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Mapping peptidergic cells in Drosophila: where DIMM fits in.

Park D, Veenstra JA, Park JH, Taghert PH - PLoS ONE (2008)

Bottom Line: The bHLH transcription factor DIMMED has been associated with the differentiation of peptidergic cells in Drosophila.Furthermore, we found that DIMM co-expression was a prevalent feature within single neuropeptide marker expression patterns.LEAP denotes Large cells that display Episodic release of Amidated Peptides.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy and Neurobiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America.

ABSTRACT
The bHLH transcription factor DIMMED has been associated with the differentiation of peptidergic cells in Drosophila. However, whether all Drosophila peptidergic cells express DIMM, and the extent to which all DIMM cells are peptidergic, have not been determined. To address these issues, we have mapped DIMM expression in the central nervous system (CNS) and periphery in the late larval stage Drosophila. At 100 hr after egg-laying, DIMM immunosignals are largely congruent with a dimm-promoter reporter (c929-GAL4) and they present a stereotyped pattern of 306 CNS cells and 52 peripheral cells. We assigned positional values for all DIMM CNS cells with respect to reference gene expression patterns, or to patterns of secondary neuroblast lineages. We could assign provisional peptide identities to 68% of DIMM-expressing CNS cells (207/306) and to 73% of DIMM-expressing peripheral cells (38/52) using a panel of 24 markers for Drosophila neuropeptide genes. Furthermore, we found that DIMM co-expression was a prevalent feature within single neuropeptide marker expression patterns. Of the 24 CNS neuropeptide gene patterns we studied, six patterns are >90% DIMM-positive, while 16 of 22 patterns are >40% DIMM-positive. Thus most or all DIMM cells in Drosophila appear to be peptidergic, and many but not all peptidergic cells express DIMM. The co-incidence of DIMM-expression among peptidergic cells is best explained by a hypothesis that DIMM promotes a specific neurosecretory phenotype we term LEAP. LEAP denotes Large cells that display Episodic release of Amidated Peptides.

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A map of DIMM-expressing neurons in the 100 hr AEL larval CNS.Top: schematic of the CNS along with cross-sections of each segmental neuromere to illustrate dorsal-ventral positions of DIMM-expressing neurons. Details on positions of individual DIMM-positive neurons in the brain hemispheres are given in later figures. Bottom: use of EVE and EN expression patterns to assign DIMM neurons to individual segments. Left: triple-labeled St. 17 embryonic CNS stained for EVE (blue) EN (green) and DIMM (red); middle: double-labeled 100 hr AEL larval CNS stained for EVE (green) and DIMM (red); right: schematic of an idealized abdominal segment showing the interpretation used to assign segmental values to DIMM neurons in the VNC.
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pone-0001896-g002: A map of DIMM-expressing neurons in the 100 hr AEL larval CNS.Top: schematic of the CNS along with cross-sections of each segmental neuromere to illustrate dorsal-ventral positions of DIMM-expressing neurons. Details on positions of individual DIMM-positive neurons in the brain hemispheres are given in later figures. Bottom: use of EVE and EN expression patterns to assign DIMM neurons to individual segments. Left: triple-labeled St. 17 embryonic CNS stained for EVE (blue) EN (green) and DIMM (red); middle: double-labeled 100 hr AEL larval CNS stained for EVE (green) and DIMM (red); right: schematic of an idealized abdominal segment showing the interpretation used to assign segmental values to DIMM neurons in the VNC.

Mentions: We studied DIMM expression in late stage embryonic CNS (St 17) and in the CNS of feeding 3rd instar larvae that were approximately 100 hr after egg laying (AEL). The earlier stage produced clear DIMM expression signals but poorly developed patterns of neuropeptide expression. The latter stage produced robust neuropeptide expression as well as strong and maintained DIMM expression. The DIMM expression pattern was basically constant between the two developmental stages, and a simplified overview is illustrated in Figure 2A. It includes 306 cells that are distributed throughout the rostral-caudal axis of the CNS: a total of 45 DIMM cells are found at different, though reproducible locations within each brain hemisphere, and 8–22 DIMM cells are observed per segmental neuromere, for a total of 216 in the VNC.


Mapping peptidergic cells in Drosophila: where DIMM fits in.

Park D, Veenstra JA, Park JH, Taghert PH - PLoS ONE (2008)

A map of DIMM-expressing neurons in the 100 hr AEL larval CNS.Top: schematic of the CNS along with cross-sections of each segmental neuromere to illustrate dorsal-ventral positions of DIMM-expressing neurons. Details on positions of individual DIMM-positive neurons in the brain hemispheres are given in later figures. Bottom: use of EVE and EN expression patterns to assign DIMM neurons to individual segments. Left: triple-labeled St. 17 embryonic CNS stained for EVE (blue) EN (green) and DIMM (red); middle: double-labeled 100 hr AEL larval CNS stained for EVE (green) and DIMM (red); right: schematic of an idealized abdominal segment showing the interpretation used to assign segmental values to DIMM neurons in the VNC.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2266995&req=5

pone-0001896-g002: A map of DIMM-expressing neurons in the 100 hr AEL larval CNS.Top: schematic of the CNS along with cross-sections of each segmental neuromere to illustrate dorsal-ventral positions of DIMM-expressing neurons. Details on positions of individual DIMM-positive neurons in the brain hemispheres are given in later figures. Bottom: use of EVE and EN expression patterns to assign DIMM neurons to individual segments. Left: triple-labeled St. 17 embryonic CNS stained for EVE (blue) EN (green) and DIMM (red); middle: double-labeled 100 hr AEL larval CNS stained for EVE (green) and DIMM (red); right: schematic of an idealized abdominal segment showing the interpretation used to assign segmental values to DIMM neurons in the VNC.
Mentions: We studied DIMM expression in late stage embryonic CNS (St 17) and in the CNS of feeding 3rd instar larvae that were approximately 100 hr after egg laying (AEL). The earlier stage produced clear DIMM expression signals but poorly developed patterns of neuropeptide expression. The latter stage produced robust neuropeptide expression as well as strong and maintained DIMM expression. The DIMM expression pattern was basically constant between the two developmental stages, and a simplified overview is illustrated in Figure 2A. It includes 306 cells that are distributed throughout the rostral-caudal axis of the CNS: a total of 45 DIMM cells are found at different, though reproducible locations within each brain hemisphere, and 8–22 DIMM cells are observed per segmental neuromere, for a total of 216 in the VNC.

Bottom Line: The bHLH transcription factor DIMMED has been associated with the differentiation of peptidergic cells in Drosophila.Furthermore, we found that DIMM co-expression was a prevalent feature within single neuropeptide marker expression patterns.LEAP denotes Large cells that display Episodic release of Amidated Peptides.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy and Neurobiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America.

ABSTRACT
The bHLH transcription factor DIMMED has been associated with the differentiation of peptidergic cells in Drosophila. However, whether all Drosophila peptidergic cells express DIMM, and the extent to which all DIMM cells are peptidergic, have not been determined. To address these issues, we have mapped DIMM expression in the central nervous system (CNS) and periphery in the late larval stage Drosophila. At 100 hr after egg-laying, DIMM immunosignals are largely congruent with a dimm-promoter reporter (c929-GAL4) and they present a stereotyped pattern of 306 CNS cells and 52 peripheral cells. We assigned positional values for all DIMM CNS cells with respect to reference gene expression patterns, or to patterns of secondary neuroblast lineages. We could assign provisional peptide identities to 68% of DIMM-expressing CNS cells (207/306) and to 73% of DIMM-expressing peripheral cells (38/52) using a panel of 24 markers for Drosophila neuropeptide genes. Furthermore, we found that DIMM co-expression was a prevalent feature within single neuropeptide marker expression patterns. Of the 24 CNS neuropeptide gene patterns we studied, six patterns are >90% DIMM-positive, while 16 of 22 patterns are >40% DIMM-positive. Thus most or all DIMM cells in Drosophila appear to be peptidergic, and many but not all peptidergic cells express DIMM. The co-incidence of DIMM-expression among peptidergic cells is best explained by a hypothesis that DIMM promotes a specific neurosecretory phenotype we term LEAP. LEAP denotes Large cells that display Episodic release of Amidated Peptides.

Show MeSH