X-Message-Number: 8497
Date: Tue, 26 Aug 1997 22:26:03 -0700 (PDT)
From: Doug Skrecky <>
Subject: 15'th update on fly longevity experiments 

    This is the fifteenth update on my fly experiments. On day 43 all
 flies were dead in the 4'th run. About all that was interesting here was
 the relative performance of the control, paprika and purple yam bottles.
 However I am not inclined to regard these results as being significant,
 since the flies for these 3 bottles were derived from several different
 old breeding bottles. To be "fair" the control bottle must come form the
 same breeding bottles as the supplements it is used to compare with. From
 now on I will be using several control bottles.

 Fourth Run                  Survival
 Supplement         DAY 10 DAY 24 DAY 34 DAY 43
 Control            100%    56%     0%   all 0%
 bactine             75      0      0
 bactine 4X          50      0      0
 garlic              20      0      0
 garlic 4X            0      0      0
 KCL                100      0      0
 KCL 4X              71      0      0
 mint listerine       0      0      0
 mint listerine 4X    0      0      0
 paprika             88     38      0
 paprika 4X          50      0      0
 pectin              40      0      0
 plax                60      0      0
 plax 4X              0      0      0
 purple yam          86     48      5
 purple yam 4X       52      5      0
 salt                47     13      0
 salt 4X             38      0      0
 sterisol             0      0      0
 sterisol 4X          0      0      0
 viadent              0      0      0
 viadent 4X           0      0      0
 water reduced 50%   90     30     10

     The results of the fifth run were characterized by exceptionally high
 mortality rates, in comparison with runs from earlier this year. I
 attribute this difference to the fact that a heat wave hit my native
 Vancouver, BC and the average temperature the flies were exposed to, rose
 first above 80 degrees and then on some days to above 90 degrees. A short
 exerpt from my fly longevity database reveals the strong link between
 temperature and average life span of drosophilia melanogaster.

 Temperature Life Span
    52 F       152 days
    64         130
    68          81
    70          86
    77          62
    81          42
    86          25
    86          20

    Given the above data I should have finished my first census of run #5
 a little quicker, while most of the flies were still alive. However even
 at this late date some useful data emerges, as well as a lesson I will
 not soon forget.
    The lesson is that several control bottles must be used to derive
 useful data, when temperatures are high. I use several breeding bottles
 (BBs) to provide enough flies for each run. There will always be some
 variations in the average age of the flies in each bottle, depending on
 how much breeding has occurred. These new BBs were "seeded" with parent
 flies 29 days before run #5 was started. If no offspring were produced
 all flies inside a breeding bottle will be over 29 days old. If a small
 amount of breeding occurs the average age will be a little lower, while
 if a lot of breeding occurs the average age will be much lower. While a
 difference of (for example) 5 days in average age between BBs will not
 have much impact if the life span of the flies is several months at cool
 temperatures, it can have a large impact when high temperature reduces
 this life span to just a few weeks, as has occurred with run #5. (I have
 always recorded which BBs are used, but had not included this in my
 updates as it did not seem to make any difference earlier. I also record
 the order in which I supply the supplement bottles from a BB.
 Surprisingly this order does not make any difference; even in the present
 run.)
    Fortunately I created 3 control bottles this time so some usable data
 emerges. Unfortunately I had to use 4 BBs when breeding bottle #3 (BB#3)
 ran out of flies before I could create a control from this breeding
 bottle. Thus the data from the supplement bottles using flies from the
 BB#3 are of relatively little value. However the total number of flies
 provided by BB#3 and BB#1 are similar, so control#1 might be used as a
 "reasonable" substitute. However even if control#2 is used, which
 problably contains more younger flies, since more flies were bred in BB#2
 than in BB#1 or BB#3, it can be seen that the lower dosage of the
 "nontoxic" bactericide/sugars handily outperformed both control#1 and
 control#2.
    The much higher survival in control#4, I attribute to the huge number
 of flies that were in BB#4. I did not use all of these. The existance of
 control#4 is a very valuable check on any misguided enthusiam on my part
 regarding carnosine. As I mentioned in the 14'th update carnosine is not
 absorbed intact, but instead is broken down to B-alanine and l-histidine,
 both of which have proven to be ineffective life-extenders in published
 experiments. If anyone knows of a source of the stable carnosine
 precursor acetylcarnosine please let me know. I would give some pretty
 fair odds that this would significantly increase fly life span.
    Of the supplements that did well in run#3, that were retested this
 time, anise was a disappointment, paba was so-so, while malt and
 activated charcoal again beat the averages. I could not be sure of the
 number of dead flies in the high dose activated carbon bottle, but will
 verify the total number of flies after they are all dead and I can open
 the bottle without fear of losing some flies.
    Although medium 4-24 contains some sucrose already, I suspect that a
 little more of either this or other sugars reduces pathogen growth and
 increases life span somewhat. The amino acids were a disappoinment as a
 group, though proline looks to be worth retesting. Proline has been found
 to increase the life span of the mutant Long Evans Cinnamon rat, which
 suffers from excessive copper accumulation and is considered an animal
 model of Wilson's disease. (Pharmacology Biochemistry and Behaviour
 52(3): 509-515 1995

 Fifth Run
  Breed                           Day 16
 Bottle# Supplement             Alive Dead Survival
 BB#1    control#1                2    18     10%
    1    l-alanine                2    13     13
    1    l-alanine 4X             0    14      0
    1    anise                    1     9     10
    1    anise 4X                 0     9      0
    1    l-glutamine              2    13     13
    1    l-glutamine 4X           0    22      0
    1    malt                     5    15     25
    1    malt 4X                  2    20      9
    1    paba                     2    11     15
    1    paba 4X                  0     9      0
    1    total                   16 + 153=169 10% (average)

    2    control#2                5    18     22
    2    l-cysteine               3    14     18
    2    l-cysteine 4X            0    15      0
    2    l-glycine                2    19     10
    2    l-glycine 4X             0    15      0
    2    l-isoleucine             3    25     11
    2    l-isoleucine 4X          1    30      3
    2    l-leucine                2    16     11
    2    dl-phenylalanine         2    22      8
    2    dl-phenylalanine 4X      3    15     17
    2    l-proline                4    11     27
    2    l-proline 4X             5    14     26
    2    l-threonine              4    14     22
    2    l-threonine 4X           0    21      0
    2    l-valine                 3    20     13
    2    l-valine 4X              3    15     17
    2    total                   40 + 286=326 12% (average)

    3    activated charcoal       4    11     27
    3    activated charcoal 4X    4     6?    40?
    3    glucose                  6    19     24
    3    glucose 4X               5    18     28
    3    l-leucine 4X             1    17      6
    3    sorbitol                 6    18     25
    3    sorbitol 4X              3    13     19
    3    sucrose                  6    13     32
    3    sucrose 4X               3    17     15
    3    total                   38 + 132=170 22% (average)

    4    control#4               17     9     65
    4    l-carnosine              9    14     39
    4    l-carnosine 2X          18    15     55
    4    l-carnosine 4X          10    20     33
    4    l-carnosine 8X           6    33     15

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