Seeing Is Believing The Bicoid Morphogen Gradient Matures

  title={Seeing Is Believing The Bicoid Morphogen Gradient Matures},
  author={Anne Ephrussi and Daniel St Johnston},

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Modelling the Bicoid gradient

It is suggested that knowing a few additional parameters, such as the lifetime of Bicoid, would help to identify and develop better models of BICoid gradient formation.

A compartmental model for the bicoid gradient.

The Bicoid gradient is shaped independently of nuclei

Surprisingly, the shape of the resulting anterior-posterior gradient as well as the centre-surface distribution are indistinguishable from those of the normal gradient, which suggests that nuclei do not shape the Bicoid gradient but instead function solely during its interpretation.

Drosophila blastoderm patterning.

The Many Facets of bicoid Gradient Formation in Drosophila

The data suggested that Bicoid requires an intact cytoarchitecture for cortical movement, and revealed several factors that played distinct roles in bicoid mRNA gradient formation, including trans-Golgi proteins, the poly(A) polymerase Wispy, CyclinB and egg-activation genes.

Morphogen gradient formation and action

An estimate of BCD half-life, <15 min, in embryos during the time of gradient formation is described, and the role of Bcd-encoded positional information in controlling the positioning and precision of developmental decisions is discussed.

Scaling of the Bicoid morphogen gradient by a volume-dependent production rate

This work investigates within-species scaling mechanisms for anterior-posterior (A-P) patterning in Drosophila melanogaster by tracing the origin of Bcd gradient scaling by showing directly that large embryos have more maternally deposited bcd mRNA than small embryos.

A Precise Bicoid Gradient Is Nonessential during Cycles 11–13 for Precise Patterning in the Drosophila Blastoderm

Results indicate that the stability of the Bicoid gradient as a function of egg length is nonessential during syncytial blastoderm stages, and presumably no gradient formed by simple diffusion on the scale of egglength could be responsible for the robust antero-posterior patterning observed.



Problems and paradigms: Morphogens and pattern formation

While the evidence is not conclusive in most of the cases considered, there is a strong case in favour of the three proteins mentioned above, which suggests that morphogens are potentially of general importance in controlling the development of multicellular organisms.

Determination of anteroposterior polarity in Drosophila.

The principles of pattern formation in embryogenesis can be studied in Drosophila by means of a powerful combination of genetic and transplantation experiments. The segmented pattern of the

A gradient of bicoid protein in Drosophila embryos

Microtubules mediate the localization of bicoid RNA during Drosophila oogenesis.

We have examined cytoskeletal requirements for bicoid (bcd) RNA localization during Drosophila oogenesis. bcd is an anterior morphogen whose proper function relies on the localization of its

The role of localization of bicoid RNA in organizing the anterior pattern of the Drosophila embryo.

The organization of the anterior pattern in the Drosophila embryo is mediated by the maternal effect gene bicoid and the mRNA is localized at the anterior tip of oocyte and early embryo until the cellular blastoderm stage.

Establishment of developmental precision and proportions in the early Drosophila embryo

It is shown that the Bcd gradient displays a high embryo-to-embryo variability, but that this noise in the positional information is strongly decreased (‘filtered’) at the level of hunchback (hb) gene expression.

Differing strategies for organizing anterior and posterior body pattern in Drosophila embryos

This work has shown that within this hunchback-free domain the pattern of abdominal segments must be specified by other morphogens, possibly by shorter range gradients of the products of zygotic gap genes Kruppel, knirps and tailless.

RNA binding and translational suppression by bicoid

It is reported that bed binds through its homeodomain to cad mRNA in vitro, and exerts translational control through a bed-binding region of cad mRNA.