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Cell proliferation in the Drosophila adult brain revealed by clonal analysis and bromodeoxyuridine labelling.

von Trotha JW, Egger B, Brand AH - Neural Dev (2009)

Bottom Line: Of the BrdU-labelled cells, 86% express the glial gene reversed polarity (repo), and 14% are repo negative.We have observed cell proliferation in the Drosophila adult brain.The dividing cells may be adult stem cells, generating glial and/or non-glial cell types.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Wellcome Trust/Cancer Research UK Gurdon Institute, Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK. j.v.trotha@gurdon.cam.ac.uk

ABSTRACT

Background: The production of new neurons during adulthood and their subsequent integration into a mature central nervous system have been shown to occur in all vertebrate species examined to date. However, the situation in insects is less clear and, in particular, it has been reported that there is no proliferation in the Drosophila adult brain.

Results: We report here, using clonal analysis and 5'-bromo-2'-deoxyuridine (BrdU) labelling, that cell proliferation does occur in the Drosophila adult brain. The majority of clones cluster on the ventrolateral side of the antennal lobes, as do the BrdU-positive cells. Of the BrdU-labelled cells, 86% express the glial gene reversed polarity (repo), and 14% are repo negative.

Conclusion: We have observed cell proliferation in the Drosophila adult brain. The dividing cells may be adult stem cells, generating glial and/or non-glial cell types.

Show MeSH
Most 5'-bromo-2'-deoxyuridine (BrdU)-positive cells co-stain with Repo and localize around the antennal nerve. (A) Three BrdU-labelled cells in a 3-day-old adult female brain stained for Repo and Elav. One cell can be clearly seen (white arrow) and two others are slightly out of the plane of focus, one more ventro-medial and one more dorso-lateral (white arrowheads). All three cells express Repo but not Elav. Single x-y confocal sections are shown, with insets showing y-z sections; the far right panel shows the merged image. (B) Fourteen percent of BrdU-labelled cells do not express Repo. One such cell (white arrow) is shown here, adjacent to a Repo-positive cell (white arrowhead), in a 10-day-old adult male brain. Single x-y confocal sections are shown, with insets showing y-z sections; the far right panel shows the merged image. (C) Two BrdU- and Repo-positive cells are shown that appear to have divided along the apico-basal axis. The single confocal sections show the more superficially localised cell (white arrow), while x-z and y-z sections (below and to the right, respectively) show the cell lying beneath it (white arrowhead). Neither cell expresses the neuronal marker Elav. Dorsal is to the top in (A, B) and to the upper left in (C); AL, antennal lobe; AN, antennal nerve. The scale bar is 10 μm. (D) A bar graph showing the results of the BrdU pulse chase experiment. Blue bars represent BrdU-labelled cells around the antennal nerve in brains dissected 6 hours after a 3 hour BrdU pulse (n = 47); orange bars represent BrdU-labelled cells in brains dissected after 4 days (n = 57). Note the increase in the number of BrdU-labelled cells in the 4 day sample.
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Figure 4: Most 5'-bromo-2'-deoxyuridine (BrdU)-positive cells co-stain with Repo and localize around the antennal nerve. (A) Three BrdU-labelled cells in a 3-day-old adult female brain stained for Repo and Elav. One cell can be clearly seen (white arrow) and two others are slightly out of the plane of focus, one more ventro-medial and one more dorso-lateral (white arrowheads). All three cells express Repo but not Elav. Single x-y confocal sections are shown, with insets showing y-z sections; the far right panel shows the merged image. (B) Fourteen percent of BrdU-labelled cells do not express Repo. One such cell (white arrow) is shown here, adjacent to a Repo-positive cell (white arrowhead), in a 10-day-old adult male brain. Single x-y confocal sections are shown, with insets showing y-z sections; the far right panel shows the merged image. (C) Two BrdU- and Repo-positive cells are shown that appear to have divided along the apico-basal axis. The single confocal sections show the more superficially localised cell (white arrow), while x-z and y-z sections (below and to the right, respectively) show the cell lying beneath it (white arrowhead). Neither cell expresses the neuronal marker Elav. Dorsal is to the top in (A, B) and to the upper left in (C); AL, antennal lobe; AN, antennal nerve. The scale bar is 10 μm. (D) A bar graph showing the results of the BrdU pulse chase experiment. Blue bars represent BrdU-labelled cells around the antennal nerve in brains dissected 6 hours after a 3 hour BrdU pulse (n = 47); orange bars represent BrdU-labelled cells in brains dissected after 4 days (n = 57). Note the increase in the number of BrdU-labelled cells in the 4 day sample.

Mentions: To complement the clonal analysis, we fed 5'-bromo-2'-deoxyuridine (BrdU) to adult flies from 1 day after eclosion onwards and dissected brains 3 or 10 days after eclosion. We detected between one and nine BrdU-positive cells per brain; on average, 3.2 ± 0.3 cells in 3-day-old brains (n = 31 brains) and 4.1 ± 0.5 cells in 10-day-old brains (n = 17 brains). Interestingly, these cells localise around the antennal nerve in an area similar to the majority of two- and three- to five-cell MARCM clones (Figure 4A–C; Additional file 3).


Cell proliferation in the Drosophila adult brain revealed by clonal analysis and bromodeoxyuridine labelling.

von Trotha JW, Egger B, Brand AH - Neural Dev (2009)

Most 5'-bromo-2'-deoxyuridine (BrdU)-positive cells co-stain with Repo and localize around the antennal nerve. (A) Three BrdU-labelled cells in a 3-day-old adult female brain stained for Repo and Elav. One cell can be clearly seen (white arrow) and two others are slightly out of the plane of focus, one more ventro-medial and one more dorso-lateral (white arrowheads). All three cells express Repo but not Elav. Single x-y confocal sections are shown, with insets showing y-z sections; the far right panel shows the merged image. (B) Fourteen percent of BrdU-labelled cells do not express Repo. One such cell (white arrow) is shown here, adjacent to a Repo-positive cell (white arrowhead), in a 10-day-old adult male brain. Single x-y confocal sections are shown, with insets showing y-z sections; the far right panel shows the merged image. (C) Two BrdU- and Repo-positive cells are shown that appear to have divided along the apico-basal axis. The single confocal sections show the more superficially localised cell (white arrow), while x-z and y-z sections (below and to the right, respectively) show the cell lying beneath it (white arrowhead). Neither cell expresses the neuronal marker Elav. Dorsal is to the top in (A, B) and to the upper left in (C); AL, antennal lobe; AN, antennal nerve. The scale bar is 10 μm. (D) A bar graph showing the results of the BrdU pulse chase experiment. Blue bars represent BrdU-labelled cells around the antennal nerve in brains dissected 6 hours after a 3 hour BrdU pulse (n = 47); orange bars represent BrdU-labelled cells in brains dissected after 4 days (n = 57). Note the increase in the number of BrdU-labelled cells in the 4 day sample.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
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Figure 4: Most 5'-bromo-2'-deoxyuridine (BrdU)-positive cells co-stain with Repo and localize around the antennal nerve. (A) Three BrdU-labelled cells in a 3-day-old adult female brain stained for Repo and Elav. One cell can be clearly seen (white arrow) and two others are slightly out of the plane of focus, one more ventro-medial and one more dorso-lateral (white arrowheads). All three cells express Repo but not Elav. Single x-y confocal sections are shown, with insets showing y-z sections; the far right panel shows the merged image. (B) Fourteen percent of BrdU-labelled cells do not express Repo. One such cell (white arrow) is shown here, adjacent to a Repo-positive cell (white arrowhead), in a 10-day-old adult male brain. Single x-y confocal sections are shown, with insets showing y-z sections; the far right panel shows the merged image. (C) Two BrdU- and Repo-positive cells are shown that appear to have divided along the apico-basal axis. The single confocal sections show the more superficially localised cell (white arrow), while x-z and y-z sections (below and to the right, respectively) show the cell lying beneath it (white arrowhead). Neither cell expresses the neuronal marker Elav. Dorsal is to the top in (A, B) and to the upper left in (C); AL, antennal lobe; AN, antennal nerve. The scale bar is 10 μm. (D) A bar graph showing the results of the BrdU pulse chase experiment. Blue bars represent BrdU-labelled cells around the antennal nerve in brains dissected 6 hours after a 3 hour BrdU pulse (n = 47); orange bars represent BrdU-labelled cells in brains dissected after 4 days (n = 57). Note the increase in the number of BrdU-labelled cells in the 4 day sample.
Mentions: To complement the clonal analysis, we fed 5'-bromo-2'-deoxyuridine (BrdU) to adult flies from 1 day after eclosion onwards and dissected brains 3 or 10 days after eclosion. We detected between one and nine BrdU-positive cells per brain; on average, 3.2 ± 0.3 cells in 3-day-old brains (n = 31 brains) and 4.1 ± 0.5 cells in 10-day-old brains (n = 17 brains). Interestingly, these cells localise around the antennal nerve in an area similar to the majority of two- and three- to five-cell MARCM clones (Figure 4A–C; Additional file 3).

Bottom Line: Of the BrdU-labelled cells, 86% express the glial gene reversed polarity (repo), and 14% are repo negative.We have observed cell proliferation in the Drosophila adult brain.The dividing cells may be adult stem cells, generating glial and/or non-glial cell types.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Wellcome Trust/Cancer Research UK Gurdon Institute, Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK. j.v.trotha@gurdon.cam.ac.uk

ABSTRACT

Background: The production of new neurons during adulthood and their subsequent integration into a mature central nervous system have been shown to occur in all vertebrate species examined to date. However, the situation in insects is less clear and, in particular, it has been reported that there is no proliferation in the Drosophila adult brain.

Results: We report here, using clonal analysis and 5'-bromo-2'-deoxyuridine (BrdU) labelling, that cell proliferation does occur in the Drosophila adult brain. The majority of clones cluster on the ventrolateral side of the antennal lobes, as do the BrdU-positive cells. Of the BrdU-labelled cells, 86% express the glial gene reversed polarity (repo), and 14% are repo negative.

Conclusion: We have observed cell proliferation in the Drosophila adult brain. The dividing cells may be adult stem cells, generating glial and/or non-glial cell types.

Show MeSH