RESUMEN
Lithornithidae, an assemblage of volant Palaeogene fossil birds, provide our clearest insights into the early evolutionary history of Palaeognathae, the clade that today includes the flightless ratites and volant tinamous. The neotype specimen of Lithornis vulturinus, from the early Eocene (approximately 53 million years ago) of Europe, includes a partial neurocranium that has never been thoroughly investigated. Here, we describe these cranial remains including the nearly complete digital endocasts of the brain and bony labyrinth. The telencephalon of Lithornis is expanded and its optic lobes are ventrally shifted, as is typical for crown birds. The foramen magnum is positioned caudally, rather than flexed ventrally as in some crown birds, with the optic lobes, cerebellum, and foramen magnum shifted further ventrally. The overall brain shape is similar to that of tinamous, the only extant clade of flying palaeognaths, suggesting that several aspects of tinamou neuroanatomy may have been evolutionarily conserved since at least the early Cenozoic. The estimated ratio of the optic lobe's surface area relative to the total brain suggests a diurnal ecology. Lithornis may provide the clearest insights to date into the neuroanatomy of the ancestral crown bird, combining an ancestrally unflexed brain with a caudally oriented connection with the spinal cord, a moderately enlarged telencephalon, and ventrally shifted, enlarged optic lobes.
Asunto(s)
Evolución Biológica , Fósiles , Paleognatos , Cráneo , Animales , Fósiles/anatomía & histología , Paleognatos/anatomía & histología , Cráneo/anatomía & histología , Sistema Nervioso Central/anatomía & histología , Encéfalo/anatomía & histología , Aves/anatomía & histología , Paleontología , FilogeniaRESUMEN
BACKGROUND: Different patterns of sex chromosome differentiation are seen in Palaeognathae birds, a lineage that includes the ratites (Struthioniformes, Rheiformes, Apterygiformes, Casuariiformes, and the sister group Tinamiformes). While some Tinamiform species have well-differentiated W chromosomes, both Z and W of all the flightless ratites are still morphologically undifferentiated. Here, we conducted a comprehensive analysis of the ZW differentiation in birds using a combination of cytogenetic, genomic, and bioinformatic approaches. The whole set of satDNAs from the emu (Dromaius novaehollandiae) was described and characterized. Furthermore, we examined the in situ locations of these satDNAs alongside several microsatellite repeats and carried out Comparative Genomic Hybridizations in two related species: the greater rhea (Rhea americana) and the tataupa tinamou (Crypturellus tataupa). RESULTS: From the 24 satDNA families identified (which represent the greatest diversity of satDNAs ever uncovered in any bird species), only three of them were found to accumulate on the emu's sex chromosomes, with no discernible accumulation observed on the W chromosome. The W chromosomes of both the greater rhea and the emu did not exhibit a significant buildup of either C-positive heterochromatin or repetitive DNAs, indicating their large undifferentiation both at morphological and molecular levels. In contrast, the tataupa tinamou has a highly differentiated W chromosome that accumulates several DNA repeats. CONCLUSION: The findings provide new information on the architecture of the avian genome and an inside look at the starting points of sex chromosome differentiation in birds.
Asunto(s)
Paleognatos , Cromosomas Sexuales , Animales , Cromosomas Sexuales/genética , Paleognatos/genética , Masculino , Femenino , Evolución Molecular , Repeticiones de Microsatélite/genética , Evolución Biológica , Hibridación Genómica ComparativaRESUMEN
The objective of this study was to describe emus' breeding performance in Brazil at different ages, grouped in couples or colonies. The duration of the breeding season and the production of eggs per female housed were recorded, and the productivity and breeding variables were associated with the variation of the photoperiod. The total production of the flock was 180 eggs, and the breeding season lasted 167 days (April-September), a period with an average of 11 h and 11min of daylight. The breeding season lasted 113, 133 and 82 days, the numbers of eggs produced per female were 7.29, 25.67 and 17.3, and productivity values were 31.6, 38.6, and 45.4% in the groups of birds with ages of two, four and seven years, respectively. The breeding season in 2016 occurred between April and August in Brazil. Older birds tended to start breeding later. The production rate observations indicated that earlier peak production was associated with lower egg production potential. Finally, there was a tendency for better breeding performance of birds housed in couples than in groups with more birds.(AU)
O objetivo deste estudo foi descrever o desempenho reprodutivo de emus de diferentes idades, agrupados em casais ou em colônias, no Brasil. A duração da estação reprodutiva e a produção de ovos por fêmea alojada foram registradas, a produtividade e as variáveis reprodutivas foram associadas às variações no fotoperíodo. A produção total do lote de aves foi de 180 ovos, e a estação reprodutiva durou 167 dias (abril-setembro), período que apresentou fotoperíodo médio de 11 horas e 11 minutos. Nos grupos de aves de dois, quatro e sete anos de idade, a estação reprodutiva durou 113,, 133 e 82 dias, o número de ovos por fêmea foi de 7,29, 25,67 e 17,3 e a produtividade foi de 31,6, 38,6 e 45,4%, respectivamente. A estação reprodutiva em 2016 ocorreu entre abril e agosto no Brasil. Aves mais velhas tenderam a iniciar o período reprodutivo mais tarde. As observações na taxa de produção podem indicar que quanto mais precoce o pico produtivo, menor o potencial de produção de ovos em emus. Houve a tendência ao melhor desempenho reprodutivo das aves alojadas em casais em comparação com as alojadas em colônias.(AU)
Asunto(s)
Animales , Reproducción , Conducta Sexual Animal , Dromaiidae/fisiología , Comportamiento de Nidificación , Brasil , PaleognatosRESUMEN
El objetivo de esta revisión fue comparar algunas características nutricionales y de calidad de huevos de tinamou, con huevos de gallina y codorniz. Los huevos de tinamou contienen menos extracto etéreo y proteína en yema, y similar cantidad de proteínas en clara que huevos de gallina y codorniz. La clara del huevo de tinamou contiene más hierro (0,5 mg/100g) que huevos de gallina y codorniz (0,1-0,2 mg/100g). El ácido oleico es el principal ácido graso de la yema de huevos de tinamou, al igual que los otros. El contenido de colesterol en yema de huevo de tinamou (21,2 mg/g) es mayor a los rangos descritos en huevos de gallina (10,9-16,3 mg/g) y codorniz (11,1-15,9 mg/g). El huevo de tinamou tiene un aspecto físico distinto a huevos de gallina y codorniz, la cáscara es de color chocolate oscuro, pesa en promedio 35 g, sus dimensiones son de 50 x 36 mm, y tienen una unidad Haugh inferior a lo registrado para huevos de gallina y codorniz. El huevo de tinamou es una alternativa muy nutritiva como alimento, de características nutricionales similares a huevos de gallina y codorniz, a excepción de su mayor contenido de colesterol en yema y hierro en clara.
The objective of this review was to compare the nutritional characteristics and quality of tinamou eggs. Tinamou eggs have less ether extract and protein in the yolk, they also have a similar quantity of protein in the egg white than hen and quail eggs. The egg white of the tinamou egg has more iron (0,5 mg/100g) compared to hen and quail eggs (0,1-0,2 mg/100g). Oleic acid is the main fatty acid in all three types of eggs. On the other hand, the amount of cholesterol in the tinamou yolk (21,2 mg/g) is higher than the amounts described for hen eggs (10,9-16,3 mg/g) and those of quail (11,1-15,9 mg/g). In terms of the physical characteristics, the tinamou eggshell has a chocolate color, weighs an average of 35g, has a length about 50 x 36 mm and has an inferior Haugh unity than hen and quail eggs. The tinamou egg represents a high nutritive alternative with similar nutritional characteristics compared to hen and quail eggs, with the exception of cholesterol in the yolk and iron in the egg white.
Asunto(s)
Animales , Calidad de los Alimentos , Paleognatos , Huevos , Valor Nutritivo , Chile , Colesterol/análisis , Ácido Oléico/análisis , Ácidos Grasos/análisis , Hierro/análisisRESUMEN
Para pesquisa de Salmonella spp. foram coletadas amostras de fígado e conteúdo cecal de 70 emas (Rhea americana) abatidas no Rio Grande do Sul - Brasil. Uma colônia morfológica e bioquimicamente compatível com Salmonella spp., isolada de uma amostra de fígado, foi sorotipada como Salmonella Anatum. Considerando-se o alto potencial zoonótico deste microrganismo, destaca-se a relevância do controle microbiológico efetivo em frigoríficos que abatem espécies silvestres, assim como no produto final.
In aiming to investigate the Salmonella spp. presence in one slaughterhouse in Rio Grande do Sul - Brazil, liver and cecum samples from 70 Greater Rhea (Rhea americana) were collected. One Salmonella-like colonie was serologically typed and identified as Salmonella Anatum. Considering the high zoonotical potential of this microorganism, an effective microbiological control of wild animal slaughterhouses and the final product is needed.