Table 2. Frequency and Genetic variability of cervical exfoliate cell derived HPV-31 variants in Long Control Region, E6 and E7 in Northern China.

		Long control region							Nucleotide position at E6							Nucleotide position at E7
Variant name	Frequency (N)	7860	7880	17	18	37	45	87	176	285	320	326	404	428	520	580	626	670	695	743	837	Variant lineage
Ref*	-	G	T	A	G	G	G	T	C	C	A	A	G	A	C	G	C	C	G	A	A	A
NC-32E3	1	A	C	G	T	A	T	G	-	T a	T	G	A	G	T b	A	-	T	A d	G e	-	C
NC-37A11	1	C	C	G	T	A	T	G	-	T a	T	G	A	G	T b	A	-	T	A d	G e	-	C
NC-11F3	3	A	C	G	T	A	T	-	-	T a	T	-	A	G	T b	A	-	T	A d	G e	-	C
NC-21D9	3	-	-	-	-	-	-	-	T	-	-	-	-	-	-	-	T c	-	-	G e	-	A
NC-12A7	1	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	T c	-	-	G e	G f	A
NC-27H9†	5	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	T c	-	-	G e	-	A
Total	14

Letters in bold represented amino acid changes compared to the reference sequence.

*Reference sequence of HPV-31 was NC_001527 and this sequence was not one of the sequences identified in the current study.

^aThe H60Y amino acid polymorphism in E6.

^bThe A138V amino acid polymorphism in E6.

^cThe H23Y amino acid polymorphism in E7.

^dThe E46K amino acid polymorphism in E7.

^eThe K62E amino acid polymorphism in E7.

^fThe N93S amino acid polymorphism in E7.

^†The sequence of NC-27H9 was the same as IN221709.