Genetic analysis of axon pattern formation in the embryonic CNS ofDrosophila

1997 ◽  
Vol 3 (2-3) ◽  
pp. 165-174 ◽  
Author(s):  
Christian Klämbt ◽  
Kristina Schimmelpfeng ◽  
Thomas Hummel
Development ◽  
2000 ◽  
Vol 127 (15) ◽  
pp. 3197-3204 ◽  
Author(s):  
K. Koizumi ◽  
M. Sugiyama ◽  
H. Fukuda

For the genetic analysis of molecular mechanisms underlying temporal and spatial regulation of vascular pattern formation, we isolated mutants of Arabidopsis thaliana that are impaired in vascular patterning. Microscopic examination of the cotyledonary venation of 3,400 M(3) lines led to the identification of 12 mutant lines. Genetic analysis of 8 of these mutant lines indicated that vein pattern formation in these lines resulted from monogenic recessive mutations in 7 different genes, designated VAN1 through VAN7. Mutations in VAN1 through VAN6 genes caused fragmentation (disconnection or partial loss) of lateral veins of the cotyledon and tertiary veins of the rosette leaf whereas they were less injurious to the formation of major veins. Detailed characterization of the van3 mutant using pAthb8::GUS and pTED3::GUS, as molecular markers for the early stage of vascular tissue formation showed that the provascular tissue of the cotyledonary lateral veins was differentiated in fragments during late embryogenesis. These phenotypes of the van mutants are discussed in relation to the auxin signal flow canalization hypothesis and the diffusion-reaction prepattern hypothesis, with the fragility of the continuity in the minor vein formation favoring the latter hypothesis.


Development ◽  
1983 ◽  
Vol 78 (1) ◽  
pp. 141-168 ◽  
Author(s):  
Jun Takano ◽  
Tsutomu Sugiyama

Morphogenetic potentials involved in head formation were examined in a hydra strain (L4) which has a very low budding rate and a large polyp size, and the results were compared to those of the normal strain (105). Hydra tissue has two types of antagonistic morphogenetic potentials which are thought to play important roles in head structure formation: the head-activation potential and the head-inhibition potential. Lateral tissue transplantation (Webster & Wolpert, 1966) was used to compare the levels of the two potentials in L4 and the normal strain. It was found that the intact polyp of L4 has a nearly normal or slightly lower head-activation potential but a significantly higher head-inhibition potential than the normal strain. During the course of regeneration after head amputation, the levels of the two potentials in L4 changed in significantly different patterns from those in the normal strain. These abnormalities of the two potentials may be responsible for the developmental and morphological abnormalities in L4. The significance of these observations is discussed in light of the current hydra pattern formation models (Wolpert, Hornchurch & Clarke, 1974; Meinhardt & Gierer, 1974).


Development ◽  
1994 ◽  
Vol 1994 (Supplement) ◽  
pp. 193-199
Author(s):  
Diethard Tautz ◽  
Markus Friedrich ◽  
Reinhard Schröder

The systematic genetic analysis of Drosophila development has provided us with a deep insight into the molecular pathways of early embryogenesis. The question arises now whether these insights can serve as a more general paradigm of early development, or whether they apply only to advanced insect orders. Though it is too early to give a definitive answer to this question, we suggest that there is currently no firm reason to believe that the molecular mechanisms that were elucidated in Drosophila may not also apply to other forms of insect embryogenesis. Thus, many of the Drosophila genes involved in early pattern formation may have comparable functions in other insects and possibly throughout the arthropods.


Development ◽  
1986 ◽  
Vol 97 (Supplement) ◽  
pp. 169-179
Author(s):  
Hans Georg Frohnhöfer ◽  
Ruth Lehmann ◽  
Christiane Nüsslein-Volhard

The establishment of pattern and polarity in the insect egg has been studied intensively using a variety of experimental approaches. Drosophila, while the system of choice for genetic analysis of pattern formation has been rather neglected as an experimental organism and species with longer developmental time and larger eggs were preferred in classical studies. Among the dipteran insects, midges such as Chironomous and Smittia with their transparent chorion and synchronous development were found more rewarding. The classical methods of ligation, puncture, transplantation, destruction or removal of material, and centrifugation were applied to eggs of a variety of insect species. Although the degree of response to experimental manipulation was found to be widely different, there were similarities in the type of abnormal patterns produced by the various treatments which suggested more general conclusions:- the anteroposterior pattern is probably controlled by two centres of activity, localized at the anterior and posterior egg pole respectively, with a long-range effect on the entire egg axis (reviewed by Sander, 1976).


1997 ◽  
Vol 61 (6) ◽  
pp. 491-496 ◽  
Author(s):  
K. HIDAKA ◽  
I. IUCHI ◽  
M. TOMITA ◽  
Y. WATANABE ◽  
Y. MINATOGAWA ◽  
...  

Pathology ◽  
2003 ◽  
Vol 35 (2) ◽  
pp. 141-144 ◽  
Author(s):  
Hiroya Kato ◽  
Sukenari Koyabu ◽  
Shigenori Aoki ◽  
Takuya Tamai ◽  
Masahiro Sugawa ◽  
...  

1993 ◽  
Vol 3 (6) ◽  
pp. 865-889 ◽  
Author(s):  
Norbert Schwenk ◽  
Hans Wolfgang Spiess
Keyword(s):  

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