Volume 7 Number 35

Subjects Discussed In This Issue: 

Genetic Engineering (Tomatoes and Pigs and Arctic Flounder)
         [Aimee Yermish]
         [Bob Werman]
Pig Tomatoes
         [Seth L. Ness]
Pigness (3)
         [Joel Kurtz, Yisrael Sundick, Hillel Markowitz]
         [Zev Farkas]


From: <ayermish@...> (Aimee Yermish)
Date: Tue, 11 May 93 16:25:17 -0400
Subject: Genetic Engineering (Tomatoes and Pigs and Arctic Flounder)

Maybe I can help clear up a few of the questions about genetic
engineering.  (In real life, I'm a grad student in Cancer Biology, and
while I've never engineered a tomato, much less a pig, I am familiar
with the techniques and technology, as well as with the basic biology)

Eitan's assurance that there is no one gene that makes a pig a pig,
that its essential "pigness" is defined by "a complex interaction of
countless genes," is right on the money.  You can't mutate one pig
gene and get a cow.  In fact, it's pretty tough to mutate one pig gene
and get anything that doesn't *very* strongly resemble a pig (assuming
the creature survives to the point where you can see it).  Not only
that, it's pretty tough to mutate a large number of pig genes and get
anything which survives which doesn't very strongly resemble a pig.
Even the simplest little things about pigs are governed by a large
number of genes, about which we know next to nothing.  From the
standpoint of a biologist, the idea that there would be one gene which
would confer "pigness" is patently ridiculous.

Another potentially relevant point which has not yet been mentioned is
the issue of homologous genes.  Many (if not most) of the genes in a
given organism have homologs in related organisms.  The more closely
related the two organisms (pigs and cows, for instance, are pretty
close in the grand scheme of things), the more their genes resemble
each other.  We humans have genes which are homologous to genes in
yeast, believe it or not, and the genes have basically the same
functions no matter what organism they're in.  Chances are pretty good
that the protein encoded by the pig gene actually has a functional
homolog in the tomato, but the tomato version is regulated differently
or has subtly different activity.  If the pig protein were all that
wildly different, it might well not be able to interact with the
existing tomato proteins, so there wouldn't be any noticeable change
in what the tomato looks like to us.  (Before you jump on me, yes, the
artic flounder gene is probably not required to interact with much of
the tomato machinery, so this comment may not apply too tightly)

Speaking of that artic flounder, the "essential characteristic
quality" which Daniel worries might be transmitted to the tomato, is
shared by many cold climate species, and if I recall correctly, that
goes for the plants as well.  They all have the same problem to solve
-- keeping their innards from freezing -- and they do it in remarkably
similar ways (many of them probably inherit their solutions from
common ancestor species).

Why do they pull the genes out of such bizarre animals?  Historical
accident.  That's where they first found a gene that they thought
would do the thing they wanted.

Bob comments that we are prohibited from touching the carcass of a
pig.  The tomato which you eat was produced entirely by the tomato
plant, eating sunlight and soil nutrients.  The seed from which that
plant grew was produced entirely by another tomato plant.  There was a
seed a long time ago which was given a piece of DNA (actually, I
suspect that it was given to a plant which was about to produce a
seed) which coded for the pig gene, probably modified to make it work
better in the tomato environment and/or to make it easier for the
investigator to figure out which seeds had picked up the DNA.  That
DNA was almost undoubtedly produced entirely by a bacterium, which
eats various raw chemical junk, usually dead yeast and the like.
(there are probably several generations of DNA produced in bacteria at
this point, but I'll leave them out for clarity).  A long time ago,
that piece of the DNA which is derived from the pig was probably
isolated from a bacteriophage (a virus which parasitizes bacteria and
which is very useful to people looking for genes).  The bacteriophage
got the DNA from an in vitro (in glass, that is, in a test tube rather
than in a living organism) reaction where a researcher took pig RNA
and gave it to enzymes which would make a DNA copy of it suitable for
further use in lab.  Only all the way back here do we get pig RNA that
is actually purified from a real, live, oinking pig.  I'm not a
scholar of halacha, but I would suspect that this
many-generations-removed distance is far enough for the tomato to no
longer qualify as a pig carcass.

As a biologist, I am constantly dismayed by the treatment of genetic
engineering ideas in the popular press.  There is very little coherent
reporting on the subject (or on any scientific subject), and I've
often been hard-pressed myself, on listening to these reports, to
figure out just what it was they were talking about.  I shuddder to
think how confusing it must be to people who don't have the training.

I'd be happy to explain in more detail any of the topics I've just
covered, or any other biological topics on which I feel I can speak
with confidence -- just send me private mail and ask.



From: <RWERMAN@...> (Bob Werman)
Date: Tue, 11 May 93 06:44:01 -0400
Subject: Non-Kosher-Tomatoes

In view of the recent discussion on the kashrut of tomatoes [with
genetic material from pigs], I think it of interest to point out that
the tomatoe was considered unkosher in part of Poland for several
hundred years.

That was not a genetic issue but a question of enchanting, it seems.
The tomato was universally considered an aphrodesiac in Europe, pomme
d'amour, etc; even in Hebrew the name, agvaniya is derived from agavim,
love-making. [eyin-gimel-bet]

__Bob Werman    <rwerman@...>    rwerman@vms.huji.ac.il


From: Seth L. Ness <ness@...>
Date: Tue, 11 May 93 00:19:12 -0400
Subject: Pig Tomatoes

daniel geretz says..
>Is genetic engineering comparable to the formulation of foods; i.e., can
>the genetic material which is being put in the tomato be considered an
>"ingredient"?  If so, then the *source* of the genetic material
>definitely should matter, even if it *could* be derived from other
>sources or synthesized.  (At least this is my understanding with respect
>to enzymes and such other items that are routinely put into our food -
>the medium/culture in which the enzyme is "grown" does seem to matter,
>even if it *could* be manufactured some other way)

Thats precisely the point here. The source of the enzyme and the DNA is
the tomato, not the pig. the odds that even one atom from a pig is present
in any tomato is so unbelievably remote i can't imagine it. Not only
*could* it not be derived from a pig, it *is* not derived from a pig. Its
derived from carbon dioxide in the air and nitrogen in the soil.
If it is the medium/culture that is important then that medium/culture is
the tomato.

Seth L. Ness                         Ness Gadol Hayah Sham


From: <kurtzj@...> (Joel Kurtz)
Date: Tue, 11 May 93 15:38:10 EDT
Subject: Pigness

I would like to offer a response to Dan Shimoff in respect of the
adoption of the pig as the representative of an entire class of unkosher

The animal fitness requirements enunciated in the Torah are twofold: 
(1) that it have a cloven hoof, and
(2) that it be ruminant.
Now, as I understand, pigs are unique among mammals in that they
satisfy the first criterion, but not the second.

Lest we are misled into believing that somehow pigs are less
objectionable than, say, hyraces, tradition has conferred on the pig an
extra measure of repugnance.

I believe that the Yiddish term "chazer feesel" represents a parody of
the "view" that since the hoof of the pig is cloven, then that part of
the pig is acceptable.

I welcome any and all responses to my thoughts on the pig.

Joel Kurtz

From: Yisrael Sundick <sas34@...>
Date: Tue, 11 May 93 16:25:28 -0400
Subject: Re: Pigness

I believe, the pig is either the only animal which has cloven hoves but
doesn't chew its cud. In other word, it has the outward characteristics
of a kosher animal, but fails in the inner characteristics. There is of
course a tremendous amount of mussar to be learned from this.  There is
also a midrash which states that in the time of the moshiach, the pig
will become kosher. presumable,it will begin to chew its cud. there was
a big deal made a few years ago, when a claim was made of some african
pig which did in fact chew its cud.

*     Yisrael Sundick       *        Libi beMizrach VeAni                   * 
*  <sas34@...>  *             beColumbia                        *

From: <H_Markowitz@...> (Hillel Markowitz)
Date: Tue, 11 May 93 17:21:24 -0400
Subject: Re: Pigness

>Whenever Jews talk of non-kosher animals, the pig is always used.  What
>makes the pig the quintessential unkosher animal?  I don't think this
>stems from the Torah, since no one I know thinks to mention a camel,
>rabbit or hyrax, those animals mentioned with the pig as animals not to
>eat, when talking of non-kosher animals.  And, as Bob points out, we
>have special restrictions on pigs too (I think there is a prohibition
>about raising pigs in the land of Israel).
>Why has the pig been singled out?  
>(<shdan@...>)  Dan Shimoff

I would say because the pig is unique in that the "outer sign" (split
hooves) are there and it is only the "inner sign" (maalei geirah - note
from other articles may not be literal cud chewing as in a cow) which
is missing.  I have seen the pig used as a metaphor for hypocrisy and
also as a metaphor for the Xian missionaries (with a picture of the pig
lieing with it feet outstretche so the hooves are visible).

Another reason would be that the pig is a food source in locations
where it is grown.  Its only purpose is a a food animal as opposed to
the camel (transportation) and the rabbit or hyrax (non-domesticated
animals and not major food sources).  THus when speaking about a
nonkosher meat producing animal the pig is the main one to come to

Note that this can also be a reason fo not allowing them in Israel.
The ONLY purpose is to grow them as a source of nonkosher meat.

Hillel Markowitz    <H_Markowitz@...>


From: Zev Farkas <farkas@...>
Date: Tue, 11 May 93 10:52:52 -0400
Subject: Pigs

A few issues back, someone spoke about a prohibition on touching the
carcass of a pig.  Is this an actual prohibition, or does it just mean
that one who touches the carcass of a pig is "tameh" (ritually impure, for
lack of a more precise translation)?  Does this apply to leather?  How
about other animals (horses, camels...)?  (If I had a pair, would I have
to give up my Hush Puppies?)

Also, Jay Shayevitz speaks of porcine heart valves, and says that the
preparation technique (marination in formalin, if i remember my
cardiology) renders them permissible.  I don't see where this is relevant.
Surgical valve replacement is certainly not "derekh akhila" (the normal
way of eating), and so is not covered by the laws of kashrut.  (Similarly,
much of the insulin in use comes from pigs and improperly slaughtered
kosher animals - even if this were not a life-or death issue, it should be
permissible since it is administered by injection, not mouth.)

Just to throw another monkey wrench into the machinery:  does the use of
blood products or biopsy specimens from animals constitute "ever min
hakhai" (the limb of a living animal) ?  Does this prohibition only apply
to eating, or any use?

Zev Farkas, PE                                :)
<farkas@...>       718 829 5278


End of Volume 7 Issue 35