Early embryonic development of the central nervous system in the Australian crayfish and the Marbled crayfish (Marmorkrebs)
- 382 Downloads
This study sets out to provide a systematic analysis of the development of the primordial central nervous system (CNS) in embryos of two decapod crustaceans, the Australian crayfish Cherax destructor (Malacostraca, Decapoda, Astacida) and the parthenogenetic Marbled crayfish (Marmorkrebs, Malacostraca, Decapoda, Astacida) by histochemical labelling with phalloidin, a general marker for actin. One goal of our study was to examine the neurogenesis in these two organisms with a higher temporal resolution than previous studies did. The second goal was to explore if there are any developmental differences between the parthenogenetic Marmorkrebs and the sexually reproducing Australian crayfish. We found that in the embryos of both species the sequence of neurogenetic events and the architecture of the embryonic CNS are identical. The naupliar neuromeres proto-, deuto-, tritocerebrum, and the mandibular neuromeres emerge simultaneously. After this “naupliar brain” has formed, there is a certain time lag before the maxilla one primordium develops and before the more caudal neuromeres follow sequentially in the characteristic anterior–posterior gradient. Because the malacostracan egg-nauplius represents a re-capitulation of a conserved ancestral information, which is expressed during development, we speculate that the naupliar brain also conserves an ancestral piece of information on how the brain architecture of an early crustacean or even arthropod ancestor may have looked like. Furthermore, we compare the architecture of the embryonic crayfish CNS to that of the brain and thoracic neuromeres in insects and discuss the similarities and differences that we found against an evolutionary background.
KeywordsArthropoda Axogenesis Evolution Neurogenesis Naupliar brain
We wish to thank E. Buchner (Würzburg) for providing the SYNORF1 antibody. B. Beltz is gratefully acknowledged for providing access to a confocal miscroscope and D. C. Sandeman for encouragement and critical discussion of the work on C. destructor. This study was supported by DFG grant HA 2540/5. S. H. is a Heisenberg fellow of the DFG. The developmental work on C. destructor was funded by an Australian Research Council Grant No. A096008682 to D. C. Sandeman.
- Dumont JPC, Wine JJ (1987) The telson flexor neuromuscular system of the crayfish. II. Segment-specific differences in connectivity between premotor neurones and the motor giants. J Exp Biol 127:279–294Google Scholar
- Fanenbruck M (2003) Die Anatomie des Kopfes und des cephalen Skelett-Muskelsystems der Crustacea, Myriapoda und Hexapoda: Ein Beitrag zum phylogenetischen System der Mandibulata und zur Kenntnis der Herkunft der Remipedia und Tracheata. Ph.D. Thesis, Ruhr-Universität Bochum (Germany)http://www-brs.ub.ruhr-uni-bochum.de/netahtml/HSS/Diss/FanenbruckMartin/
- Harzsch S (2002) From stem cell to structure: neurogenesis in the CNS of decapod crustaceans. In: Wiese K (ed) The crustacean nervous system. Springer, Berlin Heidelberg New York, pp 417–432Google Scholar
- Kilman V, Fénelon VS, Richards KS, Thirumalai V, Meyrand P, Marder E (1999) Sequential developmental acquisition of cotransmitters in identified sensory neurons of the stomatogastric nervous system of the lobsters, Homarus americanus and Homarus gammarus. J Comp Neurol 408:318–334PubMedCrossRefGoogle Scholar
- Meier T, Reichert H (1990) Neuronal development in the crustacean nervous system studied by neuron-specific antibody labelling. In: Kennedy K (ed) Frontiers in crustacean neuroscience. Birkhauser, Basel, pp 523–529Google Scholar
- Sandeman RE, Sandeman DC (1990) Development and identified neural systems in the crayfish brain. In: Kennedy K (ed) Frontiers in crustacean neuroscience. Birkhauser, Basel, pp 498–508Google Scholar
- Scholtz G (1995b) Head segmentation in Crustacea—an immunocytochemical study. Zoology 98:104–114Google Scholar
- Walossek D (1999) On the Cambrian diversity of Crustacea. In Schram FR, von Vaupel Klein JC (eds) Crustaceans and the biodiversity crisis, proceedings of the Fourth International Crustacean Congress. Kononklijke Brill NV, Leiden, pp 3–27Google Scholar
- Whitington PM (2004) The development of the crustacean nervous system. In: Scholtz G (ed) Evolutionary developmental biology of Crustacea, Crustacean issues vol. 15. AA Balkema, Netherlands, pp 135–167Google Scholar
- Zehnder H (1934a) Über die Embryonalentwicklung des Fluβkrebses. Teil 1: Die ersten Stadien der Embryonalentwicklung von Astacus fluviatilis (Rond.) L. und Astacus torrentium (Schrank) vom unbefruchteten Ei bis zur Gastrulation. Acta Zool 15:1–83Google Scholar