Preliminary characterization of two atypical soluble guanylyl cyclases in the central and peripheral nervous system of Drosophila melanogaster

Glial cells constitute the second component of the nervous system and are important during neuronal development. In this paper we describe a gene, glial cell deficient, (glide), that is necessary for glial cell fate commitment in Drosophila melanogaster. Mutations at the glide locus prevent glial cell determination in the embryonic central and peripheral nervous system. Moreover, we show that the absence of glial cells is the consequence of a cell fate switch from glia to neurones. This suggests the existence of a multipotent precursor cells in the nervous system. glide mutants also display defects in axonal navigation, which confirms and extends previous results indicating a role for glial cells in these processes.

Download Full-text

Functional differences between Ultrabithorax protein isoforms in Drosophila melanogaster: evidence from elimination, substitution and ectopic expression of specific isoforms.

Genetics ◽

10.1093/genetics/136.3.979 ◽

1994 ◽

Vol 136 (3) ◽

pp. 979-991 ◽

Cited By ~ 2

Author(s):

V Subramaniam ◽

H M Bomze ◽

A J López

Keyword(s):

Nervous System ◽

Drosophila Melanogaster ◽

Peripheral Nervous System ◽

Mutant Allele ◽

Stop Codon ◽

Functional Limitation ◽

Ectopic Expression ◽

Protein Isoforms ◽

Homeodomain Protein ◽

Alternatively Spliced

Abstract The homeotic selector gene Ultrabithorax (Ubx) specifies regional identities in multiple tissues within the thorax and abdomen of Drosophila melanogaster. Ubx encodes a family of six developmentally specific homeodomain protein isoforms translated from alternatively spliced mRNAs. The mutant allele Ubx195 contains a stop codon in exon mII, one of three differential elements, and consequently produces functional UBX protein only from mRNAs of type IVa and IVb, which are expressed mainly in the central nervous system. Although it retains activity for other processes, Ubx195 behaves like a null allele with respect to development of the peripheral nervous system, indicating that UBX-IVa and IVb alone do not contribute detectable Ubx function for this tissue. The mutant allele UbxMX17 contains an inversion of exon mII. We find that this allele only produces mRNAs of type IVa, but the expression pattern of the resulting UBX-IVa protein is indistinguishable from that of total UBX protein expression in wild-type embryos. The phenotype of homozygous UbxMX17 embryos indicates that UBX-IVa cannot substitute functionally for other isoforms to promote normal development of the peripheral nervous system. This functional limitation is confirmed by a detailed analysis of the peripheral nervous system in embryos that express specific UBX isoforms ectopically under control of a heat shock promoter. Additional observations suggest that UBX isoforms also differ in their ability to function in other tissues.

Download Full-text

Homologous patterns in the embryonic development of the peripheral nervous system in the grasshopper Schistocerca gregaria and the fly Drosophila melanogaster

Development ◽

10.1242/dev.112.1.241 ◽

1991 ◽

Vol 112 (1) ◽

pp. 241-253 ◽

Cited By ~ 3

Author(s):

T. Meier ◽

F. Chabaud ◽

H. Reichert

Keyword(s):

Nervous System ◽

Drosophila Melanogaster ◽

Embryonic Development ◽

Peripheral Nervous System ◽

Sensory Neurons ◽

Schistocerca Gregaria ◽

Spatiotemporal Pattern ◽

Developmental Mechanisms ◽

Pioneer Neurons ◽

Sensory Structures

To determine the generality of developmental mechanisms involved in the construction of the insect nervous system, the embryonic development of the peripheral nervous system in the grasshopper Schistocerca gregaria was characterized at the level of identified neurons and nerve branches and then compared to that previously described from the fly Drosophila melanogaster. For this, immunocytochemistry using a neuron-specific antibody was carried out on staged grasshopper embryos. Our results show that initially a simple peripheral nerve scaffolding is established in each segment of the animal. This scaffolding consists of a pair of intersegmental nerves that are formed by identified afferent and efferent pioneer neurons and a pair of segmental nerves that are formed by afferent pioneers situated in limb buds. Subsequently, identified sets of sensory neurons differentiate in a stereotyped spatiotemporal pattern in dorsal, lateral and ventral clusters in each segment and project their axons onto these nerves. Although segment-specific differences exist, serial homologs of the developing nerves and sensory neurons can be identified. A comparison of these results with those obtained from Drosophila shows that virtually the same pattern of peripheral nerves and sensory structures is formed in both species. This indicates that the construction of the peripheral nervous system in extremely divergent modern insects relies on conserved developmental mechanisms that evolved in ancestral insects over 300 million years ago.

Download Full-text