birdchromosomedatabase) we have compiled data on the chromosome numbers of 1,067 bird species and chromosome painting data on 96 species. We found considerable variation in the diploid numbers, which ranged from 40 to 142, although most (around 50%) of the species studied up to now have between 78 and 82 chromosomes. Despite its importance for cytogenetic research, chromosome painting has been applied to less than 1% of all bird species. The BCD will enable researchers to identify the main knowledge gaps in bird cytogenetics, including the most under-sampled groups, and make inferences on chromosomal homologies in phylogenetic studies. © 2020 S. Karger AG, BaselDatabases present a valuable source of information for research on a wide range of topics, including species inventories, cytogenetics of some key groups, chromosomal mapping of rDNA, and even complete genomic sequences [Peruzzi and Bedini, 2014;Jarvis et al., 2015;Cardoso et al., 2018;Gill and Donsker, 2018; Paresque et al., AbstractBird chromosomes, which have been investigated scientifically for more than a century, present a number of unique features. In general, bird karyotypes have a high diploid number (2n) of typically around 80 chromosomes that are divided into macro-and microchromosomes. In recent decades, FISH studies using whole chromosome painting probes have shown that the macrochromosomes evolved through both inter-and intrachromosomal rearrangements. However, chromosome painting data are available for only a few bird species, which hinders a more systematic approach to the understanding of the evolutionary history of the enigmatic bird karyotype. Thus, we decided to create an innovative database through compilation of the cytogenetic data available for birds, including chromosome numbers and the results of chromosome painting with chicken ( Gallus gallus ) probes. The data were obtained through an extensive literature review, which focused on cytogenetic studies published
In this work we performed comparative chromosome painting using probes from Gallus gallus (GGA) Linnaeus, 1758 and Leucopternis albicollis (LAL) Latham, 1790 in Synallaxis frontalis Pelzeln, 1859 (Passeriformes, Furnariidae), an exclusively Neotropical species, in order to analyze whether the complex pattern of intrachromosomal rearrangements (paracentric and pericentric inversions) proposed for Oscines and Suboscines is shared with more basal species. S. frontalis has 82 chromosomes, similar to most Avian species, with a large number of microchromosomes and a few pairs of macrochromosomes. We found polymorphisms in pairs 1 and 3, where homologues were submetacentric and acrocentric. Hybridization of GGA probes showed syntenies in the majority of ancestral macrochromosomes, except for GGA1 and GGA2, which hybridized to more than one pair of chromosomes each. LAL probes confirmed the occurrence of intrachromosomal rearrangements in the chromosomes corresponding to GGA1q, as previously proposed for species from the order Passeriformes. In addition, LAL probes suggest that pericentric inversions or centromere repositioning were responsible for variations in the morphology of the heteromorphic pairs 1 and 3. Altogether, the analysis of our data on chromosome painting and the data published in other Passeriformes highlights chromosomal changes that have occurred during the evolution of Passeriformes.
As in many other bird groups, data on karyotype organization and distribution of repetitive sequences are also lacking in species belonging to the family Hirundinidae. Thus, in the present study, we analyzed the karyotypes of 3 swallow species (Progne tapera, Progne chalybea, and Pygochelidon cyanoleuca) by Giemsa and AgNOR staining, C-banding, and FISH with 11 microsatellite sequences. The diploid chromosome number was 2n = 76 in all 3 species, and NORs were observed in 2 chromosome pairs each. The microsatellite distribution pattern was similar in both Progne species, whereas P. cyanoleuca presented a distinct organization. These repetitive DNA sequences were found in the centromeric, pericentromeric, and telomeric regions of the macrochromosomes, as well as in 2 interstitial blocks in the W chromosome. Most microchromosomes had mainly telomeric signals. The Z chromosome displayed 1 hybridization signal in P. tapera but none in the other species. In contrast, the W chromosome showed an accumulation of different microsatellite sequences. The swallow W chromosome is larger than that of most Passeriformes. The observed enlargement in chromosome size might be explained by these high amounts of repetitive sequences. In sum, our data highlight the significant role that microsatellite sequences may play in sex chromosome differentiation.
Among birds, species with the ZZ/ZW sex determination system generally show significant differences in morphology and size between the Z and W chromosomes (with the W usually being smaller than the Z). In the present study, we report for the first time the karyotype of the spot-flanked gallinule (Gallinula melanops) by means of classical and molecular cytogenetics. The spot-flanked gallinule has 2n = 80 (11 pairs of macrochromosomes and 29 pairs of microchromosomes) with an unusual W chromosome that is larger than the Z. Besides being totally heterochromatic, it has a secondary constriction in its long arm corresponding to the nucleolar organizer region, as confirmed by both silver staining and mapping of 18S rDNA probes. This is an unprecedented fact among birds. Additionally, 18S rDNA sites were also observed in 6 microchromosomes, while 5S rDNA was found in just 1 microchromosomal pair. Seven out of the 11 used microsatellite sequences were found to be accumulated in microchromosomes, and 6 microsatellite sequences were found in the W chromosome. In addition to the involvement of heterochromatin and repetitive DNAs in the differentiation of the large W chromosome, the results also show an alternative scenario that highlights the plasticity that shapes the evolutionary history of bird sex chromosomes.
O objetivo do trabalho foi avaliar o efeito de diferentes substratos, contendo lodo de esgoto, no teor de macro e micronutrientes em tecidos vegetais (raiz e parte aérea) de mudas de Parapiptadenia rigida (Benth.) Brenan. Os tratamentos foram: T1 (50% substrato comercial Plantmax® + 50% cama de equino (composto orgânico), T2 (20% lodo de esgoto + 80% composto orgânico), T3 (40% lodo de esgoto + 60% composto orgânico) e T4 (60% lodo de esgoto + 40% composto orgânico). Decorridos 180 dias após a semeadura foram mensuradas as características biométricas de altura da parte aérea, diâmetro do colo, massa seca da parte aérea e radicular, e o índice de qualidade de Dickson. Também foram determinados os teores de macro e micronutrientes no sistema radicular e na parte aérea das mudas cultivadas. Observou-se que a ordem crescente do teor total dos macronutrientes avaliados no sistema radicular foi de N > K > Mg > Ca > P > S e na parte aérea Ca > N > K > P > Mg > S; para os micronutrientes, o teor no sistema radicular e na parte aérea foi de Fe > Zn > Mn > B > Cu. O uso do lodo de esgoto como substrato proporcionou mudas de melhor qualidade nutricional, com melhor crescimento e aumento de biomassa aérea e radicular.
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