Fig. 5: Overview of KoRV transformation processes in koalas.
From: Retroviral integrations contribute to elevated host cancer rates during germline invasion
All northern koalas carry endogenous KoRVs (red koala images) which are subject to Mendelian inheritance (purple arrow). Having multiple potentially active ERVs in every cell, with reintegration (blue arrows) leading to additional IS in somatic cells (blue triangles), would confer a tremendous mutational load on the population. Both inherited and new somatic IS can potentially dysregulate oncogenes, leading to an increased risk of transformation, with additional new integrations occurring in the transformed population of cells promoting cancer and metastasis. The potential for KoRV to transduce oncogenes also increases cancer risk. Koalas without endogenous KoRV (grey koala images) will only develop cancers (at a much lower rate) through other mechanisms.
