Consulta: subjectFacets:"Polar body"
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Data/hora: 11/06/2024 04:34:51

A complementary method for production of tetraploid Crassostrea gigas using crosses between diploids and tetraploids with cytochalasin B treatments
Provedor de dados: 5
Autores: Mccombie, Helen; Ledu, Christophe; Phelipot, Pascal; Lapegue, Sylvie; Boudry, Pierre; Gerard, Andre.
We present a new method to produce tetraploid Crassostrea gigas by cytochalasin B inhibition of polar body 2 expulsion in diploid females crossed with tetraploid males. This offers a means of direct introgression of genetic characters from selected diploid to tetraploid lines, avoiding a triploid step. Offspring larval ploidy shifted over time and depended on size, with tetraploids more frequent among the smaller larvae and triploids among the large. Viable tetraploids were found at 4 and 6 months, indicating the technique was successful. The possibility that gynogenesis occurred was tested by microsatellite analysis to confirm the presence of paternally inherited alleles. These were present in all animals of the 2n x 4n + CB (female first) cross. However,...
Tipo: Text
Palavras-chave: Oyster breeding; Gynogenesis; Polar body; Cytochalasin B; Polyploidy; Crassostrea gigas.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/publication-632.pdf

Effects of cytochalasin B on fertilization and ploidy in the Pacific oyster Crassostrea gigas
Provedor de dados: 5
Autores: Ledu, Christophe; Mccombie, Helen.
The effects of cytochalasin B on fertilization and ploidy in Crassostrea gigas were examined in a controlled experiment. This enabled us to better understand why variable ploidy results have been found with the retention of polar bodies in previous studies on bivalve mollusks, and what the interaction with fertilization may be. By looking at the early development of Crassostrea gigas embryos with sequential samples stained using Hoechst 33258, a fluorescent DNA-specific dye, we compared normal evolution of fertilized eggs with that obtained with cytochalasin B treatment. In treated eggs, embryos with both three and four pronuclei were found after the second meiotic division. When embryos had three pronuclei, these were identified as the female pronucleus...
Tipo: Text
Palavras-chave: Crassostrea gigas; Fertilization; Cytochalasin B; Polar body; Polyploidy.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/publication-2845.pdf