New evidence for nucleolar dominance in hybrids of Drosophila arizonae and Drosophila mulleri
Drosophila mulleri (MU) and D. arizonae (AR) are cryptic species of the mulleri complex, mulleri subgroup, repleta group. Earlier cytogenetic studies revealed that these species have different regulatory mechanisms of nucleolar organizing activity. In these species, nucleolar organizing regions are...
| Autores: | , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2006 |
| País: | Brasil |
| Recursos: | Universidade Estadual Paulista (UNESP) |
| Repositorio: | Repositório Institucional da UNESP |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unesp.br:11449/69428 |
| Acesso em linha: | http://www.geneticsmr.com//year2006/vol5-4/pdf/gmr0225.pdf http://hdl.handle.net/11449/69428 |
| Access Level: | acceso abierto |
| Palavra-chave: | Drosophila Microchromosome Nucleolar dominance Nucleolus Polytene chromosome animal cell animal experiment autosomal dominant inheritance chromosome analysis chromosome NOR controlled study cytogenetics dominant inheritance Drosophila arizonae Drosophila mulleri female gene activation gene amplification genetic association hybrid male microchromosome nonhuman nucleolus polytene chromosome regulatory mechanism salivary gland X chromosome Animals Cell Nucleolus Crosses, Genetic Female Genetic Variation Hybridization, Genetic Inheritance Patterns Male Nucleolus Organizer Region X Chromosome mulleri subgroup repleta group |
| Resumo: | Drosophila mulleri (MU) and D. arizonae (AR) are cryptic species of the mulleri complex, mulleri subgroup, repleta group. Earlier cytogenetic studies revealed that these species have different regulatory mechanisms of nucleolar organizing activity. In these species, nucleolar organizing regions are found in both the X chromosome and the microchromosome. In the salivary glands of hybrids between MU females and AR males, there is an interspecific dominance of the regulatory system of the D. arizonae nucleolar organizer involving, in males, amplification and activation of the nucleolar organizer from the microchromosome. The authors who reported these findings obtained hybrids only in that cross-direction. More recently, hybrids in the opposite direction, i.e., between MU males and AR females, have been obtained. The purpose of the present study was to evaluate, in these hybrids, the association of the nucleoli with the chromosomes inherited from parental species in order to cytogenetically confirm the dominance patterns previously described. Our results support the proposed dominance of the AR nucleolar organizer activity over that of MU, regardless of cross-direction. ©FUNPEC-RP. |
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