luokai0 Genetics Expert
Before Starting
- Classical or molecular genetics focus?
- Human genetics or model organisms?
- Research or clinical context?
Core Expertise Areas
Mendelian Genetics
Law of Segregation: alleles separate during gamete formation. Law of Independent Assortment: genes on different chromosomes assort independently. Dominance patterns: complete, incomplete, codominance. Epistasis: gene interaction modifying phenotypic ratios. Penetrance and expressivity: not all genotypes produce expected phenotype.
Molecular Genetics
DNA replication: semi-conservative, leading/lagging strand synthesis. Transcription: promoters, enhancers, RNA polymerase, splicing. Translation: codons, tRNA, ribosome, start/stop signals. Gene regulation: operons (prokaryotes), transcription factors (eukaryotes). Epigenetics: DNA methylation, histone modification, chromatin remodeling.
Mutation and Repair
Point mutations: missense, nonsense, silent, frameshift. Chromosomal mutations: deletion, duplication, inversion, translocation. DNA repair mechanisms: BER, NER, MMR, DSBR. Mutagens: chemical, radiation, biological.
Linkage and Mapping
Genetic linkage: genes on same chromosome tend to inherit together. Recombination frequency: measure of map distance in centimorgans. Genetic maps vs physical maps. LOD score analysis for linkage detection.
Population Genetics
Hardy-Weinberg equilibrium: p2 + 2pq + q2 = 1. Deviations: mutation, selection, drift, migration, non-random mating. Genetic drift: founder effect, bottleneck effect. Natural selection: directional, stabilizing, disruptive.
GWAS and Complex Traits
Genome-wide association studies: SNPs, Manhattan plots, p-value thresholds. Polygenic traits: multiple loci each with small effect. Heritability: proportion of phenotypic variance due to genetic factors. Linkage disequilibrium: non-random association of alleles at nearby loci.
Key Patterns
Best Practices
- Always define dominance relationships before solving problems
- Use Punnett squares for simple crosses, probability for complex
- Check Hardy-Weinberg assumptions before applying equilibrium
- Distinguish between genotype and phenotype clearly
- Consider both nuclear and mitochondrial/chloroplast inheritance
Common Pitfalls
| Pitfall | Fix |
|---|---|
| Confusing penetrance with expressivity | Penetrance is all-or-nothing, expressivity is degree |
| Ignoring epistasis | Check for modified ratios in dihybrid crosses |
| Applying H-W to non-equilibrium populations | Verify all 5 conditions first |
| Confusing cM with physical distance | Recombination frequency is not linear at large distances |
Related Skills
- molecular-biology-expert
- genomics-expert
- evolutionary-biology-expert
- bioinformatics-expert