2021-11-03

Alternative splicing

Splicing quantitative trait loci (sQTLs)

  1. SNPs controlling the abundance of mRNA isoforms for a gene

  2. Similar to SNPs controlling the abundance of expression of a gene (eQTLs)

Background on data and ideas

  1. Gene-Tissue Expression project eQTL data: 49 tissues but small sample sizes (~200-1200)

  2. eqtlGen cohort: whole blood with >30,000 people

  3. Two cohort measures of cross-brain eQTLs

  4. GTEx 10-13 brain tissues (& whole body): eQTLs for ASD, ALZ, & Parkinson’s

  5. In the process, I found the sQTL data…

GTEx sQTLs

  1. Adipose (subcutaneous)
  2. Adipose (visceral omentum)
  3. Adrenal gland
  4. Artery (coronary)
  5. Artery (tibial)
  6. Cells (cultured fibroblasts)
  7. Cells (EBV-transformed lymphocytes)
  8. Colon (sigmoid)
  9. Colon (transverse)
  10. Esophagus (gastroesophageal junction)
  11. Esophagus (mucosa)
  12. Esophagus (muscularis)
  13. Heart (atrial appendage)
  14. Heart (left ventricle)
  15. Kidney (cortex)
  16. Liver
  17. Lung
  18. Minor salivary gland
  19. Muscle (skeletal)
  20. Nerve (tibial)
  21. Ovary
  22. Pancreas
  23. Whole blood

Significant-gene pairs vs “sGenes”

  • More tissues for sGenes (GTEx’s chosen top sQTL), but only one SNP

  • Can consider running SMR for the sGene data to capture breast and brain

  • Downside is that we can’t test colocalization with only one SNP per gene

  • Colocalization is a way to gain evidence that the same SNP is causal for both splicing and the GWAS phenotype

  • Without evidence of a single, underlying “causal” SNP, there is more evidence that the signal is due to genetic architecture (i.e., linkage)

Definition of nucleolar biology genes

  • Protein localization to nucleolus (GO:1902570)

  • Nucleolus organization (GO:0007000)

  • Regulation of protein localization to nucleolus (GO:1904749)

  • AmiGO search terms “ribosomal proteins” (cytosolic & mitochondrial ribosomes) & “ribosomal biogenesis”

Definition of nucleolar biology genes

1. Alzheimer’s disease (ALZ)

2. Autism spectrum disorder (ASD)

3. Education years (EduYears)

4. Forced expiratory volume in 1-second (FEV1)

5. High- and low-grade serous ovarian cancer (HLGOC)

6. High-grade serous ovarian cancer (HGOC)

7. Lung cancer (LC)

8. Ovarian cancer (OC)

9. Parkinson’s disease (PD)

To add: lifespan, healthspan, ???