RESUMO
The chromosome modal number in Muscoidea Diptera is 2n = 12, including five pairs of autosomes and one sex chromosome pair. Nevertheless, some species with 2n = 10 chromosomes have been described, all of them from the Muscidae family. We analyzed the karyotype of some Muscidae species from different subfamilies and compared the obtained data with the karyotypes of some species of the families Calliphoridae and Sarcophagidae. Comparisons of these species with other Muscidae species revealed a considerable variation among their sex chromosomes. This variation in the length of the sex chromosomes suggests that parts of these chromosomes were lost or fused with autosomes. The constitutive heterochromatic regions and the nucleolar organizer regions (NORs) were also analyzed and some aspects about the relationship between these regions and the sex chromosomes are discussed.
O número modal de cromossomos dos Dípteros Muscóideos é 2n = 12, incluindo cinco pares de autossomos e um par de cromossomos sexuais. No entanto, algumas espécies com 2n = 10 cromossomos já foram descritas, sendo todas pertencentes à família Muscidae. No presente trabalho, foram analisados os cariótipos de algumas espécies de Muscidae de diferentes subfamílias e os dados obtidos foram comparados com os cariótipos de algumas espécies das famílias Calliphoridae e Sarcophagidae. Comparações destas espécies com outras da família Muscidae revelaram uma considerável variação entre seus cromossomos sexuais. Esta variação no tamanho dos cromossomos sexuais sugere que parte destes cromossomos foram perdidos ou sofreram fusão com autossomos. As regiões de heterocromatina constitutiva e as regiões organizadoras de nucléolos (RONs) foram também analisadas e alguns aspectos sobre a relação destas com os cromossomos sexuais são discutidos.
Assuntos
Animais , Feminino , Masculino , Bandeamento Cromossômico/métodos , Dípteros/genética , Heterocromatina/genética , Cromossomos Sexuais/genética , Dípteros/classificação , Hibridização in Situ Fluorescente , Região Organizadora do Nucléolo/genéticaRESUMO
The chromosome modal number in Muscoidea Diptera is 2n=12, including five pairs of autosomes and one sex chromosome pair. Nevertheless, some species with 2n=10 chromosomes have been described, all of them from the Muscidae family. We analyzed the karyotype of some Muscidae species from different subfamilies and compared the obtained data with the karyotypes of some species of the families Calliphoridae and Sarcophagidae. Comparisons of these species with other Muscidae species revealed a considerable variation among their sex chromosomes. This variation in the length of the sex chromosomes suggests that parts of these chromosomes were lost or fused with autosomes. The constitutive heterochromatic regions and the nucleolar organizer regions (NORs) were also analyzed and some aspects about the relationship between these regions and the sex chromosomes are discussed.
Assuntos
Bandeamento Cromossômico/métodos , Dípteros/genética , Heterocromatina/genética , Cromossomos Sexuais/genética , Animais , Dípteros/classificação , Feminino , Hibridização in Situ Fluorescente , Masculino , Região Organizadora do Nucléolo/genéticaRESUMO
The blow flies Chrysomya putoria and C. megacephala have 2n=12 chromosomes, five metacentric pairs of autosomes and an XX/XY sex chromosome pair. There are no substantial differences in the karyotype morphology of these two species, except for the X chromosome which is subtelocentric in C. megacephala and metacentric in C. putoria and is about 1.4 times longer in C. putoria. All autosomes were characterized by the presence of a C band in the pericentromeric region; C. putoria also has an interstitial band in pair III. The sex chromosomes of both species were heterochromatic, except for a small region at the end of the long arm of the X chromosome. Ribosomal genes were detected in meiotic chromosomes by FISH and in both species the NOR was located on the sex chromosomes. These results confirm that C. putoria was the species introduced into Brazil in 1970s, and not C. chloropyga as formerly described.
Assuntos
Bandeamento Cromossômico , Dípteros/genética , Animais , Feminino , Hibridização in Situ Fluorescente , Cariotipagem , Masculino , Metáfase , Região Organizadora do Nucléolo/genéticaRESUMO
Muscina stabulans, M. domestica, Chrysomya putoria, C. megacephala and Stomoxys calcitrans were the most abundant muscoid flies captured in a poultry facility in southeastern Brazil. We examined the gonadotrophic profiles of the females caught at different sites and different times and found that Mu. stabulans and M. domestica, the predominant species, presented similar gonadotrophic profiles only when captured on the manure under the cages, but very different and sometimes opposite gonadotrophic profiles when sampled from wooden posts, vegetation or electric cords. We also determined sex ratios and relative abundance for these two species and found significant differences between them. More than 50% of the females of both species of Chrysomya captured on manure carried eggs or exhibited signs of recent oviposition. The vast majority of S. calcitrans presented ovaries with eggs or signs of recent oviposition. A small proportion of them had ovaries in the recent emerged condition. Our data on ovarian stages, sex ratio and relative abundance allowed us to associate different gonadotrophic profiles with each site and characterize each site as a resting, ovipositing or mating site.
Assuntos
Abrigo para Animais , Muscidae/anatomia & histologia , Oviposição , Aves Domésticas , Animais , Brasil , Feminino , Moscas Domésticas/anatomia & histologia , Masculino , Ovário/anatomia & histologia , Dinâmica Populacional , Razão de Masculinidade , Fatores de TempoRESUMO
The aim of the experiments was to explain the high number of worms found in chickens from a poultry facility. Infections by Raillietina laticanalis were achieved in chickens kept in the laboratory. Thirty cysticercoids obtained from beetles (Dermestes ater) caught at the poultry facility were administered by pipette to each chicken. The rate of recovered worms was employed to evaluate the persistence of the infection, the influence of bird age on susceptibility to infection, and the possibility of reinfection. To verify the persistence of the infection, a group of ten chickens was infected. At each of five different intervals, two chickens were necropsied. Tapeworms were recovered up to the 46th day. To verify the influence of bird age on susceptibility to infection, three different age groups were used in the experimental design: 3-4 weeks, 6-9 weeks, and 17-20 weeks. There was no difference in susceptibility to the infections across the groups. To investigate the possibility of reinfection, a group of birds received an additional dose of cysticercoids a few days after the first doses. Another group received the second dose only after the worms had already been established. There was a significant increase in the number of recovered worms in both groups when compared with the control. The short worms found in some experiments may be due to natural destrobilization. Thus, the high number of worms found in chickens from the poultry facility could result from both infections being acquired earlier and infections acquired at the laying stage, since we demonstrated the possibility of reinfection and the long lifespan of the worm.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Infecções por Cestoides/veterinária , Galinhas/parasitologia , Doenças das Aves Domésticas/imunologia , Fatores Etários , Animais , Infecções por Cestoides/imunologia , Suscetibilidade a Doenças , RecidivaRESUMO
Feulgen-DNA values and nuclear areas were evaluated microspectrophotometrically for epithelial cells of the ovarian follicle during oogenesis in Chrysomya putoria. The aim was to investigate whether polyploidization occurred in the cells surrounding the nurse chamber and/or in those around the oocyte as well as whether different DNA amounts were found regarding the cell types considered. Four DNA endoreduplicative cycles could be demonstrated for the epithelial cells regardless of their localization on the follicle, during oogenesis. A small percentage of epithelial cells reaches a 32C degree. The nuclear area, however, did not increase at the same rate in cells covering the oocyte as in those covering the nurse chamber, in some of the oogenesis stages. The meaning of endopolyploidy for these cells is discussed, considering reports on relevance of secretory activities and their maintenance in polyploid cell systems.
Assuntos
DNA/metabolismo , Dípteros/genética , Oogênese/genética , Poliploidia , Corantes de Rosanilina , Animais , Núcleo Celular/ultraestrutura , Corantes , Epitélio/ultraestrutura , Feminino , Folículo Ovariano/citologiaRESUMO
Five species of Calliphoridae, mostly females, were collected using fly-traps baited with freshly killed rodent carcasses. Female blowflies were examined to determine the stages of ovarian development. The traps were selective for certain ovarian stages which varied according to the species. Phaenicia eximia (Wiedemann) was attracted to the traps mainly to oviposit, whereas females of Chrysomya albiceps (Wiedemann), C. putoria (Wiedemann) and C. megacephala (Fabricius) were captured in intermediate stages of oogenesis but seldom with eggs mature for oviposition. It is concluded that this kind of baited trap is unsuitable for the collection of male blowflies and that samples of female blowflies are specifically biased in favour of certain ovarian conditions.