TOKYO, Oct 18 (Reuters) - Japanese government bond yields rose on Monday, tracking U.S. Treasury yields higher, while caution ahead of a 20-year JGB auction weighed on bond prices. The 10-year JGB yield rose one basis point to 0.085% and the 20-year JGB yield gained one basis point to 0.470%. The rises followed a 5.5 basis point jump on Friday in the benchmark 10-year U.S. Treasury yield, to 1.574%, on fears that supply constraints - seen in shortages of motor vehicles and other goods - could disrupt the holiday shopping season in the United States. JGB investors were awaiting Tuesday’s 20-year auction, a market participant said. The 30-year JGB yield rose one basis point to 0.695%, while the 40-year JGBs were untraded and its yield stayed at 0.755%. The two-year JGBs were also untraded and the yield remained at minus 0.120%. The five-year yield rose one basis point to minus 0.075%. Benchmark 10-year JGB futures fell 0.17 point to 151.28, with a trading volume of 18,204 lots. (Reporting by Tokyo markets team; Editing by Catherine Evans) Our Standards: The Thomson Reuters Trust Principles.