Talk:Drosophila embryogenesis

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I would like to add this information which includes a table, but I don't know how to do it and don't have the time for it right now:

Embryogenesis is commonly divided into 17 stages that are grouped into 7 common stages.(source: FlyMove, Volker Hartenstein and José Campos-Ortega )

Table: Stage #, time (at 25 degrees C.. RT) onset, process, embryo stage 1-4,, 0-2:10hr, fertilization, cleavage, syncytial blastoderm 5,2:10-2:50, cellularization, cellular blastoderm 6,7, 2:50-3:10, gastrulation, gastrula 8-11, 3:10-7:20, germ band elongation, intercalation and cell shape change, ? 12-13, 7:20-10:20, germ band retraction 14-15, 10:20-13:00 Head involution and dorsal closure 16-17, 13:00-22:00 Differentiation

Otherwise, I have some other ommissions that are listed here:

• How do we deal with segmentation (biology)? It probably should be a separate article. Morphogenesis has a lot of information on this, which maybe should be split out of that article into a separate article.
• Does drosophila have external fertilization? Is that relevant to it's usefullness as a model organism?
• Need to define a parasegment (or else direct to segmentation article)\
• Polytene chromosomes should be mentioned
• Would like to mention how to screen for developmental mutants.

AdamRetchless 00:04, 8 Apr 2004 (UTC)

I also agree on adding those stages since it helps with the chronological order in which the embryogenesis happens. (talk) 22:02, 8 May 2019 (UTC)

related information spread over multiple pages

This page is linked to from Drosophila_melanogaster#Development_and_embryogenesis. That section contains quite some information that is not here, even though this is supposed to be the "main article". It would be good to copy that information over.

Morphogenesis contains an extensive discussion on the a/p patterning system that might fit better on this page, since it's specific to Drosophila.

--131.243.56.64 02:14, 4 April 2006 (UTC)

patched

But Hedghog does not activate Patched. Hedghog blocks it, so that Patched does not block Smoothened any more! Hh does activate ptc trancription but then Hh represses Ptc protein.

Developmental mutants

For starters, define maternal effect and zygotic genes. The actual screening is rather complicated, and depends on whether you're looking for recessive, dominant, modifier, or suppressor mutations. Because of early work by Nüsslein-Volhard (and the hassle), I don't think many are doing screens for recessive maternal effect genes. Instead, they'd look for dominant modifiers or suppressors. I think this is probably beyond the scope of this article. Kodoz (talk) 21:08, 6 May 2010 (UTC)

Anterior-posterior axis patterning in Drosophila

The organization of this sectioning seems great in terms of transitioning from the top to bottom of the gene hierarchy. However, the majority of this section needs citations (along with other sections as well). (talk) 22:02, 8 May 2019 (UTC)

Dorsal-ventral pattern formation

That section is confusing enough to look incorrect. Briefly, there are 3 systems: torpedo-gurken, dorsal group genes, and the zygotic pathways (Twist, snail, all those things). Top/Grk acts in the follicle cells to establish the basic antero-dorsal layout of the embryo (ie, top mutants lack ventral features). Dorsal signaling is a maternal effect protein that acts in the embryo to establish the ventral-dorsal pattern. Twist and company layout the mesoderm and neurectoderm, and there are some complementary proteins that layout the dorsal features (you have them...dpp and zen).

Top/grk are significant because of their homology to EGF/EGFR. Top/grk probably lays out the expression of pipe, nudel, and windbuetel in the vitelline membrane. In turn, these proteins activate a protease cascade that includes gd, snake, and easter in the perivitelline space. Easter cleaves spatzle, which is the ligand for Toll. Easter, spatzle, and Toll are not expressed in a localized manner, so it's their localized activation on the ventral side that introduces asymmetry to the embryo. Toll activates some signal transduction proteins (tube and pelle) in the cytoplasm, which ultimately dissociate the cactus-dorsal complex. Dorsal is a transcription factor and NFkB homolog; cactus is an iKB homolog. When freed from Cactus, Dorsal enters the nucleus. The actual pattern of Dorsal nuclear translocation is a ventral-dorsal gradient. High dorsal concentration in the nucleus leads to expression of mesoderm-proteins, low concentration leads to expression of amnioserosa proteins. Basically, Dorsal controls expression of zygotic D/V patterning genes.

Couldn't tell you much about the zygotic genes: look into single minded, twist, snail, and rhomboid.

One cool thing about drosophila D/V patterning is that it's the opposite of vertebrate D/V patterning. The default state for fruit flies is dorsal, but in xenopus, it's ventral. Easter-Spatzle-Toll set up a ventral Spemann organizer on the ventral side of the fly embryo. Kodoz (talk) 21:41, 6 May 2010 (UTC)

I agree, much of this section is wrong. — Preceding unsigned comment added by 124.168.233.166 (talk) 10:09, 17 November 2012 (UTC)

The paragraph organization on this section makes it confusing to read. I recommend separating it into subsections. For example, the first one would start with Dorsal. Describe its function and reference to studies where they show what happens if Dorsal is mutated. Then another sub-section should describe how it's localized to the nucleus. After that, another sub-section should explain the signaling cascade. And, another sub-section should explain how the protein gradient for dorsal forms. And, so on. It doesn't have to be exactly that, but something similar to would be great since it splits a complicated topic into different parts. Make sure to cite sources along the way so that you can refer it to when editing. Highly recommend adding figures since the visual helps people to understand the content better. (talk) 22:02, 8 May 2019 (UTC)

Recent work on morphogens

There has been a lot of recent work on morphogens that substantially challenges or revises the traditional view of factors such as Bicoid. The April, 2012 Cell commentary by Roth and Lynch provides an overview of these advances ([1]). SpectraValor (talk) 14:09, 27 April 2012 (UTC)

Research history

I find the sentences about research discoveries and nobel prizes in the middle of a section explaining the molecular and genetic aspects of embryogenesis to be distracting (ex: "Addition segmentation gene" section). I recommend sentences of those types that highlight important discoveries should either be done in the beginning of each section OR compile them all in a separate section. (talk) 22:02, 8 May 2019 (UTC)

References

I recommend finding primary research articles on the topics and cite them instead of using mostly secondary sources like a textbook since those can possibly be out of date depending on the edition used. (talk) 22:02, 8 May 2019 (UTC)