Re: [Killietalk] Use of Acriflavine (was: carbonates (probably)/my twocents)

["Robert Goldstein" <rgoldstein at rjgacarolina_com>]

Brian's observation brings back memories. In the old days (60s and 70s), 
there were several reports of two-headed fry or fry joined at the belly or 
other doubles. We used lots of acriflavin in those days, not so much today. 
I rarely use it, and haven't seen this problem in years. So I'm not 
surprised that a departure from acriflavine use might be associated with a 
lack of these teratogenic killifish fry. To repeat (or clarify) what several 
have said before, a mutagen induces a heritable change in DNA, a teratogen 
induces developmental deformities but not changes in the germ plasm DNA, and 
a carcinogen induces cancers. A chemical can have more than one effect and 
fall into two or three categories, but the history of the terms is that they 
were established for distinctly different outcomes. BTW, acriflavine is not 
one specific drug, but a mixture of flavine dyes.

  ----- 
From: "Brian Watters" <bwatters at shaw_ca>
To: "killifish discussion list" <killietalk at aka_org>
Sent: Monday, January 02, 2006 2:03 PM
Subject: [Killietalk] Use of Acriflavine (was: carbonates (probably)/my 
twocents)


> Bruce J. Turner wrote:
>
>> ........ With acriflavine we are on perhaps firmer ground,
>> for the proflavins as a group are
>> intercalating dyes that can get between the paired bases of a DNA
>> double helix and distort it.  Repair
>> mechanisms go to work which can then cause deletions and/or additions of
>> single bases, resulting in lethal
>> "frameshift" mutations.  Although I've used large amounts of
>> acriflavine in the past, I would not now have i(t) in my fishroom.
>>
>
> I also tend to avoid using Acriflavine because of an experience I had some
> years ago with mutations that I feel sure were caused by the excessive use
> of this dye. I have also heard from others who have had similar 
> experiences.
> A few years ago, I related this experience on KillieTalk so some of you 
> will
> probably remember it. However, for the benefit of those who do not, or are
> new to this forum, I will copy it below:
>
> --------
> "Many years ago, I had very bad cases of velvet in a couple of populations
> of
> wild Nothos from Malawi and I treated these with very heavy doses of
> acriflavine added to the breeding setups. (This in itself was unusual
> because wild Nothos tend to be very much more resistant to velvet than
> aquarium raised specimens). When I hatched eggs spawned in both these 
> setups
> (from the couple of weeks or so that I was using the heavy medication), I
> got a small proportion (less than one percent) of fry that were siamezed 
> in
> various ways. I had fry joined at the abdomen, fry with two heads (with a 
> Y
> shape, the bifurcation being immediately behind the gills), four-eyed fry,
> etc. Incidentally, I have some interesting photomicrographs of these 
> little
> "monsters". I hatched out large numbers of fry from other spawning groups 
> at
> the same time, that were not treated with acriflavine, and none of those
> produced any such mutants.
>
> Deformities of this nature could, I suppose, have been the result of other
> factors but the correlation between the occurrence of the siamezed fry and
> the very heavy acriflavine treatment used at the time the eggs were 
> spawned
> would then have to be an amazing coincidence."
> -------
> ________________________________________
> Brian Watters
> 6141 Parkwood Drive
> Nanaimo, British Columbia V9T 6A2, Canada
> Tel: (250) 760-0564
> E-mail: bwatters at shaw_ca
>
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