter experiment with estradiol-treated females. We did not find a clear female preference for brighter or older males, as females spent the same proportion of time with males of similar breast brightness that differed in age or with males of similar age that differed in breast brightness. Our results do not support the hypothesis that breast brightness is a cue used by female tawny-bellied seedeaters at the time of choosing males. We propose that, in this species, male plumage coloration might play a role in intrasexual competition.Fil: Facchinetti, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Reboreda, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin

Detection and Frequency of Lily Viruses in Argentina

In a survey of lily growing fields in various regions of Argentina, three viruses, Lily symptomless virus (LSV), Lily mottle virus (LMoV), and Cucumber mosaic virus (CMV), were found in Longiflorum, Asiatic, Oriental, Longiflorum × Asiatic (LA), and Oriental × Trumpet (OT) hybrids. The areas surveyed were between latitude 26° 56′ S and 43° 03′ S, and longitude 65° 21′ W and 71° 29′ W. Virus detection was performed by double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) using polyclonal antiserum. In infected samples, viruses detected in decreasing order were LSV (60.5%), LMoV (51.0%), and CMV (28.7%) present in single or mixed infections. Virus infection varied among tested hybrids from 36.0% (Oriental Montecristo) to 94.7% (Lilium longiflorum Avita) in 2006 and from 38.9% (OT Yelloween) to 82.1% (LO Triumphator) in 2007, with an overall incidence of 64.1 and 70.7% in 2006 and 2007, respectively. A variation in virus incidence among localities was also observed. The highest virus incidence (89.6 and 87.6% in 2006 and 2007, respectively) was observed in Bahía Blanca (38° 44′ S, 62° 16′ W). The lowest virus incidences, detected in Trevellin (43° 03′ S, 71° 29′ W) and in Malargüe (35° 28′ S, 69° 35′ W), were 47.4 and 48.6% in 2006 and 2007, respectively. Moreover, a different distribution of each virus was observed between localities. The high occurrence of viruses infecting lily crops in Argentina could be due to both the use of infected bulbs for propagation and the lack of preventive virus vector control measures.Fil: Chinestra, Silvia Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; ArgentinaFil: Facchinetti, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; ArgentinaFil: Curvetto, Nestor Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; ArgentinaFil: Marinangeli, Pablo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; Argentin

La muda preformativa en los parásitos de cría Tordo Pico Corto (Molothrus rufoaxillaris) y Tordo Renegrido (M. bonariensis)

Molt and plumage cycles are poorly known in Neotropical birds in general and in South American brood parasitic cowbirds in particular. The Screaming Cowbird (Molothrus rufoaxillaris) is one of the more specialized brood parasites that use almost exclusively the Baywing (Agelaioides badius), while the Shiny Cowbird (M. bonariensis) is an extreme generalist brood parasite that uses more than 250 known hosts. Fledglings of Screaming Cowbird are mimetic in plumage coloration to fledglings of Baywings, while Shiny Cowbird fledglings have female-like plumage. We measured and analyzed plumage changes of Screaming and Shiny Cowbirds since the time of fledging (i.e. 12-14 days of age) until young completed the preformative molt. There were not sexual differences in molting pattern for both species. Screaming Cowbirds started to molt before Shiny Cowbirds (37 vs. 61 days of age). They first molted under-wing coverts, followed by chest, the rest of the body, and finally tail and external coverts. Shiny cowbird molt started at the crown, breast and back, followed by throat, under-wing coverts, and finally upper-wing covers and tail. In both species flight feathers began molting after body feathers and the pattern of molt was similar, starting with the primaries. For both species the preformative molt was completed at the same age (167-181 days). The beginning of the preformative molt in Screaming Cowbirds coincides with the age at which young become independent of their foster parents and join conspecific flocks. This shorter latency to start molting in Screaming Cowbirds could be related to the acceptance of juveniles in conspecifics flocks.La muda de las aves neotropicales en general y la de los parásitos de cría de Sudamérica en particular es poco conocida. El Tordo Pico Corto es uno de los parásitos de cría más especializado en el uso de hospedadores utilizando casi exclusivamente al Músico (Agelaioides badius) mientras que el Tordo Renegrido es un parásito de cría generalista extremo que utiliza más de 250 hospedadores. Los juveniles del Tordo Pico Corto tienen un plumaje de coloración mimética al del Músico, mientras que los de Tordo Renegrido tienen un plumaje similar a las hembras de su especie. Medimos y analizamos la muda del Tordo Pico Corto y del Tordo Renegrido desde que los pichones salieron del nido (12-14 días de edad) hasta que los juveniles completaron la muda preformativa. No encontramos diferencias sexuales en el patrón de muda de ambas especies. En el Tordo Pico Corto la muda preformativa comenzó antes que en el Tordo Renegrido (37 vs. 61 días de edad) y se inició por las cobertoras internas, siguió por el pecho y resto del cuerpo y finalizó por la cola y cobertoras externas. A su vez, la muda del Tordo Renegrido comenzó por la corona, pecho y dorso, siguió por la garganta y cobertoras externas y finalizó por la cola y cobertoras internas. En ambas especies, la muda de las plumas de vuelo comenzó luego del inicio de la muda de las plumas del cuerpo y comenzó con la muda de las primarias. La edad a la que los juveniles adquirieron el plumaje formativo fue similar en ambas especies (167-181 días). Nuestros resultados muestran que el comienzo de la muda preformativa en el Tordo Pico Corto coincide con la edad en la que los juveniles se independizan de los padres adoptivos y se unen a bandadas de conespecíficos. Esta corta latencia en el inicio de la muda podría favorecer la aceptación de los juveniles del tordo pico corto en bandadas de conespecíficos.Fil: Ursino, Cynthia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; ArgentinaFil: Facchinetti, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; ArgentinaFil: Reboreda, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Ecología y Comportamiento Animal; Argentin

Las bases biológicas del aprendizaje

Cátedra: Biología: comportamiento, desarrollo y aprendizaje. La biología y las neurociencias intentan dar respuestas a las preguntas sobre el aprendizaje. Sus implicancias tienen cada vez más vigencia y frecuencia en ámbitos educativos. Esto se manifiesta a través de diferentes investigaciones sobre el desarrollo de la niñez y la adolescencia, desde la educación inicial y primaria hasta la escuela secundaria y el ámbito universitario.Libros de Cátedr

The PDE4 inhibitor tanimilast shows distinct immunomodulatory properties associated with a type 2 endotype and CD141 upregulation

Tanimilast is a novel and selective inhaled inhibitor of phosphodiesterase-4 in advanced clinical development for chronic obstructive pulmonary disease (COPD). Tanimilast is known to exert prominent anti-inflammatory activity when tested in preclinical experimental models as well as in human clinical studies. Recently, we have demonstrated that it also finely tunes, rather than suppressing, the cytokine network secreted by activated dendritic cells (DCs). This study was designed to characterize the effects of tanimilast on T-cell polarizing properties of DCs and to investigate additional functional and phenotypical features induced by tanimilast