Turdus rufiventris and Turdus albicollis, two songbirds belonging to the family Turdidae (Aves, Passeriformes) were studied by C-banding, 18S rDNA, as well as the use of whole chromosome probes derived from Gallus gallus (GGA) and Leucopternis albicollis (LAL). They showed very similar karyotypes, with 2n = 78 and the same pattern of distribution of heterochromatic blocks and hybridization patterns. However, the analysis of 18/28S rDNA has shown differences in the number of NOR-bearing chromosomes and ribosomal clusters. The hybridization pattern of GGA macrochromosomes was similar to the one found in songbirds studied by Fluorescent in situ hybridization, with fission of GGA 1 and GGA 4 chromosomes. In contrast, LAL chromosome paintings revealed a complex pattern of intrachromosomal rearrangements (paracentric and pericentric inversions) on chromosome 2, which corresponds to GGA1q. The first inversion changed the chromosomal morphology and the second and third inversions changed the order of chromosome segments. Karyotype analysis in Turdus revealed that this genus has derived characteristics in relation to the putative avian ancestral karyotype, highlighting the importance of using new tools for analysis of chromosomal evolution in birds, such as the probes derived from L. albicollis, which make it possible to identify intrachromosomal rearrangements not visible with the use of GGA chromosome painting solely.

Saltator is a genus within family Thraupidae, the second largest family of Passeriformes, with more than 370 species found exclusively in the New World. Despite this, only a few species have had their karyotypes analyzed, most of them only with conventional staining. The diploid number is close to 80, and chromosome morphology is similar to the usual avian karyotype. Recent studies using cross-species chromosome painting have shown that, although the chromosomal morphology and number are similar to many species of birds, Passeriformes exhibit a complex pattern of paracentric and pericentric inversions in the chromosome homologous to GGA1q in two different suborders, Oscines and Suboscines. Hence, considering the importance and species richness of Thraupidae, this study aims to analyze two species of genus Saltator, the golden-billed saltator (S. aurantiirostris) and the green-winged saltator (S. similis) by means of classical cytogenetics and cross-species chromosome painting using Gallus gallus and Leucopternis albicollis probes, and also 5S and 18S rDNA and telomeric sequences. The results show that the karyotypes of these species are similar to other species of Passeriformes. Interestingly, the Z chromosome appears heteromorphic in S. similis, varying in morphology from acrocentric to metacentric. 5S and 18S probes hybridize to one pair of microchromosomes each, and telomeric sequences produce signals only in the terminal regions of chromosomes. FISH results are very similar to the Passeriformes already analyzed by means of molecular cytogenetics (Turdus species and Elaenia spectabilis). However, the paracentric and pericentric inversions observed in Saltator are different from those detected in these species, an observation that helps to explain the probable sequence of rearrangements. As these rearrangements are found in both suborders of Passeriformes (Oscines and Suboscines), we propose that the fission of GGA1 and inversions in GGA1q have occurred very early after the radiation of this order.

Among birds, Tyrannidae comprises one of the most diverse and species‐rich families. Although cytogenetic data have shown interesting results in this family, such as variations in the macrochromosome morphology and diploid number, only a few species have had their karyotypes described. In the present study, we report the characterization of the karyotype of Elaenia spectabilis (Passeriformes, Tyrannidae) by means of classical and molecular cytogenetics. The results show that syntenic groups of Gallus gallus (GGA) were conserved, except GGA1 and GGA4, which were divided into two different pairs each. However, the results obtained with Leucopternis albicollis probes revealed the occurrence of inversions in segments homologous to GGA1q, similar to those observed in other Passerifomes (Turdus), and one inversion in GGA1p. These results suggest that the centric fission in GGA1, as well as the inversions observed in segments homologous to GGA1q, appeared in the early history of Passeriformes because they could be detected in Oscine and Suboscine species. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 115, 391–398.

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

RESUMO -Utilizando 53.433 observações da raça Nelore, foram obtidas estimativas de parâmetros genéticos para pesos padronizados aos 120, 240 e 550 dias de idade (P120, P240 e P550), para número de dias para ganhar 160 kg até a desmama (D160), dias para ganhar mais 240 kg entre o desmame e o ponto final (D240) e perímetro escrotal aos 550 dias de idade (PE550). Adotou-se o método REML, sob modelo animal, e utilizaram-se modelos que incluíram como fixos os efeitos de grupo contemporâneo (constituído por fazenda, época do ano, sexo e regime alimentar) e classe de idade da vaca ao parto (<36, 36-47, 48-59, 60-71, 72-119 e >120 meses) e, como aleatórios, os efeitos genéticos direto, materno e de ambiente permanente da vaca. As herdabilidades diretas (h a 2 ), obtidas a partir das análises bi-caráter (PE550 com todas as outras), foram 0,19 para P120 e P240, 0,34 para P550, 0,09 para D160, 0,16 para D240 e média da h a 2 para PE550 foi de 0,36. As herdabilidades maternas variaram de 0,02 a 0,12 para as características de crescimento. As correlações foram todas de mediana magnitude. Os pesos padronizados constituem-se melhor critério de seleção, baseando-se nas estimativas de herdabilidade, do que o critério dias para atingir determinado peso. Entre as características utilizadas, o P550 apresenta a maior herdabilidade direta estimada e a melhor resposta correlacionada em PE550, indicando maior ganho genético, quando se considera a seleção direta para essa característica. Devido às baixas herdabilidades encontradas para as características D160 e D240, a adoção desse critério levaria à menor resposta à seleção do que para os pesos padronizados.Palavras-chave: bovinos, características de crescimento, Nelore, parâmetros genéticos, perímetro escrotal Comparison Between Some Selection Criteria for Growth Traits Correlated to Scrotal CircumferenceABSTRACT -Data to 53433 of Nellore cattle were used to estimate genetic parameters for standardized weights at 120, 240, and 550 days of age (P120, P240, and P550 respectively), scrotal circumference at 550 days (PE550), days to reach 160 kg (D160), and 240 kg (D240) of live weigh. It was used software the MTDFREML with mixed-model analysis using animal model. Model included fixed effects of contemporary groups (GC) and classes of age-of-dam calving and random direct and maternal genetic effects, the dam permanent environmental effect and the error. Direct heritability (h 2 a), in multiple-trait analysis between PE550 and all others traits, were .19 (for P120 and P240), .34 (for P550), .09 (for D160), .16 (for D240) and .36 (mean for PE550). Maternal heritability for growth traits ranged from .02 to .12. Genetic correlations among PE550 and the others traits had medium magnitude. Standardized weights rather than days to live weight, were better selection criteria when heritabilities and selection response were consideraded.Key Words: bovine, genetic parameters, growth traits, Nellore, scrotal circumference Rev. bras. zootec., 30(3):714-718, 2001 1 Departamento de Genética -Bloco C -Fa...

The Southern lapwing (Vanellus chilensis) is endemic to America and is well-known because of the vast expansion of its geographical distribution and its involvement in air accidents. Despite its popularity, there is no information concerning the genomic organization and karyotype of this species. Hence, because other species of the genus Vanellus have variable diploid numbers from 2n = 58 to 76, the aim of this report was to analyze the karyotype of V. chilensis by means of classical and molecular cytogenetics. We found that 2n = 78 and chromosome painting using probes of Gallus gallus (GGA) and Leucopternis albicollis revealed an organization similar to the avian putative ancestral karyotype, except for the fusion of GGA7 and GGA8, also found in Burhinus oedicnemus, the only Charadriiforme species analyzed by FISH so far. This rearrangement may represent a cytogenetic signature for this group and, in addition, must be responsible for the difference between the diploid number found in the avian putative ancestral karyotype (2n = 80) and V. chilensis (2n = 78).

Pigeons and doves (Columbiformes) are one of the oldest and most diverse extant lineages of birds. However, the karyotype evolution within Columbiformes remains unclear. To delineate the synteny-conserved segments and karyotypic differences among four Columbidae species, we used chromosome painting from Gallus gallus (GGA, 2n = 78) and Leucopternis albicollis (LAL, 2n = 68). Besides that, a set of painting probes for the eared dove, Zenaida auriculata (ZAU, 2n = 76), was generated from flow-sorted chromosomes. Chromosome painting with GGA and ZAU probes showed conservation of the first ten ancestral pairs in Z. auriculata, Columba livia, and Columbina picui, while in Leptotila verreauxi, fusion of the ancestral chromosomes 6 and 7 was observed. However, LAL probes revealed a complex reorganization of ancestral chromosome 1, involving paracentric and pericentric inversions. Because of the presence of similar intrachromosomal rearrangements in the chromosomes corresponding to GGA1q in the Columbidae and Passeriformes species but without a common origin, these results are consistent with the recent proposal of divergence within Neoaves (Passerea and Columbea). In addition, inversions in chromosome 2 were identified in C. picui and L. verreauxi. Thus, in four species of distinct genera of the Columbidae family, unique chromosomal rearrangements have occurred during karyotype evolution, confirming that despite conservation of the ancestral syntenic groups, these chromosomes have been modified by the occurrence of intrachromosomal rearrangements.

Birds are characterized by a low proportion of repetitive DNA in their genome when compared to other vertebrates. Among birds, species belonging to Piciformes order, such as woodpeckers, show a relatively higher amount of these sequences. The aim of this study was to analyze the distribution of different classes of repetitive DNA—including microsatellites, telomere sequences and 18S rDNA—in the karyotype of three Picidae species (Aves, Piciformes)—Colaptes melanochloros (2n = 84), Colaptes campestris (2n = 84) and Melanerpes candidus (2n = 64)–by means of fluorescence in situ hybridization. Clusters of 18S rDNA were found in one microchromosome pair in each of the three species, coinciding to a region of (CGG)10 sequence accumulation. Interstitial telomeric sequences were found in some macrochromosomes pairs, indicating possible regions of fusions, which can be related to variation of diploid number in the family. Only one, from the 11 different microsatellite sequences used, did not produce any signals. Both species of genus Colaptes showed a similar distribution of microsatellite sequences, with some difference when compared to M. candidus. Microsatellites were found preferentially in the centromeric and telomeric regions of micro and macrochromosomes. However, some sequences produced patterns of interstitial bands in the Z chromosome, which corresponds to the largest element of the karyotype in all three species. This was not observed in the W chromosome of Colaptes melanochloros, which is heterochromatic in most of its length, but was not hybridized by any of the sequences used. These results highlight the importance of microsatellite sequences in differentiation of sex chromosomes, and the accumulation of these sequences is probably responsible for the enlargement of the Z chromosome.