Mosaics

[Roland]

Saw a short spell back someone enquiering regards Colours etc.

Been sleep and jolted me mind, and thought this site might havebeen / is of use.

Some loverly strange coloured ones I feel.

 

http://www.angelfire.com/ga/huntleyloft/mosaics.html

 

[DOVEScot]

We have had this in our rollers, it looks really strange especially from white parents

[Ronnie]

Saw a short spell back someone enquiering regards Colours etc.

Been sleep and jolted me mind, and thought this site might havebeen / is of use.

Some loverly strange coloured ones I feel.

 

http://www.angelfire.com/ga/huntleyloft/mosaics.html

 

Very Very interesting

 

Now if we get a hen that can produce mosaic's then seperate it and when due for pairing put it in with our two best racing cocks i wonder if we could get lucky and get half and half now if them two best racing cocks happened to be brothers would that intensify the winning gene pool even more than normal?

 

A great article thanks Roland

 

[DOVEScot]

 

Very Very interesting

 

Now if we get a hen that can produce mosaic's then seperate it and when due for pairing put it in with our two best racing cocks i wonder if we could get lucky and get half and half now if them two best racing cocks happened to be brothers would that intensify the winning gene pool even more than normal?

 

A great article thanks Roland

 

I don't think you can produce a mosaic it just happens by chance :-/

 

 

[bewted]

 

I don't think you can produce a mosaic it just happens by chance :-/

 

 

i think you right on that one !!!

[sir_nico]

hi everyone...what do you call this color

cheerss

[kirky]

red shalie for me,

[OLDYELLOW]

aye and most of colour will moult out

[Larry Lucas]

If I understand the mosaic issue, it is produced when a sperm cell from two different cocks fertilize the egg at the same time.

[DOVEScot]

If I understand the mosaic issue, it is produced when a sperm cell from two different cocks fertilize the egg at the same time.

 

I would find that one biologically challenged :-/

[traynor]

i think it is impossible for the sperm off two different cocks to fertilize one egg. simply because the first cock to inseminate the hen, his sperm will get to the egg first.

[OLDYELLOW]

be a Jeremy Kyle pigeon from a rough loft having a threesome

[traynor]

hahahaha double whammy

[DOVEScot]

be a Jeremy Kyle pigeon from a rough loft having a threesome

 

Ménage à trois de klaks ;D ;D ;D

[Larry Lucas]

 

I would find that one biologically challenged :-/

 

I agree it runs counter to common sense, but here is an article by Dr. Gibson on bipaternity (two sperm cells with one egg) and the production of the mosaic pattern:

 

Bipaterity sperm Mutations

 

by Dr. Lester Paul Gibson

 

I think in order to form a basis of understanding for the possible formation of what we call a mosaic pigeon; we must start at the cellular level.

 

At one phase of the cell division, there occurs a different type of cell division from mitosis.   This type of cell division is called REDUCTION DIVISION which forms the germ cells or gametes.   This formation of gametes is known as maturation.

 

We know that normally a new individual is started by the union of two gametes, a sperm cell and an egg cell.  Sperm cells are formed by two cell divisions.   Two primary spermatocyte chromosomes become paired closely in what is known as synapsis.   Each splits in reduction division so that now there are four chromatids (a tetrad).   These separate loosely and one from each dyad goes to each end of the cell and now the cells contain only 1 chromosome of each pair.   The other two spermatocytes (the two not used above) divide by mitosis and form spermatids.   These form sperm without further division.

 

If during the reduction division part of each exchange sections with the other; we have what is known as a chiasma. THIS IS WHAT WE CALL A CROSSOVER.

 

In the formation of the egg from potential egg cells, a similar series of events takes place.   The only difference is that instead of the process producing 4 gametes (like the sperm production), three of the four are normally small and disintegrate.   We call these POLAR BODIES.   The fourth gets all of the cytoplasm and becomes a mature egg.   Each of these cells will have one chromosome of each pair, the difference is that only one gets the cytoplasm and the others do not get any.

 

If during this process instead of only one remaining, one of the others (a polar body) should also get some of the cytoplasm or the division is not complete and the polar body does not deteriorate; then we get a dual cell egg (a bipolar egg).  In this case, each of the two poles may now become  fertilized by a different sperm (bipaterity).

 

Depending upon the size and viability of each; the area of mosaicism may be half or somewhat less than half of the resultant organism.

 

Chromosomal aberrations occur in several ways but lets reserve our discussion to those that may produce mosaics.   One type is called non-disjunction in which during cell division, both chromosomes go to the same end of the cell and thus producing a cell without a chromosome and one with both.   This is not a theory because it is known to happen.   Certain resultant combinations do not produce viable embryos and thus do not live and others instead of producing diploids may produce triploids, tetraploids, or monoploids for certain chromosomal pairs.  

 

Work with drosophila flies has proven that they can and do occur.  Another type is called translocation (another crossover mechanism).  Another type is called segmental interchange (a double crossover mechanism).  Another type is called deletion (a mutational mosaic mechanism).

 

It has been stated that a cell with three chromosomes cannot live.   That has been patently proven to be false in many insect and plant genetic tests and manipulation results.   It is known to even occur in a number of human cases in the sex chromosomes in which individuals may have the sex configurations of XXX, XXY, XXXY, XXYY, or even XXXXY.    

 

Somatic mosaics can occur anytime after fertilization of the egg.   If early in the development, there may be near 50% of the organism or if later only a few cells.

 

Let's consider the bipaterity sperm theory.   If the sperm fertilize the egg at or nearly at the same time you would get a configuration somewhat like below:

__   __   __   __   _________  Sperm A

------------------------------------------   Egg

---  ---   ---  ---   --------------------  Sperm B

 

As the egg starts dividing the Sperm A and the egg would produce cells that become the right half and Sperm B and the egg would produce the left half.

In the case of a bird like the half black homozygous Chinese Owl/Sooty Blue bar hetero Baldhead Roller reared by Marvin Lee; the above would work better if we have a bipolar body egg or if you prefer a Siamese egg.

 

_____ ____ _________   Owl sperm for black

----------------------------------   Egg Owl black

-----------------  ---------------   Egg Owl blue bar

---   ---  ---   -----------------   Roller sperm for Bh Blue bar

 

This would allow one side to produce the homo Owl side and the other to produce the hetero Owl/Roller side.        

 

I have the mounted bird.   Dr. Hollander assured me that it was a waste of money to have it mounted and preserved because everyone will just say it is a hoax.  The Owl side is completely Owl with all the Owl attributes including the pantaloons and the Roller side distinctly Roller with the distinct hetero Baldhead marking. Even measurements of the beak show one side Owl and the other Roller.

 

I said the bird is question would have the brown (or even dun if it proved to be dun) parts female and the black parts male.   That is a given because the traits are sex-linked.  

 

Keep up the good work.

 

Dr. Lester Paul Gibson

[DOVEScot]

 

I agree it runs counter to common sense, but here is an article by Dr. Gibson on bipaternity (two sperm cells with one egg) and the production of the mosaic pattern:

 

Bipaterity sperm Mutations

 

by Dr. Lester Paul Gibson

 

I think in order to form a basis of understanding for the possible formation of what we call a mosaic pigeon; we must start at the cellular level.

 

At one phase of the cell division, there occurs a different type of cell division from mitosis.   This type of cell division is called REDUCTION DIVISION which forms the germ cells or gametes.   This formation of gametes is known as maturation.

 

We know that normally a new individual is started by the union of two gametes, a sperm cell and an egg cell.  Sperm cells are formed by two cell divisions.   Two primary spermatocyte chromosomes become paired closely in what is known as synapsis.   Each splits in reduction division so that now there are four chromatids (a tetrad).   These separate loosely and one from each dyad goes to each end of the cell and now the cells contain only 1 chromosome of each pair.   The other two spermatocytes (the two not used above) divide by mitosis and form spermatids.   These form sperm without further division.

 

If during the reduction division part of each exchange sections with the other; we have what is known as a chiasma. THIS IS WHAT WE CALL A CROSSOVER.

 

In the formation of the egg from potential egg cells, a similar series of events takes place.   The only difference is that instead of the process producing 4 gametes (like the sperm production), three of the four are normally small and disintegrate.   We call these POLAR BODIES.   The fourth gets all of the cytoplasm and becomes a mature egg.   Each of these cells will have one chromosome of each pair, the difference is that only one gets the cytoplasm and the others do not get any.

 

If during this process instead of only one remaining, one of the others (a polar body) should also get some of the cytoplasm or the division is not complete and the polar body does not deteriorate; then we get a dual cell egg (a bipolar egg).  In this case, each of the two poles may now become  fertilized by a different sperm (bipaterity).

 

Depending upon the size and viability of each; the area of mosaicism may be half or somewhat less than half of the resultant organism.

 

Chromosomal aberrations occur in several ways but lets reserve our discussion to those that may produce mosaics.   One type is called non-disjunction in which during cell division, both chromosomes go to the same end of the cell and thus producing a cell without a chromosome and one with both.   This is not a theory because it is known to happen.   Certain resultant combinations do not produce viable embryos and thus do not live and others instead of producing diploids may produce triploids, tetraploids, or monoploids for certain chromosomal pairs.  

 

Work with drosophila flies has proven that they can and do occur.  Another type is called translocation (another crossover mechanism).  Another type is called segmental interchange (a double crossover mechanism).  Another type is called deletion (a mutational mosaic mechanism).

 

It has been stated that a cell with three chromosomes cannot live.   That has been patently proven to be false in many insect and plant genetic tests and manipulation results.   It is known to even occur in a number of human cases in the sex chromosomes in which individuals may have the sex configurations of XXX, XXY, XXXY, XXYY, or even XXXXY.    

 

Somatic mosaics can occur anytime after fertilization of the egg.   If early in the development, there may be near 50% of the organism or if later only a few cells.

 

Let's consider the bipaterity sperm theory.   If the sperm fertilize the egg at or nearly at the same time you would get a configuration somewhat like below:

__   __   __   __   _________  Sperm A

------------------------------------------   Egg

---  ---   ---  ---   --------------------  Sperm B

 

As the egg starts dividing the Sperm A and the egg would produce cells that become the right half and Sperm B and the egg would produce the left half.

In the case of a bird like the half black homozygous Chinese Owl/Sooty Blue bar hetero Baldhead Roller reared by Marvin Lee; the above would work better if we have a bipolar body egg or if you prefer a Siamese egg.

 

_____ ____ _________   Owl sperm for black

----------------------------------   Egg Owl black

-----------------  ---------------   Egg Owl blue bar

---   ---  ---   -----------------   Roller sperm for Bh Blue bar

 

This would allow one side to produce the homo Owl side and the other to produce the hetero Owl/Roller side.        

 

I have the mounted bird.   Dr. Hollander assured me that it was a waste of money to have it mounted and preserved because everyone will just say it is a hoax.  The Owl side is completely Owl with all the Owl attributes including the pantaloons and the Roller side distinctly Roller with the distinct hetero Baldhead marking. Even measurements of the beak show one side Owl and the other Roller.

 

I said the bird is question would have the brown (or even dun if it proved to be dun) parts female and the black parts male.   That is a given because the traits are sex-linked.  

 

Keep up the good work.

 

Dr. Lester Paul Gibson

 

Very good, everyday is a school day

[Guest IB]

Well, going back to my school days, two sperm fertilising the same ovum just can't happen; there can be only one winner, the first sperm body to penetrate the outer membrane loses its tail and sets off a chemical chain reaction in that membrane making it impervious to all other sperm.

 

The numbers wouldn't add up either. A normal pigeon cell has a total of 40 chromosomes; 20 from the father in the sperm, and 20 from the hen in the ovum. 2 sperm and one ovum would = 60.

[DOVEScot]

Well, going back to my school days, two sperm fertilising the same ovum just can't happen; there can be only one winner, the first sperm body to penetrate the outer membrane loses its tail and sets off a chemical chain reaction in that membrane making it impervious to all other sperm.

 

The numbers wouldn't add up either. A normal pigeon cell has a total of 40 chromosomes; 20 from the father in the sperm, and 20 from the hen in the ovum. 2 sperm and one ovum would = 60.

 

Looks like things have evolved from our school days, I thought the very same thing :-/

[bewted]

Well, going back to my school days, two sperm fertilising the same ovum just can't happen; there can be only one winner, the first sperm body to penetrate the outer membrane loses its tail and sets off a chemical chain reaction in that membrane making it impervious to all other sperm.

 

The numbers wouldn't add up either. A normal pigeon cell has a total of 40 chromosomes; 20 from the father in the sperm, and 20 from the hen in the ovum. 2 sperm and one ovum would = 60.

 

but,,,theres allways the oddball of nature !!!

[Guest IB]

Also posted in other thread on mosiacs, that the true mosiac looks like two different pigeons fused together to make one; e.g. 'a red' on one side and 'a blue' on the other. Haven't a scooby what causes it tho.  

 

I'm sure Jimmy White posted a pic of one of these mosiac pigeons a while back.

[Guest IB]

 

but,,,theres allways the oddball of nature !!!

 

There are some basic rules that cannot be broken. Mr Lucas has thrown some smoke screens into his piece. Yes there are gene crossovers between chromosomes but in single cells only: a single cell can divide to make 2; 2 divide to make 4; etc but 2 of these multiplying groups of cells cannot merge to make 1, if it did you would expect a duplex individual - 2 heads, 4 wings, 4 legs etc., 2 hearts etc.

 

The best human example is the down syndrome child - known as the child with something extra - the something extra is an extra chromosome which causes physical and learning difficulties in a person with this condition.

 

There's also the horse mule / ass? because of the different number of chromosomes the resultant offspring is sterile, and cannot reproduce itself. Got to obey the basic laws of nature?

[Ronnie]

from reading the article in the first post.I took it that the hen that produced mosaic's failed to produce the chemical that stopped other sperms fertalising the egg's ,thus enabling another sperm to enter and fertalise.I dont pretend to understand most of it i just try and get the basic priciples then throw idea's about to see if they work .

[Larry Lucas]

 

There are some basic rules that cannot be broken. Mr Lucas has thrown some smoke screens into his piece. Yes there are gene crossovers between chromosomes but in single cells only: a single cell can divide to make 2; 2 divide to make 4; etc but 2 of these multiplying groups of cells cannot merge to make 1, if it did you would expect a duplex individual - 2 heads, 4 wings, 4 legs etc., 2 hearts etc.

 

The best human example is the down syndrome child - known as the child with something extra - the something extra is an extra chromosome which causes physical and learning difficulties in a person with this condition.

 

There's also the horse mule / ass? because of the different number of chromosomes the resultant offspring is sterile, and cannot reproduce itself. Got to obey the basic laws of nature?

 

IB, sorry, but I did not write the article -- no smoke screen there. My PhD is not in genetics, but Dr. Gibson is somewhat familiar with the subject -- he is the author of "Genetics of Pigeons" and other journal articles on the subject.  He and W.F. Hollander have done some of the best work on pigeon genetics for the fancy. I think if you re-read what I posted you will find he is describing what occurs within pigeons genetically to account for the mosaic pattern. The information he provides seems to suggest that a crossover fusion is at the heart of the matter. For what it is worth, people are free to take it or leave it.

 

 

[DOVEScot]

 

Yes there are gene crossovers between chromosomes but in single cells only: a single cell can divide to make 2; 2 divide to make 4; etc but 2 of these multiplying groups of cells cannot merge to make 1, if it did you would expect a duplex individual - 2 heads, 4 wings, 4 legs etc., 2 hearts etc.

 

 

But that is possible also, you get conjoined twins  :-/

[Guest IB]

 

IB, sorry, but I did not write the article -- no smoke screen there. My PhD is not in genetics, but Dr. Gibson is somewhat familiar with the subject -- he is the author of "Genetics of Pigeons" and other journal articles on the subject.  He and W.F. Hollander have done some of the best work on pigeon genetics for the fancy. I think if you re-read what I posted you will find he is describing what occurs within pigeons genetically to account for the mosaic pattern. The information he provides seems to suggest that a crossover fusion is at the heart of the matter. For what it is worth, people are free to take it or leave it.

 

 

Sorry, I did not mean to infer that you had introduced a smokescreen, rather that the article you posted seemed to fudge some issues, e.g. on the viability of 'beings' having incorrect numbers of chromosomes. My reading is that he is suggesting that a single egg is fertilised by two seperate sperm to form two seperate 'beings' which then fuse to become one. How that could happen in the first place (polyspermy) and then to produce only the colour of two seperate 'beings' - without their limbs or organs - seems to me to be an inconvenient fact conveniently left out. The lay persons guide to these things seems to support that two sperm fertilizing one ovum (in any organism) is still considered against the general laws of nature.

 

http://en.wikipedia.org/wiki/Polyspermy