Nondisjunction on purpose: Reasonable?

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Nondisjunction on purpose: Reasonable?

Postby caters on September 22nd, 2017, 3:59 pm 

In spermatogenesis in males or hermaphrodites when it comes to numbers as a species, the meiosis after the first division is asymmetric.

They have 6 types of chromosomes.

First, there are autosomes. These are only duplicated once and the chromatids separate once. From then on, only 2 sperm per secondary spermatocyte end up with these autosomes.

The other types of chromosomes can end up in any of the 6 sperm produced. Those are:

  • Sex Chromosomes(there are 4 sex chromosomes and each viable combination leads to a different result unless you are comparing XYYY to XXXY)
  • Operational chromosomes(These determine the value of the number, more specifically the first sperm to fertilize the egg detemines what operation is done)
  • Color chromosome(This is a chromosome specialized for color of all kinds and is specialized for color patterns as well)
  • Size chromosome(This chromosome determines the size of everything in the body based on mixed genetics(incomplete dominance in the middle, complete dominance towards the extremes for any given body part) and every gene affects the result, some more than others. So for example if the gene for the heart has the allele for extra small, than the whole body is going to be extra small regardless of the actual genetics for full body size)
  • Circular chromosome(This chromosome codes for very few genes, most of them having to do with nuclear proteins)
As an example here is 1 possible result for an XXXY male:

1st sperm produced from division: X, circular chromosome, color chromosome, size chromosome, multiplication chromosome, autosomes
2nd sperm produced: autosomes, Y, addition chromosome
3rd sperm produced: subtraction chromosome
4th sperm produced: X, division chromosome
5th sperm produced: nth root chromosome
6th sperm produced: X, exponentiation chromosome

Now, in the zygote, this will sometimes lead to triploidy of the autosomes and will always lead to 1 more sex chromosome than needed. Since triploidy is not viable in numbers and having an extra sex chromosome could cause problems, the egg cell carries with it DNase enzymes in the nucleus. These are only activated when needed to get rid of chromosomes. So with every zygote, the DNase is activated when there are 5 sex chromosomes so that the number doesn't develop any problems from having an extra sex chromosome.

But, is this nondisjunction a good thing in this case?
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Re: Nondisjunction on purpose: Reasonable?

Postby BioWizard on October 18th, 2017, 4:43 pm 

I don't understand several things about your post. Including "6 sperm produced", "size chromosome", "color chromosome", etc. Phenotypic traits aren't determined by chromosomes.
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Re: Nondisjunction on purpose: Reasonable?

Postby caters on November 13th, 2017, 1:12 pm 

The fact that 6 sperm are produced stems from the asymmetry in the divisions and the number of operational chromosomes being 6. And I am not saying that phenotypic traits are determined by chromosomes. I am just saying that all the genes for size are on a single chromosome and that all the genes for color are on a single chromosome. I know that phenotypic traits are determined by alleles and I am not denying that. And if you imagine a situation where you have operations being done to the female's numerical value to get the baby's numerical value and the male is who determines what operation is being done by the first sperm fertilizing an egg than you can imagine all 36 possibilities for every possible pair of numbers including pairs with the same number(as is the case with self fertilizing hermaphrodites). As an example, if the female's numerical value is 144, the male's numerical value is 2, and the first sperm to fertilize the egg has the nth root chromosome, than the numerical value of the baby is going to be sqrt(144) which is 12.
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Re: Nondisjunction on purpose: Reasonable?

Postby BioWizard on November 14th, 2017, 9:34 am 

nth root chromosome? While I realize this is alien biology, I'm not following.
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Re: Nondisjunction on purpose: Reasonable?

Postby caters on November 15th, 2017, 12:47 am 

Basically an equation is going on during conception. The female's numerical value determines the number that is affected in the equation. The male's numerical value determines to what magnitude that number is affected. In the case of self fertilizing hermaphrodites it is the same although it doesn't really matter whether you view it as the female's value being affected or the male's value being affected since for hermaphrodites, those values are the same.

The 6 operational chromosomes(and more specifically the 1 operational chromosome in the first sperm to fertilize the egg) determine what operation is done with the 2 numerical values. That 36 in there was a mistake. That 36 would only be true if the order of male and female numerical values was independent. The order is not independent, the male always determines the magnitude of which the female's numerical value is affected.

So here are the possibilities for the case of 144 being female and 2 being male:

144+2=146
144-2=142
144*2=288
144/2=72
144^2=20736
sqrt(144)=12

Does that make it any easier to understand?
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