Subject: Re: [Q] Anther culture - Space aliens stole my mitochondria!

From: [email-masked] (Marco_Bleeker)
Date: Sun, 18 Jun 1995 01:48:35

>When using anther culture, pollen grains are dusted onto the surface of a 
>nutrient medium.  Occasionally, one will germinate into a monoploid plant.  My 
>question is:
>   Where does this plant get its mitochondria from?
>Do pollen grains have mitochondria?

  That appears to be the case than.

> If so, how come mitochondrial DNA is always inherited down the maternal line?

  A pollen is not exactly a spermcell. It grows out to become a very small 
gametophyt. Think of ferns, but then much smaller and on/ in  the receptical 
of the overy. This explains the presence of the mitochondria. The gametophyt 
in turn, produces the male 'sperm', not much more then a nucleus, which has no 
mitochondria. The exceptional monoploid plant your talking about, must have 
taken mitochondria from other tissue of the same gametophyt...

  Well, I have no experience here, just a shot at it as you called it, based 
on more general knowledge...

  Bye, marco

<[email-masked]>------------<http://www.euronet.nl/users/mbleeker/>
>-------------<Plants, Programs, Primitive creatures>------------------<
<Marco Bleeker>------------<nl-en-de-fr>------------<Amsterdam, Holland>

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From: [email-masked]
Date: 16 Jun 1995 19:14:44 +0100

I have been studying A-level biology, and techniques such as anther culture have 
been on the syllabus.  However, I have a query which no-one has yet been able to 
solve and I was hoping someone here might be able to throw some light on it.

When using anther culture, pollen grains are dusted onto the surface of a 
nutrient medium.  Occasionally, one will germinate into a monoploid plant.  My 
question is:
   Where does this plant get its mitochondria from?
Do pollen grains have mitochondria? If so, how come mitochondrial DNA is always 
inherited down the maternal line?

Any one know the answer to this?

Any response would be received with great interest.

Mark

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From: [email-masked] (Wayne Parrott)
Date: Sun, 18 Jun 1995 14:21:40

In article <[email-masked]> [email-masked] writes:
>From: [email-masked]
>Subject: [Q] Anther culture - Space aliens stole my mitochondria!
>Date: 16 Jun 1995 19:14:44 +0100

>Mark

Good question.  The same goes for the chloroplasts.

First, in the cases that I am familiar with, the haploid plant (not 
necessarily a monoploid-- if your plant is a polyploid to begin with, what you 
recover from anther culture will have more than one genome in it, so it won't 
be a monoploid!) originates from the microspore or pollen that is still at the 
uninucleate stage-- this is a stage before the mitotic divisions take place 
that lead to the formation of mature pollen, and a complete cell is still 
present.

Secondly, pollen transmission of cytoplasmic organelles in angiosperms is 
probably more common than previously thought.

Here are a couple of references for those interested:

Herberle-Bors E (1985) In vitro haploid formation from pollen: a critical review.
Theor Appl Genet 71:361-374

Reynolds TL (1990) Ultrastructure of pollen embryogenesis. In: Bajaj YPS (Ed) 
Biotechnology in agriculture and forestry, Vol. 12  Haploids in crop 
improvement I (pp 66-82). Springer-Verlag, Berlin Heidelberg

Lee DJ, Blake TK & Smith SE (1988) Biparental inheritance of chloroplast DNA 
and the existence of heteroplasmic cells in alfalfa.  Theor Appl Genet 
76:545-549

Erickson L, Kemble R & Swanson E (1989) The Brassica mitochondrial plasmid can 
be sexually transmitted. Pollen transfer of a cytoplasmic genetic element.  
Mol Gen Genet 218:419-422

Erickson L & Kemble R (1990) Paternal inheritance of mitochondria in rapeseed 
(Brassica napus).  Mol Gen Genet 222:135-139

Dulieu H, Derepas A & Cornu A (1990) Le rôle du pollen dans la transmission 
des chloroplasts et des mitochondries.  Etude d'un cas particulier chez 
Petunia.  Bull Soc bot Fr , Actual bot 137:49-56