Ectopic expression of transcription factor AP‐2δ in developing retina: effect on PSA‐NCAM and axon routing
Bibliographic record
Abstract
Abstract Retinal ganglion cells transmit the visual signal from the retina to the brain. We have previously shown that the activator protein 2 (AP‐2)δ (TFAP2D) transcription factor is expressed in one third of ganglion cells in developing retina suggesting a specialized role for these AP‐2δ‐expressing cells. Here, we address the role of AP‐2δ in retina by in ovo electroporation of RCAS/AP‐2δ retroviral constructs into the eyes of chick embryos at day 2 of gestation. Ectopic expression of AP‐2δ does not affect lineage differentiation in the developing retina. However, immunostaining of retinal tissue with markers associated with axonal growth such as growth‐associated protein 43 and polysialic acid‐neural cell adhesion molecule (PSA‐NCAM) demonstrates axonal misrouting and abnormal axonal bundling. Treatment of AP‐2δ‐misexpressing retinal cell cultures with endoneuraminidase, an enzyme that removes PSA from NCAM, decreases AP‐2δ‐induced axonal bundling. Our data suggest a role for AP‐2δ in polysialylation of NCAM, with ectopic expression of AP‐2δ resulting in premature bundling of emerging axons and misrouting of axons. We propose that expression of AP‐2δ in a subset of ganglion cells contributes to the fine‐tuning of axonal growth in the developing retina. image AP‐2δ is a transcription factor expressed in one third of retinal ganglion cells. Chick embryonic retinas which have been in ovo electroporated with a RCAS GFP‐AP‐2δ expression construct show axonal abnormalities. We propose a model whereby GFP‐AP‐2δ‐positive (green) non‐ganglion cells produce substrate or signaling molecules (e.g., PSA‐NCAM; indicated by asterisks) that cause misrouting and increased bundling of ganglion cell axons.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".