Autogamic reproductive behavior and sex cell structure in Thalassiosira angulata (Bacillariophyta)
Bibliographic record
Abstract
Our understanding of diatom reproduction is limited, especially for marine planktonic centric diatoms. This project aimed to elucidate sexual behavior and gametogenesis in the mediophycean diatom, Thalassiosira angulata , and to determine the fine structure of its reproductive cells. A monoclonal culture of T. angulata was successfully induced and enumerated, and all stages of auxosporulation documented. Spermatogenesis was absent in all inductions. Nuclear behavior of the auxospore mother cell (AMC) during auxosporulation indicated that reproduction was autogamic. In our clone, reproduction began with a differentiating mitosis and subsequent pervalvar expansion of the AMC, a meiocyte. The smaller cell often continued normal vegetative growth. In the AMC, meiosis I was acytokinetic and resulted in one viable haploid and one pycnotic nucleus. Meiosis II resulted in the production of two viable haploid nuclei, which we postulate later fused to produce the zygotic nucleus. Cell expansion was observed in very young AMCs both prior to and following autosyngamy. The initial cell valves were produced after at least two acytokinetic and pycnotic mitotic divisions, after which the cell was capable of undergoing its first normal mitosis involving production of two sibling hypovalves.
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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 source (direct Gemma or distilled Codex), 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".