RESUMEN
Many organisms carry nuclear sequences of mitochondrial origin (NUMTs). We have identified 76 NUMTs in 25 genomic locations in the jewel wasp Nasonia vitripennis. The total amount of NUMTs in Nasonia is 42 972 bp exceeding over four-fold that found in Tribolium castaneum and almost fifty-fold that found in Drosophila melanogaster, whereas Apis mellifera has an even larger number of NUMTs in its genome (over 230 kb). The Nasonia NUMTs were inserted by multiple independent events and frequently involved large fragments spanning multiple mitochondrial genes. Most of the NUMTs are recent transfers that occurred less than one million years ago after the speciation of N. vitripennis. Duplications and rearrangements in the nucleus have also occurred. Data suggest that NUMTs may be more common in hymenoptera than in other insect genomes.
Asunto(s)
Núcleo Celular/genética , ADN Mitocondrial/genética , Evolución Molecular , Filogenia , Avispas/genética , Animales , Abejas/genética , Biología Computacional , Drosophila melanogaster/genética , Funciones de Verosimilitud , Modelos Genéticos , Especificidad de la Especie , Tribolium/genéticaRESUMEN
We report three novel small RNA viruses uncovered from cDNA libraries from parasitoid wasps in the genus Nasonia. The genome of this kind of virus is a positive-sense single-stranded RNA with a 3' poly(A), which facilitates cloning from cDNAs. Two of the viruses, NvitV-1 and NvitV-2, possess a RNA-dependent RNA polymerase that associates them with the family Iflaviridae of the order Picornavirales. A third virus, NvitV-3, is most similar to the Nora virus from Drosophila. A reverse transcription-PCR method developed for NvitV-1 indicates that it is a persistent commensal infection of Nasonia.
Asunto(s)
Biblioteca de Genes , Filogenia , Virus ARN/genética , Avispas/virología , Secuencia de Aminoácidos , Animales , Biología Computacional , Minería de Datos , Etiquetas de Secuencia Expresada , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Alineación de SecuenciaRESUMEN
The doublesex (dsx) gene of the parasitic wasp Nasonia vitripennis is described and characterized. Differential splicing of dsx transcripts has been shown to induce somatic sexual differentiation in Diptera and Lepidoptera, but not yet in other insect orders. Two spliceforms of Nasonia dsx mRNA are differentially expressed in males and females. In addition, in a gynandromorphic line that produces haploids (normally males) with full female phenotypes, these individuals show the female spliceform, providing the first demonstration of a direct association of dsx with somatic sex differentiation in Hymenoptera. Finally, the DNA binding (DM) domain of Nasonia dsx clusters phylogenetically with dsx from other insects, and Nasonia dsx shows microsynteny with dsx of Apis, further supporting identification of the dsx orthologue in Nasonia.
Asunto(s)
Proteínas de Insectos/genética , Procesos de Determinación del Sexo , Avispas/genética , Empalme Alternativo , Secuencia de Aminoácidos , Animales , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Evolución Molecular , Femenino , Haploidia , Proteínas de Insectos/metabolismo , Masculino , Datos de Secuencia Molecular , ARN Mensajero/metabolismo , Homología de Secuencia de Aminoácido , Avispas/metabolismoRESUMEN
Sequences from three gene regions from the nuclear and mitochondrial genomes were used to examine the extent and nature of hierarchical structure in the Drosophilamojavensis cluster (Drosophila arizonae, D. mojavensis and D. navojoa) of the D. repleta species group. To determine the genetic divergence of these three species, sequence data were analyzed using maximum parsimony and population aggregation analysis. Individual and combined gene genealogies indicate that D. arizonae and D. mojavensis are neither diagnosable nor monophyletic with respect to one another. Although D. navojoa has differentiated from D. arizonae and D. mojavensis, as diagnosed by nuclear gene sequences, it may have undergone a reticulation event with D. arizonae. Our results suggest that either these taxa are still undergoing differentiation at the molecular level or have experienced gene flow in the recent past.
