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Coexistence of cytotypes and chromosomal mosaicism in Hoplias malabaricus (Characiformes, Erythrinidae) Biol. Res.
DA ROSA,RENATA; RUBERT,MARCELÉIA; BERTOLLO,LUIZ A C; MARTINS-SANTOS,ISABEL C; GIULIANO-CAETANO,LUCIA.
Karyotypes of seventeen Hoplias malabaricus specimens, collected in the fish culture station of UNOPAR (University of Northern Paraná), were analyzed. The station is in the Claro River system in the Tibagi River basin. Two distinct and coexistent karyotype forms (cytotypes) were identified, comprising either 42 chromosomes (cytotype A) or 40 chromosomes (cytotype C), both presenting metacentric and submetacentric chromosomes. In two specimens, one male and one female, it was not possible to characterize a modal diploid number because different cell lines were observed, with a predominance of 2n=41 and 2n=42 chromosomes at a frequency of 38.24% and 41.12%, respectively. The karyotype with 2n=41 showed some putative monosomic and trisomic chromosomes, while...
Tipo: Journal article Palavras-chave: Hoplias malabaricus; Chromosomal mosaicism; Coexistence of cytotypes; RAPD; Reproductive isolation.
Ano: 2009 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602009000300003
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Evolution of species-specific major seminal fluid proteins in placental mammals by gene death and positive selection Naturalis
Meslin, C.; Laurin, M.; Callebaut, I.; Druart, X.; Monget, P..
The seminal fluid is a complex substance composed of a variety of secreted proteins and has been shown to play an important role in the fertilisation process in mammals and also in Drosophila. Several genes under positive selection have been documented in some rodents and primates. Our study documents this phenomenon in several other mammalian taxa. We study the evolution of genes that encode for 20 proteins that are quantitatively predominant in the seminal fluid of at least one out of seven domestic animal species. We analyse the amino acid composition of these proteins for positive selection and for the presence of pseudogenes. Genes that disappeared through pseudogenisation include KLK2 in cattle, horse and mice. Traces of positive selection are found...
Tipo: Article / Letter to the editor Palavras-chave: Molecular evolution; Multivariate phylogenetic pairwise comparisons; Reproductive isolation; Speciation; Comparative biology; Pseudogenisation; 42.64; 42.13; 42.70.
Ano: 2015 URL: http://www.repository.naturalis.nl/record/575180
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Is more better? Sexual confusion during courtship between two sympatric and synchronic tarantulas: Acanthoscurria suina and Eupalaestrus weijenberghi Rev. Bras. Zool.
Costa,Fernando G.; De Oca,Laura Montes; Perdomo,Cintya; Ortiz-Villatoro,David; Baruffaldi,Luciana; Pérez-Miles,Fernando.
When two similar species co-occur in time and space, strong mechanisms isolating them from each other are expected. Acanthoscurria suina Pocock, 1903 and Eupalaestrus weijenberghi (Thorell, 1894) are two sympatric and synchronic tarantulas that inhabit burrows in Uruguay's meadows. Here we test how and when reproductive isolation operates between these species. We exposed females of each species simultaneously to two males: either one male of each species, or two males of the same species. Males courted females of both species. Contrary to expectations, however, females of A. suina responded more effusively to heterospecific than to conspecific males, whereas females of E. weijenberghi only responded to conspecific males. Clasping (prelude of mating) was...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Courtship; Neotropical tarantulas; Reproductive isolation; Sex pheromone; Sexual selection.
Ano: 2013 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702013000500011
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Maintenance of genetic differentiation across a transition zone in the sea: discordance between nuclear and cytoplasmic markers ArchiMer
Lemaire, Christophe; Versini, J; Bonhomme, Francois.
To investigate the origin and maintenance of the genetic discontinuity between Atlantic and Mediterranean populations of the common sea bass (Dicentrarchus labrax) we analysed the genetic variation at a fragment of mitochondrial cytochrome b sequence for 18 population samples. The result were also compared with new or previously published microsatellite data. Seven mitochondrial haplotypes and an average nucleotidic divergence of 0.02 between Atlantic and Mediterranean populations that matches a Pleistocene allopatric isolation were found. The frequency variation at the cytochrome b locus was many times greater between Atlantic and Mediterranean populations ((θ) over cap (C) = 0.67) than at microsatellite loci ((θ) over cap (N) = 0.02)....
Tipo: Text Palavras-chave: Reproductive isolation; Phylogeography; MtDNA; Microsatellites; Genetic transitions.
Ano: 2005 URL: http://archimer.ifremer.fr/doc/2005/publication-776.pdf
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Reproductive isolation among three populations of the genus Grammostola from Uruguay (Araneae, Theraphosidae) Iheringia, Sér. Zool.
Postiglioni,Rodrigo; Costa,Fernando G..
Ethological isolation of individuals from three allopatric Grammostola populations of Uruguay, G. iheringi (Keyserling, 1891), G. mollicoma (Auserer, 1875) northern population and G. mollicoma southern population, was tested under laboratory conditions. Grammostola iheringi behaved as a reproductive isolated species, whereas the two populations of G. mollicoma did not show ethological isolation between them. However, ecological isolating reproductive mechanisms could be acting on G. mollicoma populations. Artificial burrows seem to be important for reproductive isolation in these species.
Tipo: Info:eu-repo/semantics/article Palavras-chave: Grammostola iheringi; Grammostola mollicoma; Reproductive isolation; Ethological isolation.
Ano: 2006 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212006000100013
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Simulation of pattern of gene flow in Canjerana fragments in the Brazilian Atlantic Rainforest for evaluating genetic conservation strategies Ciência Rural
Serrote,Caetano Miguel Lemos; Reiniger,Lia Rejane Silveira; Costa,Leonardo Severo da; Stefanel,Charlene Moro; Silva,Karol Buuron da; Rabaiolli,Silvia Machado dos Santos.
ABSTRACT: Gene flow is important for the conservation of genetic resources to allow connectivity of geographically isolated populations and which genetic variability is reduced. Gene movement is a function of flow rate and model. Understanding how gene flow occurs can contribute to the conservation and selection of priority populations that could benefit from an eventual intervention. Simulation softwares allow making inferences about past events based on current datasets or predict future phenomena under real genetic scenarios. Adverse phenomena can be predicted and actions can be taken to avoid them. The aim of this study was to identify a model and the gene flow rates that could explain genetic structure of eight forest fragments of Cabralea canjerana...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Cabralea canjerana; Reproductive isolation; Genetic variability; EASYPOP; Microsatellites.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782019000800301
Registros recuperados: 6
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