May 17, 1955

Miss Jean Husted

W.B, Saunders Company
West Washington Square
Philadelphia 5, Pa,

Dear Miss Husted:

I hope it 1s not too late for a useful reply to your letter of April
13, You asked about | number of terms (in effect) and I wanted some téme
to thik about them. Actually I am somewhat surprised that you should ask
for a definition of transduction , unless you plan to include ouite a num
ber of equally relevant genetic terms,

Transduction is the transfer of a genetic fragment from ons cell to
another, e.gg, the "pneumecoccus transformation" (Briffith,192¢) and virus-
mediated transduction in Salmonella (Zinder & Lederberg, 1952).

leterozenote is a cell which has an additional genetic fragment, different
from its intact genotype. It usually results fron transduction.

Prototropnic. means having the nutritional characteristics of the proto-
type strain, (Compare Davist neologism, auxotroph).
intra-~
Plasmid is a generic term for ali types of/cellular inclusions that can be
considered as having genetic functions, including plastids, viruses, plasmagenes,
endosymbionts,

There are many additional, fairly new terns that others have coined, and
still othera that are important in established genetic terminology. You sould
consider definitions for the following:

lysogenic; colicin; heterokaryon; position effect; allelic; pecud re elie§
karyonide; micronucleus; macronucl ileus; secrecation; hemlizycous; monosomics; igre
ploids endonitosis; prophage; praprophace
I assume you already have such terms as:
heterozygous, homozygous; haploid; diploid; snevploids; lecus; DIA; clone.
If I can be of any further assistance with the above please let 6 imow,
Yours sincerely,

Josina Lederberg
Provessor of Genetics