I am quantifying amoA genes (bacteria) in soils samples. I heard that these genes have more than one copy in single genome. So I would like to ask that is there any relevant literature available which showed accurate numbers for this gene........
Although a bit outdated, this article will be useful:
Klotz, Martin G., and Jeanette M. Norton. "Multiple copies of ammonia monooxygenase (amo) operons have evolved under biased AT/GC mutational pressure in ammonia-oxidizing autotrophic bacteria." FEMS microbiology letters 168.2 (1998): 303-311.
You can check subsequent articles that cited this one in google scholar for example. I hope that helps. Best regards.