nichtallelisch

Nichtallelisch is a term used in genetics to describe genes that are located at different positions on the same chromosome or on different chromosomes. Alleles, in contrast, are different versions of the same gene found at the same locus (position) on homologous chromosomes. Therefore, nichtallelische Gene are distinct genetic entities that can influence different traits or aspects of an organism's phenotype.

The concept of nichtallelisch is fundamental to understanding genetic inheritance patterns and gene interactions. When genes are nichtallelisch, they are inherited independently of each other, unless they are physically close together on the same chromosome, in which case linkage can occur. The study of nichtallelische Gene allows geneticists to map gene locations, understand how different genes cooperate or antagonize each other, and predict the inheritance of complex traits influenced by multiple genes.

For example, if a person has a gene for eye color on one chromosome and a gene for hair color on a different chromosome, these genes are nichtallelisch. Their inheritance would typically follow Mendel's Law of Independent Assortment, meaning the allele inherited for eye color does not influence the allele inherited for hair color. However, if two genes are located very close together on the same chromosome, they are considered nichtallelisch but are linked, and their inheritance patterns may deviate from independent assortment due to recombination frequency. Understanding the distinction between allelic and nichtallelisch genes is crucial for comprehending the complexity of the genome and its expression.