The origin and behavior of cuti; the origin and behvior of S&-ml. I. Review of previous discussion. 1. Attempted to show the action of AC on two diff'crent loci it cant-ols when these are located in two di?fzr~snt chroy;osa:.??ies in the same nucleus. a). Both req?ond .zlike i..m: any one k<::=nel to doses of AC -- 1, 2 and 3 AC. b), Somatic changes in AC leading to forzati n of sector with altered dosage action -- reflected in the mutation or b~cak behavior at both loci. 2. Question would a3Pear: Does AC ccntrol not onlp the time during develo--meni; Ghen chnnges at c-ml or Ds will occur, but also the cell in w--,i.ch it will occur? a). The test of t.!?is: c-ml wx / c-ml wx / c lfx Ds, Ac AC ac. The set tor>s in w:Gc!~ the AC action h:~d altered ex?:~in~>d to give patc;?es of C and patches of wxu Do these patc3ss coincide? Do tl?ey repiYes3nt events occurring to c-ml and to Ds in the very: s.ti,me sell? b). ilow tXs could be told: Assume, during development, mutation to c and break at Ds ol;cur in the saye cell: A11 ceils arising from t.>is one ~~oulcii be C in geno"cJTe All cells arising fro-? this one wozld also be FTX in cm o-W,e. Sector would be formed from t_.;is cell: The outer x2 rt of this sector terminates in the aleurone la;rer -- C color. in the cells of endospey tjculd s(t-f-n wx: Underneath, the starch 'iag::~~m of the sector: CL Would expect coincidences to a::p:::ar in ilig:l numbers, on?g if the states'were reciprocal in this case -- the state of c-ml must give a very high friiquency of mukaticns to C and fc~ &f any breaks. a high f'rccuenc;f of br-::aks to eiiminnke the Yx. Thr-t of Es nust give Deviations frcn these Tao t;Tpes of behzvior would not give a coincident C wx sector, d). En the test mzde, a high co?ncidentie of G aleurone with unde-lging wx starch, Tkis indicates that both c-ml and Ds are altered in the same cell at the same time. 3. Conclusions: The coincidence observed su:~gzsk s that Ac erfzcts ti:.e expression of Ds, wk::rev.2r it may be located and regar%les:: of nuzb-:rs, in t3e same cell at the saxe time -- wit-in limits dif2'ic::l.t to de&ermine, %e time fiurf.n[; development and the cel$s in with Ac-control?ed changes at tr!e loci it controls is notOr-.random":""' Some cozdit? ens must arise in tbeze cells, undeti;the influe?.lce of AC, that r:::sults in c:-rances at both c-ml and at Ds-stanL?rd !l.ocz.tion. z- -2- IIL Review - continued: 1, Attempt made to show that the control of when and in >jhat cells Ds breaks or mutations at c-ml will occur depends u??on the state as well as the dose of AC . Used "stabilized ' Ac state as an illustraticn, 2. General conclusions: a). AC controls when nnc.? whT.re changes will occur at the various loci it controls -- cm-l, bz-ml, Ds at any location. by state and dose of AC. rhis by dose of AC, and b), The consequence of a change at an Ac-controlled locus de--ends on the state of that locus itself: State 1 series of cells X X X X X in which ch,anges occur State 2 G c 3. The question of Dr. Lewis: Does the addition of Ds loci to the nucleus have anp affect on the action of these loci -- that is, modify Ac action? Answer: No effects have been noted of the addit?.cn of Ds to the action of AC. Appear to be independent. iscussed briefly the origin and bebvior of bz-ml, 14~~~~ like that of 5. Began the discussion of c-m2; its origin, III. Continue account of c-m2, pape 3 of Feb. 15 outline, IV. General conclusions from discussi :?s of c-ml and c-m2. 1. Mutations of c-ml: not produced, To original C ty:e action. intermediate al!.eles 2. Mutations of c-m2: Exhibit a varietT7 of xhenot?-eic actTons' tguantitative and qualitative differences in action ed!.i&ted~by mutants. the' various dif.,:crent 3. What dots this mean with regard to the genie action at the normal C locus y. 4. Does the action 5. If not, what is locus of c-m2 that is action? of c-m2 indicate the the C locus is compound? the nature of tjze change, or series of chanaes at the /- res?onsible for the v,a&.ety of different tp?es of 6. "iow may we interpret genie action ah a single locus ? Does some tT:?e Of control exhist at the locus W-:ich alters the ty-e and degree of ,genic v action? Can we ep>lain the behavior of c-m2 on some basis other than tlla-t it reflects a compound gene? it be tested? Is there some bett;;r interp:~etaticn and `?.OIJ can 7. Before attmpting to find answers for these qusstl.ons it w~ulci. be better to wait until xore of the actions at mu?;a'?le loci hnv& been considered. The origin and Se1havior of wx-ml I, The origin: o- 9a" c sh wx ds ac femles x c-m2 Sh wx AC - dh AC male I-% = c-m2 Sh ?:Jx % P ,I :Frnels: Nearly all c to C Sh Wx. m i One kemels: c-C Sh; wx t; Ux. Wx spotis in a xx background, Aleurom lagej: sliced off and starch in endospem cells below stained with l-XI solution: Areas of different intensities of blue stai:--ing in a red-staining backCyround. -.. EL. Plant from tM.s kernel grown. Pollen examined: loPollen: ?czz=z Eow produced; haploid conditil-n; starch in gr;?ain; Appezrance pzi th WX; App:;zrance with noxal !nJx -- dee-: 5lue, wLth I-111 solution-b, Pollen of particu1n.r plant: Most grains wx. Intensi+ of Few grains stai ing blue 5 th I-K1 stain vaxied from pal& lavender to intense blue, Indicated that a mu-isble wx locus present. Tests, incXzeted below, C-EL? Sh chro :oso-:le. Origin, then, showed that mutable wx carried by the in the c-m2 Sh Xx pa::ent plant, 2. The c~?osses of t-is plant to those that were c sh FJX ac: - .-.- _. a>. Linkage relat:T.ons of c to C and VJX to Yl: kernels inc . wx wx xx endosperm -- starch is amylotxctin i . Stains red r;ritl; I-KI Stains blue xith I-ICI 4. P'.&~aLa~..gza.r&ce of the di.ff'erent kernels above: -... --- ' XElE53andle wx in ap~:e2rance; VX wx wx wx is -- more translucent, 2. the known Wxa mu'ant from S.A. -- one dose 0.65;; amylose, very f'ai;:t lavendar, Physicz.1 aF?;dz:::;a&e, I-m::y, Stains 3. Mutants produced by wx-ml. appearance, On criteria of' both sLaining anti nh,ysical many diffc:-ent levels of production of amylose, All different types can apTYear in same endosperm: c wx/c wx/ c wx-nil. 1 AC: Diagram of types: 4. Types of erminal # mutetions: 'Whole ke:nels with mutation to one of tl2.e alleles of *x. - St;ain f rom faint la-$-endar to ve::y deep blue, P~~sicx~.....~~~~~~rance f'oll.ows the star?L-:ing reacticn -- from waxy to very translucent. b). The low axylose allele: Show faint sta?.ning, Iiajoritv a?-e associ.atcd with altered ~-~~~~41...~.e.:)~~-~.n,~ in endosncrm -- outer regi.on of endospe-im seems fough and wr?.nkled. This condit?.on not seen in the ker-ne1s w5th the higher alleles of iix. Condltjcn ex:@:?essed ns a dominant, b). In above CTOSS, two ty:)es of kernels wit5 respect to stabilities : those that s::ow no change in staining tk:~ou@~out t--e kernel and tllose i-riteh arc':s of alt.-j7ed si;a~nin,g reactions -- wx, lig3.t lavend,arJ OF darqk blue, 4. "he tgao types asnociatcd wi.th izresence and absence of Ac. * Stability of mutant when AC absant; as wit': the pinks from c-L?, M'hen AC pre:Tc~:nt, fui'th?qi7 mutations occur, alt ough, tile rate much reduced over wx-ml. 01~ c-m2. 5. COnClUSic?IS : (1). Vhen AC present, mutatio?-1s at wx-ml to various 23.leles of I-ix -- quantitatively cx?ressed, When AC absent, no change 3t the locus, (2). Gern;inal mutatj.ons 0cc.u.r to v--riol_:s al!.eles, Ti?&esc s%:-.3le in absence of AC but unsta..le l,:--en AC 2: .2sent, (3). Behavior of wx-E?L quite sSmi.lr.~~ to c-m2 in essentials; Iguantitative expressions; two tmes of mutants; rela-?i-L:e s-kabitit:T of t?e ge;:$.nal mu.1;. nts wi'th AC in cnr,%:::rison T.Cth eit?lr-r or:i.ginal, that is, c-m2 or >.rx-ml. Tates. 6. The additive effects of doses of tile nutmts wit.? 1OM a3lpose production,- a>. lirea;ra::c-fusion-bridge c;.-cle: Female, wxs x male, vhTozzcsome 9 ~5.t;l broken end 2nd of 32: r ran rjx-ml: b). The dosage action of the lo~r alleles in 1, 2 and 3 doses: :;lx*a!.lele, wx box i" Jx-al:.ele, I;lx-allele, wx '{Ix-allele, Yx-allele, Xx-al7_ele 4. Cher2ica.J. anal:irses of amylose content doses OP them: