Chromosome Painting in Neotropical Long- and Short-Tailed Parrots (Aves, Psittaciformes): Phylogeny and Proposal for a Putative Ancestral Karyotype for Tribe Arini.

: Most Neotropical Psittacidae have a diploid number of 2n = 70, and a dichotomy in chromosome patterns. Long-tailed species have biarmed macrochromosomes, while short-tailed species have telo/acrocentric macrochromosomes. However, the use of chromosome painting has demonstrated that karyotype evolution in Psittacidae includes a high number of inter/intrachromosomal rearrangements. To determine the phylogeny of long- and short-tailed species, and to propose a putative ancestral karyotype for this group, we constructed homology maps of Pyrrhura frontalis (PFR) and Amazona aestiva (AAE), belonging to the long- and short-tailed groups, respectively. Chromosomes were analyzed by conventional staining and fluorescent in situ hybridization using whole chromosome paints of Gallus gallus and Leucopternis albicollis. Conventional staining showed a karyotype with 2n = 70 in both species, with biarmed macrochromosomes in PFR and telo/acrocentric chromosomes in AAE. Comparison of the results with the putative avian ancestral karyotype (PAK) showed fusions in PFR of PAK1p/PAK4q (PFR1) and PAK6/PAK7 (PFR6) with a paracentric inversion in PFR6. However, in AAE, there was only the fusion between PAK6/7 (AAE7) with a paracentric inversion. Our results indicate that PFR retained a more basal karyotype than long-tailed species previously studied, and AAE a more basal karyotype for Neotropical Psittacidae analyzed so far

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

Chromosomal characterization of four antarctic procellariiformes

The karyotype and C-banding patterns of Southern Giant Petrels Macronectes giganteus, Cape Petrels Daption capense, Black-bellied Storm Petrels Fregetta tropica and Wilson’s Storm Petrels Oceanites oceanicus were analyzed. To obtain metaphases, the direct culture technique was used on feather bulbs and lymphocytes of peripheral blood of 34 specimens. Both Southern Giant and Cape Petrels share 2n = 80 chromosomes. Pair 1 is metacentric; pairs 2 and 4 are submetacentric; pairs 3, 5, 6 and 7 are acrocentric; and the remaining ones are telocentric. The Z chromosome is submetacentric, and the W is submetacentric in Southern Giant Petrels and metacentric in Cape Petrels. In Black-bellied Storm Petrels (2n = 74), pair 1 is metacentric; pair 3 is submetacentric; pairs 2, 4, 5 and 6 and the remaining ones are telocentric; while the Z is submetacentric, and the W is telocentric. In Wilson’s Storm Petrels (2n = 70), pairs 1 and 3 are metacentric; pair 2 is acrocentric; and pairs 4, 5 and 6 are submetacentric; all remaining ones are telocentric. The Z chromosome is metacentric, and the W is submetacentric. All chromosomes except the Z chromosome of Black-bellied Storm Petrels revealed centromeric heterochromatin. The W chromosomes of all species were heterochromatic. We observed a numerical and morphological chromosome homology between the Southern Giant Petrels and the Cape Petrels, but very different phenotypes, while Black-bellied and Wilson’s Storm Petrels are phenotypically similar, but their karyotypes differ in chromosome number and morphology.Fil: Garnero, Analia del V.. Universidade Federal do Pampa; BrasilFil: Boccelli, Marcela. Universidad Nacional de Misiones. Facultad de Cs.exactas Químicas y Naturales. Departamento de Genetica; ArgentinaFil: Olivera, Jean C. P.. Universidade Federal do Pampa; BrasilFil: Ledesma, Mario A.. Ministerio de Ecología y Recursos Naturales Renovables. Estación de Hidrobiología y Piscicultura; ArgentinaFil: Montalti, Diego. Departamento de Ciencias Biológica.Instituto Antártico Argentino; ArgentinaFil: Coria, Néstor Rubén. Departamento de Ciencias Biológica.Instituto Antártico Argentino; ArgentinaFil: Gunski, Ricardo J.. Universidade Federal do Pampa; Brasi

Karyotype evolution and distinct evolutionary history of the W chromosomes in swallows (Aves, Passeriformes)

Universidade Federal do Pampa. Programa de Pós-graduação em Ciências Biológicas. Laboratório de Diversidade Genética Animal. São Gabriel, RS, Brazil.Universidade Federal do Rio Grande do Sul. Programa de Pós-graduação em Genética e Biologia Molecular, Laboratório de Citogenética e Evolução. Porto Alegre, RS, Brazil.Universidade Federal do Pampa. Programa de Pós-graduação em Ciências Biológicas. Laboratório de Diversidade Genética Animal. São Gabriel, RS, Brazil.Universidade Federal do Pampa. Graduação em Ciências Biológicas Licenciatura. Laboratório de Diversidade Genética Animal. São Gabriel, RS, Brazil.Universidade Federal do Paraná. Programa de Pós-graduação em Genética. Laboratório de Citogenética e Genética da Conservação Animal. Curitiba, PR, Brazil.Universidade Federal do Pará. Programa de Pós-Graduação em Genética e Biologia Molecular. Laboratório de Cultura de Tecidos e Citogenética. Belém, PA, Brazil.Universidade Federal do Pará. Instituto de Ciências Exatas e Naturais. Belém, PA, Brazil / Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura de Tecidos e Citogenética. Ananindeua, PA, Brasil.Universidade Federal de São Carlos. Departamento de Genética e Evolução. São Carlos, SP, Brazil.Universidade Federal do Pampa. Programa de Pós-graduação em Ciências Biológicas. Laboratório de Diversidade Genética Animal. São Gabriel, RS, Brazil.Universidade Federal do Pampa. Programa de Pós-graduação em Ciências Biológicas. Laboratório de Diversidade Genética Animal. São Gabriel, RS, Brazil.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

Genomic Organization of Repetitive DNA in Woodpeckers (Aves, Piciformes): Implications for Karyotype and ZW Sex Chromosome Differentiation

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

Mitochondrial DNA single nucleotide polymorphism associated with weight estimated breeding values in Nelore cattle (Bos indicus)

We sampled 119 Nelore cattle (Bos indicus), 69 harboring B. indicus mtDNA plus 50 carrying Bos taurus mtDNA, to estimate the frequencies of putative mtDNA single nucleotide polymorphisms (SNPs) and investigate their association with Nelore weight and scrotal circumference estimated breeding values (EBVs). The PCR restriction fragment length polymorphism (PCR-RFLP) method was used to detect polymorphisms in the mitochondrial asparagine, cysteine, glycine, leucine and proline transporter RNA (tRNA) genes (tRNAasn, tRNAcys, tRNAgly, tRNAleu and tRNApro). The 50 cattle carrying B. taurus mtDNA were monomorphic for all the tRNA gene SNPs analyzed, suggesting that they are specific to mtDNA from B. indicus cattle. No tRNAcys or tRNAgly polymorphisms were detected in any of the cattle but we did detect polymorphic SNPs in the tRNAasn, tRNAleu and tRNApro genes in the cattle harboring B. indicus mtDNA, with the same allele observed in the B. taurus sequence being present in the following percentage of cattle harboring B. indicus mtDNA: 72.46% for tRNAasn, 95.23% for tRNAleu and 90.62% for tRNApro. Analyses of variance using the tRNAasn SNP as the independent variable and EBVs as the dependent variable showed that the G -> T SNP was significantly associated (p < 0.05) with maternal EBVs for weight at 120 and 210 days (p < 0.05) and animal's EBVs for weight at 210, 365 and 455 days. There was no association of the tRNAasn SNP with the scrotal circumference EBVs. These results confirm that mtDNA can affect weight and that mtDNA polymorphisms can be a source of genetic variation for quantitative traits

Abordagem bayesiana multivariada para características de crescimento, fertilidade e escores visuais de rebanhos da raça Brangus

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