White eye American roaches

[Arachnocat]

I've seen some pics of the white eye Periplaneta americana but I can't find info about them. I read that radiation gave them the white eye mutation. Were they just a lab experiment? Anyone know the history of the white eye roaches?

[esotericman]

TITLE: Peculiarities of eye ultrastructure and visual pigment in the white-eyed mutants of American cockroach, Periplaneta americana
AUTHOR, EDITOR, INVENTOR: Bobkova,-M-V [Reprint-author]; Shukolyukov,-S-A [Reprint-author]; Jarvilechto,-M [Author]
SOURCE: Sensornye-Sistemy. 2002; 16(3): 190-201
ABSTRACT: Compared to wild-type Periplaneta americana eye, the eye of white-eyed mutants has the same elements of dioptric and light-accepted, in addition the ommatidium structures seems to be similar. However, some peculiarities in mutant eye ultrastructure were detected. In photoreceptors, premirt and secondary pigment cells the electron-dense (but non-stained in vivo), membrane-limited granules were found. Similar to ommochrome screening pigment granuled in ommatidia of wild type eye, these organelles are involved in radial migration in respond to light and darkness actions. In opposite to wild-type rhabdomers, the mitant rhabdomers loor more deorganized and is displayed in microvillar swelling. In the state of dark adaptation the area of cross-section of mutant rhabdom is approximately 3 times less tyhan that of wild-type. Due to a high density of the screening ommochrome pigments in the wild-type ommatidium that interfere detection of visual pigment, the microspectrophotometric procedure can be only applied to the mutant ommatidium. After rhabdom adaptation to red and blue light, the absorbance spectra that was corrected on light scattering correspond twi photoproducts with lambdamax 485 nm and 490 nm (presumably rhodopsin and metarhodopsin, respectively). In addition to lambdamax shift the conversion of rhodopsin to metarhodopsin is also accompanied by a small increase of amplitude of the absorbance spectra. The difference between rhabdom absorbance recorded with two e-vector orientation, across (perpendicular) and along (parallel) rhabdom axis, illustrates a "pure" (without light scatter interference) rhodopsin and metarhodopsin spectra. Short wave part of these spectra appear to be significantly narrower than the same part of spectra in vertebrate rhodopsin templates which was constructed taking in account of beta-band contribution. Relation of maximal meanings of the rhodopsin spectra, was measured with two e-vector orrientation (dichroism), was approximately 3, implaying that in P. americana rhabdom the rhodopsin molecules in oriented predominantly along the microvilli axis. No differences in rhabdom ultrastructure and rhodopsin content between carotenoid (retinoid)-fortified and carotenoid (retinoid)-depleted animals were found.


This is a translation from Russian, and just the abstract, but from this I guess it's not radiation thing, but a naturally occurring mutation.

Also if you have access to Nature:

http://www.nature.com/nature/journal.../182892b0.html

In this paper from 1958, the white eyed mutant was found in a coal mine and raised in a department for 11 years... took a bit of looking to find that one, but I guess they make up 5% of the population in this cave population.

Christian

[BugChick]

A fine-looking species. Thanks for the info, Christian.

[Arachnocat]

Thanks! I thought the roach mutated by radiation story sounded cooler. lol. That was the only info I could find online about why their eyes were white. Being from a cave environment makes more sense though. I hope to have some of these one day. They're really cool looking!

I got this info from the allpet roaches website (http://www.angelfire.com/oh2/Roaches/):

American cockroach Periplaneta americana "White-eye" form
Where found: Nowhere in nature.

Adult length: 20-30mm.

This somewhat interesting strain of the common American cockroach actually has white eyes throughout its life; other roaches have black eyes even during molting. Supposedly someone exposed some P.americana to radiation and some mutated into the white-eye. It is hard to say if this strain is blind or not because American roaches use many sensory hairs, antennae, and cerci, so well that eyes are not necessary. This strain is about 25% smaller than the normal form and does not breed quite as well. Of course it is an excellent glass climber and lays many ova.

If you bred these, what percentage of them would have the white eye mutation?

[BugChick]

All of the ones in my colony have white eyes. The radiation story never made sense to me because the mutation wouldn't be passed onto the offspring.

[TheRoachKeeper]

If two roaches, let's call them the parental generation (P1), are exposed to a dose of radiation, they may not actually display the effects of that exposure themselves. That is to say, for example, that black eyed roaches would remain black eyed roaches after exposure to radiation. However, one of our P1 roaches may have produced gametes, sperm or egg cells, that could contain a genetic mutation. For the sake of this example let's say that the gene for eye pigmentation on one of the female's chromosomes is mutated to result in a lack of pigment, or white eyes.

If we then allow our P1 adults to produce offspring (the first filial generation, or F1), one half of the individuals produced would carry the mutation. These individuals may or may not display the effects of the mutation depending on whether or not the new (mutated) gene, from their mother, is dominant or recessive when paired with the normal (non-mutated) version, which they would have inherited from their father. In this case, I'll say the new version is recessive. This means that the white eye effect of the mutation will not be displayed unless an individual is homozygous (inherits two copies) for the mutation, which none of our F1 generation did. So all of the F1 roaches in this case would display normal, black eyes.

If we then allow our F1 generation to produce offspring (the second filial generation, or F2), and by chance a male carrying the mutation mates with a female, also carrying the mutation, then 1/4 of their offspring would be homozygous for the new gene. These F2 individuals would then finally display the results of the radiation exposure suffered by their grandparents, the P1 generation, and be white eyed roaches.

This is only one possible explanation of how radiation exposure could produce a genetic, heritable, mutation. I'm sure there are other ways this could happen, but this seems to me to be the most likely.

Also, I should say that I don't know that white-eyed American roaches were produced by exposure to radiation. But, it is indeed possible for such exposure to produce heritable traits. If anyone wants to check out what I have described in my example, I used basic mendelian genetics in my figuring.

I hope I didn't end up confusing anyone more than necessary with my somewhat long winded explanation.

-Mike-

[esotericman]

5% of the natural population is steady in the white eyed state, as per the Nature article.

The first article shows someone is doing real research on them also, which should indicate they're NOT artificial.

[lanasingh]

could add some salt but not knowing how tollerant they are of it i would only add 1 table spoon per 10 gallons thats 1/2 dose see if that helps but keep an eye on them for any stress tho
Sorry for offtop: melting point of tamiflu