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from! a! few! to! a! hundred! strains,! differing! in! a! wide! range! of! properties.! Since!
asexual! reproduction! prevails! with! blooms,! clones! of! ancient! divergence! can! be!
quite! different! from! one! another! due! to! mutations,! selection,! chance! and! history!
(reviewed! in! 62,! 63).! Little! is! known! about! the! inheritance! of! these! cell! surface!
glycans,!which!are!lectin?binding!sites!in!cyanobacteria,!although!apparently!these!
glycans! show! genetic! polymorphism! and! Mendelian! inheritance! in! algae! (56).!
Moreover,! strains! of! ancient! divergence! apparently! show! more! differences! for! a!
lectin?binding!pattern!that!clones!of!contemporary!divergence!(56,!64).!

After! analyzing! four! distinct! blooms,! differences! in! the! lectin?binding!
patterns!were!found!among!the!diverse!strains!isolated!from!a!same!bloom!as!well!
as!among!the!different!colonies!directly!analysed!from!the!same!water!samples.!In!
this!context,!this!would!demonstrate!that!M.)aeruginosa!blooms!are!constituted!by!
different!strains!that!differ!in!composition!of!cell!surface!glycans.!

From!a!practical!point!of!view,!the!most!relevant!question!is!elucidating!the!
relationship! between! microcystin! production! and! lectin?binding! pattern.! It! is! well!
establish! that! not! all! M.) aeruginosa! cells! of! a! bloom! are! toxic! and! cell! density!
cannot!be!directly!related!to!toxicity.!Thus,!it!would!be!extremely!useful!to!identify!
the! abundance! of! toxic! cells! in! a! bloom! during! routine! observation! of!
phytoplankton!under!microscopy!that!performs!most!of!water!supply!enterprises,!
since!the!visual!examination!of!lectin?binding!activity!by!optical!staining!quality!is!
a! rapid,! straightforward! and! easy! method! to! differentiate! M.) aeruginosa! strains.!
This! method! could! provide! an! operative! typing! of! M.) aeruginosa! colonies! directly!
collected!from!the!environment.!!

A!significant!regression!between!toxin!production!and!the!number!of!lectin!
was!observed,!suggesting!that!positively!lectins?labelled!could!be!a!promising!way!
to! discriminate! between! toxic! and! non?toxic! M.) aeruginosa! cells.! Since,! the! most!
toxic!strains!are!labelled!by!very!few!lectins!whereas!non?toxic!strains!are!labelled!
by! the! most! of! lectins.! Thus,! it! could! be! assumed! that! the! absence! of! lectins! that!
label!the!three!most!toxic!strains!indicates!a!scarce!presence!of!lectin!binding!sites!
in!the!most!toxic!M.)aeruginosa!strains.!

Previous! studies! have! characterized! morphospecies! and! strains! of!
Microcystis) sp.! using! lectins! (56);! however,! they! did! not! show! the! important!
relationships! between! lectin?binding! pattern! and! microcystin! production.!
Hierarchical! cluster! analysis! (Figure! 1)! reveals! that! lectin?binding! pattern! of! each!
strain!is!close!related!to!its!microcystin!production.!Lectin?binding!pattern!classify!
the! different! strains! into! three! different! alignments.! Firstly,! the! four! strains! with!
higher! microcystin! production! are! separated! and! next! separating! non?toxic! from!
moderately! toxin?producing! strains.! Taking! into! account! only! one! strain! appears!
incorrectly!aligned!strengh!of!this!alignment!is!evident.!!

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