RESUMO
The mitochondrial genotype of all F(1) female offspring (426 individuals) of a single Drosophila mauritiana female, heteroplasmic for two types of mtDNA (a short and a long genome), was established. All descendants were heteroplasmic. The earliest eggs laid by this female show the cytoplasmic genetic structure of ovariole stem cells at the end of development. Cohorts of females from the eggs laid day after day by this female, throughout the 31 days of its life, provide information on the evolution of the mitochondrial genotypes in the course of successive divisions of stem cells. An increase of the percentage of long DNA in offspring was observed as the female aged. Moreover, the variance of the genotypes increases as rounds of stem cell division progress. These results are supported by observations based on the adults issued from the early and late eggs, for three additional heteroplasmic females.
RESUMO
The results of a comparative quantitive study of morphology in eudiploids and three types of trisomics of adult Pleurodeles waltlii are discussed. General morphologies are specified by mean measurement values. Statistical bivariate analysis demonstrate differential growths and give some new details on sexual dimorphism. Trisomies 8 and 11 have opposite effects on growth allometries, while no significant effect of trisomy 10 has been detected. As a rule, characters of trisomics are more variable than those of diploids.
Assuntos
Diploide , Pleurodeles/genética , Salamandridae/genética , Trissomia , Animais , Feminino , Masculino , Pleurodeles/anatomia & histologia , Pleurodeles/crescimento & desenvolvimento , Fatores SexuaisRESUMO
Neonatal hypothyroidism accelerates the postnatal evolution of the adrenal dopamine (DA) content and concentration in the young rat. In 14-day-old control animals, insulin-hypoglycaemia leads to a transient increase in adrenal dopamine content up to 159% above the value in saline-injected animals. This increase is already at its maximum 1 h after insulin administration and lasts 7 h. In the hypothyroid animals, the DA increase evoked by hypoglycaemia is impaired in magnitude (74%) and duration (4 h).