genengetal

Genengetal (Dutch for "gene count") is a metric used in genomics to denote the number of distinct genes in a genome or a reference gene set. It typically counts protein-coding genes and may include non-coding RNA genes, pseudogenes, and other annotated loci depending on the definition used by researchers or databases. Because gene annotations vary with sequencing quality, assembly version, and the criteria for calling a gene, the genengetal is not a fixed property of a species but a value that can change with new data.

Counting strategies differ: some workflows report only protein-coding genes, others report total genes including rRNA, tRNA, miRNA genes, and long non-coding RNAs. In addition, across populations a pan-genome concept captures presence and absence of genes, affecting the observed genengetal.

Typical ranges: in humans the number of protein-coding genes is around twenty thousand, while other organisms range from several thousand to tens of thousands of genes depending on complexity and annotation depth. Model organisms such as yeast and Arabidopsis thaliana have distinct gene counts, reflecting genome architecture and annotation standards.

Applications and limitations: genengetal facilitates cross-species comparisons, genome annotation quality assessment, and evolutionary studies, but it is sensitive to annotation conventions and can shift with new releases. It should be interpreted alongside definitions used and the scope of included gene types.

See also: gene annotation, genome annotation, pan-genome, copy number variation, orthology.