Bilateral colour asymmetry

Richard Gordon gordonr at cc.umanitoba.ca
Wed Oct 23 00:06:36 EST 1996


Dear Hamp,
Curious answer, "a genetic mosaic from the time of fertilization", to the
question of the origin of bilateral color asymmetry in lobsters, because an
embryologist dealing with regulating embryos would have answered
"compartmental boundary", which, of course, was originally well known in
insects. An example is found in:

Mintz, B. (1967). Gene control of mammalian pigmentary differentiation, I.
Clonal origin of melanocytes. Proc. Natl. Acad. Sci. USA  58, 344-351.

Furthermore, we have recent reports of bilateral asymmetry in gene
expression, which definitely don't involve genetic mosaicism:

Levin, M., R.L. Johnson, C.D. Stern, M. Kuehn & C.J. Tabin (1995). A
molecular pathway determining left-right asymmetry in chick embryogenesis.
Cell  82(5), 1-20.

How about some key refs to the genetic mosaic mechanism of bilateral
asymmetry, for those of us not raised on fruit flies?

Yours, -Dick Gordon

At  2:51 PM 10/22/96 -0700, Hampton Carson wrote:
>Geoff:
>
>What you have described is very likely to be a genetic mosaic from the
>time of fertilization.  Lots of these are known in Drosophila of different
>species.The bilateral asymnmetry you have described, on a strict saggital
>line, is well known.
>
>Color patterns of lobsters would be an interesting research
>topic. The land crab, Gecarcinus ruricola, a land crab from the Caribbean
>has incredible color polymorphism among adults buts nothing is known about
>its inheritance.
>
>With Aloha from
>
>Hamp Carson
>
>
>On Tue, 22 Oct 1996, Geoff Ralling wrote:
>
>> I believe this group might be able to answer my questions about an unusual
>> lobster since drosophila types are interested in genes for body symmetry.
>>
>> I work at the University of Prince Edward Island which houses the Atlantic
>> Veterinary College.  In one of the student demonstration tanks is an
>>Atlantic
>> Lobster which shows complete bilateral colour asymmetry.  I have two
>>questions:
>>
>>       What sort of mutation would cause this?  I can only think of a somatic
>> mutation in a colour gene occuring early in the development of the embryo.
>> Can someone support this or suggest an alternative?
>>
>>       Has anyone ever heard of or seen such a thing in any animal?  This
>> creature is wild-type colour on the RHS and bright red on the LHS with a
>>razor
>> sharp line down its midline dividing left and right.  Bright red colour
>> mutants are occasionally caught around here but this left-right asymmetrical
>> is in my view spectacular.  It hasn't seemed to impress anyone else though.
>>
>> Thanks for any insights.  Hope this is an appropriate group.
>>
>> Geoff Ralling
>> University of Prince Edward Island
>> ralling at upei.ca
>>
>>
>>
>>

--------------------------------------------------------------------
Dr. Richard Gordon, Department of Radiology
University of Manitoba, Room ON104, Health Sciences Centre
820 Sherbrook Street, Winnipeg, MB R3A 1R9 Canada
Phone: (204) 789-3828,  Fax: (204) 787-2080, Home: (204) 589-0411
E-mail: GordonR at cc.UManitoba.ca





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