Lecture 6, Janua:ry 25, 195'4 Continuaticn of inheritance behavior of AC, I, Rev&ew of previous talk: b). Backcross tests: AC ac x ac ac L AC ac : 1 ac ac d. AC AC x 8c ac 85 AC ac : 1 no ac. _--- d), The ears produced by Re c sh ldxds ac Re c sh 'E;ix ds ac x C Sh 1%~ Ds, ac (1). The regular pattern of variegation -- majority of kernels. (2). The unusual types of kernels: No c spots or areas Completely colored krnels Tiny specks of c Late Ds breaks in develol-ment Areas only with few c specks Early losses or Ds bre(aks -- Like 1 AC. 2. The effects of dosa of AC: 'Lhe higher the dose, the later in idtime of development +T na breaks occur at Ds, 3. The different fgolates of AC: In two doses: ,;j"-, a). ~~~~~~~~~~-~~~~~essive spots: late but uniform pattern of breaks at Ds -- in certain cells, late in development. b). Areas, distributed ov::r kernel, in which bre;'ks ot;cur in some cells, often associated with areas trJhere no breaks occur. Remainder of kernel has speckled pattern of Ds breaks 4. %rnels whsrv3 changes occur early to give sectors: Lhe se resemble 0 AC, 1 AC, 2 A c and 3 AC in same kernel. Suggest that somet?ing is hap;>ening to AC during early development that resembles somatic segregation. II. The analysis of the unusual kernels on tne ea.--s produced by Re c sh Xx AC Re c sh lfx AC x CShwxDs,noAc 1. Initial experiment: selected koynels showing no c specks, th:t is, no evidence of presence of AC and 2 kernels tna-L showed very late losses or breaks at Ds. 2. aecause material available was not great, first ex~*:~rimcnt was sc?et`-ing of a trial to determine sor:lething of nature of events. 2(4nlants derived from aberrant kernels: Analysis made of 2 i'rom k<,rnels shozir\g late losses of C, 2$ from kernels ~it'n no c specks, and 3. 14ecessar;!i- to determine if AC present or not, if Ds present in C chr~.mosome and if trcnsmissions of chro;nosomes 9 in next generation w:re normal -- that is -that no altorations had occurred to effect inheritance of chr-moso:?es. 4. The tests: Self pollination of each :-&n-t; Zach plant crossed to c ds/c ds, ac ac \ 'I, .3 &:q Each 13lan.t crossed to d ds / c ds AC AC ?;:;>t 2:. I '..;* L : Each $lant crossed by AC-tester: I Sh wx Ds, no AC. -.:l(.l+ ;\c !' I p:.,y, III. &rnel types on ear from initial tests: 1, The plants showing no AC: i: 1 Self-pollinated ear gave @atio of 3 Colored, non-var. : 1 colorles Crossed by I Sh wx Ds: All kernels colorless in wx class 4. No evidence of Ac. Crossed to c ds / c ds, ac ac Ratio of 1 Colored, non-var : 1 c/c d). Crossed to c ds / c ds, AC Ac: 25 Colored, non-variegated or not obviously variegated 11 9 Colored with arcas of c produced by Ds breaks 1 & colorless ( c/c class) Shows that Ds in C Sh wx chromosome is active in presence of AC. 4. Con&:-sions: (\\ \;q,;,, i" ,i.. :ut> il. b*:. ..:, No Bc is present in these 19,plants. ,I. I*' 2. Plants derived from colored kernels tn:lt gave no evidence of Ds breaks: AC present from tests. The AC constitutions differed among the plants. lLpQaL";c1 4. 9 plants: tests showed that --2 AC factors present. Not linked. (p&q$; i;- .f J;j 5) b)e 2 plants: 1 AC factor present b&in action it resembles two doses of original AC. ( ~,~~X-ki)m&! d. 2 plants: either 1 A@ with double dose action or 2 AC very closely 1inked;er marked change in action of a t&&be AC factorE, __.." -_._- _,i_. -- _- a-.-- . .._... _ _ . .._.__^.._ --'-"- "I -m-a. 4. Crossed to c ds/c ds, ac ac: Gave: (Example) 67 C, non-variegated kernels 266 Colored ke:nels w%th c areas: Two distinct classes of kernels; those with early losses of Ds, thus some large colorelss areas; those with late losses of ti producing kerrls with specks of c. 342 colorless kernels : the c/c class. b). Crossed to plants that TnJere c ds/c ds, AC AC. 25% Colored kernels; not obv@L~Lsly var-Jega-t;ed , cllas: ~8~ir. ';q2 ' i + dd. 6 Colored kernels >W-fully sneckeld with c 70 Colored kernels - 461 colorless kernels ObVioUslg v:!Wriegated for c areas ( the c/c class) 4. Crossed by AC tjgetier stock This was Re C Sh 11x jfs / I Sh wx Ds, ac/ac, Kernel types on resulting ears in the 2 a%acsn wx class N CShwxDs Re c sh Wx ds Re C Sh Wx ds ac X a I Sh wx Ds ac Only the I wx kernels can be considered: $.Zi 4 wx kernels with no bbvious variegation for C areas wx kernels with heavily speckled pattern of C (color) 494 I Wx ( th e c Wx / I wx class; cant test AC in these kernels) Diagram of ap:;elrance of 1 wx kernels: d). If we assumed plants being tested were Ac ac; AC ac, the gametic ratios for AC would be: 1 Acl Ac2 : 1 Ad : 1 Ac2 : 1 no AC or: 1Ac + AC : 2 AC : 3 no AC, Gametic ratio for AC is 3 with AC to 1 with no AC 4. In cross to c ds/ c ds, no AC would expect a ratio of 3 c - c variegated kernels to 1 with no variegation. Observed 266 variegated to 61 non-variegated. Two t:Tes of variegated kernels: 1 with 2 AC and 1 witn 1 AC, Di'ferences should be seen. f). In cro3s to c d.s/ c ds, AC AC plants wc~ld get: From female: c ds c ds AC AC From male: AC constitution: ratio dose 1 C Ds; no AC 2 AC 2 ' ; 1 AC 3 AC 1 I' ; 2 AC 4 AC In alored class would expect 1 with 2 AC : 2 with 3 AC : 1 with 4 AC 1 AcAcAcAc : 2 AC AC AC : 1 AC AC If 4 AC is too- of kernel, high a dose to give Ds breaks early enoug?: in develonment kernels. then this class would be non-variegated. This would give C 3:: wx AC tester stock used as female had an AC that gives almost n-! effect in 3 doses. The sm.e.11 specks of c that might q>pesr difficult to see. 27 Thus, Ac AC Ac cletss could appear non-variegated, The 4 doses and doses of AC would produce kernels that we:;e not obviously v::riegated, LIUS, ratio expected would be: 3 C kernels, 1 that was variegated, showing speckles of c. not obviously variegated : Observed: 256 C, non-variegated : 70 C and 6 odd kernels - c variega?&d and speckled. Appearance of kernels: -- only areas of specks of c: de In cross by I Sh wx DS ac: C Sh wx Ds - c Sh wx b 1 Expect: Observed: The wx class of colorles kernels: I Sh wx Ds Female contribution AC Ac AC AC : 2 AC AC : 1 with no AC 4 AC No obvious var. 2 AC 1-c var. no AC No var. 258 I wx, no certainly var. (some lzad few C s:>ecks 1 218 1 wx clearly var. for C specks If this projected coilstitution S_s correct, then it should be possible to prove it by progeny tests: This was done for 4 of the 6 plants that gave ratios in these i itial tests indicating the presence of 2 AC factors, independently located in chroi?osome coqlement and not linked to factors in short arm of chromosome 9. IV. The progeny tests conducted with plants assummed to be AC ac; AC ac, 1. T'ne Appearance of plants: Table on board, 2, The reason for the white streaks and their freq,uency: 4 . Ds break could occur in either chromosome; If in %? ti Ds chroaos ze, a whi-te streak t~uld appear. If a coincident Ds in both chromoso:nes, be formed. then cells homoz;:gous deficient, for 2/3 of shortlarm w--:ld These do not prodxe tissue that can he seen. be cells with enormous nuclei: hey appear to I This seen in the examination of the glumes of such plants: b). If AC dose is high, then events occur very late. w streaks may not be seen in the green background, If 1 AC present, Ds breaks occur early enoug? to produce a good streak, easri.lg seen. 3. Tests of the plants in columns A and B for AC inheritance. TWO plants selected from both A and B of each culture in Fig. 2 4. &ch plant crossed to a C sh bx wx ds, ac plant: The cross: Female iGal e Column A c sh be ds, ac I Sh Bz Ds AC ac; AC ac C Sh Bz Ds Column B ti il AC ac b), &pected ratio of kernel tmes from crosses of plants In column A: (1)Gametes: 1Ac AC : 2 AC : 1 no AC j# with AC to 1 with no AC Kernels should be in both 1 and C classes: 3 variegated to 1 non-var, (a). The observed ratio of kernel types: Figure 3 ?Y on board. -..a-^*.... " ..&a All ratios as expected exceT3-t for 1 aberrant plant: rJj-L i g plant had new change of AC. It wa3 A?Ac ac. "eason why C Bz variegated kernels fewer than ex2ected: - Can not see variegation in a purely speckleci pattern* iLhe two types of v ariegated kernels: %te losses of Dominant:2Au &rly losses of " .l AC 4. Tests of plants in column 13 for AC inhez>itance, selected from each culture to be tested: The Two ?lnnts ratio for AC - 1 with 1 AC exuected gametic : 1 wit11 no AC. The expected ratio of kernel types: 1 variegated to 1 non-varieg, %e obs erved types of kernels in cross: Figure 4, on board, 5. Conclusions: 1. Summary of procedure 30 far: a). b). f$ ac plants self-pollinated 'ound the expected I. AC AC : 2,Ac ac : 1 ac ac in F 2 4. (Allelic) Gametes of AC AC plants tested for AC. by CTOSS h=tve 1 AC wi. t? ac . '"ajo-ity of kernels had expected pattr,rn produced by AC All s:oul Few une,xpected ty-pes of keinels. no evidence of AC, Among &em, 31 :r?,e xith 23 s-~chlrkernels removed from eD-?.rs, tested for AC, 11 plants: Wo evidence for AC, AC AC plant, AC not in zametc produced by 12 plants: AC present. In 6 of t'nem, constitution wa4 ap9Caz+entljr AC ac; AC ac. Two non-allelic, non-ltnked AC factors from plant that ~~23 AC AC, nlI.elic, All gamete3 shou2.d kve had only 1 kc, 7' - ,' - P>?ogeny from 4 of the 6 plants assumed to h:?ve AC ac; AC L~C tested. These tests confirmed the AC cc; AC ac co sti.tu- tlcn in t';le I& select d cases derived from. C non-v:kr. k-m. 2. The reason that AC not seen in ori$nal non-variegated kernel: The dose of AC too high: 4 AC present in the endospe??m, 3. To see the AC action, must use an AC ac; AC ac plant as a pollen -8rent . Then, kelme3.s hzve eithez.7 AC AC or AC - 2 or 1 dose of AC. 4-. Evidence so fn~ s>otrs that AC can be lost to a gzmte in an AC AC plant (allelic posdticns of AC), Or, an extra AC factor can aFne 88 I rn,ii'$&: e few specks of C : 8 I wx, hecvily : 111 I Nx I speckled with C All had few wd streaks (Like 2 AC action & original AC) 5. 2 plants crossed to f 7, (> b' 4. females: C sh bz, ds, ac 5.~1 Both C-j&& crossed to 53; f females: C sh bz ds, ac I, non-var. I-Cbz C Bz CBz-Cbz Iynon, I-Cbz CBz CBz-bz var. Plant 1 74 63 40 ?lant 1 97 111 84 6. Conclusions: Altered AC acts like AcAc -- double dose of AC action at a single locus or: Two AC loci presmt, closely linked. VI, Although first er,ileziment showed much, I was not satisfied with the tests in every case, especially the ones that a!:-Jeared to show altered AC action as well as altered numbers. Also, the tests were not large enough for any one -plant; also, the Ac- tester stocks could have been better. '%he-efore, the second experiment conducted, and much EoIae precisely with regard to details, smmary of results of the cotioi-ed experiments, I and II. 42 plants examined from C, non-variegated kernels: 19 - No AC 16 - AC ac; AC ac Two non-lii-ked AC 1 A%c ac; AC ac Two non-licked AC; one rzrith dolJble-dose 6 AZ& ac action. 8 plants from kernels shotiiI:g onl;: a few c specks 4 AC ac; AC ac Twnoc-linked AC P". 1 AcAc ac; AC ac Two non-linked AC; one with double dose acti& 3 A& ac 8 plants-from kernels showing a heavily meckled pattern of c dots. Late losses of G but unifom in pattern, 2 AcAc ac or two closely Ainked AC. In one dose, very irregular patterns; Gametic ratios imegvlar; many altered Fypes of patt&ns of var. Suggests early ~. Ac tz;nsposlticns of AC Cne AC but dosage action increased over thr:t of ori&nal AC but not doubled in action, 1 "AzAc" ac, The AC action altered. Produces early sectorials in one dose. 1 AC ac. One AC, Could not discover any rnodificat4on in action corzp,?-Ld to original AC, __.-- __.___.- -. .- ,, ..-- - .- - -- .- - .---- - _._ ..-. --._.~ -_._ ..__ - ._._ __-.. ;I ---- .-..__..I,-. -... _._-. .- __ -$i$J$~. j __._ _ __. 4- ,`&a, + - I :f , I , ! I ./ I 1 -. I 1 / I I ? / I 2- i c -i n 6 0 a 5 3- Y 0 2. . L 6 b Y 0 . _. 0 113 t- lu- J-n -- `by