Evolutionary genetics of dikaryosis and diploidy in the basidiomycete Schizophyllum commune
Bibliographic record
Abstract
To examine differences in the phenotypic plasticity of different ploidy states, the evolved dikaryons, neohaplonts, evolved haploids, and dikaryons created by mating evolved haploids were grown in various environments. The evolved dikaryons and neohaplonts had a higher degree of phenotypic variation than the evolved haploids, while the dikaryons constructed from the evolved haploids had little phenotypic variation. The evolved haploid lines had a higher fitness in the selective environment than the others tested, indicating adaptation. Using Dik-, a mutation that induces diploidy, I compared the immediate phenotypic response of dikaryons and their corresponding, isogenic diploids to 50 different experimental treatments. Three different responses were found: (a) the dikaryons grew significantly faster than the diploids in 13 treatments, (b) there was no significant difference between the dikaryons and diploids in 26 treatments, and (c) the diploids grew significantly faster than the dikaryons in 11 treatments. Further quantitative genetic analysis indicated that there are differences between ploidy states in additive and non-additive components of genetic variation for mycelial growth. The dikaryon represents a novel alternative to diploidy in that both gametic genomes are present, but are maintained in separate nuclei in each cell. The objective of my thesis research was to evaluate the evolutionary implications of dikaryosis, relative to those of haploidy and diploidy. Laboratory populations of dikaryons and haploid monokaryons were allowed to evolve for 24 months or sim;17,500 generations. Dikaryotic mycelia responded to selection with increases in growth rate, while haploid monokaryotic mycelia did not. To determine if the haploid components of the dikaryon adapt reciprocally to one another's presence over time, I recovered the intact haploid components of dikaryotic mycelia at different time points and mated them with nuclei of different evolutionary histories. I found evidence for co-adaptation between nuclei in one dikaryotic line, a dominant deleterious mutation in a nucleus was followed by a compensatory mutation in the other nucleus. Using a 24-locus genotyping system based on single nucleotide polymorphisms, I observed genetic exchange and recombination between the nuclei of several different dikaryons.
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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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".