Table 7. pfam GPCR abundance and diversity.

Serpentine receptor class	Pfam domain	Cele	Pred	Bxyl	Ppac	Mhap	Asuu	Bmal	Tspi
7TM GPCR chemoreceptor Srh	PF10318.2	593	196	221	154	2	9	0	0
7TM GPCR chemoreceptor Srd	PF10317.2	446	131	206	146	28	16	0	0
7TM GPCR chemoreceptor Str	PF10326.2	441	152	238	176	20	13	0	0
7TM GPCR chemoreceptor Sri	PF10327.2	367	129	90	61	0	1	0	0
7TM GPCR chemoreceptor Srj	PF10319.2	338	63	143	131	2	6	0	0
7TM GPCR chemoreceptor Srx	PF10328.2	138	28	23	50	9	20	9	2
7TM GPCR chemoreceptor Srw	PF10324.2	170	22	27	15	5	23	7	4
7TM GPCR chemoreceptor Srsx	PF10320.2	82	70	62	41	60	35	2	18
Srg family chemoreceptor	PF02118.14	101	82	13	39	8	1	0	0
7TM GPCR chemoreceptor Srbc	PF10316.2	88	9	4	4	0	4	0	0
7TM GPCR receptor class ab chemoreceptor	PF10292.2	80	42	51	25	13	5	5	1
Sre G-protein-coupled chemoreceptor	PF03125.11	68	51	30	38	9	5	2	0
7TM GPCR chemoreceptor Srv	PF10323.2	60	44	10	36	1	2	0	4
7TM GPCR chemoreceptor Srz	PF10325.2	72	0	0	0	0	0	0	1
7TM GPCR chemoreceptor Srt	PF10321.2	63	40	33	35	21	3	0	1
7TM GPCR chemoreceptor Sra	PF02117.9	59	4	6	5	2	1	3	0
7TM GPCR chemoreceptor Sru	PF10322.2	47	11	0	1	1	1	0	0
7TM GPCR chemoreceptor Srb	PF02175.9	30	0	0	4	0	1	0	0
Serpentine receptor-like protein, class xa	PF03383.8	16	1	0	0	0	0	0	0
Total serpentine GPCR Domains		3259	1075	1157	961	191	146	28	31
No. of proteins with multiple GPCR domains		768	276	296	229	34	24	3	3
No. of proteins with only one GPCR domain		746	290	198	307	115	78	20	25
Total no. of GPCR domain-containing proteins		1514	566	494	536	149	102	23	28

Repertoire of seven transmembrane receptor domain families across various nematode species identified by hmmscan and pfam is shown (Finn et al. 2011). C. elegans exhibits a dramatic expansion of various subfamilies of these proteins. In contrast, the parasitic species do not display a large number of domains for this class of genes.