scholarly journals Manipulating the anteroposterior pattern of the Drosophila embryo

Development ◽  
1986 ◽  
Vol 97 (Supplement) ◽  
pp. 169-179
Author(s):  
Hans Georg Frohnhöfer ◽  
Ruth Lehmann ◽  
Christiane Nüsslein-Volhard
Keyword(s):  
Pattern Formation ◽  
Genetic Analysis ◽  
Developmental Time ◽  
Experimental Manipulation ◽  
Drosophila Embryo ◽  
Range Effect ◽  
Classical Studies ◽  
Experimental Organism ◽  
Synchronous Development ◽  
Experimental Approaches

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).

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
Keyword(s):  
Pattern Formation ◽  
Genetic Analysis ◽  
Embryonic Cns

scholarly journals GENETIC ANALYSIS OF NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER IN JAPAN. II. THE MEASUREMENT OF FITNESS AND FITNESS COMPONENTS IN HOMOZYGOUS LINES

Genetics ◽  
1984 ◽  
Vol 108 (1) ◽  
pp. 213-221 ◽  
Author(s):  
Tsuneyuki Yamazaki ◽  
Yasuko Hirose
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
Natural Population ◽  
Natural Populations ◽  
Distribution Patterns ◽  
Developmental Time ◽  
Fitness Components ◽  
Isogenic Lines ◽  
Genetic Structures

ABSTRACT Fifty lethal-free, sterility-free isogenic lines of Drosophila melanogaster that were randomly sampled from a natural population were tested for net fitness and other components of fitness by competition with D. hydei. Larval viability and developmental time were also measured using the balanced marker method. Distribution patterns of these fitness components were similar, but correlation between the fitness components varied depending on the combinations used. The highest correlations were obtained between net fitness and productivity (rp = 0.6987, rg = 0.9269). The correlation between net fitness and total larval viability was much lower (rp = 0.1473 and rg = 0.2171). These results indicate that measuring net fitness, not just a component of fitness, is necessary for the good understanding of the genetic structures of natural populations.

A series of novel mutants of Arabidopsis thaliana that are defective in the formation of continuous vascular network: calling the auxin signal flow canalization hypothesis into question

Development ◽  
2000 ◽  
Vol 127 (15) ◽  
pp. 3197-3204 ◽  
Author(s):  
K. Koizumi ◽  
M. Sugiyama ◽  
H. Fukuda
Keyword(s):  
Arabidopsis Thaliana ◽  
Pattern Formation ◽  
Genetic Analysis ◽  
Molecular Mechanisms ◽  
Vascular Tissue ◽  
Early Stage ◽  
Diffusion Reaction ◽  
Signal Flow ◽  
Vein Formation ◽  
Mutant Lines

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.

scholarly journals Pattern Formation by Graded and Uniform Signals in the Early Drosophila Embryo

2012 ◽  
Vol 102 (3) ◽  
pp. 427-433 ◽  
Author(s):  
Jitendra S. Kanodia ◽  
Hsiao-Lan Liang ◽  
Yoosik Kim ◽  
Bomyi Lim ◽  
Mei Zhan ◽  
...  
Keyword(s):  
Pattern Formation ◽  
Drosophila Embryo ◽  
Early Drosophila Embryo

scholarly journals Dynamics of Spaetzle morphogen shuttling in the Drosophila embryo shapes pattern

2018 ◽  
Author(s):  
Neta Rahimi ◽  
Inna Averbukh ◽  
Shari Carmon ◽  
Eyal D. Schejter ◽  
Naama Barkai ◽  
...  
Keyword(s):  
Pattern Formation ◽  
Dynamic Environment ◽  
Drosophila Embryo ◽  
Morphogen Gradients ◽  
Extracellular Milieu ◽  
Early Embryos

AbstractEstablishment of morphogen gradients in the early Drosophila embryo is challenged by a diffusible extracellular milieu, and rapid nuclear divisions that occur at the same time. To understand how a sharp gradient is formed within this dynamic environment, we followed the generation of graded nuclear Dorsal (Dl) protein, the hallmark of pattern formation along the dorso-ventral axis, in live embryos. We show that a sharp gradient is formed through extracellular, diffusion-based morphogen shuttling that progresses through several nuclear divisions. Perturbed shuttling in wntD mutant embryos results in a flat activation peak and aberrant gastrulation. Re-entry of Dl into the nuclei at each cycle refines the signaling output, by guiding graded accumulation of the T48 transcript that drives patterned gastrulation. We conclude that diffusion-based ligand shuttling, coupled with dynamic readout, establishes a refined pattern within the diffusible environment of early embryos.

Genetic analysis of developmental mechanisms in hydra. VIII. Head-activation and head-inhibition potentials of a slow-budding strain (L4)

Development ◽  
1983 ◽  
Vol 78 (1) ◽  
pp. 141-168 ◽  
Author(s):  
Jun Takano ◽  
Tsutomu Sugiyama
Keyword(s):  
Pattern Formation ◽  
Genetic Analysis ◽  
Structure Formation ◽  
Tissue Transplantation ◽  
Normal Strain ◽  
Polyp Size ◽  
Developmental Mechanisms ◽  
Head Formation ◽  
Lower Head ◽  
Activation Potential

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).

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