Evolutionary developmental biology focuses heavily on the constructive evolution of body plan components, but there are many instances such as parasitism, cave adaptation, or postembryonic growth rate optimization where evolutionary regression is of adaptive value. This is particularly true in the nervous system because of its massive energy costs. However, comparatively little effort has thus far been made to understand the evolutionary developmental trajectories of adaptive nervous system reduction. This review focuses on the organization and evolution of the Drosophila larval brain, which represents an exceptional example of miniaturization, most dramatically in the visual system. It is specifically discussed how the dependency of outer optic lobe development on retinal innervation can be assumed to have facilitated a first evolutionary phase of larval visual system reduction. Afferent input-contingent development of neu- ral compartments very likely plays a widespread role in adaptive brain evolution. Understanding the complete deconstruction of the larval optic neuropiles in Drosophila awaits expanded comparative analysis but has the promise to inform about further developmental trajectories and mechanisms underlying regressive evolution of the brain.

Keywords:
Drosophila, Diptera, Neuroanatomy, Comparative biology, Brain reduction, Regressive evolution, Evolution of development, Larva, Cave adaptation, Miniaturization
1.
Anderson H (1978a): Postembryonic development of the visual system of the locust, Schistocerca gregaria. 2. An experimental investigation of the formation of the lamina-retina projection. J Embryol Exp Morphol 46:147–170.
2.
Anderson H (1978b): Postembryonic development of the visual system of the locust, Schistocerca gregaria. 1. Pattern of growth and developmental interactions in the retina and optic lobe. J Embryol Exp Morphol 45:55–83.
3.
Beutel RG, Hörnschemeyer T (2002): Larval morphology and phylogenetic position of Micromalthus debilis LeConte (Coleoptera: Micromalthidae). Syst Entomol 27:169–190.
4.
Beutel RG, Pohl H, Hünfeld F (2005): Strepsipteran brains and effects of miniaturization (Insecta). Arthropod Struct Dev 34:301–313.
5.
Bolwig N (1946): Senses and sense organs of the anterior end of the house fly larvae. Vidensk Med Dansk Naturh Foren 109:81–217.
6.
Boyan G, Wiliams L (2002): A single cell analysis of engrailed expression in the early embryonic brain of the grasshopper Schistocerca gregaria: ontogeny and identity of the secondary headspot. Arthropod Struct Dev 30:207–218.
7.
Brandt E (1880): Vergleichend-anatomische Untersuchungen über das Nervensystem der Zweiflügler (Diptera). St Petersburg, Horae Societatis Entomologicae Rossicae, vol 15, pp 84–101.
8.
Brown P, Sutikna T, Morwood M, Soejono R (2004): A new small-bodied hominin from the late pleistocene of Flores, Indonesia. Nature 431:1055–1061.
9.
Buschbeck E, Friedrich M (2008): Evolution of insect eyes: tales of ancient heritage, deconstruction, reconstruction, remodeling and recycling. Evol Educ Outreach 1:448–462.
10.
Campos AR, Lee KJ, Steller H (1995): Establishment of neuronal connectivity during development of the Drosophila larval visual system. J Neurobiol 28:313–329.
11.
Chang T, Mazotta J, Dumstrei K, Dumitrescu A, Hartenstein V (2001): Dpp and Hh signaling in the Drosophila embryonic eye field. Development 128:4691–4704.
12.
Cherniak C (1994): Component placement optimization in the brain. J Neurosci 14:2418.
13.
Cherniak C, Mokhtarzada Z, Rodriguez-Esteban R, Changizi K (2004): Global optimization of cerebral cortex layout. Proc Natl Acad Sci USA 101:1081–1086.
14.
Christiansen K (2005): Morphological adaptations; in Culver DC, White WB (eds): Encyclopedia of Caves. San Diego, Academic Press, pp 386–397.
15.
Clandinin TR, Feldheim DA (2009): Making a visual map: mechanisms and molecules. Curr Opin Neurobiol 19:174–180.
16.
Clarke JB, Sokoloff L (1999): Circulation and energy metabolism of the brain; in Siegel GJ, Agranoff BW, Albers RW, Fisher SK, Uhler MD (eds): Basic Neurochemistry, ed 6. Philadelphia, Lippincott-Raven, pp 637–669.
17.
Culver D, Pipan T (2009): The Biology of Caves and Other Subterranean Habitats. Oxford, Oxford University Press.
18.
Culver DC, Wilkens H (2000): Critical review of the relevant theories of the evolution of subterranean animals; in Wilkens H, Culver DC, Humphries WF (eds): Ecosystems of the World: Subterranean Animals. Amsterdam, Elsevier.
19.
Culver DC, White WB (2004): Diversity patterns in Europe: in Culver DC, White WB (eds): Encyclopedia of Caves. San Diego, Academic Press, p 197.
20.
Dakubo G (2003): Retinal ganglion cell-derived sonic hedgehog signaling is required for optic disc and stalk neuroepithelial cell development. Development 130:2967–2980.
21.
Darwin C (1859): On the Origin of Species by means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. London, John Murray.
22.
Dechmann DKN, Safi K (2009): Comparative studies of brain evolution: a critical insight from the Chiroptera. Biol Rev Camb Philos Soc 84:161–172.
23.
Dong Y, Dinan L, Friedrich M (2003): The effect of manipulating ecdysteroid signaling on embryonic eye development in the locust Schistocercaamericana. Dev Genes Evol 213:587–600.
24.
Dong Y, Friedrich M (2005): Comparative analysis of wingless patterning in the embryonic grasshopper eye. Dev Genes Evol 215:177–197.
25.
Dong Y, Friedrich M (2010): Enforcing biphasic eye development in a directly developing insect by transient knockdown of single eye selector genes. J Exp Zool B Mol Dev Evol 314B:104–114.
26.
Emery DJ, Bell KA, Chapco W, Steeves JD (1984): Characterization of a reduced-eye mutant of the grasshopper, Melanoplus sanguinipes. J Embryol Exp Morphol 83:189–211.
27.
Faille A, Ribera I, Deharveng L, Bourdeau C, Garnery L, Queinnec E, Deuve T (2010): A molecular phylogeny shows the single origin of the Pyrenean subterranean Trechini ground beetles (Coleoptera: Carabidae). Mol Phylogenet Evol 54:97–106.
28.
Fischbach K (1983): Neural cell types surviving congenital sensory deprivation in the optic lobes of Drosophilamelanogaster. Dev Biol 95:1–18.
29.
Friedrich M (2006): Continuity versus split and reconstitution: exploring the molecular developmental corollaries of insect eye primordium evolution. Dev Biol 299:310–329.
30.
Friedrich M (2008): Opsins and cell fate in the Drosophila Bolwig organ: tricky lessons in homology inference. Bioessays 30:980–993.
31.
Gerber B, Stocker RF (2007): The Drosophila larva as a model for studying chemosensation and chemosensory learning: a review. Chem Senses 32:65.
32.
Ghaffar H, Larsen JR, Booth GM, Perkes R (1984): General morphology of the brain of the blind cave beetle, Neaphaenops tellkampfii Erichson (Coleoptera: Carabidae). Int J Insect Morphol Embryol 13:357–371.
33.
Gilbert C (1994): Form and function of stemmata in larvae of holometabolous insects. Annu Rev Entomol 39:323–349.
34.
Gislen T (1948): Aerial plankton and its conditions of life. Biol Rev Camb Philos Soc 23:109–126.
35.
Grebennikov VV (2008): How small you can go: factors limiting body miniaturization in winged insects with a review of the pantropical genus Discheramocephalus and description of six new species of the smallest beetles (Pterygota: Coleoptera: Ptiliidae). Eur J Entomol 105:313–327.
36.
Grebennikov VV, Beutel RG (2002): Morphology of the minute larva of Ptinella tenella, with special reference to effects of miniaturisation and the systematic position of Ptiliidae (Coleoptera: Staphylinoidea). Arthropod Struct Dev 31:157–172.
37.
Hassan J, Iyengar B, Scantlebury N, Rodriguez Moncalvo V, Campos AR (2005): Photic input pathways that mediate the Drosophila larval response to light and circadian rhythmicity are developmentally related but functionally distinct. J Comp Neurol 481:266–275.
38.
Helfrich-Förster C, Edwards T, Yasuyama K, Wisotzki B, Schneuwly S, Stanewsky R, Meinertzhagen IA, Hofbauer A (2002): The extraretinal eyelet of Drosophila: development, ultrastructure, and putative circadian function. J Neurosci 22:9255–9266.
39.
Heming BS (1982): Structure and development of the larval visual system in embryos of Lytta viridana LeConte (Coleoptera, Meloidae). J Morphol 172:23–43.
40.
Hinke W (1961): Das relative postembryonale Wachstum der Hirnteile von Culex pipiens,Drosophilamelanogaster und Drosophila- mutanten. Zoomorphology 50:81–118.
41.
Hobbs HH 3rd (2004): Diversity patterns in the United States; in Culver DC, White WB (eds): Encyclopedia of Caves. San Diego, Academic Press, pp 171–183.
42.
Howarth FG (1983): Ecology of cave arthropods. Annu Rev Entomol 28:365–389.
43.
Howard J, Blakeslee B, Laughlin S (1987): The intracellular pupil mechanism and photoreceptor signal: noise ratios in the fly Lucilia cuprina. Proc R Soc Lond B Biol Sci 231:415.
44.
Huang Z, Kunes S (1996): Hedgehog, transmitted along retinal axons, triggers neurogenesis in the developing visual centers of the Drosophila brain. Cell 86:411–422.
45.
Huang Z, Kunes S (1998): Signals transmitted along retinal axons in Drosophila: Hedgehog signal reception and the cell circuitry of lamina cartridge assembly. Development 125:3753–3764.
46.
Huang Z, Shilo BZ, Kunes S (1998): A retinal axon fascicle uses Spitz, an EGF receptor ligand, to construct a synaptic cartridge in the brain of Drosophila. Cell 95:693–703.
47.
Inoue Y, Miyawaki K, Terasawa T, Matsushima K, Shinmyo Y, Niwa N, Mito T, Ohuchi H, Noji S (2004): Expression patterns of dachshund during head development of Gryllus bimaculatus (cricket). Gene Expr Patterns 4:725–731.
48.
Iyengar BG, Chou CJ, Sharma A, Atwood HL (2006): Modular neuropile organization in the Drosophila larval brain facilitates identification and mapping of central neurons. J Comp Neurol 499:583–602.
49.
Jefferis GS, Marin EC, Watts RJ, Luo L (2002): Development of neuronal connectivity in Drosophila antennal lobes and mushroom bodies. Curr Opin Neurobiol 12:80–86.
50.
Jeffery WR (2001): Cavefish as a model system in evolutionary developmental biology. Dev Biol 231:1–12.
51.
Jeffery WR (2009): Regressive evolution in Astyanax cavefish. Annu Rev Genet 43:25–47.
52.
Julian GE, Gronenberg W (2000): Reduction of brain volume correlates with behavioral changes in queen ants. Brain Behav Evol 60:152–164.
53.
Kaneko M, Hall JC (2000): Neuroanatomy of cells expressing clock genes in Drosophila: transgenic manipulation of the period and timeless genes to mark the perikarya of circadian pacemaker neurons and their projections. J Comp Neurol 422:66–94.
54.
Kaphingst K, Kunes S (1994): Pattern formation in the visual centers of the Drosophila brain: wingless acts via decapentaplegic to specify the dorsoventral axis. Cell 78:437–448.
55.
Kirkpatrick TW (1937): Colour vision in the triungulin larva of a strepsipteron (Corixenos antestiae Blair). R Entomol Soc Lond Proc Ser A 12:40–44.
56.
Lai K, Kaspar BK, Gage FH, Schaffer DV (2002): Sonic hedgehog regulates adult neural progenitor proliferation in vitro and in vivo. Nat Neurosci 6:21–27.
57.
Lamprecht G, Weber F (1983): Activity control in the eyeless carabid beetle Typhlochoromus stolzi, an inhabitant of a superficial underground compartment. Mem Biospeologie 10:377–383.
58.
Lamprecht G, Weber F (1992): Spontaneous locomotion behaviour in cavernicolous animals: the regression of the endogenous circadian system; in Camacho AI (ed): The Natural History of Biospeleology – Monographs. Madrid, Museo Nacional de Ciencias Naturales, pp 225–262.
59.
Lass M (1905): Beiträge zur Kenntnis des histologisch-anatomischen Baues des weiblichen Hundeflohes (Pulex canis Dugess, Pulex serraticeps Taschenberg). Z Wiss Zool 79:73–131.
60.
Laughlin SB, van Steveninck RR, Anderson JC (1998): The metabolic cost of neural information. Nat Neurosci 1:36–41.
61.
Leys R, Watts C (2008): Systematics and evolution of the Australian subterranean hydroporine diving beetles (Dytiscidae), with notes on Carabhydrus. Invertebr Syst 22:217–225.
62.
Leys R, Watts C, Cooper S, Humphreys W (2003): Evolution of subterranean diving beetles (Coleoptera: Dytiscidae, Hydroporini, Bidessini): in the arid zone of Australia. Evolution 57:2819–2834.
63.
Lilly M, Carlson J (1990): Smellblind: a gene required for Drosophila olfaction. Genetics 124:293.
64.
Liu Z, Yang X, Dong Y, Friedrich M (2006): Tracking down the ‘head blob’: comparative analysis of wingless expression in the embryonic insect procephalon reveals progressive reduction of ocular segment patterning in higher insects. Arthropod Struct Dev 35:341–356.
65.
Malpel S, Klarsfeld A, Rouyer F (2002): Larval optic nerve and adult extra-retinal photoreceptors sequentially associate with clock neurons during Drosophila brain development. Development 129:1443–1453.
66.
Mazzoni EO, Desplan C, Blau J (2005): Circadian pacemaker neurons transmit and modulate visual information to control a rapid behavioral response. Neuron 45:293–300.
67.
Meinertzhagen IA, Hanson TH (1993): The development of the optic lobe. in Bate M, Martinez Arias A (eds): The Development of Drosophilamelanogaster. Cold Spring Harbor, Cold Spring Harbor Laboratory Press, vol 2, pp 1363–1491.
68.
Menuet A, Alunni A, Joly JS, Jeffery WR, Retaux S (2007): Expanded expression of sonic hedgehog in Astyanax cavefish: multiple consequences on forebrain development and evolution. Development 134:845–855.
69.
Melzer RR (1994a): Optic lobes of the larval and imaginal scorpionfly Panorpa vulgaris (Mecoptera, Panorpidae): a neuroanatomical study of neuropil organization, retinula axons, and lamina monopolar cells. Cell Tissue Res 275:283–290.
70.
Melzer RR (1994b): Die Evolution des Larvalauges bei den Diptera: Stemma-axone und Anordnung der Elemente bei eu-, hemi- und acephalen Larven. Zool Beitr N F 35:27–46.
71.
Melzer RR, Paulus HF (1989): Evolutionswege zum Larvalauge der Insekten – die Stemmata der höheren Dipteren und ihre Abwandlung zum Bolwig-Organ. Z Zool Syst Evolutionsforsch 27:200–245.
72.
Melzer RR, Paulus HF, Kristensen NP (1994): The larval eye of nannochoristid scorpionflies (Insecta, Mecoptera). Acta Zool 75:201–208.
73.
Merry JW, Kemp DJ, Rutowski RL (2011): Variation in compound eye structure: effects of diet and family. Evolution, in press.
74.
Meyerowitz EM, Kankel DR (1978): A genetic analysis of visual system development in Drosophila melanogaster. Dev Biol 62:112–142.
75.
Mitchell RW, Russell WH, Elliott WR (1977): Mexican Eyeless Characin Fishes, Genus Astyanax: Environment, Distribution, and Evolution. Lubbock, Texas Tech Press.
76.
Monsma SA, Booker R (1996): Genesis of the adult retina and outer optic lobes of the moth, Manduca sexta. 1. Patterns of proliferation and cell death. J Comp Neurol 367:10–20.
77.
Mukhopadhyay M, Campos AR (1995): The larval optic nerve is required for the development of an identified serotonergic arborization in Drosophilamelanogaster. Dev Biol 169:629–643.
78.
Nassif C, Noveen A, Hartenstein V (2003): Early development of the Drosophila brain. 3. The pattern of neuropile founder tracts during the larval period. J Comp Neurol 455:417–434.
79.
Niven JE (2005): Brain evolution: getting better all the time? Curr Biol 15:R624–R626.
80.
Niven JE (2008): Evolution: convergent eye losses in fishy circumstances. Curr Biol 18:R27–R29.
81.
Niven JE, Anderson JC, Laughlin SB (2007): Fly photoreceptors demonstrate energy-information trade-offs in neural coding. PLoS Biol 5:e116.
82.
Niven J, Graham C, Burrows M (2008): Diversity and evolution of the insect ventral nerve cord. Annu Rev Entomol 53:253–271.
83.
Niven JE, Laughlin SB (2008): Energy limitation as a selective pressure on the evolution of sensory systems. J Exp Biol 211:1792–1804.
84.
Niven J, Vähäsöyrinki M, Juusola M (2003): Shaker K(+)-channels are predicted to reduce the metabolic cost of neural information in Drosophila photoreceptors. Proc Biol Sci 270:S58–S61.
85.
Oakley TH, Plachetzki DC, Rivera AS (2007): Furcation, field-splitting, and the evolutionary origins of novelty in arthropod photoreceptors. Arthropod Struct Dev 36:386–400.
86.
Oland LA, Orr G, Tolbert LP (1990): Construction of a protoglomerular template by olfactory axons initiates the formation of olfactory glomeruli in the insect brain. J Neurosci 10:2096–2112.
87.
Oland LA, Tolbert LP (1996): Multiple factors shape development of olfactory glomeruli: insights from an insect model system. J Neurobiol 30:92–109.
88.
Ott S, Rogers S (2010): Gregarious desert locusts have substantially larger brains with altered proportions compared with the solitarious phase. Proc Biol Sci 277:3087–3096.
89.
Peck SB (1990): Eyeless arthropods of the Galapagos Islands, Ecuador: composition and origin of the cryptozoic fauna of a young, tropical, oceanic archipelago. Biotropica 22:366–381.
90.
Peck SB (1998): Phylogeny and evolution of subterranean and endogean Cholevidae (=Leiodidae, Cholevinae): an introduction; in Giachino PM, Peck SB (eds): Phylogeny and Evolution of Subterranean and Endogean Cholevidae (=Leiodidae, Cholevinae): Proceedings of a Symposium (30 August, 1996, Florence, Italy), XX International Congress of Entomology. Torino, Atti del Museo Regionale de Scienze Naturali.
91.
Pereanu W, Kumar A, Jennett A, Reichert H, Hartenstein V (2010): Development-based compartmentalization of the Drosophila central brain. J Comp Neurol 518:2996–3023.
92.
Pohl H, Beutel RG (2008): The evolution of Strepsiptera (Hexapoda). Zoology (Jena) 111:318–338.
93.
Polilov A (2005): Anatomy of the feather-winged beetles Acrotrichis montandoni and Ptilium myrmecophilum (Coleoptera, Ptiliidae). Entomol Rev 85:467–475.
94.
Power ME (1943): The effect of reduction in numbers of ommatidia upon the brain of Drosophilamelanogaster. J Exp Zool 94:33–71.
95.
Protas M, Conrad M, Gross JB, Tabin C, Borowsky R (2007): Regressive evolution in the Mexican cave tetra, Astyanax mexicanus. Curr Biol 17:452–454.
96.
Renn SC, Armstrong JD, Yang M, Wang Z, An X, Kaiser K, Taghert PH (1999): Genetic analysis of the Drosophila ellipsoid body neuropil: organization and development of the central complex. J Neurobiol 41:189–207.
97.
Ribera I, Fresneda J, Bucur R, Izquierdo A, Vogler A, Salgado J, Cieslak A (2010): Ancient origin of a Western Mediterranean radiation of subterranean beetles. BMC Evol Biol 10:29.
98.
Rodriguez Moncalvo VG, Campos AR (2005): Genetic dissection of trophic interactions in the larval optic neuropil of Drosophilamelanogaster. Dev Biol 286:549–558.
99.
Roonwal ML (1936): Studies on the embryology of the African migratory locust, Locusta migratoria migratorioides Reiche and Frm. (Orthoptera, Acrididae). 2. Organogeny. Philos Trans R Soc Lond B 227:175–244.
100.
Safi K, Seid M, Dechmann D (2005): Bigger is not always better: when brains get smaller. Biol Lett 1:283–286.
101.
Sawin ME, Sokolowski MB, Campos AR (1995): Characterization and genetic analysis of Drosophilamelanogaster photobehavior during larval development. J Neurogenet 10:119–135.
102.
Sbita SJ, Morgan RC, Buschbeck EK (2007): Eye and optic lobe metamorphosis in the sunburst diving beetle, Thermonectus marmoratus (Coleoptera: Dytiscidae). Arthropod Struct Dev 36:449–462.
103.
Seid MA, Castillo A, Wcislo WT (2011): The allometry of brain miniaturization in ants. Brain Behav Evol 77:5–13.
104.
Seidel C, Bicker G (2002): Developmental expression of nitric oxide/cyclic G;P signaling pathways in the brain of the embryonic grasshopper. Brain Res Dev Brain Res 138:71–79.
105.
Selleck SB, Gonzales C, Glover DM, White K (2002): Regulation of the G1-S transition in postembryonic neuronal precursors by axon ingrowth. Nature 355:253–255.
106.
Shiga S, Numata H, Yoshioka E (1999): Localization of the photoreceptor and pacemaker for the circadian activity rhythm in the band-legged ground cricket, Dianemobius nigrofasciatus. Zoolog Sci 16:193–201.
107.
Smith A, Seid M, Jimenez L, Wcislo W (2010): Socially induced brain development in a facultatively eusocial sweat bee Megalopta genalis (Halictidae). Proc Biol Sci 277:2157–2163.
108.
Sprecher SG, Desplan C (2008): Switch of rhodopsin expression in terminally differentiated Drosophila sensory neurons. Nature 454:533–537.
109.
Sprecher SG, Pichaud F, Desplan C (2007): Adult and larval photoreceptors use different mechanisms to specify the same rhodopsin fates. Genes Dev 21:2182–2195.
110.
Stocker RF (1994): The organization of the chemosensory system in Drosophilamelanogaster: a review. Cell Tissue Res 275:3.
111.
Strecker U, Faundez VH, Wilkens H (2004): Phylogeography of surface and cave Astyanax (Teleostei): from Central and North America based on cytochrome b sequence data. Mol Phylogenet Evol 33:469–481.
112.
Tan S, Amos W, Laughlin SB (2005): Captivity selects for smaller eyes. Curr Biol 15:R540.
113.
Tix S, Minden JS, Technau GM (1989): Pre-existing neuronal pathways in the developing optic lobes of Drosophila. Development 105:739–746.
114.
Toh Y, Mizutani A (1994): Structure of the visual-system of the larva of the tiger beetle (Cicindela chinensis). Cell Tissue Res 278:125–134.
115.
Traiffort E, Moya KL, Faure H, Hässig R, Ruat M (2001): High expression and anterograde axonal transport of aminoterminal sonic hedgehog in the adult hamster brain. Eur J Neurosci 14:839–850.
116.
Truman JW, Riddiford LM (1999): The origins of insect metamorphosis. Nature 401:447–452.
117.
Truman JW, Riddiford LM (2002): Endocrine insights into the evolution of metamorphosis in insects. Annu Rev Entomol 47:467–500.
118.
Veleri S, Rieger D, Helfrich-Forster C, Stanewsky R (2007): Hofbauer-Buchner eyelet affects circadian photosensitivity and coordinates TIM and PER expression in Drosophila clock neurons. J Biol Rhythms 22:29–42.
119.
Voneida TJ, Sligar CM (1976): A comparative neuroanatomic study of retinal projections in two fishes: Astyanax hubbsi (the blind cave fish), and Astyanax mexicanus. J Comp Neurol 165:89–105.
120.
Weston EM, Lister AM (2009): Insular dwarfism in hippos and a model for brain size reduction in Homo floresiensis. Nature 459:85–88.
121.
Wiegmann BM, Trautwein MD, Winkler IS, Barr NW, Kim JW, Lambkin C, Bertone MA, Cassel BK, Bayless KM, Heimberg AM, Wheeler BM, Peterson KJ, Pape T, Sinclair BJ, Skevington JH, Blagoderovir V, Caravas J, Kutty SN, Schmidt-Ott U, Kampmeier GE, Thompson FC, Grimaldi DA, Beckenbach AT, Courtney GW, Friedrich M, Meier R, Yeates DK (2011): Episodic radiations in the fly tree of life. Proc Natl Acad Sci USA 108:5690–5695.
122.
Xiang Y, Yuan Q, Vogt N, Looger L, Jan L, Jan Y (2010): Light-avoidance-mediating photoreceptors tile the Drosophila larval body wall. Nature 468:921–926.
123.
Yamamoto Y, Jeffery WR (2000): Central role for the lens in cave fish eye degeneration. Science 289:631–633.
124.
Younossi-Hartenstein A, Salvaterra PM, Hartenstein V (2003): Early development of the Drosophila brain: 4. Larval neuropile compartments defined by glial septa. J Comp Neurol 455:435–450.
125.
Zacharias D, Williams J, Meier T, Reichert H (1993): Neurogenesis in the insect brain – cellular identification and molecular characterization of brain neuroblasts in the grasshopper embryo. Development 118:941–955.
© 2011 S. Karger AG, Basel
2011
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.