Consulta: subjectFacets:"Genetic bottleneck"
Registros recuperados: 4
Data/hora: 09/06/2024 13:23:28

Genetic diversity of Brazilian Brahman cattle by pedigree analysis
Provedor de dados: 86
Autores: Cavani,Ligia; Silva,Rafael Medeiros de Oliveira; Carreño,Luis Orlando Duitama; Ono,Rafael Keith; Bertipaglia,Tássia Souza; Farah,Michel Marques; Millen,Danilo Domingues; Fonseca,Ricardo da.
Abstract: The objective of this work was to evaluate the genetic diversity of Brahman cattle in Brazil with pedigree analysis. Genealogical records of a subpopulation were used considering all pedigree information (Pt) and the pedigree information divided into two periods (P1, from 1994 to 2004; and P2, from 2005 to 2012) or according to the raising system (Ppt, animals on pasture; or Pst, on stable). Estimates were obtained for average inbreeding coefficients, generation intervals (GI), number of equivalent known generation (CGE), number of founders (Nf), effective number of founders (fe), effective number of ancestors (fa), and founder genome equivalents (fg). The average inbreeding coefficients were 11.97, 7.79, 11.95, 11.74, and 11.31% for Pt, P1, P2,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Beef cattle; Founders; Genetic bottleneck; Inbreeding.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018000100074

Innovative molecular approach to the identification of Colossoma macropomum and its hybrids
Provedor de dados: 42
Autores: Gomes,Fátima; Schneider,Horacio; Barros,Claudene; Sampaio,Dioniso; Hashimoto,Diogo; Porto-Foresti,Fábio; Sampaio,Iracilda.
Tambaqui (Colossoma macropomum) is the fish species most commonly raised in the Brazilian fish farms. The species is highly adaptable to captive conditions, and is both fast-growing and relatively fecund. In recent years, artificial breeding has produced hybrids with Characiform species, known as "Tambacu" and "Tambatinga". Identifying hybrids is a difficult process, given their morphological similarities with the parent species. This study presents an innovative molecular approach to the identification of hybrids based primarily on Multiplex PCR of a nuclear gene (α-Tropomyosin), which was tested on 93 specimens obtained from fish farms in northern Brazil. The sequencing of a 505-bp fragment of the Control Region (CR) permitted the identification of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pisciculture; Multiplex PCR; Mitochondrial DNA; Genetic bottleneck.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652012000200020

Evidences of delayed size recovery in Araucaria angustifolia populations after post-glacial colonization of highlands in Southeastern Brazil
Provedor de dados: 42
Autores: Stefenon,Valdir M.; Behling,Hermann; Gailing,Oliver; Finkeldey,Reiner.
Up to date, little is known about the relationship between historical demography and the current genetic structure of A. Angus As a first effort towards overcoming this lack, microsatellite data scored in six populations and isozyme allele frequencies published for 11 natural stands of this species were analysed in order to assess molecular signatures of populations' demographic history. Signatures of genetic bottlenecks were captured in all analysed populations of southeastern Brazil. Among southern populations, signatures of small effective population size were observed in only three out of 13 populations. Southern populations likely experienced faster recovery of population size after migration onto highlands. Accordingly, current genetic diversity of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Araucaria angustifolia; Genetic bottleneck; Population size recovery; Demographic history; Climate dynamics; Paleobotany.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652008000300005

Genetic diversity in natural populations of Hancornia speciosa Gomes: Implications for conservation of genetic resources
Provedor de dados: 64
Autores: Fajardo,Cristiane Gouvêa; Costa,Daniel Ferreira da; Chagas,Kyvia Pontes Teixeira das; Vieira,Fábio de Almeida.
ABSTRACT The continuing fragmentation of forests has been a threat to the maintenance of genetic resources. Genetic diversity is fundamental to the survival of species in natural environments in the long term, as well as being the basis for genetic improvement. The objective of this study was to evaluate the genetic diversity in natural populations of Hancornia speciosa and to contribute to the development of conservation strategies. We sampled 105 individuals of H. speciosa, distributed in seven populations. The ISSR (Inter-Simple Sequence Repeat) markers provided 70 loci, of which 81% were polymorphic. The mean genetic diversity of Nei (h) was 0.19, and the Shannon index (I) was 0.27. The h and I diversity indices ranged respectively from 0.16 to 0.24 in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Apocynaceae; Genetic structure; Genetic bottleneck; ISSR; Mangabeira.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542018000600623