Volume 7 Number 29
Subjects Discussed In This Issue:
Genetic Engineering (4)
[Daniel Geretz, Bernard Katz, Anthony Fiorino, Jay Shayevitz]
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From: imsasby!<dgeretz@...> (Daniel Geretz)
Date: Mon, 10 May 93 19:59:58 -0400
Subject: Genetic Engineering
In response to the recent query by Bob Werman about genetic engineering,
Seth Ness replied:
> The DNA is definately not connected to the pig. Every atom in it has long
> since been derived from other sources. the only connection is the
> information in the sequence. do you really think the halachic essence of
> pigness is in its genes?
A fundamental question about this whole discussion is in order:
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)
However, if the genetic material is not an "ingredient", then perhaps a
different set of rules should apply.
Daniel Geretz
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From: <bkatz@...> (Bernard Katz)
Date: Sun, 9 May 93 15:23:07 -0400
Subject: Re: Genetic Engineering
Bob Werman asks how one can be sure that "the quality that makes a pig
recognizable as such" is defined by countless genes rather than a single
gene. He goes on to observe:
> A tomato can never be a pig, and still be a tomato. However we
> are prohibited not only from eating pig but touching their
> carcass; there is something in the pig other than its behavior in
> life [which indeed is a sign of whether we can eat them or not]
> that makes them a prohibited animal. The chewing of cud and
> cloven hoof are not the essence of kosher/non-kosher but the
> signs we are given to identify the kashrut. Or have I got that
> all wrong, too?
I don't see how any genetic alteration in tomatoes, by itself, would
render them unkosher, for our manner of determining whether something is
kosher is not based on genetics.
Suppose we agree that there is some characteristic, K, in virtue of
which kosher mammals are kosher. K, in other words, is the essence of
what makes a mammal kosher. What property or set of properties might K
be? Does K consist in some set of behavioural properties, some set of
biological or genetic ones, or some other yet more complicated
collection? I don't know, and I don't think anyone else does either. I
agree with Bob that it is implausible to think that K is nothing more
than being a cloven-hoofed ruminant. We know, however, that whatever
property or set of properties K might be (genetic or otherwise), having
cloven hooves and chewing its cud are *infallible signs* of the presence
of K. So, if we happen on a new species of animal that has these signs,
then it seems to me that we are entitled to infer that it is kosher, no
matter what genetic similarities there may be between these newly
discovered creatures and pigs. (I take it, however, that no matter how
similar they are genetically, these newly discovered creatures would not
count as pigs, at least halachically, for the supposition that there are
pigs that chew their cud would be inconsistent with Vayyikra 11:7.)
Of course, we use completely different criteria for determining whether
plants are kosher. But so long as these criteria are not affected by
the genetic alteration of tomatoes, it is irrelevant what genetic
similarities there are between tomatoes and (say) pigs.
Bernard Katz
University of Toronto
<bkatz@...>
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From: Anthony Fiorino <fiorino@...>
Date: Sun, 9 May 93 04:11:22 -0400
Subject: Genetic Engineering
> >The idea that a single gene somehow encodes for the "uniqueness" of an
> >organism is the fundamental flaw here. There is no such "uniqueness"
> >gene; species are defined by a complex interaction of countless genes.
> I wonder where Eitan gets his assurance from.
While not claiming to be an expert, I was a molecular biology major in
college and am currently studying for a PhD in the field.
> Why is the quality that makes a pig recognizable as such defined by
> "countless genes?"
(I apologize in advance for the techno-jargon. I have lost the ability to
communicate about these things in lay terms.)
Well, in truth, the story is rather complex and not well understood. All
mammals share a rather large ammount of common genes. The specific
genetic determinants of morphological features are not well understood.
It is not as simple as having an "split hoof" gene vs. a "single hoof"
gene. How each animal's form develops is due to a complex regulation of
the expression of various growth factors, extracellular matrix molecules,
and cell migrations. Another set of mechanisms controls cell growth,
and cell death. There are at dozens and dozens of growth factors,
and dozens and dozens of matrix molecules. These genes are regulated by
different transcription factors, which adds another unknown number of
genes to the mix. Then there are the genes which control cell divisions,
responsible for determining size of a tissue. And the list goes on and on.
> A tomato can never be a pig, and still be a tomato. However we are
> prohibited not only from eating pig but touching their carcass; there is
> something in the pig other than its behavior in life [which indeed is a
> sign of whether we can eat them or not] that makes them a prohibited
> animal. The chewing of cud and cloven hoof are not the essence of
> kosher/non-kosher but the signs we are given to identify the kashrut.
But I thought the whole reason one becomes tamei upon touching a pig
carcass is exactly because a pig is a treif animal. Thus, the signs
indicate that a pig is a non-kosher animal; independently, we know that
the carcass of a non-kosher animal makes one tamei.
Or, perhaps one becomes tamei simply because it is a carcass. Does one
become tamei upon touching the carcass of a properly slaughtered kosher
cow? I wouldn't think so, otherwise the kohanim would have become tamei
every time they slaughtered a korban, thus disqualifying them from
offering korbanot. Also putting them in a situation where they would
have to become tamei, which wouldn't make sense because there is an
issur for kohanim to become tamei.
It still seems to me that no matter what, if a tomato still grows like a
plant, still contains those features essential for placing an organism
in the category of "plant" vs. "animal" (ie, contains chloroplasts,
cellulose cell walls), then it would have to be kosher no matter how
many animal genes it contains. Because we have no concept of treif
plants, and no concept of dead plants making people tamei.
I'll even go this far -- let's say there is a particular protein which
is unique in all of the word to pigs. This is not unlikely; there are
subtle amino acid changes in the sequences of the same gene in different
species. I say even if one makes a tomato plant which is producing
grams of this protein unique to pigs, the plant is still kosher because
it is still a plant, and all plants are kosher.
I'll bring a raya from gelatin -- the gelatin one makes from a kosher
animal's bones is the same stuff that one makes from a treif animal's
bones. Yet the gelatin from trief animals is considered trief. Thus,
we see that the animal of origin determines whether a substance is
kosher or not. Tomato plants churning out pig proteins would be kosher
-- the "animal" of origin of the protein would be a plant.
The gemara discusses a few of these issues; there is a discussion of the
case where a cow gives birth to a pig; the gemara asks if such a pig
kosher? (sorry, I don't know the answer). Also, there is some
discussion of the de novo creation of animals; I think that if one makes
a pig, it is not trief. I believe there is the idea that part of being
treif is being born from a treif animal. Sorry, I don't know where
these gemaras are found, my Rabbi told me about them very briefly over
shabbos.
Eitan Fiorino
<fiorino@...>
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From: Jay Shayevitz <Jay.Shayevitz@...>
Date: Fri, 7 May 93 18:21:04 -0400
Subject: Re: Genetic Engineering
Eitan Fiorino writes:
>The idea that a single gene somehow encodes for the "uniqueness" of an
>organism is the fundamental flaw here. There is no such "uniqueness"
>gene; species are defined by a complex interaction of countless genes.
Indeed, I once asked our LOR if there would be any prohibitions against
using recombinant human insulin secreted by bacteria transformed by
inserting into them the human gene encoding insulin. His answer was that
halacha, as a rule, is concerned only with what is visible to the
unaided human eye, and, since bacteria and genes do not fall into this
category, they would be considered 'halachically neutral.' One of the
exceptions to this rule seems to be the concept of transferring
'essences' of food from the food to the vessel in which it is cooked, or
from vessel to vessel during the process of cooking, but this is
specifically discussed d'rabbanan.
Although currently falling out of favor with those of us who are
concerned with such things, one modality of therapy for people with
severely calcified heart valves, who are experiencing symptoms due to
congestive heaert failure, is to replace the bad valve with a similar
valve from a pig. Requiring a porcine valve replacment intitally was a
matter of concern for shomer kashrus Jews, but I believe it is now
fairly well accepted that these valves are OK to use, largely because
the manner in which they are prepared for human use renders them no
longer pig-like.
If such a macroscopic object as a porcine heart valve can be considered
halachically neutral, why not something on the molecular scale, such as
genetically transformed foods?
Another, different, approach: Let's suppose, hypothetically, that
someone wished to market DNA cloned from white blood cells from a living
cow (i.e. one copy was made of the original, and this copy replicated
repeatedly until macroscopic quantities were available) as a topping for
ice cream (DNA is very sticky and syrupy when obtained in large
quantities - kind of like toffee). Would it be OK to eat this new,
cow-derived topping with ice cream? Would it be OK to eat this new
cow-derived topping at all, since the animal was not properly shechted
first? I think these are the types of questions which should be answered
when referring to genetically transformed foods. If the hypothetical
tomato transformed by a pig gene does indeed exist, then there may be
enough pig genetic material in a half dozen or a dozen tomatoes to be
visible - but this genetic material is many - perhaps hundreds of
thousands of - generations removed from the pig from which it was
derived, probably by cloning from white blood cell chromosomes obtained
from a living animal. If this material is no longer PART of the animal,
then why would it be assur?
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End of Volume 7 Issue 29
