Haploid male ant germ cells

[Major7]

In the haploid male ant, I assume these must occur in preparation for mating:

(1) Germ cells do not start meiosis.

(2) Germ cells are converted to sperm cells.

 

Are these assumptions correct?

 

Obviously something works; I'm curious about the details.

 

Regarding (1), meiosis generally works only with diploid germ cells, correct?

Whereas the gene works OK with female ants, is it turned off for males?

Or does the gene interrogate the germ cells? Such interrogation would be wasted on 99% of the germ cells.

 

Regarding (2), the final part of spermatogenesis, following meiosis:

"Spermatids mature further in a developmental process called spermiogenesis, becoming

spermatozoa."

http://en.wikipedia....ki/Spermatocyte

Do these descripitions apply to insects as well?

 

Do the male genes that cause spermiogenesis recognize/utilize the haploid germ cells, bypassing meiosis?

 

Do all cells have a basic identification, so that genes know which ones to process?

 

Or does a male ant send a germ cell (not a mature spermatozoa) to the female?

[Major7]

The answer is not found in 732-page book "The Ants" by Holdobbler and Wilson.

 

Is this question in the wrong forum?

 

 

 

 

 

Edited January 27, 2012 by Major7

[CharonY]

From what I remember meiosis still occurs, however, no chromsome separation happens. Essentially there will be a restriction and a non-nucleated cytoplasm bud will be formed (and the rest maintains the whole genome). For nice pictures see Transactions of the American Microscopic Society Vol. 58, No. 3, Jul., 1939).

 

Note that sometimes also diploid males are found, and not all of them are sterile (just remember that it was krieger et al. sometime in the 90s but forgot the whole reference).

 

[Major7]

no chromsome separation happens.

In what phase?

 

In Prophase I, are there genes to cause the homologous pairs to get close for crossovers?

They cannot do their job; does that not cause a "signal" problem?

 

In Metaphase I, spindle fibers link from centrioles at poles to sister chromatids closest to them.

I assume a sister chromatid's kinetochore connects to only one kinetochore microtubule, the first to do this from either pole?

 

In Anaphase I,

The spindle fibers shorten; normally sister chromatids are separated from their homologous partners and pulled towards each pole.

If there are no homologous pairs, what happens?

I considered two options:

(1) If some are pulled to one side and some to the other side, all the resulting sperm cells are incomplete.

(2) If they're all pulled to the same side, half the resulting sperm cells are good, the other half are empty.

 

 

For nice pictures see Transactions of the American Microscopic Society Vol. 58, No. 3, Jul., 1939).

How do I access those pictures?

[CharonY]

In the metaphase you see the usual condensation, however, the chromosomes are not separated. You will have to google and see if you got access to the paper. I think it has free access, but I may be wrong.

[Major7]

You are apparently commenting on the appearance which does provide clues.

 

Several months ago I had learned the mechanics of meiosis in a normal diploid germ cell. I'm referring to descriptions of the individual proteins etc. at work in each phase. Being a computer programmer, I think "How could I write a program to illustrate this?"

 

So, when I read about the male ant being haploid, I tried to figure out what happens in that meiosis to generate a sperm cell. In my last post I mentioned my amateur results.

 

The same DNA provides for different versions of meiosis. Perhaps we don't understand it yet.

 

Of course the ant DNA / development provide other "variations" (e.g. body size available in several standard "models", a feature not seen in most animal species).

 

Could this meiosis occur in a female haploid? Is it unique with ants and similar insects or could it occur in other species? In other words, can all meiosis proteins generate good sperm cells from either diploid or haploid?

 

And if anyone has found the microscope pictures, please post.