Open AccessDiversity of and Selection Acting on Cylindrospermopsin cyrB Gene Adenylation Domain Sequences in Florida
Author(s) -
Mete Yılmaz,
Edward J. Phlips
Publication year - 2011
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.02252-10
Subject(s) - biology , cylindrospermopsin , adenylylation , aphanizomenon , genetics , negative selection , gene , genome , cyanobacteria , biosynthesis , bacteria , anabaena
Aphanizomenon ovalisporum is the only confirmed cylindrospermopsin producer identified in the United States to date. On the other hand,Cylindrospermopsis raciborskii is a prominent feature of many lakes in Florida and other regions of the United States. To see the variation in cylindrospermopsincyrB gene adenylation domain sequences and possibly discover new cylindrospermopsin producers, we collected water samples for a 3-year period from 17 different systems in Florida. Positive amplicons were cloned and sequenced, revealing that approximately 92% of sequences wereA. ovalisporum -like (>99% identity). Interestingly, 6% of sequences were very similar (>99% identity) tocyrB sequences ofC. raciborskii from Australia and ofAphanizomenon sp. from Germany. Neutrality tests suggest thatA. ovalisporum -likecyrB adenylation domain sequences are under purifying selection, with abundant low-frequency polymorphisms within the population. On the other hand, when compared between species by codon-based methods, amino acids of CyrB also seem to be under purifying selection, in accordance with the one proposed amino acid thought to be activated by the CyrB adenylation domain.