Subject(s)
Cervix Uteri/metabolism , Fibronectins , Glycoproteins/analysis , Obstetric Labor, Premature/diagnosis , Vagina/metabolism , Adrenal Cortex Hormones/therapeutic use , Adult , Anti-Bacterial Agents/therapeutic use , Birth Weight , Female , Fetal Death/diagnosis , Fetal Death/etiology , Gestational Age , Humans , Infant, Newborn , Obstetric Labor, Premature/prevention & control , Predictive Value of Tests , Pregnancy , Sensitivity and Specificity , Tocolytic Agents/therapeutic useABSTRACT
The peripheral sensory system of the Drosophila adult has been used for the genetic analysis of axon guidance because of its accessibility for experimental manipulation and mutant screens. Wing, leg, antenna, or eye sensory axons are able to pathfind normally under different perturbations, indicating that sensory axon guidance is a highly canalized process. Similarly to other model systems, sensory growth cones seem to use multiple, simultaneous cues for guidance. In addition, sensory axons from peripheral structures seem to be capable of using alternative substrates for pathfinding. Developmental regulation could account for the high stability of axon guidance under experimental and natural perturbation conditions. Despite this flexibility, functional characterization of genes involved in sensory axon guidance is being carried out in situations where there appears to be less system redundancy.
Subject(s)
Axons/ultrastructure , Drosophila/growth & development , Animals , Chemoreceptor Cells/growth & development , Chemoreceptor Cells/ultrastructure , Drosophila/physiology , Drosophila/ultrastructure , Mechanoreceptors/growth & development , Mechanoreceptors/ultrastructure , Neural Pathways/growth & development , Neural Pathways/ultrastructure , Neurons, Afferent/ultrastructure , Photoreceptor Cells, Invertebrate/growth & development , Photoreceptor Cells, Invertebrate/ultrastructureABSTRACT
Formation of neural precursors in Drosophila is determined by proneural genes. The distinctive pattern of expression of some genes of the achaete-scute complex in the embryonic neuroectoderm has prompted the speculation that they could also function in the specification of neural precursor identity in the CNS. To test this hypothesis, we have analysed the capacity of different proneural proteins to promote the development of a particular CNS precursor, the MP2 precursor. Our results indicate that: (i) all known proneural proteins are similarly able to support the formation of a neural precursor at the position of MP2; (ii) different proneural proteins promote the expression of different characteristics of MP2; and (iii) a totally normal specification of the MP2 fate can only be attained by the proneural genes achaete or scute.
