Complex sentence: By 1981, geneticists had located the WRN gene on chromosome 8, leading to its cloning in 1996.The cloning of the WRN was significant because it revealed the predicted WRN protein was made from a family of DNA helicases.
Split into simpler sentences: By 1981, geneticists had located the WRN gene on chromosome 8, leading to its cloning in 1996. This cloning of the WRN was significant because it revealed the predicted WRN protein was made from a family of DNA helicases.