FRANSDUCTIOnS OF “FLA AaD“H FACTORS FROM SIuGLE PHASE CULTURES OF
SAL. ABOwY (SW803 Fla* b:enx) 0 SAL. TYPHIMBRIUK (SW1157 Fla™
4:1,2).

Report by Tetsuo Iino

Feb. 22, 1956

In the earier report or "the effect of phase difference on the
H-antigen transductéon in Salmonella", Sal. abony SW803 Fla* phase-1l (or
phase-2 )—-~x Sal. heidelberg 3W1092 Fla” phase-l(or phase-2)was performed.
The result has shown that H, is transduced simultaneously with Fla ogo in
certain frequercies and the phase of traneduction is exclusively determined
by the phase of recipient. These results has led to the introduction of *"Ho-
epistatic, unstable hypothesis".

The present report deals with the similar experiment used Sal.
typhismrium TM2 Fla mutant SW1157 (-- Fla -5 in the previous report) as a
recipient. The experiment was planned in order to confirm the previous
result and to test its generality. At the same time, frequencies of linked
transduction were compared.

MATERIALS AND METHODS.

Sw1297 are Fla” mutant obtained by ultra-violet treatment of Sal.
typhimurium TM2, As reportou in the previous report, Fla factor correspond
to Fla” locus of SW1092 (designated tentatively as Flajg§7) is transduced
linked with Hy in certain frequency but aot with Hp. Flaiis7 belongs different
loci from Flacce and Fla, g99' which also have beer found out to be transduced
linked with H, and have beer used in the previous experiments.

fhe method of preparation of single phase cultures or lysates and

the procedure of transduction experiment are the same as the previous experiment.
RESULTS AnD DISCUSSIOu.

The results were summarized in Table 1.

With very few exceptions, which may be explained by phase variation
during the course of experiment, following articles, observed in the previous
experiment, are confirmed in the present experiment.

1). The difference of donor phase gives no different result.

2). The phase of the transformed cell is the same with the phase of

the recipient.

3). x is transduced linked with Fla in certain frequencies regardless
the phase of donor or recipient, whereas E, is not transduced
lirked to Fla.

The ratio of linked transduction (RL?) range from 0.09 to 0.28.
However, X2-test calculated from the Brandt and Snedecor's formula shows P-
value 0.3<P<0.5, This means the difference of RLT between different phase
combinations are not regarded as significant, contraly with the result of
the previous experiment. Therecis clear difference betweer the present experi-
ment and the previous on RLT: the ratio of H,~ linked transduction in 81157
is about one fourth of the case of SW1092. Whether these difference of
frequencies represents the relationships of local distance or not is still
uncertain. In order to get more clear sight on the local relationships,
following experiments may be helpful:

SW1092(Fla 95 Hy”) —=x 801157 (Flay 167 H,*)
Fla*- SW1092(Flatyo, Hy ) ---x "

SW1157(Flajys7 Hy ) ---x sW1092(Flay 9, Hy")

™2 (Fla‘ H+) ---x *

Select Fla* on MGA-plates and compare RLT between Fla and Re
4 fe" adh VW
\ yr bi ue
\ WA
Table 1.

Transductions of Fla and H factors from single phase cultures
of Sal. abony (SW803 Fla* brenx) to Sal. typhimurium (SW1157

Fla” 1:1,2). Flayis9 was used as selective marker.

 

 

 

 

 

H-antigern types of Fla-transduction cells Ratio
Phase Phase of . Unlinked type Linked type of
of 7 Total linked
_donor recipient 1(1,2) (4)1,2 Total b(1,2) (b)1,2 Total traysduction
lb wa 21 0 21 2 0 2 23 0.09
1. bd 2. 1,2 3 30 33 0 ? 7 4o 0.18
2. enx lei 13 0 13 5 0 5 18 0.28
2. enx 2. 1,2 1 23 2h 0 4 4 28 0.14
fotal 38 53 91 7 11 18 109 0.17
APPENDIX.

Test of homogeneity of the frequency of linked transduction of H, to Fla i57-
x* = 2.42 calculated from the Branit and Snedecar's formula.

n = 3, 0.3 <P<0.5

ye Wore * A [.
f a4 A0 (0 f