Dataset S4. Phylogenetic tree of the 180 Tas2r genes identified from the genome sequence of the American bullfrog, rooted using a fish V1R3 (accession number: BAM35766). 


(V1R3:3.1135918221,Tas2r27:0.0000021304,((Tas2r26:0.0813333967,Tas2r25:0.1679715647)100:0.3363624966,(Tas2r1:0.2723505696,((Tas2r4:0.0398461527,Tas2r3:0.0852319873)100:0.0952409624,(Tas2r2:0.1546578518,(Tas2r24:0.8514620153,((Tas2r101:0.1112728941,Tas2r100:0.2026359854)100:0.8165522650,(((((Tas2r97:0.2303477539,Tas2r84:0.0201311584)100:0.1815816273,(Tas2r85:0.0000025457,Tas2r43:0.0312822483)100:0.2864378287)100:0.2128035100,(Tas2r82:0.2467654809,(Tas2r83:0.1156544251,(Tas2r163:0.1757144155,(Tas2r69:0.1705580879,(Tas2r115:0.1957052854,Tas2r44:0.1599917982)100:0.0653447782)99:0.0413535776)100:0.0436947023)100:0.1879896683)100:0.1777522525)100:0.2043254893,((Tas2r9:0.9180190209,((Tas2r155:0.0910051732,(Tas2r78:0.1027640600,Tas2r77:0.2481022150)99:0.0335234793)100:0.5603177184,(Tas2r57:0.6872450514,(Tas2r8:0.3012248090,(Tas2r11:0.4647723911,(Tas2r10:0.4235173463,((Tas2r7:0.3545194470,(Tas2r6:0.4760906832,Tas2r5:0.5695746099)99:0.1180931346)36:0.0571259062,(Tas2r16:0.3408870740,((Tas2r126:0.0913866821,Tas2r12:0.4181179780)100:0.1861100909,(Tas2r14:0.2501282863,(Tas2r15:0.2283973761,Tas2r13:0.1484518931)94:0.0272344850)100:0.0600327155)100:0.2647088981)47:0.0581745428)53:0.0610892177)94:0.0780399104)94:0.1787117472)100:0.6158732866)89:0.0775500093)86:0.0729682496)94:0.1660312876,((Tas2r48:0.0136899652,(Tas2r47:0.0555356738,Tas2r46:0.1338680103)100:0.0575128967)100:0.5435497412,((Tas2r28:0.1479941240,(Tas2r178:0.0000020131,Tas2r99:0.0000020131)100:0.0435767050)100:0.4445596866,(((Tas2r108:0.0303348608,(Tas2r165:0.0000025163,(Tas2r109:0.1238862753,Tas2r107:0.0072447452)53:0.0313205200)39:0.0000025794)100:0.5309121977,((Tas2r162:0.1215375264,Tas2r30:0.0978508741)100:0.0465929871,(Tas2r120:0.0424967118,(Tas2r169:0.1138287645,Tas2r146:0.0606971981)100:0.0307911318)9100:0.1983339689)100:0.3423604049)56:0.0520800606,(((Tas2r75:0.1874690182,(Tas2r73:0.0936594969,Tas2r72:0.1176772202)79:0.0000025907)100:0.1558962793,((Tas2r164:0.1370565156,(Tas2r62:0.0859736513,Tas2r63:0.0473256676)100:0.0795259237)100:0.1636145470,((Tas2r156:0.0939620013,Tas2r137:0.0597350628)100:0.0599072970,(Tas2r132:0.0484314557,(Tas2r149:0.0000020131,Tas2r133:0.0311467352)100:0.0083516860)100:0.0760192488)100:0.2901978483)86:0.0588123190)100:0.2412365205,((Tas2r29:0.5337147311,(Tas2r68:0.5382781103,(Tas2r65:0.8220297041,(Tas2r94:0.0878024524,((Tas2r179:0.0240040036,Tas2r175:0.0249476751)100:0.1096822394,(Tas2r93:0.1377213821,(Tas2r177:0.0159398469,Tas2r150:0.0158314206)100:0.0847789419)97:0.0178453031)92:0.0000029215)100:0.2779694710)99:0.0765528013)99:0.1897984245)98:0.1566264870,((Tas2r32:0.2460822245,(Tas2r33:0.1392125891,Tas2r31:0.1310548652)99:0.1273610271)100:0.4277315710,((Tas2r102:0.4546876396,(Tas2r142:0.4602655753,(Tas2r129:0.0026380670,Tas2r103:0.0201592923)100:0.2690407524)100:0.2148450749)77:0.0562613930,(Tas2r49:0.3753942628,((Tas2r161:0.0144130703,Tas2r134:0.0068395528)100:0.1876607569,(Tas2r111:0.1885189715,Tas2r35:0.1265146925)100:0.0923593369)100:0.2443572781)100:0.4004984733)61:0.0624400166)52:0.0585176720)43:0.0711582215)44:0.0289067496)100:0.1894055222)97:0.1236658042)99:0.1681272938)95:0.1017945544)85:0.1184529154,(((Tas2r37:0.0737897967,Tas2r36:0.1098900162)99:0.0346292692,((Tas2r152:0.0000022749,Tas2r127:0.0153252150)100:0.0155241612,(Tas2r113:0.0309870054,Tas2r98:0.0233520691)100:0.0327380952)100:0.0937877068)100:1.0367343230,(((Tas2r96:0.2360280450,Tas2r22:0.6335025757)100:0.5452593722,((Tas2r140:0.0000020244,(Tas2r86:0.1037913475,(Tas2r123:0.0703590846,(Tas2r153:0.0620643799,(Tas2r124:0.0343257561,Tas2r119:0.1795327318)80:0.0362228795)74:0.0363145736)72:0.0288626928)60:0.0600169416)100:0.5646334172,((Tas2r45:0.5208871279,(Tas2r138:0.4188175059,(Tas2r61:0.1331099336,(Tas2r167:0.1203214886,Tas2r60:0.1533570712)100:0.0384925850)100:0.2335586231)100:0.0546150734)100:0.3927986678,((Tas2r67:0.0965587379,Tas2r66:0.0000026012)100:0.4734417891,(Tas2r34:0.0793870685,((Tas2r122:0.3156826649,Tas2r121:0.0710744971)85:0.0073885162,(Tas2r92:0.0254962919,(Tas2r125:0.0416244977,Tas2r74:0.0539817971)74:0.0079444182)74:0.0174837724)94:0.0504957368)100:0.3185901971)96:0.1174077776)89:0.0535429658)99:0.1665403759)68:0.0213366712,(Tas2r59:0.3510832553,((Tas2r95:0.4591343547,(Tas2r136:0.2028246116,(Tas2r50:0.3808943132,(Tas2r55:0.0804822356,(Tas2r53:0.0277483296,(Tas2r54:0.0337260947,Tas2r52:0.0978250638)38:0.0151847625)38:0.0456703587)100:0.1772357278)94:0.0803419344)93:0.1233243413)71:0.0820344021,(((Tas2r143:0.1959548888,(Tas2r131:0.1103100941,Tas2r87:0.1082513491)100:0.1629893733)100:0.1655178360,(Tas2r51:0.4067424014,((Tas2r20:0.0718082550,Tas2r19:0.0000020487)100:0.4205869794,(Tas2r21:0.1184872773,(Tas2r17:0.0303545991,(Tas2r23:0.0227355393,Tas2r18:0.0305038816)98:0.0079655269)98:0.0869852583)100:0.4307169231)39:0.0794455194)37:0.0330701998)100:0.1105388757,(Tas2r64:0.5268442151,(((Tas2r176:0.0421733104,Tas2r106:0.0171040037)100:0.0494720760,(((Tas2r171:0.0000023241,Tas2r160:0.0072921128)100:0.0998441001,(Tas2r105:0.0405737477,Tas2r104:0.0817293838)100:0.0932513688)72:0.0329129216,((Tas2r180:0.0078654296,Tas2r130:0.0381313540)100:0.0570650715,(Tas2r139:0.0090847363,(Tas2r173:0.0314158784,Tas2r135:0.0225176586)98:0.0153045133)99:0.0268025661)100:0.0294886198)70:0.0507617340)100:0.4124915000,(Tas2r79:0.0365537537,((Tas2r90:0.3594554445,(Tas2r41:0.0386405135,(Tas2r40:0.0592842307,Tas2r39:0.0525200185)94:0.0127171446)85:0.0319693520)50:0.0074784263,(Tas2r141:0.0639167671,((Tas2r91:0.0642381630,Tas2r76:0.0302253459)63:0.0156306606,((Tas2r71:0.0404184613,Tas2r42:0.0781554815)60:0.0240534711,(((Tas2r168:0.0392442585,(Tas2r144:0.0626644090,Tas2r88:0.0075889622)49:0.0076420000)28:0.0000020558,((Tas2r174:0.0313514889,Tas2r172:0.0188263313)56:0.0115077786,(Tas2r112:0.0324683034,(Tas2r154:0.0000020678,Tas2r116:0.0917640216)80:0.0227718730)31:0.0076887824)43:0.0085360609)57:0.0076801325,(((Tas2r81:0.1003028924,Tas2r56:0.1153996811)61:0.0346100423,(Tas2r170:0.0277376020,(Tas2r151:0.0356884763,Tas2r80:0.0436086611)97:0.0156274481)89:0.0241393709)48:0.0035286163,((Tas2r128:0.0157032302,(Tas2r159:0.0328202213,(Tas2r118:0.0320286443,(Tas2r117:0.0154906185,Tas2r110:0.0231791657)100:0.0076475836)100:0.0236005531)90:0.0077476315)97:0.0235595489,(((Tas2r70:0.0233736030,Tas2r58:0.0000023920)97:0.0154745833,(Tas2r38:0.0312916533,(Tas2r147:0.0730453646,Tas2r114:0.0394108088)88:0.0072800441)68:0.0000028836)73:0.0077118939,(Tas2r148:0.0406912952,((Tas2r166:0.0295704967,Tas2r145:0.0435099806)52:0.0118452595,(Tas2r157:0.0000020131,(Tas2r158:0.0230924821,Tas2r89:0.0467196220)64:0.0000020131)52:0.0000020607)49:0.0077592048)83:0.0076807917)55:0.0000023854)39:0.0077864861)38:0.0076415499)43:0.0083054450)36:0.0000021949)71:0.0224108260)36:0.0000023810)77:0.0274314002)100:0.5002302060)91:0.0716097415)67:0.0387171238)69:0.0434828346)94:0.2010381700)96:0.2986806584)71:0.1615257916)93:0.1977459513)67:0.1318214091)80:0.0910810628)90:0.4352915788)51:0.0499788919)12:0.0624487568)27:0.0636286599)52:0.2180757861);


Note: The 11 differentially expressed Tas2r genes selected for assays (6 highly expressed in tadpoles and 5 highly expressed in adults) are Tas2r1, Tas2r26, Tas2r32, Tas2r55, Tas2r99, Tas2r127, Tas2r16, Tas2r38, Tas2r137, Tas2r143 and Tas2r175.