Abstract Although Rallidae is the most diverse family within Gruiformes, there is little information concerning the karyotype of the species in this group. In fact, Gallinula melanops, a species of Rallidae found in Brazil, is among the few species studied cytogenetically, but only with conventional staining and repetitive DNA mapping, showing 2n=80. Thus, in order to understand the karyotypic evolution and phylogeny of this group, the present study aimed to analyze the karyotype of G. melanops by classical and molecular cytogenetics, comparing the results with other species of Gruiformes. The results show that G. melanops has the same chromosome rearrangements as described in Gallinula chloropus (Clade Fulica), including fission of ancestral chromosomes 4 and 5 of Gallus gallus (GGA), beyond the fusion between two of segments resultants of the GGA4/GGA5, also fusions between the chromosomes GGA6/GGA7. Thus, despite the fact that some authors have suggested the inclusion of G. melanops in genus Porphyriops, our molecular cytogenetic results confirm its place in the Gallinula genus.

Abstract Hummingbirds (Trochilidae) are one of the most enigmatic avian groups, and also among the most diverse, with approximately 360 recognized species in 106 genera, of which 43 are monotypic. This fact has generated considerable interest in the evolutionary biology of the hummingbirds, which is reflected in a number of DNA-based studies. However, only a few of them explored chromosomal data. Given this, the present study provides an analysis of the karyotypes of three species of Neotropical hummingbirds, Anthracothorax nigricollis (ANI), Campylopterus largipennis (CLA), and Hylocharis chrysura (HCH), in order to analyze the chromosomal processes associated with the evolution of the Trochilidae. The diploid number of ANI is 2n=80 chromosomes, while CLA and HCH have identical karyotypes, with 2n=78. Chromosome painting with Gallus gallus probes (GGA1-12) shows that the hummingbirds have a karyotype close to the proposed ancestral bird karyotype. Despite this, an informative rearrangement was detected: an in-tandem fusion between GGA7 and GGA9 found in CLA and HCH, but absent in ANI. A comparative analysis with the tree of life of the hummingbirds indicated that this fusion must have arisen following the divergence of a number of hummingbird species.

Abstract Despite the richness of species in the Hirudinidae family, little is known about the genome organization of swallows. The Progne tapera species presents genetic and morphological difference when compared to other members of the same genus. Hence, the aims of this study were to analyze the chromosomal evolution of three species Progne tapera, Progne chalybea and Pygochelidon cyanoleuca - by comparative chromosome painting using two sets of probes, Gallus gallus and Zenaida auriculata, in order to determine chromosome homologies and the relationship between these species. All karyotypes exhibited 76 chromosomes with similar morphology, except for the 5th, 6th and 7th chromosome pairs in P. cyanoleuca. Additionally, comparative chromosome painting demonstrated the same hybridization pattern in the two Progne, which was similar to the putative avian ancestral karyotype, except for the centric fission in the first pair, as found in other Passeriformes. Thus, these data display a close relationship between the Progne species. Although P. cyanoleuca demonstrated the same fission in the first pair of the ancestral syntenic (GGA1), it also showed an additional chromosomal rearrangement for this species, namely a fusion with a microchromosome in the seventh pair.

Abstract The distribution of 45S rDNA cluster in avian karyotypes varies in different aspects, such as position, number of bearer chromosomes, and bearers being macro- or microchromosomes. The present study investigated the patterns of variation in the 45S rDNA-bearer chromosomes of birds in order to understand the evolutionary dynamics of the cluster configuration and its contribution to the evolution of bird karyotypes. A total of 73 bird species were analyzed, including both published data and species for which rDNA-FISH was conducted for the first time. In most birds, the 45S rDNA clusters were located in a single pair of microchromosomes. Hence, the location of 45S rDNA in macrochromosomes, observed only in Neognathae species, seems to be a derived state, probably the result of chromosomal fusion between microchromosomes and distinct macrochromosomes. Additionally, the 45S rDNA was observed in multiple microchromosomes in different branches of the bird phylogeny, suggesting recurrence of dispersion processeses, such as duplications and translocations. Overall, this study indicated that the redistribution of the 45S rDNA sites in bird chromosomes followed different evolutionary trajectories with respect to each lineage of the class Aves.

Abstract Cytogenetic analyses of the Suboscines species are still scarce, and so far, there is no karyotype description of any species belonging to the family Conopophagidae. Thus, the aim of this study is to describe and analyze the karyotype of Conopophaga lineata by chromosome painting using Gallus gallus (GGA) probes and to identify the location of the 18/28S rDNA cluster. Metaphases were obtained from fibroblast culture from two individuals of C. lineata. We observed a diploid number of 2n=78. GGA probes showed that most ancestral syntenies are conserved, except for the fission of GGA1 and GGA2, into two distinct pairs each. We identified the location of 18S rDNA genes in a pair of microchromosomes. The fission of the syntenic group corresponding to GGA2 was observed in other Furnariida, and hence may correspond to a chromosomal synapomorphy for the species of Parvorder Furnariida.

Abstract The order Charadriiformes comprises three major clades: Lari and Scolopaci as sister group to Charadrii. Until now, only three Charadriiformes species have been studied by chromosome painting: Larus argentatus (Lari), Burhinus oedicnemus and Vanellus chilensis (Charadrii). Hence, there is a lack of information concerning the third clade, Scolapaci. Based on this, and to gain a better understanding of karyotype evolution in the order Charadriiformes, we applied conventional and molecular cytogenetic approaches in a species belonging to clade Scolopaci - the wattled jacana (Jacana jacana) - using Gallus gallus and Zenaida auriculata chromosome-specific probes. Cross-species evaluation of J. jacana chromosomes shows extensive genomic reshuffling within macrochromosomes during evolution, with multiple fission and fusion events, although the diploid number remains at high level (2n=82). Interestingly, this species does not have the GGA7-8 fusion, which was found in two representatives of Charadrii clade, reinforcing the idea that this fusion may be exclusive to the Charadrii clade. In addition, it is shown that the chromosome evolution in Charadriiformes is complex and resulted in species with typical and atypical karyotypes. The karyotypic features of Scolopaci are very different from those of Charadrii and Lari, indicating that after divergence, each suborder has undergone different chromosome rearrangements.

Abstract The Passeriformes is the most diverse and cytogenetically well-known clade of birds, comprising approximately 5,000 species. The sooty-fronted spinetail (Synallaxis frontalis Aves: Furnariidae) species, which belongs to the order Passeriformes, is typically found in South America, where it is widely distributed. Polymorphisms provide genetic variability, important for several evolutionary processes, including speciation and adaptation to the environment. The aim of this work was to analyze the possible cytotypes and systemic events involved in the species polymorphism. Of the sampled 19 individuals, two thirds were polymorphic, an event supposedly linked to mutations resulting from genomic evolution that can be transmitted hereditarily. A chromosomal polymorphism was detected between the 1st and 3rdpairs of autosomal macrochromosomes. This type of polymorphism is related to a pericentric inversion in regions involving chromosomal rearrangements. Differently from other polymorphism studies that report a link between polymorphic chromosomes and phenotypic changes, S. frontalis did not present any morphological variation in the sampled individuals.

Abstract Zonotrichia capensis is widely distributed in the Neotropics. Previous cytogenetic studies demonstrated the presence of polymorphisms in two chromosome pairs (ZCA2 and ZCA4). Here, we report results based on comparative chromosome painting, using probes derived from Gallus gallus and Leucopternis albicollis, focused on characterizing the chromosome organization of Z. capensis. Our results demonstrate the conservation of ancestral syntenies as observed previously in other species of passerine. Syntenies were rearranged by a series of inversions in the second chromosome as described in other Passeriformes, but in this species, by using probes derived from L. albicollis we observed an extra inversion in the second chromosome that had not previously been reported. We also report a paracentric inversion in pair 3; this chromosome corresponds to the second chromosome in Zonotrichia albicollis and may indicate the presence of ancestral inversions in the genus. The chromosomal inversions we found might be important for understanding the phenotypic variation that exists throughout the distribution of Z. capensis.

Abstract An extensive karyotype variation is found among species belonging to the Columbidae family of birds (Columbiformes), both in diploid number and chromosomal morphology. Although clusters of repetitive DNA sequences play an important role in chromosomal instability, and therefore in chromosomal rearrangements, little is known about their distribution and amount in avian genomes. The aim of this study was to analyze the distribution of 11 distinct microsatellite sequences, as well as clusters of 18S rDNA, in nine different Columbidae species, correlating their distribution with the occurrence of chromosomal rearrangements. We found 2n values ranging from 76 to 86 and nine out of 11 microsatellite sequences showed distinct hybridization signals among the analyzed species. The accumulation of microsatellite repeats was found preferentially in the centromeric region of macro and microchromosomes, and in the W chromosome. Additionally, pair 2 showed the accumulation of several microsatellites in different combinations and locations in the distinct species, suggesting the occurrence of intrachromosomal rearrangements, as well as a possible fission of this pair in Geotrygon species. Therefore, although birds have a smaller amount of repetitive sequences when compared to other Tetrapoda, these seem to play an important role in the karyotype evolution of these species.

O peso ao nascer constitui característica produtiva de elevada importância zootécnica, devido à sua relação com a taxa de sobrevivência à desmama e com os pesos nas demais fases de desenvolvimento do animal, quer seja para a produção de carne, leite ou em animais que se destinam à reprodução. O objetivo deste trabalho foi obter estimativas de herdabilidade e tendências fenotípicas e genéticas do peso ao nascer, em bubalinos do Estado do Pará, Brasil. Foram calculadas as estatísticas descritivas e realizado o teste de Normalidade de Shapiro-Wilk por meio do pacote estatístico Statistical Analisys System. As estimativas de herdabilidade foram obtidas por inferência Bayesiana. O peso ao nascer apresentou média de 36,6 kg. O modelo de análise considerou como fixos os efeitos de sexo, ano de nascimento e composição racial do animal e como efeitos aleatórios animal, efeito materno e residual. A distribuição da herdabilidade direta apresentou-se platicúrtica (achatada) e com maior assimetria, tendo uma distribuição bimodal com a primeira moda próxima a 0,10 e a segunda próxima a 0,30; a materna apresentou-se trimodal, com picos bem próximos a 0,15 e outro menos evidente próximo a 0,20. A tendência genética direta do peso ao nascer mostrou-se negativa (-0,03kg ano-1) e a tendência genética materna próxima à zero (0,001 kg ano-1), ainda que a tendência fenotípica tenha sido positiva (0,156kg ano-1). Existe variabilidade genética possível de ser trabalhada em um programa de melhoramento, no entanto, pouco foi feito quanto à seleção para crescimento em búfalos no Estado do Pará.

Birth weight is a performance parameter of great zootechnical importance for both meat and dairy production, as well as for breeding animals, mainly due to its relation to survival rate at weaning, and the weight of animals throughout their developmental and growth phases. Therefore, the objective of this work was to establish heritability estimates, as well as phenotypic and genetic trends of birth weight of water buffaloes from State of Pará, Brazil. Descriptive statistics were calculated and the Shapiro-Wilk Normality test was performed with a Statistical Analysis System package. Heritability estimates were established by Bayesian inference. BW was 36.6 kg in average. The statistical model considered sex, year of birth and breed composition of the animals as fixed effects, and animal, maternal and residual as random effects. Direct heritability was platykurtic (flattened) and with higher asymmetry, presenting a bimodal distribution with the first mode close to 0.10, and the second mode close to 0.30; the maternal heritability was trimodal, with peaks very close to 0.15, and another, less evident, close to 0.20. The direct genetic trend of birth weight was negative (-0.03kg year-1) and maternal genetic trend was close to zero (0.001kg ano-1), even though the phenotypic trend had been positive (0.156 kg year-1). There is genetic variability to be addressed in a breeding program, however, very little was done as far as selection for growth of water buffaloes in the State of Pará.

Domestic buffaloes are divided into two group based on cytogenetic characteristics and habitats: the "river buffaloes" with 2n = 50 and the "swamp buffaloes", 2n = 48. Nevertheless, their hybrids are viable, fertile and identified by a 2n = 49. In order to have a better characterization of these different cytotypes of buffaloes, and considering that NOR-bearing chromosomes are involved in the rearrangements responsible for the karyotypic differences, we applied silver staining (Ag-NOR) and performed fluorescent in situ hybridization (FISH) experiments using 18S rDNA as probe. Metaphases were obtained through blood lymphocyte culture of 21 individuals, including river, swamp and hybrid cytotypes. Ag-NOR staining revealed active NORs on six chromosome pairs (3p, 4p, 6, 21, 23, 24) in the river buffaloes, whereas the swamp buffaloes presented only five NOR-bearing pairs (4p, 6, 20, 22, 23). The F1 crossbreed had 11 chromosomes with active NORs, indicating expression of both parental chromosomes. FISH analysis confirmed the numerical divergence identified with Ag-NOR. This result is explained by the loss of the NOR located on chromosome 4p in the river buffalo, which is involved in the tandem fusion with chromosome 9 in this subspecies. A comparison with the ancestral cattle karyotype suggests that the NOR found on the 3p of the river buffalo may have originated from a duplication of ribosomal genes, resulting in the formation of new NOR sites in this subspecies.

Podocnemis expansa and P. unifilis present 2n = 28 chromosomes, a diploid number similar to those observed in other species of the genus. The aim of this study was to characterize these two species using conventional staining and differential CBG-, GTG and Ag-NOR banding. We analyzed specimens of P. expansa and P. unifilis from the state of Tocantins (Brazil), in which we found a 2n = 28 and karyotypes differing in the morphology of the 13th pair, which was submetacentric in P. expansa and telocentric in P. unifilis. The CBG-banding patterns revealed a heterochromatic block in the short arm of pair 13 of P. expansa and an interstitial one in pair 13 of P. unifilis, suggesting a pericentric inversion. Pair 14 of P. unifilis showed an insterstitial band in the long arm that was absent in P. expansa, suggesting a duplication in this region. Ag-NORs were observed in the first chromosome pair of both species and was associated to a secondary constriction and heterochromatic blocks.

Cytogenetic studies in birds are still scarce compared to other vertebrates. Woodcreepers (Dendrocolaptidae) are part of a highly specialized group within the Suboscines of the New World. They are forest birds exclusive to the Neotropical region and similar to woodpeckers, at a comparable evolutionary stage. This paper describes for the first time the karyotypes of the Olivaceous and the Narrow-billed Woodcreeper using conventional staining with Giemsa and silver nitrate staining of the nucleolar organizer regions (Ag-NORs). Metaphases were obtained by fibular bone marrow culture. The chromosome number of the Olivaceous Woodcreeper was 2n = 82 and of the Narrow-billed Woodcreeper, 2n = 82. Ag-NORs in the largest macrochromosome pair and evidence of a chromosome inversion are described herein for the first time for this group.

O objetivo deste trabalho foi estimar parâmetros genéticos e tendências genéticas e fenotípicas de uma população da raça Brangus. As características peso, circunferência escrotal e escores visuais de conformação, precocidade, musculatura e umbigo, padronizadas para 550 dias de idade, foram avaliadas a partir de 6.789 registros de animais nascidos de 288 touros e 5.949 vacas, entre 1991 e 2001, em 49 fazendas localizadas nas regiões Centro‑Oeste, Sudeste e Sul do Brasil. Para a estimação dos parâmetros, das correlações e das tendências genéticas, foi adotado o modelo animal linear‑limiar hexacaracterística. As estimativas de herdabilidade direta foram de 0,39 e 0,27, para peso e circunferência escrotal, respectivamente, e de 0,22, 0,20, 0,23 e 0,33 para conformação, precocidade, musculatura e umbigo, o que indica considerável variação genética aditiva e que é possível obter ganho genético por meio da seleção. As correlações genéticas entre peso e circunferência escrotal com os escores de conformação, precocidade e musculatura mostram a possibilidade de resposta correlacionada. As tendências genéticas estimadas indicam grande contribuição de fontes de variação não genéticas para todas as características no período estudado, e apontam a necessidade de melhoria das condições ambientais, para que os animais expressem todo seu potencial genético.

The objective of this work was to estimate genetic parameters, and genetic and phenotypic trends of a Brangus breed population. Weight, scrotal circumference, and visual scores of conformation, precocity, musculature, and navel, adjusted to 550 days of age, were evaluated from records of 6,789 animals sired by 288 bulls and 5,949 dams, born between 1991 and 2001 in 49 farms located in the Center‑West, Southeast, and South regions of Brazil. To estimate parameters, correlations, and genetic trends, a six‑trait, linear‑threshold animal model was adopted. Direct heritability estimates were 0.39 and 0.27 for weight and scrotal circumference, respectively, and 0.22, 0.20, 0.23, and 0.33 for conformation, precocity, musculature, and navel, indicating considerable additive genetic variation, and that it is possible to obtain genetic gain by selection. Genetic correlations between weight and scrotal circumference with the scores of conformation, precocity, and musculature show the possibility of correlated responses. Genetic trends indicate great contribution of non‑genetic sources of variation in the evaluated traits, which leads to the necessity of improving environmental conditions, in order for the animals to fully express their genetic potential.

Com o objetivo de ajustar modelos não-lineares ao crescimento ponderal para búfalos criados em terras baixas no Estado do Rio Grande do Sul, foram utilizados registros mensais mensurados do nascimento aos dois anos de idade de 64 machos e 63 fêmeas, nascidos no período de 1982 a 1989. Utilizaram-se os modelos: Von Bertalanffy, Brody, Gompertz e Logístico. Os parâmetros foram estimados usando o procedimento NLIN e os critérios utilizados para verificar o ajuste dos modelos foram: desvio padrão assintótico; coeficiente de determinação; desvio médio absoluto dos resíduos e o índice assintótico. Os modelos Von Bertalanffy e Brody superestimaram o peso assintótico (A) para os machos em 15,9 e 171,3kg, respectivamente, e os modelos Gompertz e Logístico, subestimaram em 4,5 e 13,4kg, respectivamente. Para as fêmeas, o modelo Logístico subestimou o peso assintótico (-2,09kg) e os modelos Gompertz, Von Bertalanffy e Brody superestimaram esse parâmetro em: 8,04; 17,7 e 280,33kg, respectivamente. O maior desvio médio absoluto foi estimado pelo modelo Brody para ambos os sexos, caracterizando o melhor índice. Considerando os critérios, recomenda-se o modelo Gompertz e o modelo Logístico para ajustar a curva de crescimento de fêmeas e machos da raça Murrah.

With the objective of to adjust nonlinear models for the growth curves for a buffaloes herd raised in floodable lands in Rio Grande do Sul state, monthly records measured from birth to two years-old of 64 males and 63 females born between 1982 and 1989 were used. The models used were: Von Bertalanffy, Brody, Gompertz and Logistic. The parameters were estimated by NLIN procedure and the criteria used to evaluate the adjustment given by the models were: asymptotic standard deviation; coefficient of determination; average absolute deviation of residues and asymptotic index. Von Bertalanffy and Brody models overestimated the male asymptotic weight (A) in 15.9 and 171.3kg, respectively, and the Gompertz and Logistic models underestimated it in 4.5 and 13.4kg, respectively. For females, the Logistic model underestimated the asymptotic weight (-2.09kg), and Gompertz, Von Bertalanffy and Brody overestimated this parameter in 8.04, 17.7, and 280.33kg, respectively. The biggest average deviation was estimated by Brody model for both sexes, characterizing the biggest index. Considering the criteria, it is recommended the Gompertz and Logistic models for adjust females and males Murrah buffaloes breed growth curves.