?url_ver=Z39.88-2004&rft_id=arXiv%3A1705.07850&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Feprints.imtlucca.it%2F3751%2F&rft.title=Essentiality%2C+conservation%2C+evolutionary+pressure+and+codon+bias+in+bacterial+genes&rft.creator=Dilucca%2C+Maddalena&rft.creator=Cimini%2C+Giulio&rft.creator=Giansanti%2C+Andrea&rft.subject=Q+Science+(General)&rft.subject=QH301+Biology&rft.description=Essential+genes+constitute+the+core+of+genes+which+cannot+be+mutated+too+much+nor+lost+along+the+adaptive+evolutionary+history+of+a+species.+Natural+selection+is+expected+to+be+stricter+on+essential+genes+and+on+conserved+(highly+shared)+genes%2C+than+on+genes+that+are+either+nonessential+or+peculiar+to+a+single+or+a+few+species.+In+order+to+further+assess+this+expectation%2C+we+study+here+how+essentiality+of+a+gene+is+connected+with+its+degree+of+conservation+among+several+unrelated+bacterial+species%2C+each+one+characterised+by+its+own+codon+usage+bias.+Confirming+previous+results+on+E-+Coli%2C+we+show+the+existence+of+a+universal+exponential+correlation+between+gene+essentiality+and+conservation+in+bacteria.+Moreover%2C+we+show+that%2C+within+each+bacterial+genome%2C+there+are+at+least+two+groups+of+functionally+distinct+genes%2C+characterised+by+different+levels+of+conservation+and+codon+bias%3A+i)+a+core+of+essential+genes%2C+mainly+related+to+cellular+information+processing%3B+ii)+a+set+of+less+conserved+genes+with+prevalent+functions+related+to+metabolism.+The+genes+in+the+first+group+are+more+retained+among+species%2C+are+subject+to+a+relatively+purifying+conservative+selection+and+display+a+more+selected+choice+of+synonymous+codons.The+core+of+essential+genes+is+close+to+the+minimal+bacterial+genome%2C+which+is+in+the+focus+of+recent+studies+in+synthetic+biology%2C+though+we+confirm+that+othologues+of+genes+that+are+essential+in+one+species+are+not+necessarily+essential+in+other+species.+We+also+list+a+set+of+highly+shared+genes%2C+which+could+constitute+a+reservoir+of+targets+for+new+anti-microbial+drugs.&rft.publisher=arXiv&rft.date=2017&rft.type=Working+Paper&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.rights=cc_by_nc_nd&rft.identifier=http%3A%2F%2Feprints.imtlucca.it%2F3751%2F1%2F1705.07850.pdf&rft.identifier=++Dilucca%2C+Maddalena+and+Cimini%2C+Giulio+and+Giansanti%2C+Andrea++Essentiality%2C+conservation%2C+evolutionary+pressure+and+codon+bias+in+bacterial+genes.++Working+Paper+++arXiv+++++++(Submitted)+++&rft.relation=https%3A%2F%2Farxiv.org%2Fabs%2F1705.07850&rft.relation=arXiv%3A1705.07850