Mutationsinsertions

Mutationsinsertions are mutations characterized by the addition of nucleotides into a DNA sequence. They can occur in coding or noncoding regions and may affect gene function in direct or indirect ways.

Types of insertions include single-nucleotide insertions, which add one base, and larger insertions, which add multiple bases. When insertions are not a multiple of three, they shift the reading frame of a protein-coding gene (a frameshift), altering downstream amino acids and often creating a premature stop codon. Insertions of trinucleotide or larger repeats can expand repetitive sequences, potentially affecting protein structure or gene regulation. Insertions can also involve mobile genetic elements, such as transposons, that insert themselves into new genomic locations and may disrupt or modify gene expression.

Causes of insertions include replication errors (such as polymerase slippage), repair of DNA damage, unequal crossing over during meiosis, and activity of transposable elements.

Consequences range from disruptive frameshifts and altered protein function to changes in gene expression when insertions occur in regulatory regions or splice sites. Some insertions are neutral or even beneficial, contributing to genetic variation and evolution, while others can contribute to disease by disrupting normal gene function.

Detection and study of insertions rely on sequencing technologies that align reads to a reference genome; long-read sequencing can improve resolution of larger insertions. Bioinformatics tools identify the size, location, and potential impact of insertion events, supporting research in genetics, evolution, and medicine.