Evidence for positive selection acting on microcystin synthetase adenylation domains in three cyanobacterial genera

Table 2 Genetic information

Genus	No of seq	Length (bp)	π	Sequence variation	No of segregating sites/informative sites	Putative recombination events
						Mosaic structure of informative sites	Detected by programs of RDP2 package	Detected by SplitsTree (Phi test for recomb)
Anabaena
mcyB	21	1068	0.032	0–6%	100/79	Y	Y	Y, (P < 0.01)
mcyC	21	1068	0.009	0–2.4%	31/28	Y	N	Y, (P < 0.01)
mcyBC	42	1068	0.036	0.7–7.2%*	107/94	Y	Y	Y, (P < 0.01)
Microcystis
mcyB	12	1059/1062	0.033	0–6.3%	111/57	Y	Y	Y, (P < 0.01)
mcyC	18	1059/1062	0.035	0–7.1%	131/99	Y	Y	Y, (P < 0.01)
mcyBC	30	1059/1062	0.073	8.6–12.4%*	222/192	Y	Y	Y, (P < 0.01)
Planktothrix
mcyB	18	1080	0.023	0–3.6%	61/61	Y	Y	Y, (P < 0.01)
mcyC	18	1068	0.003	0–1.2%	27/0	N	N	N
mcyBC	36	1068/1080	0.158	29.8–30.8%*	354/353	N	N	Y, (P < 0.01)^&
Comparison of adenylation domains between genera
mcyB1	51	1062–1080	0.206	27–34%^#	487/487	N^‡	N^‡	N^‡
mcyC	57	1068	0.161	18–29%^§	411/411	N^‡	N^‡	N^‡

π Nucleotide diversity – the average number of nucleotide differences per site between two sequences
* Sequence variation between mcyB1 and mcyC sequences
^# Sequence variation is 27–30% between Anabaena and Microcystis, 30–32% between Anabaena and Planktothrix, 32–34% between Microcystis and Planktothrix.
^§ Sequence variation is 26–29% between Anabaena and Microcystis, 18–19% between Anabaena and Planktothrix, 23–26% between Microcystis and Planktothrix.
^‡ Recombination detection between genera
^&Recombination detected within mcyB1

ISSN: 2730-7182