gmo_me.pptx

7/25/2019 GMO_ME.pptx

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ME and GMO

Chapter 10 Beebee & Rowe



GMO

• Genetically modifed organism – ‘transgenic orgasnism into which one or

more gens !rim a di"erent species ha#e

been introd$ced by the %' manip$lationproced$res o! molec$lar biology

• ($blic concerns)

1* (ossible e"ect on h$man health

+* (ercei#ed ris,s o! ‘genetic poll$tion in theen#ironment

• ME can help to address the +nd iss$e



En#ironmental ris,s !romGMOs

• (ossible ha-ards !rom relasing GMOinto the wilds)

1* .ill GMOs spread e/tensi#ely beyond

theior release sites possiblyo$tcompeting wild species

+* .ill new genes spread beyond theiroriginal hosts int other species

2* .ill the acti#ities o! introd$ced genesa"ect species that interact with 3e*gprey $pon4 GMOs



• Rish, assessment) not easy – Ecosystem are e/tremely comple/

– %i"erent types o! GMOs may well ha#e#arying e"ect

• Comparations) allien speciesintrod$ction

– 5n#aders with tens o! tho$dands gensnew to the en#ironment

– 'mong the greatest threats to global

biodi#ersity



6he role o! ME

1* 5denti!y the GMOs

+* 5denti!y the gen 7ow !rom themodifed oorganism into otherspecies

a* 8ertical 3normal4 transmission)hybridi-ation o! GM9crops with wild

plantb* :ori-ontal transmission

2* .hether e/pression o! the new

genes poses threats to other



Case ;1) common soil !$ng$s3Trichodema virens4

• Biocontrol agent o! other plant9pathogenic !$ngi

•Modifed to incl$de bacterialorganophosphate9degrading3opd4 gene

–<$ng$s will also remo#eorganophosphate pesticides !romcontaminated soils



• %etection) – Con#entional c$lt$ring techni=$es

– (CR based amplifcation o! the opd gene

!rom %' e/tracted directly !rom soil• 1091000 times more sensiti#e



8etical gene trans!er

• Cross !ertili-ation) GM9plants witheither no9GM #arieties o! the sameplant or with the close relati#es

• hybridi-ation o! GM9crops with wild plant



Case;+a 314) Oilseed rape3Brassica napus4

• 're able to hybridi-e with wild t$rnip 3B.rapa4 and wild cabbage 3B. oleracea4

• 5dentifcation o! hybrid)

– Genotype9specifc microsatellite mar,ers !or+ transgenes 3npt 55 !or antibiotic resistanceand bar !or gl$!osinate herbicide resitance4

– 6wo genotype9specifc R<>( mar,ers

– ?i/ R'(% primers

• :ybrids were #ery rare) 0@*00A o! seed



Case;+a3+4) ?$gar beet 3Beta

vulgaris4

• GM ?$gar beet) containining threeintrod$ced genes 3cpBNYVV !or #ir$sresistance npt 55 and bar 4

• (rod$ced pollen that s$cces!$lly!ertili-ed 0 o! male stile ‘baitplants some o! which were $p to +00

m away downwind• :ybrid tested)

– (CR amplifcation o! the tree transgenes



:ori-ontal gene trans!er3:G64

• 6ransmission o! genetic in!ormationbetween contemporary generation o!organisms and can occ$rs the same

or di"erent species – ot re=$ire consec$ti#e cell di#ision or

no generation times to elapse

– (otential to spread #ery =$ic,ly thro$ghthe en#ironment



:ori-ontal Gene 6rans!er

•

'lso called >ateral Gene 6rans!er• :G6 and >G6 !or short

• 2 ways to do it – Transformation9 na,ed %' short pieces

common in bacteria that trans!orm

• Clay D+ hrsF ocean s$r!ace 9 A92 hrsF oceansediment9+2A

– 6ransd$ction D phage donorHrecipient sharereceptors closely related bacteria %') amo$ntin phage head

–ConI$gation9plasmidsHtransposons cell to cellcontact distant relations long %'



Jnown 5nstances o! :G6

• 'ntibiotic resistance genes onplasmids

• 5nsertion se=$ences

• (athogenicity islands

• 6o/in resistance genes on plasmids

•'grobacteri$m 6i plasmid

• 8ir$ses and #iroids

• Organelle to n$cle$s trans!ers



:ow can yo$ detect :G6’s

• %' se=$ence in!ormation – (hylogenetic trees

– GKC Content

– Codon bias

– ?e=$ences new to a genome will retain

3!or a while4 the signat$res o! the donorgenome and disting$ished !romancestral %'



GKC Content

• %' is do$ble stranded G pairingwith C

• Meas$re the amo$nt o! GKC contentin regions

• 5! one region #aries !rom most o! thegenome than li,ely :G6

A+ A+

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