Fruit Flies

[Tzunu un]

I'll add some info.

I'm no fly expert but had a couple of friends that worked in fly research labs in the past.

Will have to update my knowledge .....may take a few days as I'm swamped with other commitments until after wed.



J

[Tzunu un]

Hi, apologies on the long break in responding.

As mentioned above, there are many types of "flightless" fruit flies.

Alleles are different versions of the same gene. As such, different mutations in a given gene gives rise to different alleles which can differ in their effect.
Different alleles for a given gene can differ by the extent of the defect/phenotype, whether other defects also occur, and whether it causes lethality, etc.

So "flightless" isn't an allele or a mutation in one specific gene. It is a general categorization of flies that cannot fly no matter the cause or phenotype.

In the hobby, there a problem with the commonly used nomenclature for fruit fly cultures as they are advertised and sold; there is some confusion as to what we actually use as feeders as the fly cultures are named often independently of what the actual scientific genotype of the fly is (by the general public/retailers).


If one looks at Flybase, one can find that there are >6000 alleles in Drosophila that are linked to wing phenotype !!! Many of these may have lost the ability to fly or to fly normally. That is just wing structure / phenotype.

In addition to alleles in wing phenotype, other mutations / alleles can cause flies to lose the ability to fly.....one example are alleles that affect the wing muscle function.


So what are the fruit flies that we actually use and see for sale? (I will limit this to flightlessness and not eye color) :

"wingless" Drosophila melanogaster : these would have an apterous allele which causes a complete lack of wings.

"vestigial" Drosophila melanogater : a real allele name ...yea! These have a vestigial allele and these flies have very very small wings that look like nubs.

"curly winged" or "glider" (as in Turkish Gliders) Drosophila melanogaster : these would most likely contain either a Curly allele or a curled allele which alters the ability to fly well but theycan often glide. Turkish Gliders is a name made up by whoever first started selling them in the hobby.

"flightless" Drosophila hydei : The real allele is presently unknown.....but someone studied them for their thesis in a university and most likely these flies have a mutation affecting the flight muscles and not the wing structure itself. Most likely it is a mutation in the actin gene, but the actual allele still hasn't been identified/confimed.



So, commonly used nomenclature in the hobby is different than that using the scientific nomenclature of alleles. "Flightless" in the hobby generally means that they have wings but can't fly or glide, "wingless" generally means lack of wings, and "glider/curly" generally means that they can glide or fly poorly. As shown above, sometimes these strains used in the hobby have unknown alleles (scientific culture source is not identified and the flies from the culture have not been studied).

Also the specific culture strains used in the hobby are selected to be easy to culture....many alternate alleles that cause the same fly phenotype may be less fit for hobby culture due to slow culture, low production, lethality, or only a proportion of the mutant flies in the culture populations showing the phenotypic defect.


Here is a link that shows several alleles in Drosophila and includes drawings/pictures for some of the alleles (also includes eye color, etc.):
CGS Phenotypes

Here is the link to the thesis that studied the "flightless" Drosophila hydei (culture from Black Jungle). It also has some discussion of insect flight:
https://ida.mtholyoke.edu/xmlui/bits...pdf?sequence=1


Cheers!

James

[Tzunu un]

Oh, I guess I forgot one.

"flightless" Drosophila melanogaster : These have wings but it's unclear to me what the alleles actually are for the different cultures that are in the hobby. More than one allele is probably present in the hobby. As several different alleles could cause loss of flight with wing retention, each fly culture would need to be examined to guess.


One final point: fruit flies with wings have more surface area so they will carry more calcium/vitamins when dusting for feeding.