Análise bayesiana do índice perímetro escrotal/peso de animais nelore do estado do tocantins, Brasil

Objetivou-se com este trabalho estimar os parâmetros genéticos do índice perímetro escrotal/peso padronizado para 365 dias de idade (IND365), via inferência bayesiana, sob dois modelos de análise distintos, em animais da raça Nelore criados no Estado do Tocantins, Brasil. O arquivo final estava constituído de 693 registros do IND365 distribuídos em 16 grupos de contemporâneos. Os componentes de variância foram analisados via inferência bayesiana, por meio de programas em linguagem Fortran. Amostragem a cada 100 ou 500 rodadas e um burn-in pouco conservador poderão ser implementados. As médias pontuais para os coeficientes de herdabilidade direta e materna para o IND365 foram respectivamente: 0,18 (com ou sem efeito materno) e 0,14. Estes resultados sugerem que o IND365 possa ser utilizado como critério alternativo nos programas de melhoramento e responder de forma satisfatória ao processo de seleçãoThe aim of this study was to estimate the genetic parameters of the index scrotal circumference/weight standarized for 365 days of age (IND365), via bayesian inference, in two separate models of analysis on Nellore animals born in the Tocantins state, Brazil. The file was composed of 693 records of the IND365 divided into 16 contemporaneous group. Variance components were analyzed via bayesian inference, through the programs in Fortran language. Sampling of every 100 or 500 rounds and a little conservative burn-in can be implemented. Means of direct heritabilities were 0.18 (with and without maternal effect) and 0.14 for maternal heritabilities. These results suggest that the IND365 can be used as alternative criterion in breeding programs to Nellore cattle and respond satisfactorily to the selection process.EEA ChubutFil: Marcondes, Cintia Righetti. Embrapa Pecuária Sudeste; BrasilFil: Araújo, Ronyere Olegário. Universidade de Brasília. Programa de Pós-graduação em Ciências Animais; BrasilFil: Vozzi, Pedro Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; ArgentinaFil: Gunski, Ricardo José. Universidade Federal do Pampa; BrasilFil: Garnero, Analía del V. Universidade Federal do Pampa; BrasilFil: Lôbo, R.B. Associação Nacional de Criadores e Pesquisadores; Brasi

Belostoma estevezae Ribeiro and Alecrim (Heteroptera: Belostomatidae) reveals a new karyotype complement in Belostoma Latreille from mitotic metaphases

Belostoma Latreille comprende 74 especies de insectos acuáticos depredadores, con 42 de ellas registradas en Brasil. Este grupo se caracteriza por presentar cromosomas holocéntricos con sistemas de determinación sexual múltiple o simple. En Belostomatidae Leach, unas pocas especies presentan microcromosomas. Belostoma estevezae Ribeiro y Alecrim, especie endémica de Brasil, pertenece al grupo plebejum y se parece mucho a Belostoma micantulum Stål. En este trabajo describimos el complemento cromosómico y el contenido y distribución de la heterocromatina C constitutiva en machos de B. estevezae. Las células mitóticas de B. estevezae fueron obtenidas a partir de embriones provenientes de tres masas de huevos. Las preparaciones cromosómicas fueron teñidas con Giemsa 2% para la caracterización cariotípica de la especie y para la técnica de bandas C implementada. El cariotipo masculino de B. estevezae fue estimado como 26 + 4m + XY (2n = 32), lo que representa un complemento cariotípico nuevo para Belostoma. El sistema de determinación sexual y los patrones de distribución de bandas-C registrados en está especie son similares a los observados en B. plebejum y B. micantulum. Diferentes eventos de fisión de autosomas pueden explicar el alto número diploide encontrado en B. estevezae

The molecular cytogenetic characterization of Conopophaga lineata indicates a common chromosome rearrangement in the Parvorder Furnariida (Aves, Passeriformes).

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

Identificação citogenética de quatro gerações de búfalos mestiços mantidos em um programa de conservação na ilha de Marajó/Brazil

The domestic buffaloes were divided in two groups: the river buffalo, which has chromosome number 2n=50 and the swamp buffalo, 2n=48. The crosses between these animals result in F1 specimens with 2n=49 which are viable and fertile. In Brazil the Baio type and the Carabao breed buffalo are found in small number and maintained in genetic conservation programs that aim to keep these groups separated, this way conserving their genetic heritage in situ as well as ex situ. The objective of this study was to evaluate cytogenetically buffaloes from Carabao breed, Baio type and its F1, F2, F3 and F4 crossbreeds kept in a genetic conservation program. The metaphases were obtained from blood culture of 50 animals Carabao breed, 45 Baio type and 10 animals belonging to the crossbreed progeny. The Baio type presented 2n=50 and the Carabao breed 2n=48. In the progeny were observed specimens with chromosome number 2n=48 or 2n=49 with morphological variations in the first pair of chromosomes. The diploid number 2n=49 confirms crossbreeding of the animals from the conservation program. Thus, the exclusion of these animals from the original herds is highly recommended in order to keep separate genotypes for each genetic group.Os búfalos domésticos são divididos em dois grupos: os búfalos de rio, com número diploide 2n= 50 e os búfalos de pântano, 2n= 48. O cruzamento F1 entre estes resultam em animais com 2n= 49, que são viáveis e férteis. No Brasil os búfalos do tipo Baio e da raça Carabao são mantidos em um programa de conservação genética que visa manter esses grupos separados, conservando seu patrimônio genético in situ e ex situ. O objetivo deste estudo foi avaliar citogeneticamente búfalos da raça Carabao, tipo Baio e suas crusas F1, F2, F3 e F4 mantidos em um programa de conservação genética. As metáfases foram obtidas a partir de cultura de linfócitos de 50 animais da raça Carabao, 45 do tipo Baio e 10 descendentes de uma fêmea mestiça. Os animais do tipo Baio apresentaram 2n= 50, os da raça Carabao 2n= 48. Para os descendentes foram observados 2n= 48 e 2n= 49, com variações morfológicas no primeiro par. O número diplóides 2n= 49 confirma a presença de animais cruzados no programa de conservação. Assim, a exclusão destes animais e seus descendentes é altamente recomendada dos rebanhos originais a fim de manter os genótipos separados para cada grupo genético

Chromosomal Evolution in the Phylogenetic Context: A Remarkable Karyotype Reorganization in Neotropical Parrot Myiopsitta monachus (Psittacidae).

Myiopsitta monachus is a small Neotropical parrot (Psittaciformes: Arini Tribe) from subtropical and temperate regions of South America. It has a diploid chromosome number 2n = 48, different from other members of the Arini Tribe that have usually 70 chromosomes. The species has the lowest 2n within the Arini Tribe. In this study, we combined comparative chromosome painting with probes generated from chromosomes of Gallus gallus and Leucopternis albicollis, and FISH with bacterial artificial chromosomes (BACs) selected from the genome library of G. gallus with the aim to shed light on the dynamics of genome reorganization in M. monachus in the phylogenetic context. The homology maps showed a great number of fissions in macrochromosomes, and many fusions between microchromosomes and fragments of macrochromosomes. Our phylogenetic analysis by Maximum Parsimony agree with molecular data, placing M. monachus in a basal position within the Arini Tribe, together with Amazona aestiva (short tailed species). In M. monachus many chromosome rearrangements were found to represent autopomorphic characters, indicating that after this species split as an independent branch, an intensive karyotype reorganization took place. In addition, our results show that M. monachus probes generated by flow cytometry provide novel cytogenetic tools for the detection of avian chromosome rearrangements, since this species presents breakpoints that have not been described in other species

Chromosomal evolution and phylogenetic considerations in cuckoos (Aves, Cuculiformes, Cuculidae).

The Cuckoos have a long history of difficult classification. The species of this order have been the subject of several studies based on osteology, behavior, ecology, morphology and molecular data. Despite this, the relationship between Cuculiformes and species of other orders remains controversial. In this work, two species of Cuculidae, Guira guira (Gmelin, 1788) and Piaya cayana (Linnaeus, 1766), were analyzed by means of comparative chromosome painting in order to study the chromosome evolution of this group and to undertake the first chromosome mapping of these species. Our results demonstrate high chromosomal diversity, with 2n = 76 in G. guira, with fission and fusion events involving ancestral syntenies, while P. cayana presented only fissions, which were responsible for the high diploid number of 2n = 90. Interestingly, there were no chromosomal rearrangements in common between these species. Our results, based on Giemsa staining, were compared with previous data for other cuckoos and also with taxa proposed as sister-groups of Cuculiformes (Otidiformes, Musophagiformes and Opisthocomiformes). Cytogenetic comparisons demonstrated that cuckoo species can be divided into at least three major groups. In addition, we found no evidence to place Cuculiformes close to the groups proposed previously as sister-groups

Variabilidade genética do peso ao nascer e seleção para crescimento em bubalinos do Estado do Pará, Brasil

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.EEA ChubutFil: Aguiar, Juliana Flor de. Agência Goiana de Defesa Agropecuária (AGRODEFESA); BrasilFil: Marcondes, Cintia Righetti. Embrapa Pecuária Sudeste; BrasilFil: Marques, José Ribamar Felipe. Embrapa Amazônia Oriental; BrasilFil: Vozzi, Pedro Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; ArgentinaFil: Camargo Junior, Raimundo Nonato Colares. Instituto Federal de Educação, Ciência e Tecnologia do Pará; BrasilFil: Marques, Larissa Coelho. Universidade Federal do Pará. Programa de Pós-graduação em Ciência Animal; BrasilFil: Araújo, Ronyere Olegário. Universidade de Brasília. Programa de Pós-graduação em Ciências Animais; BrasilFil: Gunski, Ricardo José. Universidade Federal do Pampa; Brasi

Highly Conserved Microchromosomal Organization in Passeriformes Birds Revealed via BAC-FISH Analysis

Passeriformes birds are widely recognized for their remarkable diversity, with over 5700 species described so far. Like most bird species, they possess a karyotype characteristic of modern birds, which includes a bimodal karyotype consisting of a few pairs of macrochromosomes and many pairs of microchromosomes. Although the karyotype is typically 2n = 80, the diploid number can atypically vary greatly, ranging from 56 to approximately 100 chromosomes. In this study, we aimed to understand the extent of conservation of the karyotype’s organizational structure within four species of this group using Bacterial Artificial Chromosomes via Fluorescence In Situ Hybridization (BAC-FISH) with microchromosome probes from Chicken (Gallus gallus) or Zebra Finch (Taeniopygia guttata) per microchromosomes (GGA10-28, except GGA16). By examining the chromosome complement of four passerine species—the Streaked Flycatcher (Myiodynastes maculatus), Shiny Cowbird (Molothrus bonariensis), Southern House Wren (Troglodytes aedon), and Double-collared Seedeater (Sporophila caerulescens)—we discovered a new chromosome number for Southern House Wren. Through FISH experiments, we were able to observe the same pattern of microchromosome organization as in the common ancestor of birds. As a result, we propose a new diploid number for Southern House Wren and confirm the conservation status of microchromosome organization, which may confer evolutionary advantages to this group