# y: yellow location: 1-0.0. references: Morgan and Bridges, 1916, Carnegie Inst. Washington Publ. No. 237: 27, 33. Brehme, 1941, Proc. Nat. Acad. Sci. USA 27: 254-61. Waddington, 1941, Proc. Zool. Soc. London A III: 173-80. Sutton, 1943, Genetics 28: 210-17. Hannah, 1953, J. Exp. Zool. 123: 523-60. Lefevre, 1970, DIS 45: 32. Nash and Yarkin, 1974, Genet. Res. 24: 19-26. Lefevre, 1976, Genetics and Biology of Drosophila (Ashburner and Novitski, eds.). Academic Press, London, New York, San Francisco, Vol. 1a, pp. 31-66. Nash, 1976, Dev. Biol. 48: 336-43. Green, 1980, Ann. Rev. Genet. 14: 109-20. Lefevre, 1981, Genetics 99: 461-80. Modolell, Bender, and Meselson, 1983, Proc. Nat. Acad. Sci. USA 80: 1678-82. Nash, Kamerow, and Merril, 1983, Biochem. Genet. 21: 1135-41. Biessmann, 1985, Proc. Nat. Acad. Sci. USA 82: 7369-73. Campuzano, Carramolino, Cabrera, Ruiz-Gomez, Villares, Boronat, and Modolell, 1985, Cell 40: 327-38. Mason, 1985, Genetics 110: s33. Biessmann and Green, 1986, J. Mol. Biol. 191: 573-76. Chia, Howes, Martin, Meng, Moses, and Tsubota, 1986, EMBO J. 5: 3597-3605. Geyer, Spana, and Corces, 1986, EMBO J. 5: 2657-62. Parkhurst and Corces, 1986, Mol. Cell. Biol. 6: 47-53. Geyer and Corces, 1987, Genes Dev. 1: 996-1004. Biessmann and Mason, 1988, EMBO. J. 7: 1081-86. Geyer, Green, and Corces, 1988a, Proc. Nat. Acad. Sci. USA 85: 3938-42. Geyer, Richardson, Corces, and Green, 1988b, Proc. Nat. Acad. Sci. USA 85: 6455-59. phenotype: The yellow locus controls the melanotic pigment pat- tern of the cuticle of the adult fly and the pigmented mouth parts and denticle belts of the larval cuticle. y mutants can be separated into the following phenotypic classes, each group involving a color change from gray-black to yellow-brown (Nash, 1973, Genetics 74: s191): (1) Mutants that show a total loss of pigmentation from the cuticle (y-type) and (2) mutants that show a mosaic pigment pattern, some regions of the cuticle being wild type and others yellow in color (y2- type). In the latter type of mutants, at least 40 different adult cuticular structures can express their color indepen- dently (Nash and Yarkin, 1974); phenotypes of these mutants indicate that they may play a regulatory role in the expres- sion of yellow (Chia et al., 1986). Some of these type (2) mutants are not temperature-sensitive; others are heat- or cold-sensitive (Nash et al., 1983). For the most part, the yellow gene is autonomous in mosaics, but there is some nonau- tonomy over limited distances (Hannah, 1953). The function of the gene product in the pigmentation process is still unknown (Biessmann, 1985; Geyer et al., 1986). Hemizygous males are at a mating disadvantage when paired with wild type females (Bastock, 1956, Evolution 10: 421-39), exhibiting a reduced level of locomotion and abnormal courtship (Wilson, Burnet, Eastwood, and Connolly, 1976, Genet. Res. 28: 75-88; Burnet and Wilson, 1980, Genet. Res. 36: 235-47). alleles: Mutant alleles (but not revertants) are tabulated below. Deficiencies are described in the rearrangement sec- tion. Table I includes extant alleles from Russia, Table IIa extant alleles, Table IIb lost alleles. Table I( alleles origin | comments cytology ______________________________________________________________ yA66c / ray like y1 yA71k1 / ray like yc4 yA71l2 / ray like y1 yA72a / ray like y1 yA72d1 / ray like y1 yA72d3 / ray like y1 In(1)1B1-2;20A yA72d4 / ray like y1 yA74b46 C+/ ray like y1 yA74b51 C+/ ray like yc4 In(1)1B1-2;20D yA74b121 C+/ ray like y1 yA74c40 C+/ ray like y1 T(1;4)1B1-2;101F yA74c166 C+/ ray like yc4 In(1)1B4-9;9D yA74d1 C+/ ray like y1 yA74e / ray like y1 In(1)1B1-2;20D yA74e3 spont like y1 yA75l2 / ray like y1 yA76a110 / ray like *y39e yA76a123 / ray like y1 yA76b37 / ray like yc4 T(1;2)1B1-2;60F yA76b94 / ray like ytd In(1)1B1-2;16C8 yA77d neutrons like yc4 yA77f AD+/ ray like y1 yA78j / ray like y1 T(1;3)1B1-2;82A1 yA79b18 / ray like y1 yA79b21 / ray like y1 In(1)1B1-2;16D yA79d neutrons like y1 T(1;2)1A6-B2;23E5 yA79d2 / ray like y1 In(1)1B1-2;20A-B yA79d3 / ray like y1 yA79dsd neutrons+/ ray females like y2; males like yc4 yA79g / ray like y1 yA79h1 / ray like y1 yA81c1 / ray like y1 yA81c2 / ray like y1 yA81c3 / ray like y1 yA81k29 / ray like yc4 yA82c1 / ray like y1 yA82c2 / ray like y1 yA82c3 / ray like y1 yA83c / ray lethal yA83f12 / ray like y1 yA83f26 / ray like y1 yA83f58 / ray like y2s yA83fXL X ray like y1 In(1)1B1-2;20E-F yA84dS spont like y1 yA84eS spont like y1 yA84e61S spont like y1 ( Reference for all alleles: Alexandrov, Ankina, and Alexan- drova, 1985, DIS 61: 212-13. | Other information: C = caffeine; AD = actinomycin-D. Table IIa alleles origin discoverer ref ( name and/or comments cytology ________________________________________________________________________________________________________________________________________________ y1 spont E.M. Wallace, 11a 2-5, 11, adult body yellow, hairs and 17-19, bristles brown with yellow tips, 24, 33, wing veins, hairs yellow; 47-49, larval setae, mouth parts yellow 57 to brown y1#4 HD Green 18 like y1 y1#6 HD Green 18 like y1 y1#7 HD Green 18 like y1 y1#8 HD Green 18 like y1 y2 spont Bridges, 25j26 2, 5, 8, adult body yellow, hairs and 10, 17, bristles black, wing veins gray; 21, 24, larval mouth parts wild type; 33, 39, y2/y35a like y+/y+; reverts to 48-49, y1 with X rays or mutator gene; 51, 57 suppressed by su(Hw)2 y2#1 HD 18 like y2 y2#4 HD 18 like y2 y2S spont Bridges 2, 5, adult body darker than y2, 48-49, bristles lighter; larval mouth 51, 57 parts golden-brown, mouth hooks light y3d spont Sturtevant, 1933 2, 5, adult body and bristles yellow, 48-49 wings gray; larval mouth parts yellow, mouth hooks light y3M spont Muller 46 like *y3 y3P | X ray Patterson, 31e25 2, 5, 10, adult body tan, most bristles In(1)1B1-2;20 45, 48a, 49, black, although patches of yellow 52, 59 bristles and hairs; larval mouth parts light at prongs y4 X ray Serebrovsky 2, 10, 15, like y1 In(1)1A8-B1;18A3-4 48, 51 y16 EMS 48 adult body yellow; larval mouth parts and microsetae yellow y18CH1 Muller 48-49 like y1 y25 51 adult body yellow y31d X ray Patterson, 31d 5, 49, like y2; larval mouth parts in In(1)sc8 53, 59 light at prongs; y31d/y35a like y31d/y31d y31e see y3P y34c spont Curry, 34c13 2, 13, 48, adult body and antennae tan; 49, 57 larval mouth parts like y1; viability excellent y50k X ray Green 22 like y1 y53i X ray Luning, 53i 32 y/y53iY fertile y54j spont Mohler, 55j24 40 adult body and antennae yellow, bristles brownish, wings almost wild type; y54j/y1 intermediate in color, may overlap y54j homozygotes y56k 48 like y1 y59b X ray Green 8, 21, like y1; y59b complements y2sc+, 22, 48 but does not complement y2 sc y59c spont Clancy, 59c 12, 48, like y1 49 y60b X ray Green 22 like y1 y61d on tritiated Hughes, Hildreth 28 body pale yellow, bristles medium yellow, wings wild type y62a spont Ehrlich, 62a 2, 35, 48, adult body yellow, bristles, 49 hairs brown; tip of male abdomen black; y62a/y2 like y2, y62a/y1 like y1 y62d 2 like y1 y62k19 spont Pratt, 62k19 13 like y1 y65f4 X ray Lefevre, 65f4 31 body darker than in y2, In(1)1B2-3;1B14-C1 bristles dark; fertile y67j EMS Williamson 65 adult body yellow, bristles black in y/BSYy67j y67k5 X ray Lefevre, 67k5 31 yellow; male viable, fertile T(1;3)1B1-2;98C y68c 48 like y1 y68d EMS Hayman, Maddern 23a like y1 y68e EMS Hayman, Maddern 26a like y2 y68h EMS Hayman, Maddern 26a like y1 y70a Gethmann 48 like y2 y71f spont Whitney, Lucchesi 64 like y1 y72a spont Thompson 48 like y2 y72k Green 22a y73d spont Periquet, 73d 1a like y1 y74i EMS Craymer, 74i3 14 like y1 y75 Lefevre 48 like y2 y76d28 HD Geyer 18 adult cuticle tan, many revertants y80e14(6) HD Green 2, 3 like y1 y80h16 HD Green 2, 3 like y1 y82 spont Blount 3a like y1 yA3-2 MR Green 24 adult body and bristles yellow; yA3-2/y2 like y2 yA3-5 MR Green 24 adult body and bristles yellow; yA3-5/y2 like y+ yA3-20 MR Green 24 adult body and bristles yellow; yA3-20/y2 like y+ ybab spont Hanks, Newlin 8, 25, 26, yellow-brown abdomen; 48-49 abdomen brown where black in wild type yBC16 HD Adler 2 like y1 ybg Muller 2, 48-49 like y2 ybl spont Sandler 2, 8, 48, yellow bristle; body color Dp(1;1)1B2-3;4F8-9;5D4-5 49, 56 wild type, bristles yellow; changes to y+ and y1; ybl/y1 like ybl; ybl/y2 like y+ yc spont 24 yellow-complementing; body and bristles yellow; yc/y2 almost wild type yc4 / spont Muller 16, 21, like y1 but bristles darker; in In(1)ScS1+S 44, 51 yc4/yS1 like yc4; yc4/y2 wild type; yc4/y2 sc like y2 yCAA1 HD Adler 2 like y1 yCAF2 HD Adler 2 like y1 yCAG1 HD Adler 2 like y1 yCAM3 HD Adler 2 like y1 yCAP1 HD Adler 2 like y1 yci-X spont Muller 7 yellow-cubitus In(1)1A;20 ycts EMS Craymer, 74f 2, 14 yellow-complementing-ts; y+ at 18; like y1 but lighter at 25; ycts/y2 same at all temperatures yCU2 HD Adler 2 like y1 yd28 MR Green 23, 24 like y2; a few reversions yEMS-112 EMS Nash 48a like y1; no yellow protein in wing yEMS1-35c EMS 48 like y1 yf22 MR Green 23 like y1; a few reversions yhd1 to yhd14 HD Chia 11 yellow-hybrid-dysgenesis; like y1 yj22 MR Green 24 adult body and bristles yellow; yj22/y2 like y2; y+ reversions yM spont Nash 48-49 like y2 except for variegation in sex combs and some bristles yM1 spont Nash 48-49 like y2 except for variegation in some cell types yM2 spont Nash 48-49 like y1; no yellow protein in wing yM2v spont Nash 2, 48 like y2 yNeb X ray Graham 57 like y1 except eyes duller yntg NNG Kaufman 29, 48 like y2; y/yntg are y2 yox 2, 48 like y2 yP59 spont Perkovic, 59h 36 yellow of Perkovic; adult body, wings yellow, bristles dark yP~~ HD Engels like y1 ypx bl see *yG yr2 spont 48 some cuticle structures show y variegation at 16; wild type above 26 yR1 X ray Roberts 55 yellow of Roberts; T(1;2;3)1B4-8;12F;21D2;41;97F male viable, fertile yR2 X ray Roberts 55 male viable, fertile yR3 X ray Roberts 55 male viable, fertile T(1;2)1B2-3;1E2-3;35F yR4 X ray Roberts 55 female sterile yR5 X ray Roberts 55 male viable, fertile yR6 X ray Roberts 55 male viable, fertile yR7 X ray Roberts 55 male viable, sterile T(1;2)1A6-B1;49F yR8 X ray Roberts 55 male lethal T(1;2;3)1A6-B1;47A;67D yR9 X ray Roberts 55 female sterile yR10 X ray Roberts 55 male viable, fertile In(1)1A5-B1;20 yR11 X ray Roberts 55 male viable, fertile yR12 X ray Roberts 55 male viable, fertile yR17 X ray Roberts 55 male viable, fertile yR19 X ray Roberts 55 male viable, fertile T(1;3)1A5-B1;87A yR20 X ray Roberts 55 male lethal In(1)1A6-8;1E2-3 yR21 X ray Roberts 55 male viable, fertile yR22 X ray Roberts 55 male viable, fertile yR23 X ray Roberts 55 female sterile yR24 X ray Roberts 55 male lethal yR25 X ray Roberts 55 female sterile yR26 X ray Roberts 55 male viable, sterile T(1;3)17C;70C (?) yR28 X ray Roberts 55 male lethal yR29 X ray Roberts 55 male viable, sterile T(1;2;4)1E4-F1;20;26A;35BC;101 yR30 X ray Roberts 55 male viable, fertile ys see yc4 yS1 spont Singh, 1940 48, 58 yellow of Singh; like y1 In(1)1B2-3;20F ySi see yc4 ytd spont Spencer, 361 5, 6, 48, yellow-tanoid; adult body 49, 57 rich tan, antennae light yellow, bristles black; larval mouth parts golden brown yts1,2,3 EMS Nash 48 yellow-ts; temperature- sensitive (body cuticle) yts4,5,6 EMS Nash 48, 48a like y2, but temperature sensitive (for sex combs, wing bristles, and, except for yts5, bristles of head, thorax, abdomen); no yellow protein in wing yv2 spont Schultz, 35k1 2, 5, 48, yellow-variegated; adult body 57 color mostly wild type, head bristles mostly black, thoracic bristles often yellow; larval bristles dark with lighter basal prongs ywm4 48 yellow-white-mottled; like y2 Table IIb alleles origin discoverer ref ( name and/or comments cytology ____________________________________________________________________________________________________________________________________________________________ *y1S X ray Schultz, 34k15 5 like y1 *y3 spont Morgan, 26a 5, 48 adult body tannish; bristles dark brown to black, hairs yellow to black; larval mouth parts golden at basal prongs; mouth hooks, mentum wild type *y5 Patterson 13 male lethal In(1)1A-B;14D *y6 X ray 5 body yellow, bristles brown with yellow tips; larval mouth parts like y1 *y31b X ray Patterson, 31b 5, 48 like y1; some sc variegation in In(1)sc8 *y31c X ray Patterson, 31c 5 bristles black with some y in In(1)sc8 variegation; larval mouth parts as in y3 *y35a X ray Stone, 35a 59 like y1; larval mouth parts golden; y35a/y1 like y1; y35a/y2 wild type; y35a/y31d like y31d or y2 *y39e spont Mather, 39e15 34 body yellow, bristles brown *y40a spont Buzzati-Traverso 9 like y2 *y50e spont Thoday 62 *y51g spont Redfield, 51g 22, 54 body yellow, bristles like y2 *y53e X ray Luning, 53e12 32 homozygous lethal *y62b radio Mickey, 62b21 38 waves *y62k spont Mickey, 62k8 38 *y94-1 spont Moree, 46f6 41, 42 like y1 *y260-11 X ray Sutton, 39a 60 like y1; male viable but sterile T(1;3)1B2-3;85F1-5 *y260-12 X ray Sutton, 1939 60 like y1 *y260-13 X ray Sutton, 1939 60 body wild type, bristles yellow; T(1;2)1A4-5;36D reduced fertility in males *y260-21 X ray Sutton, 1939 60 y260-21/y1 like y1; male lethal *y260-24 X ray Sutton, 1939 60 like y1 *y260-28 X ray Sutton, 39l26 60 like y1; reduced male viability *y260-30 X ray Bishop, 1940 60 like y1 *y260-31 X ray Fano, 1941 60 y260-31/y1 like y1; homo- and hemizygous lethal *yG ` spont Goldschmidt 20 yellow of Goldschmidt; like y2 In(1)1A;1C3-4 *yH51 spont Tanaka, 37e30 61 yellow from Hakozaki; body, wings, legs yellow; bristles, hairs black *yN X ray Neuhaus 50 yellow of Neuhaus; body color wild type; yN/y1 like yN; yN/y2 like wild type *yo spont Kiil, 43k18 30 yellow-orange; body yellow, bristles, hairs black *ys spont Cattell, 12d 43 yellow-spot; large yellow spots on dorsal midline near tip of abdomen, on scutellum, and in narrow stripe along thorax *yS61 spont Shuman, 61f 37 yellow of Schuman; like y1 *yv1 X ray Schultz, 33a11 6 yellow-variegated *yv56 X ray Hinton, Smith 27 variegated for y; suppressed by extra Y chromosomes ( 1 = Anxolabehere and Periquet, 1973, DIS 50: 21; 2 = Biessmann, 1985, Proc. Nat. Acad. Sci. USA 82: 7369-73; 3 = Biessmann and Green, 1986, J. Mol. Biol. 191: 573-76; 3a = Blount, 1982, DIS 58: 154; 4 = Brehme, 1937, Proc. Soc. Exp. Biol. Med. 37: 578-80; 5 = Brehme, 1941, Proc. Nat. Acad. Sci. USA 27: 254-61; 6 = Bridges, 1937, DIS 7: 16; 7 = Brosseau, 1969, DIS 44: 45; 8 = Burnet and Wil- son, 1980, Genet. Res. 36: 235-47; 9 = Buzzati-Traverso, 1940, DIS 13: 49; 10 = Campuzano, Carramolino, Cabrera, Ruiz-Gomez, Villares, Boronat, and Modolell, 1985, Cell 40: 327-38; 11 = Chia, Howes, Martin, Meng, Moses, and Tsu- bota, 1986, EMBO J. 5: 3597-3605; 12 = Clancy, 1960, DIS 34: 48; 13 = CP627; 14 = Craymer, 1980, DIS 55: 197-200; 15 = Dubinin and Friesen, 1932, Biol. Zentralbl. 52: 147- 62; 16 = Frye, 1960, DIS 34: 49; 17 = Geyer, Green, and Corces, 1988, Proc. Nat. Acad. Sci. USA 85: 3938-42; 18 = Geyer, Richardson, Corces, and Green, 1988, Proc. Nat. Acad. Sci. USA 85: 6455-59; 19 = Geyer, Spana, and Corces, 1986, EMBO J. 5: 2657-62; 20 = Goldschmidt, 1945, Univ. Calif. Publ. Zool. 49: 307, 398-401; 21 = Green, 1961, Genetics 46: 671-82, 1385-88; 22 = Green, 1962, Genetics 47: 483-88; 22a = Green, 1975, Mutat. Res. 29: 77-84; 23 = Green, 1977, Proc. Nat. Acad. Sci. USA 74: 3490-93; 24 = Green, 1979, Mutat. Res. 59: 291-93; 25 = Hanks and Newlin, 1968, DIS 43: 61; 26 = Hanks and Newlin, 1969, DIS 44: 47; 26a = Hayman and Maddern, 1968, DIS 44: 50; 27 = Hinton and Schmidt, 1956, DIS 30: 121; 28 = Hughes and Hildreth, 1967, DIS 42: 86-87; 29 = Kaufman, 1970, DIS 45: 34; 30 = Kiil, 1946, DIS 20: 66; 31 = Lefevre, 1970, DIS 45: 32; 32 = Luning, 1953, DIS 27: 58; 33 = Mason, 1985, Genetics 110: s33; 34 = Mather, 1941, DIS 14: 39; 35 = McCloskey, 1963, DIS 37: 50; 36 = Meyer, 1959, DIS 33: 97; 37 = Meyer, 1963, DIS 37: 51; 38 = Mickey, 1963, DIS 38: 29; 39 = Modolell, Bender, and Meselson, 1983, Proc. Nat. Acad. Sci. USA 80: 1678-82; 40 = Mohler, 1956, DIS 30: 79; 41 = Moree, 1946, DIS 20: 66; 42 = Moree, 1947, DIS 21: 69; 43 = Morgan and Bridges, 1916, Carnegie Inst. Washington Publ. No. 237: 27, 33; 44 = Muller, 1946, DIS 20: 68; 45 = Muller and Prokofyeva, 1935, Proc. Nat. Acad. Sci. USA 21: 16-26; 46 = Muller and Valencia, 1947, DIS 21: 70; 47 = Nash, 1975, Genetics 80: s60-61; 48 = Nash, 1976, Dev. Biol. 48: 336-43; 48a = Nash, Kam- erow, and Merril, 1983, Biochem. Genet. 21: 1135-41; 49 = Nash and Yarkin, 1974, Genet. Res. 24: 19-26; 50 = Neuhaus, 1936, DIS 5: 26; 51 = Parkhurst and Corces, 1986, Mol. Cell. Biol. 6: 47-53; 52 = Patterson, 1934, DIS 1: 31; 53 = Patterson, 1935, DIS 4: 12; 54 = Redfield, 1952, DIS 26: 68; 55 = Roberts, 1974, Mutat. Res. 22: 139-44; 56 = Sandler, Hart, and Nicoletti, 1960, DIS 34: 103-4; 57 = Sanger, 1969, DIS 44: 45; 58 = Singh, 1940, DIS 13: 75; 59 = Stone, 1935, DIS 4: 62-63; 60 = Sutton, 1943, Genetics 28: 210-17; 61 = Tanaka, 1937, DIS 8: 11; 62 = Thoday, 1954, DIS 28: 78; 63 = Thompson and Purnell, 1972, DIS 48: 16; 64 = Whitney and Lucchesi, 1972, DIS 49: 35; 65 = Williamson, 1968, DIS 43: 65. | Synonym: y31e. / Synonym: ys (Muller, 1946; preoccupied); ySi (Green, 1961; error). ` Synonym: ypx-bl: yellow-plexus blistered. cytology: Located at the tip of the X chromosome at 1B1 on the cytological map (Lefevre, 1976, 1981). molecular biology: The yellow locus has been cloned by chromo- some walking (Biessmann, 1985) and a y transcript of 1.9-2.1 kb identified (Biessmann, 1985; Campuzano et al., 1985; Chia et al., 1986; Parkhurst and Corces, 1986). The transcript consists of two exons processed in both larval and pupal stages into an mRNA of 1990 bp. The nucleotide sequence of yellow genomic DNA has been determined (Geyer et al., 1986; Geyer and Corces, 1987), and the amino acid sequence of the yellow protein predicted from it. Breakpoints of chromosomal aberrations of type 1 and type 2 mutants have been located on the molecular map. Most of the type 1 mutants show structural lesions in the yellow coding region; a majority of the type 2 lesions, however, have been mapped 5' to the transcription start point (Biessmann, 1985; Biessmann and Green, 1986; Chia et al., 1986; Biessmann and Mason, 1988). The allele y2 is associated with the insertion of the transposable element gypsy 700 bp distal to the yellow coding region (Biessmann, 1985; Parkhurst and Corces, 1986); revertants of y2 are obtained by excision of gypsy, leaving behind a long terminal repeat (LTR) (Geyer et al., 1986) or by replacing the central part of gypsy with another transposable element, wallaby, and leaving behind all of the 3' LTR and half of the 5' LTR (Geyer et al., 1988a). Another allele, y76d28, results from the insertion of a P element into the 5' untranslated part of the yellow gene (Geyer et al., 1988b). A high frequency of rever- sion occurs among the progeny of y76d28 males carrying the element. Each revertant carries residual P-element DNA in the 5' untranslated region. Sequence analysis of several pheno- typically wild-type revertants shows imprecise excision of P- element sequences within the inverted repeats (20 bp remaining in y+1, 4 in y+13, 7 in y1#7+, and 340 in y+13-11) (Geyer et al., 1988b). Sequencing of two y mutants arising from the revertant y+13-11 indicates that these mutants are produced by insertion of another P-element at the exact site of the origi- nal one without duplication of P DNA or y DNA. P-element- mediated transformations of mutants with plasmids carrying y DNA with various deletions in the 5' region show which sequences are responsible for regulation of y transcription in wings, body, and bristles of adults and mouth parts and denti- cle belts of larvae (Geyer and Corces, 1987). The same upstream controlling regions have also been identified using terminal chromosome deficiencies (Biessmann and Mason, 1988). The yellow polypeptide (60,752 daltons) was localized by immuno-histochemical techniques in the epidermis and adult cuticle of three- and four-day old pupae. Its expression pre- cedes visible melanin deposition by 26 hours. Spatial distri- bution anticipates the later cuticular melanization pattern. Expression in the embryo was detected in the head region, at the ventral setal belts, and in cells scattered near the ven- tral nerve cord (Walter, Black, Afshar, Kermabon, Wright, and Biessmann, 1991, Dev. Biol.). # Ybb: see bbY # Y2: see fs(1)Ya # yea: yeast origin: Induced by ethyl methanesulfonate. references: Falk and Nash, 1974, Genetics 76: 755-66. phenotype: A group of genes (all sex-linked) whose mutants require the addition of dead yeast to the standard sucrose Drosophila medium in order to show either normal viability or normal rate of development under certain temperature condi- tions. Some mutants are sensitive to cold or to heat even on yeast-supplemented media. These yeast-auxotroph genes are described in the following table: genetic number temperature effects ( locus location of alleles with yeast without yeast ____________________________________________________________________________________ yea1 | 1-37 1 lethal at 18; viable lethal or almost lethal at at 25 and 29 temperatures tested yea2 1-16 1 viable at 29 viable at 20; lethal at 29 yea3 1-0.8 1 viable at 18 and 25; lethal at 25 lethal at 29 yea4-1 / 1-(3-5) 2 develop normally at 29 develop slowly at 29 -2 / viable at 29 lethal at 29 yea5 1-66 1 viable at 18 and 25; lethal at 25 lethal at 29 yea6 1-45 1 viable at 29 viable at 20; lethal at 29 yea7 1-53 1 develop normally develop slowly at 29; at 29 (delay of four to five days) ( Temperatures used in tests given in table. | Females sterile. / Noncomplementing mutant alleles; yea4-1 shows a developmen- tal delay of about three to five days when grown without yeast at the high temperature. # yellow: see y # yem: yema location: 3- {99}. origin: Differential screen for genes active during oogenesis whose transcripts disappear at gastrulation. references: Ait-Ahmed, Thomas, Cavallin, and Rosset, 1987, Dev. Biol. 122: 153-62. phenotype: Cluster of maternal effect genes active in oogenesis that have been isolated through their messenger RNAs and located by molecular methods at the distal end of 3R. cytology: Located in 98F3-10 by in situ hybridization. molecular biology: Genomic clone obtained that codes for four transcripts of 4.5, 4, 2.8, and 2.6 kb that are synthesized during oogenesis, are abundant throughout the preblastoderm embryo, and disappear during gastrulation. All of the tran- scripts show germ line specific expression in the female. The 4 kb transcript seems to be synthesized in the nurse cells and is transferred to the oocyte; it reappears at postembryonic stages (Ait-Ahmed et al., 1987). # yl: yolkless location: 1-48. origin: Induced by ethyl methanesulfonate. references: Waring, DiOrio and Hennen, 1983, Dev. Biol. 100: 452-63. Mohler and Carroll, 1984, DIS 60: 236-41. Perrimon, Mohler, Engstrom, and Mahowald, 1986, Genetics 113: 695-712. phenotype: Female-sterile locus affecting late oogenesis. Eggs of mutants lack proteinaceous yolk and collapse; ultrastruc- turally abnormal chorion at anterior end and especially at base of respiratory filaments. No abnormality detectable in chorion protein synthesis. Uptake of the three yolk proteins by yl oocytes is severely reduced, although the proteins accu- mulate in the hemolymph. alleles: allele synonym ref ( _________________________________ yl1 fs(1)29 4 yl2 fs(1)117 4 yl3 fs(1)445 4 yl4 fs(1)A148 1 yl5 fs(1)A305 1 yl6 fs(1)A332 1 yl7 fs(1)A1061 1 yl8 fs(1)A1081 1 yl9 fs(1)A1130 1 yl10 fs(1)A1186 1 yl11 fs(1)K184 2 yl12 fs(1)K294 2 yl13 fs(1)K621 2 yl14 fs(1)11-73 3 yl15 fs(1)11-380 3 yl16 fs(1)11-432 3 yl17 fs(1)12-1259 3 yl18 fs(1)12-2252 3 yl19 fs(1)12-5004 3 yl20 fs(1)12-5262 3 yl21 fs(1)14-465 3 yl22 fs(1)5(2) 3 yl23 fs(1)205(2) 3 yl24 fs(1)L186(3) 3 yl25 fs(1)L193(3) 3 yl26 fs(1)L196(3) 3 yl27 fs(1)L211(3) 3 ( 1 = Gans, Audit, and Masson, 1975, Genetics 81: 683-704; 2 = Komitopoulou, Gans, Margaritis, Kafatos, and Masson, 1983, Genetics 105: 897-920; 3 = Mohler and Carroll, 1984, DIS 60: 236-41; 4 = Waring, DiOrio, and Hennen, 1983, Dev. Biol. 100: 452-63. cytology: Located in 12E1-12F1, the region of overlap between Df(1)g-l = Df(1)11F10;12F1 and Df(1)KA9 = Df(1)12E1;13F5 (War- ing et al., 1983). # Ylt: see PinYt # yok: yolky origin: Induced by ethyl methanesulfonate. references: Eberl and Hilliker, 1988, Genetics 118: 109-20. phenotype: Mutants are embryonic lethals with an undispersed yolk plug and no visible Malpighian tubules. Cuticle pheno- type normal. alleles: allele synonym ______________________ yok1 l(1)EH160 yok2 l(1)EH272 yok3 l(1)EH328 yok4 l(1)EH352 cytology: Located in 2D1-3A. Included in y+Y. # Yolk protein: see Yp # yolkless: see yl # yolky: see yok # Yp: Yolk protein Three yolk proteins, YP1, YP2 , and YP3, are synthesized in the fat body and ovarian follicle cells of wild-type adult female flies (Gelti-Douka et al., 1974; Kambysellis, 1977; Bownes and Hames, 1978; Bownes, 1979; Brennan et al., 1980, 1982; Postlethwait and Shirk, 1981). These proteins are the major tyrosine-sulfonated proteins in female flies (Baeuerle and Huttner, 1985). After their synthesis, the yolk proteins are secreted into the hemolymph and transported to the egg, where they are converted into the mature form and packaged in the yolk granules (Warren et al., 1979; Brennan et al., 1982). Fat body cells produce approximately equal amounts of YP1, YP2, and YP3 mRNA and protein, but follicle cells synthesize considerably less YP3 transcript and gene product (Barnett et al., 1980; Brennan et al., 1982; Williams and Bownes, 1986). Ovaries transplanted from females into male hosts produce some YP mRNA and protein, but female fat cells transplanted into male hosts do not (Kambysellis, 1977; Postlethwait et al., 1980). The three YP proteins are of similar molecular weight [approximately 44,700-47,000 daltons (Bownes and Hames, 1977; Hames and Bownes, 1978; Warren and Mahowald, 1979; Bownes, 1982)], but have different isoelectric points (Warren and Mahowald, 1979). Each protein is encoded by a single copy, X-linked gene, Yp1, Yp2, or Yp3 (Barnett et al., 1980). Regu- lation occurs by means of 20-hydroxyecdysone (involved in the accumulation of Yp transcripts in the fat body of females) and juvenile hormone (involved in the development of ovarian fol- licles) (Postlethwait and Handler, 1979; Jowett and Postlethwait, 1980; Bownes, 1982a, 1982b, 1986). Male and female larvae and adult males do not normally produce YPs. Some yolk protein, however, is produced in males injected with 20-hydroxyecdysone; juvenile hormone does not induce YP syn- thesis in male flies (Postlethwait et al., 1980; Bownes and Nothiger, 1981; Bownes, 1982; Bownes et al., 1983a). The pro- ducts of the sex-determining genes, ix, tra, tra2, and dsx may influence the expression of the yolk protein genes (Bownes et al., 1983b; Belote, Handler, Wolfner, Livak, and Baker, 1985, Cell 40: 339-48; Kraus et al., 1988). X/X flies carrying tra/tra, tra2/tra2, or dsxD/dsx do not produce detectable amounts of yolk protein, but intersexes carrying ix/ix, dsx/dsx, or dsxD/+ do synthesize YPs (although in reduced amounts) (Bownes and Nothiger, 1981; Bownes et al., 1983b). references: Gelti-Douka, Gingeras, and Kambysellis, 1974, J. Exp. Zool. 187: 167-72. Kambysellis, 1977, Amer. Zool. 17: 535-49. Bownes and Hames, 1977, J. Exp. Zool. 200: 149-56. 1978, J. Embryol. Exp. Morphol. 47: 111-20. Hames and Bownes, 1978, Insect Biochem. 8: 319-28. Postlethwait and Handler, 1979, J. Insect. Physiol. 25: 455- 60. Warren, Brennan, and Mahowald, 1979, Proc. Nat. Acad. Sci. USA 76: 2848-52. Warren and Mahowald, 1979, Dev. Biol. 68: 130-39. Barnett, Pachl, Gergen, and Wensink, 1980, Cell 21: 729-38. Bownes and Hodson, 1980, Mol. Gen. Genet. 180: 411-18. Brennan, Warren, and Mahowald, 1980, J. Cell Biol. 87: 516- 20. Jowett and Postlethwait, 1980, Dev. Biol. 80: 225-34. Postlethwait, Bownes, and Jowett, 1980, Dev. Biol. 79: 379- 87. Postlethwait and Jowett, 1980, Cell 20: 671-78. Bownes and Nothiger, 1981, Mol. Gen. Genet. 182: 222-28. Hovemann, Galler, Walldorf, Kupper, and Bautz, 1981, Nucleic Acids Res. 9: 4721-34. Hung and Wensink, 1981, Nucleic Acids Res. 9: 6407-19. Postlethwait and Shirk, 1981, Amer. Zool. 21: 687-700. Riddell, Higgins, McMillan, and White, 1981, Nucleic Acids Res. 9: 1323-38. Bownes, 1982a, J. Insect. Physiol. 28: 317-28. 1982b, Q. Rev. Biol. 57: 247-74. Brennan, Werner, Goralski, and Mahowald, 1982, Dev. Biol. 89: 225-36. Hovemann and Galler, 1982, Nucleic Acids Res. 10: 2261-74. Hung, Barnett, Woolford, and Wensink, 1982, J. Mol. Biol. 154: 581-602. Bownes, Blair, Kozma, and Dempster, 1983a, J. Embryol. Exp. Morphol. 78: 249-68. Bownes, Dempster, and Blair, 1983b, J. Embryol. Exp. Morphol. 75: 241-57. Hung and Wensink, 1983, J. Mol. Biol. 164: 481-92. Baeuerle and Huttner, 1985, J. Biol. Chem. 260: 6434-39. Garabedian, Hung, and Wensink, 1985, Proc. Nat. Acad. Sci. USA 82: 1396-1400. Shepherd, Garabedian, Hung, and Wensink, 1985, Cold Spring Harbor Symp. Quant. Biol. 50: 521-26. Bownes, 1986, Annu. Rev. Entomol. 31: 507-31. Garabedian, Shepherd, and Wensink, 1986, Cell 45: 859-67. Saunders and Bownes, 1986, Mol. Gen. Genet. 205: 557-60. Williams and Bownes, 1986, Eur. J. Biochem., 161: 95-101. Garabedian, Shirras, Bownes, and Wensink, 1987, Gene 55: 1-8. Yan, Kunert, and Postlethwait, 1987, Nucleic Acids Res. 15: 67-85. Baeuerle, Lottspeich, and Huttner, 1988, J. Biol. Chem. 15: 14925-29. Kraus, Lee, Lis, and Wolfner, 1988, Mol. Cell Biol. 8: 4756- 64. Wahli, 1988, TIG 4: 227-32. Aprison, Osterbur, and Bonner, 1989, Dev. Genet. 10: 24-32. # Yp1 location: 1-30. discoverer: Postlethwait, 80c. phenotype: Structural gene for the yolk protein YP1 found in recently-emerged female flies. Protein migrates at different rates in SDS-polyacrylamide gels when encoded by the electro- phoretic variants Yp1F (fast) and Yp1S (slow), alleles that are female fertile and produce normal amounts of YP1. Yp1ts1, which maps near the Yp1 locus and is believed to be an allele, produces a slow-migrating translation product that is present in reduced amounts in the hemolymph and the ovaries (Bownes and Hodson, 1980); this mutant is female sterile. alleles: Yp1F (=Yp1LC), Yp1S (in Canton-S and Oregon-R stocks), and Yp1ts1. The Yp1ts1 allele is a female sterile mutant [synonym = fs(1)1163 (Bownes and Hodson, 1980)]. It is homoz- ygous female sterile at 18 and homo- and heterozygous female sterile at 29, producing flaccid eggs and reduced amounts of yolk protein at the high temperature (Bownes and Hodson, 1980). Yp1ts1 is female sterile over Df(1)C52, a deficiency for the Yp1 locus (Postlethwait and Shirk, 1981). cytology: Yp1 has been located in 8F-9B by in situ hybridiza- tion of cloned DNA to the salivaries (Barnett et al., 1980; Riddell et al., 1981); cytological location between 9A and 9B since found between the X breakpoints of T(1;Y)B52 = T(1;Y)9A;YL and T(1;Y)J2a = T(1;Y)9B;YS. molecular biology: The gene for YP1 has been cloned from Canton-S wild type and its nucleotide sequence obtained (Bar- nett et al., 1980; Hovemann et al., 1981; Hovemann and Galler, 1982; Hung et al., 1982; Hung and Wensink, 1981, 1983; Riddell et al., 1981). Yp1 is 1635 bp long and present as a single copy, with a short exon followed by a very short intron (76 bp) and a long exon (Hung and Wensink, 1981, 1983). It is transcribed in a proximal to distal direction. The length of the transcript is about 1559 nucleotides plus poly(A) tail; the protein predicted from the nucleotide sequence is made up of 439 amino acids. The mutant Yp1ts1 has been cloned and sequenced (Saunders and Bownes, 1986); the mutant protein was found to differ from the wild-type protein by an amino acid substitution (isoleucine to asparagine) at position 92. Transformation experiments indicate that two enhancer sequences upstream from Yp1 determine its tissue specificity (fat body or follicle cells) (Garabedian et al., 1985, 1986; Shepherd et al., 1985; Tamura, Kunert, and Postlethwait, 1985, Proc. Nat. Acad. Sci. USA 82: 7000-04). A Yp1-Adh fusion gene has been used to transform an Adh- chromosome; adult females (but not adult males or male and female larvae) expressed enzymatically active ADH (Aprison et al., 1989). tra2ts2 homozygotes with two X chromosomes show expression of the fusion gene only when they are raised at 16, the temperature at which they are morphologically female and produce yolk proteins. Endogenous yolk protein genes show the same pattern of temperature expression as the fusion gene in females homozygous for tra2ts (Belote, Handler, Wolfner, Livak, and Baker, 1985, Cell 40: 339-48). # Yp2 location: 1-29.5. discoverer: Postlethwait, 79a. phenotype: Structural gene for the yolk protein YP2 found in recently-emerged female flies. Protein migrates at different rates in SDS-polyacrylamide gels when encoded by the electro- phoretic variants Yp2F (fast) and Yp2S (slow), alleles that are female fertile and produce normal amounts of YP2. A mutant Yp2M (=Yp212-1245) is female fertile but lays fewer eggs than normal (Mohler, Postlethwait, and Shirk) and does not contain yolk protein in the hemolymph or ovaries. alleles: Yp2F (in Canton-S and Oregon-R stocks), Yp2S [=Yp2Po (Postlethwait and Jowett, 1980)], and Yp2M, [induced by Mohler and believed to be a mutant allele (Mohler, 1977, Genetics 85: 259-72; Mohler and Carroll, 1984, DIS 60: 236-41; Tamura et al., 1985)]. cytology: Yp2 has been located in 8F-9B by in situ hybridiza- tion (Barnett et al., 1980; Riddell et al., 1981); cytological location between 9A and 9B since found between the X break- points of T(1;Y)B52 = T(1;Y)9A;YL and T(1;Y)J2a = T(1;Y)9B;YS. molecular biology: The gene for YP2 has been cloned from Canton-S wild type and its nucleotide sequence obtained (Bar- nett et al., 1980; Hovemann et al., 1981; Hovemann and Galler, 1982; Hung et al., 1982; Riddell et al., 1981). Yp2 is 1614 bp long (1225 bp distant from Yp1) and is present as a single copy, with a short exon followed by a very short intron (68 bp) and a long exon (Hung and Wensink, 1983). It is tran- scribed in a distal to proximal direction (opposite from the transcription direction of Yp1). There are two transcripts of 1614 and 1698 nucleotides in length. The protein predicted from the nucleotide sequence is made up of 442 amino acids. Yp1 and Yp2 show about 53% sequence identity (Yan et al., 1987). The site of tyrosine sulfonation has been identified in this secretory protein (Baeuerle et al., 1988); it is simi- lar in amino acid composition and secondary structure to known tyrosine sulfonation sites in vertebrates. # Yp3 location: 1-44. discoverer: Postlethwait, 79g. phenotype: Structural gene for the yolk protein YP3 found in recently-emerged female flies. Protein migrates at different rates in SDS-polyacrylamide gels when encoded by the electrophoretic variants Yp3F (fast) and Yp3S (slow), alleles that are female fertile and produce normal amounts of YP3. Yp3RI, which maps close to the Yp3 locus, has no detectable YP3 protein in the hemolymph or ovary, but is not female sterile (Postlethwait and Jowett, 1980; Postlethwait and Shirk, 1981). alleles: Yp3F (=Yp3CB), Yp3S (in Canton-S and Oregon-R stocks), and Yp3RI, which behaves like a cis-acting regulatory variant and was found by Laurie-Ahlberg in wild stock RI14 (Postlethwait and Shirk, 1981). cytology: Yp3 has been located in 12B-C by in situ hybridiza- tion (Barnett et al., 1980; Riddell et al., 1981); cytological location between 12A6-7 and 12D3, the region deleted from Df(1)HA92 = Df(1)12A6-7;12D3. molecular biology: The gene for YP3 has been cloned from Canton-S wild type and its nucleotide sequence obtained (Bar- nett et al., 1980; Hovemann et al., 1981; Hovemann and Galler, 1982; Hung et al., 1982; Hung and Wensink, 1981; Riddell et al., 1981; Garabedian et al., 1987; Yan et al., 1987). Yp3 is 1624 bp long and present as a single copy. It has two small introns and is transcribed in a distal to proximal direction (Yan et al., 1987). The transcript is about 1499 nucleotides plus poly(A) tail in length; the protein predicted from the nucleotide sequence is made up of 420 amino acids. The mutant Yp3RI produces no translatable message in females, but carries normal amounts of transcripts that hybridize to the Yp3 gene probe (Postlethwait and Shirk, 1981). The overall amino acid sequence identity of the three yolk protein genes is 43% (Gar- abedian et al., 1987). Yp1 and Yp3 show about 53% identity in their amino acid sequences; Yp2 and Yp3 show about 48% iden- tity. These identical sequences occur mainly in translated regions (Yan et al., 1987). Two small regions identical to the Yp1 fat body enhancer region have been found in Yp3 flanking sequences (Garabedian et al., 1987). # yrt: yurt location: 3-52. origin: Induced by ethyl methanesulfonate. references: Jurgens, Wieschaus, Nusslein-Volhard, and Kluding, 1984, Wilhelm Roux's Arch. Dev. Biol. 193: 283-95. phenotype: Embryonic lethal mutation. Embryos show a dorsal posterior hole. alleles: Three alleles identified, *yrt1, yrt2, and yrt3 (weak allele), isolated as 5G, 9G, and 10H. cytology: Located in 87D14-F12; uncovered by Df(3R)l26c = Df(3R)87D14-E1;87F11-12 but not by Df(3R)kar-Sz8 = Df(3R)87C1-2;87D14-E1.