Reg BN fri from Albino's

gofish · Post by **gofish** » 04 Mar 2007, 23:50

Is it possible to get reg BN babies from Albino BN pleco's? I just had a batch of fri and all of them except for two seem to be dark. This is my first time breeding these fish so I not quite surte what to expect. I don't have any reg BN so I know that the parents have to be albino's.

Bas Pels · Post by **Bas Pels** » 05 Mar 2007, 11:06

In almost all animals albinism is subjective to the normal colour. The mechanism is that albinism implys something which normally would produce the normal pigments, does not work - hence no colour.

However, it is possible, the lack of locour can result later in life. A humane example is boldness: many men are destined toget bold, but when boys they have a 9more or less) normal hairgrowth.

So I would assume your fry will loose their colour later in life.

MatsP · Post by **MatsP** » 05 Mar 2007, 13:09

Whilst Bas description of "male patter baldness" is an interesting concept of genetically programmed "deficencies", albinism in Bristlenoses is almost certainly not that sort of thing.

My suspicion is that this is two different variations of albinism that have been crossed, which leads to the offspring not having a full set of albino genetics from either both parents. What I'm trying to say is that there's a combination of genes that MAY generate albinism [there's several things that make the colour appear in the skin-cells in the first place, so there are several places in the genetics where this can break].

Since all (known) forms of albinism (in common Ancistrus) are "recessive" traits (i.e. they must be inherited from both parents), if we have two variants of albinism from the respective parents, you don't get any albino off-spring.

The other alternative is of course that you also have a brown bristlenose that is actually the parent - in which case the offspring would only be albino if the brown bristlenose also have albino trait. All my babies from Gus (badly named female) & Warren (male) have "hidden" albino trait, so offspring of the next generation from those give 25% albino fish.

--
Mats

Bas Pels · Post by **Bas Pels** » 05 Mar 2007, 13:45

Thank you Mat,

In my terms, you basically say: assuming the two parents come from different albino forms, it is very well possible the deficiencies in the genes from the male are repaired by those from the female, and vice versa.

Very goot possibility

That would also mean that other (hidden) deficiencies are repaired, and thus, ths fry would grow faster than regular, and be more resistant to deseases.

MatsP · Post by **MatsP** » 05 Mar 2007, 14:19

Bas Pels wrote:That would also mean that other (hidden) deficiencies are repaired, and thus, ths fry would grow faster than regular, and be more resistant to deseases.

Yes, indeed, any other inherited problems would also "go away" if they are only present on one side of the parents.

I must say I haven't noticed any tendency for albino's to grow slower or otherwise not behave just like their brown brothers and sisters. Of course, in a batch of bristlenoses, there's always some that grow a bit faster, and others that grow slower - usually because the smaller gets bullied off the food by the larger ones, so the larger ones keep growing. Hence the recomendation a while back by Shane to remove the biggest to a separate tank as soon as you see a noticable size difference (or sell the biggest ones, and let the smaller ones "catch up").

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Mats

apistomaster · Post by **apistomaster** » 05 Mar 2007, 16:19

Barbie, forum moderator, has told me that there are two forms of albino bushy noses she has that if crossed produce only normal colored fry. I do not know how this can be but she does not make up stories.
You can contact her via her fish forum at http://www.fishaholics.org after you register for free.
Maybe she can give you her take on this phenomena.

MatsP · Post by **MatsP** » 05 Mar 2007, 16:27

You can probably point Barbie in this direction (copy the URL at the top of the thread) by sending a PM or e-mail to Barbie here on this site too.

--
Mats

apistomaster · Post by **apistomaster** » 05 Mar 2007, 16:41

I forgot about that option. However her forum welcomes memers from around the world as well.
The main point is it was from Barbie that I first heard of two albinos producing normal colored fry and as I said, I cannot account for the genetics that would make this possible.

MatsP · Post by **MatsP** » 05 Mar 2007, 17:06

I've seen posts by Barbie on that subject too.

It is quite obvious (if you think about it) that there are different ways to "achieve" albinism -

1. the cells producing melanin (the brown/black pigment) can be "produced wrong", it doesnt' take a lot to change something "colourfull" into a dull non-coloured chemical. This is like colour-blindness in humans

2. The cells can have functioning melanin production stations, but the signal substance that tells the cell to produce melanin is broken. There are several examples of this in human "diseases".

3. Some other component necessary for the body to produce melanin is missing (i.e. the metabolism necessary to produce melanin is not working right). This is similar to for example diabetes in humans, where the insulin production is "broken" (I'm referring to the type that is inherited, not "age-diabetes" that occurs later in life and whilst genetical in some sense, it's related to lifestyle as well).

I'm sure if we think about it long enough, we'd come up with an almost endless list of how and why a particular function in a particular animal can be "broken".

I'll do a quick run-down through the "two types of albinism": We have two genes, A and B. They have a dominant form (A and B) and a recessive form (a and b). All genes work in a pair (at least - many things, like hair-colour in humans for example - are more complex than that), so there are several combinations of A and a, and B and b:
aa, Aa, aA and AA. Only aa gives albinism.
bb, Bb, bB and BB. Only bb gives albinism.

Of course, since all creatures have both the A and the B gene (but only need either aa or bb [or both] to make it albino), we have 16 combinations:
[X marks "albino", N means "brown"]
aabb, aaBb, aabB, aaBB (XXXX)
aAbb, aABb, aAbB, aABB (XNNN)
Aabb, AaBb, AabB, AaBB (XNNN)
AAbb, AABb, AAbB, AABB (XNNN)

So out of those 16 combinations, only 7 gives albino form.

If we take a pair of parents that we know have albino, they must have either aa or bb. If we also assume that the "other side" is AA or BB, then the cross will be aaBB x AAbb. Each parent will give one "half" of A and one "half" of B gene, so the offspring will ALL be:
aABb, which means that they are NOT albino!

Make sense?

--
Mats

apistomaster · Post by **apistomaster** » 05 Mar 2007, 18:14

Hi Mat.
Believe or not your explanation was how I understood that getting the normal form from albinos was possible. I just did not have the confidence in my Mendelian genetics was sufficient to lay it out for anyone.

Well done, Mat

It is still an unusual set of circumstances and a rare occurrence.

gofish · Post by **gofish** » 06 Mar 2007, 05:42

My head hurts. (LOL)

Persephone · Post by **Persephone** » 06 Mar 2007, 15:59

MatsP wrote:Of course, since all creatures have both the A and the B gene (but only need either aa or bb [or both] to make it albino), we have 16 combinations:
[X marks "albino", N means "brown"]
aabb, aaBb, aabB, aaBB (XXXX)
aAbb, aABb, aAbB, aABB (XNNN)
Aabb, AaBb, AabB, AaBB (XNNN)
AAbb, AABb, AAbB, AABB (XNNN)

So out of those 16 combinations, only 7 gives albino form.

If we take a pair of parents that we know have albino, they must have either aa or bb. If we also assume that the "other side" is AA or BB, then the cross will be aaBB x AAbb. Each parent will give one "half" of A and one "half" of B gene, so the offspring will ALL be:
aABb, which means that they are NOT albino!

Make sense?

--
Mats

You could get all non albino if the parents were this combination or you could have parents of
Aabb aaBb

In a cross you would get 1/4 AaBb 1/4 aabb 1/4 Aabb
and 1/4 aaBb resulting in in 3/4 albino phenotype 1/4 brown phenotype.
If albinism is based on 2 gene sets then it is completly possible you would get mostly albino fry with a few brown.

** Pattern baldness is actually a sex limited trait.
It is expressed by the presence of the sex hormone testosterone and that is why you normally wouldnt see it in younger children. If we represent it with b+/b genes dominance is dependant upon the sex in wich it resides. That is: b/b in both males and females will always result in pattern baldness and b+/b+ will result in non pattern baldness in both sexes. However
in males with b+/b b+ will take dominance(and result in pattern baldness) where as
in females with b+/b b will take dominance and result in no pattern baldness.

Persephone · Post by **Persephone** » 06 Mar 2007, 16:06

I read that wrong i thought you had just a few non alb in the fry. Well hopefully it may still help as a ref if someone has a batch with mostly alb and a few non