Table 1. Minimum and maximum nucleotide differences among antibody heavy chain V-gene sequences from various species and different specificities.

	Human RF	Human anti-DNA	Mouse RF	Mouse anti-DNA	Chicken (all)	Shark (all)
human RF	1/147	1/161	45/148	38/149	89/156	114/186
human anti-DNA		1/156	45/158	39/163	89/167	115/187
mouse RF			1/140	1/151	97/154	118/185
mouse anti-DNA				1/151	97/158	115/185
chicken (all)					1/50	121/185
shark (all)						1/167