. 2014 Apr 16;10(5):479–489. doi: 10.7150/ijbs.8739

Table 4.

Codon usage pattern of the 13 mitochondrial protein-coding genes from three horseshoe crab species, Carcinoscorpius rotundicauda, Tachypleus tridentatus, and Limulus polyphemus

Amino acids	Codon	No.			Amino acids	Codon	No.			Amino acids	Codon	No.
Amino acids	Codon	C	T	L	Amino acids	Codon	C	T	L	Amino acids	Codon	C	T	L
Nonpolar					Phe	UUC	46	66	85	Ser	AGA	75	83	66
Ala	GCA	48	45	55		UUU	333	310	246		AGC	5	4	8
	GCC	27	16	39	Trp	UGA	101	102	94		AGG	2	7	12
	GCG	4	9	6		UGG	10	6	17		AGU	24	21	22
	GCU	73	84	76							UCA	116	114	98
Ile	AUC	43	42	107	Polar						UCC	49	31	65
	AUU	346	335	241	Asn	AAU	126	139	103		UCG	2	3	6
Leu	CUA	41	42	94		AAC	35	20	44		UCU	106	122	110
	CUC	17	18	55	Cys	UGC	7	7	9	Acidic
	CUG	2	1	4		UGU	43	47	40	Asp	GAC	14	11	24
	CUU	85	80	106	Gln	CAA	59	63	52		GAU	48	51	36
	UUA	348	363	226		CAG	10	3	15	Glu	GAA	68	69	64
	UUG	44	38	84	Gly	GGA	110	119	109		GAG	14	14	23
Met	AUA	215	229	171		GGC	8	11	21	Basic
	AUG	40	23	43		GGG	32	28	66	Arg	CGA	32	35	34
Pro	CCA	60	64	52		GGU	67	59	41		CGC	3	3	7
	CCC	14	8	27	Thr	ACA	78	77	84		CGG	4	2	7
	CCG	2	2	4		ACC	29	31	40		CGU	20	20	14
	CCU	60	68	69		ACG	1	0	2	His	CAC	19	13	41
Val	GUA	76	62	82		ACU	59	65	53		CAU	56	64	37
	GUC	6	5	14	Tyr	UAC	26	20	34	Lys	AAA	85	84	66
	GUG	11	19	36		UAU	105	108	87		AAG	16	8	19
	GUU	73	86	90

Bold numbers indicate strong differences (+/-25%) to Limulus polyphemus.