RESUMEN
The global population of Dicotyles tajacu (Linnaeus, 1758) (Cetartiodactyla: Tayassuidae), commonly known as the collared peccary and distributed in the Neotropics, is currently in decline due to anthropogenic pressures. In this study, five microsatellite loci were used to genetically characterize a group of 20 captive-born collared peccaries intended for reintroduction. This study aimed to evaluate the genetic diversity and relatedness of captive individuals using microsatellite markers. The genetic data generated were used to evaluate the viability of the reintroduction and to propose measures for the management and conservation of this species. In this study, we found relatively high genetic diversity indices, indicating that the group was genetically diverse. Inbreeding coefficients with negative values were observed, indicating an excess of alleles in heterozygosis and an absence of inbreeding. One locus showed deviation from Hardy-Weinberg equilibrium, which may have been caused by the mixing of individuals from different origins. Relatedness analysis indicated that some individuals were highly related, with coefficients indicating they may be first-degree relatives. Our findings indicate that the studied group has enough genetic diversity to be released into nature, but the high individual relatedness found would require the adoption of strategies after the release of animals in the wild to ensure their persistence.
Asunto(s)
Animales de Zoológico , Artiodáctilos , Animales , Genotipo , Animales de Zoológico/genética , Artiodáctilos/genética , Repeticiones de Microsatélite/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Variación GenéticaRESUMEN
The hemoglobin of jawed vertebrates is a heterotetramer protein that contains two α- and two ß-chains, which are encoded by members of α- and ß-globin gene families. Given the hemoglobin role in mediating an adaptive response to chronic hypoxia, it is likely that this molecule may have experienced a selective pressure during the evolution of cetaceans, which have to deal with hypoxia tolerance during prolonged diving. This selective pressure could have generated a complex history of gene turnover in these clusters and/or changes in protein structure themselves. Accordingly, we aimed to characterize the genomic organization of α- and ß-globin gene clusters in two cetacean species and to detect a possible role of positive selection on them using a phylogenetic framework. Maximum likelihood and Bayesian phylogeny reconstructions revealed that both cetacean species had retained a similar complement of putatively functional genes. For the α-globin gene cluster, the killer whale presents a complement of genes composed of HBZ, HBK, and two functional copies of HBA and HBQ genes, whereas the dolphin possesses HBZ, HBK, HBA and HBQ genes, and one HBA pseudogene. For the ß-globin gene cluster, both species retained a complement of four genes, two early expressed genes-HBE and HBH-and two adult expressed genes-HBD and HBB. Our natural selection analysis detected two positively selected sites in the HBB gene (56 and 62) and four in HBA (15, 21, 49, 120). Interestingly, only the genes that are expressed during the adulthood showed the signature of positive selection.
Asunto(s)
Cetáceos/genética , Hipoxia/genética , Oxígeno/sangre , Globinas alfa/genética , Globinas beta/genética , Secuencia de Aminoácidos , Animales , Artiodáctilos/genética , Carnívoros/genética , Quirópteros/genética , Eulipotyphla/genética , Evolución Molecular , Datos de Secuencia Molecular , Familia de Multigenes , Filogenia , Primates/genética , Estructura Terciaria de Proteína , Selección Genética , Alineación de SecuenciaRESUMEN
The collared peccary (Tayassu tajacu) is widely distributed over the American continent, being found from the south of the USA to the north of Argentina. In Brazil, it is spread all over the country, being one of the potential species to be raised in captivity. Therefore, the cytogenetic techniques could be a potential tool for reproductive monitoring of animals raised in captivity, mainly when destined for commercial purposes. This study had the objective of determining the chromosome number of two populations raised in captivity and characterizing them by GTG banding. For this purpose, an analysis was made of mitotic metaphases obtained from lymphocyte cultures made from blood samples of 11 animals, six of which from the Northeast and five from the North of Brazil. The results of this analysis showed the same karyotype pattern for the species (2n=30 chromosomes and NF=48), besides corresponding to the South American pattern of the species, i.e., without a translocation between autosomes 1 and 8, chromosome X acrocentric, and no differences were found between the two populations studied. However, chromosomal polymorphisms were observed compared to data from the literature on populations from North and South America.
Asunto(s)
Artiodáctilos/genética , Cromosomas de los Mamíferos/genética , Animales , Brasil , Cariotipificación , Masculino , Cromosoma X , Cromosoma YRESUMEN
The collared peccary (Tayassu tajacu) is widely distributed over the American continent, being found from the south of the USA to the north of Argentina.In Brazil, it is spread all over the country, being one of the potential species to be raised in captivity. Therefore, the cytogenetic techniques could be a potencial tool for reproductive monitoring of animals raised in captivity, mainly when destined for commercial purposes. This study had the objective of determining the chromosome number of two populations raised in captivity and characterizing them by GTG banding. For this purpose, an analysis was made of mitotic metaphases obtained from lymphocyte cultures made from blood samples of 11 animals, six of which from the Northeast and five from the North of Brazil. The results of this analysis showed the same ka ryotype pattern for the species (2n=30 chromosomes and NF=48), besides corresponding to the South American pattern of the species, i.e., without a translocation between autosomes 1 and 8, chromosome X acrocentric, and no differences were found between the two populations studied. However, chromosomal polymorphisms were observed compared to data from the literature on populations from North and South America.(AU)
Asunto(s)
Masculino , Animales , Artiodáctilos/genética , Cromosomas de los Mamíferos/genética , Cariotipificación , Cromosoma X , Cromosoma Y , BrasilRESUMEN
The collared peccary (Tayassu tajacu) is widely distributed over the American continent, being found from the south of the USA to the north of Argentina.In Brazil, it is spread all over the country, being one of the potential species to be raised in captivity. Therefore, the cytogenetic techniques could be a potencial tool for reproductive monitoring of animals raised in captivity, mainly when destined for commercial purposes. This study had the objective of determining the chromosome number of two populations raised in captivity and characterizing them by GTG banding. For this purpose, an analysis was made of mitotic metaphases obtained from lymphocyte cultures made from blood samples of 11 animals, six of which from the Northeast and five from the North of Brazil. The results of this analysis showed the same ka ryotype pattern for the species (2n=30 chromosomes and NF=48), besides corresponding to the South American pattern of the species, i.e., without a translocation between autosomes 1 and 8, chromosome X acrocentric, and no differences were found between the two populations studied. However, chromosomal polymorphisms were observed compared to data from the literature on populations from North and South America.
Asunto(s)
Masculino , Animales , Artiodáctilos/genética , Cromosomas de los Mamíferos/genética , Cariotipificación , Brasil , Cromosoma X , Cromosoma YRESUMEN
Research has been conducted as part of the Small Ruminant Collaborative Research Support Program (SR-CRSP) on evaluation of genetic resources and methods of effecting genetic improvement of small ruminants in the participating countries. In Kenya, the focus has been on development of a dual-purpose goat for milk and meat production in farming areas, utilizing two locally adapted breeds, Galla and East African, and two imported dairy breeds, Anglo-Nubian and Toggenburg, into a single stock. That research now has reached the stage of field testing. In Morocco, the performance of a highly prolific breed of sheep, the D'Man, and of a less prolific but larger breed, commonly raised under extensive management, the Sardi, and of their F1, F2 and backcross progeny has been evaluated for several reproduction and growth traits. Prolificacy of the D'Man was transmitted additively, but there was favorable heterosis for age at puberty, fertility and growth rate, resulting in substantial heterosis in total performance. In Indonesia, a high degree of variability in prolificacy in sheep appears to be due to segregation of a gene with large effect on ovulation rate, similar in some respects to the Booroola gene. In Peru, work has involved evaluation of effectiveness of current selection programs and estimation of phenotypic and genetic parameters, in unimproved and improved types of sheep, with a limited amount of work also on alpacas. Fiber production is the principal economic trait in alpacas. There also has been work on evaluation of hair sheep in Brazil, Kenya and Indonesia.
Asunto(s)
Artiodáctilos/genética , Cruzamiento , Camélidos del Nuevo Mundo/genética , Cabras/genética , Ovinos/genética , Animales , Femenino , Variación Genética , Genotipo , Indonesia , Kenia , Masculino , Marruecos , PerúRESUMEN
The location and frequency of Ag-stained NORs and sites of rDNA hybridization were studied in the chromosomes of the South American camelids. In the four camelids these regions occur distally on chromosomes 18, 21, and 27 and the smallest biarmed elements. Quantitative analysis of NOR distribution showed variations between both cells and species. In llama, guanaco and alpaca the NORs number averaged 6 per cell, this being higher than in vicuña where the average was 3. Relative frequencies of NOR-bearing chromosomes in the four camelids were similar. Yet, in vicuña virtual absence of NOR sites on one of the smallest biarmed pairs was observed. The rDNA sites assessed in llama and vicuña by in situ hybridization with cloned 18S DNA were coincident with the NOR locations and with the frequencies characteristics for each species. Moreover, varying the exposure time of the autoradiographs, labeling patterns specific for each camelid were observed. Grain counts on individual chromosomes indicated that under our conditions one month exposure is enough to demonstrate all the rDNA sites available in the complement of llama. Conversely, at least two months are necessary to show the total sites existing in vicuña. Most probably this finding reflects the presence of variations in the amount of copies of the ribosomal genes per chromosome.
Asunto(s)
Artiodáctilos/genética , Camélidos del Nuevo Mundo/genética , Cromosomas/análisis , ADN Ribosómico/análisis , Hibridación de Ácido Nucleico , Región Organizadora del Nucléolo/análisis , Animales , ADN Ribosómico/genética , Femenino , Cariotipificación , Masculino , Plata , América del Sur , Coloración y Etiquetado , Factores de TiempoRESUMEN
The DNA composition and the in situ hybridization of satellite fractions were analysed in the New World camelids llama, alpaca, guanaco and vicuña. In the four camelid forms, it was possible to identify a similar main band DNA and five satellite fractions (I-V) with G + C base contents ranging from 32% to 66%. Satellites II-V from llama were in situ reannealed on chromosomes from the four camelid forms. The results obtained were: (a) the four satellites hybridized with regions of C-banding (centromeric regions of all chromosomes and short arms of some autosomes); (b) in general, homologous hybridizations (llama DNA versus llama chromosomes) were more efficient than heterologous reassociations; there were however three exceptions to this rule (vicuña and alpaca satellite fraction II, chromosome group B; vicuña fraction V, chromosome groups A and B); (c) X chromosomes from the four camelids had satellites III-V but lacked satellite II, (d) no satellite fraction was detected on chromosome Y. The analysis of the in situ hybridization patterns allowed to conclude that most or all C-banded chromosome regions comprise several satellite DNA fractions. It is, moreover, proposed that there is an ample interspecies variation in the number of chromosomes that cross-react with a given satellite fraction. Our data give further support to the close genomic kinship of New World camelids.