Crosses: Female parent advantages

[Patrina_Pepperina]

I discovered recently that mitochondria have DNA separate to the nucleus of the cell, and the following excerpt from Wikipedia explains it:

From Wikipedia, the free encyclopedia

Jump to: navigation, search

Mitochondrial DNA (some captions in German)




Mitochondrial DNA (mtDNA) is the DNA located in organelles called mitochondria. Most other DNA present in eukaryotic organisms is found in the cell nucleus. Nuclear and mitochondrial DNA are thought to be of separate evolutionary origin, with the mtDNA being derived from the circular genomes of the bacteria that were engulfed by the early ancestors of today's eukaryotic cells. In the cells of current organisms, the vast majority of the proteins present in the mitochondria (numbering approximately 1500 different types in mammals) are coded for by nuclear DNA, but the genes for some of them, if not most, are thought to have originally been of bacterial origin, having since been transferred to the eukaryotic nucleus during evolution.




In mammals, all mitochonrial DNA in a fertilized egg (zygote) is inherited only from the mother, as the sperm does not contribute any mitochondria; this holds true for most other organisms as well. (PP: my emphasis)


This is the reason why it makes a slight difference which plant you use for the female in tomato crosses. Since mitochondria are the energy suppliers for the organism, I think it might be important in some cases.


I wonder whether relative numbers of mitochondria affect flavour in terms of greater numbers of mitochondria = greater energy of the plant being able to affect the amount of sugars laid down in fruits?


I wonder whether mitochondrial DNA makes tree-type dwarf plants so robust with their leaf to stem ratio - they are generally broad leafed, and rugose which increases the amount of surface area receiving sun.


Do we have any biologists here in T'ville?


Patrina

[pierre rutten]

Chloroplast DNA is also maternally inherited.

I am not a specialist but vaguely remember cases of cytoplasm (mitochondrias, chloroplasts...) nucleus disharmony possibilities.

Chloroplast DNA mutations are frequently used as a tool to search evolutionary trees.

[Jeffery_Goss]

Occasionally chloroplast and mitochondrial DNA ends up being inherited from the male progenitor as well, but this is rare.

[Tom Wagner]

Do we have any biologists here in T'ville?

I took graduate level Cytogenetics forty years ago, so long ago that the gals in the lab had more in common with the Mitochondrial Eve; (mt-mrca) is the name given by researchers to the woman who is the matrilineal most recent common ancestor (MRCA) for all living humans.

I remember my attractive lab partner was from England and we took turns looking at microscope slides of meiosis and cytoplasm and I suppose I was a bit mitofondaer. I let our relationship "slide" however.

I recall writing down on paper what I saw in the microscope exams and the other post graduates were writing down what they wanted to see, much to the chagrin of the professor. I took it for granted that the mitochondrial cytoplasm was inherited maternally at that time.


It made sense through all these years about the inheritance of cytoplasmic particles, but bananas are peculiar in that their chloroplast DNA is maternally inherited while the mitochondrial DNA is paternally inherited. If that doesn't make sense, think Banana Seeds. See links.


http://www.botgard.ucla.edu/html/bot...Musaseeds2.jpg

http://www.apsnet.org/education/feature/banana/


More confusion:
Chloroplast DNA is paternally inherited for Redwoods and all other conifers studied.

• Within humans. A few cases of patients have been found to have mitochondrial DNA that was recombined from both their mother and father! Researchers are saying that the mitochondrial genetics is more complex than we first thought. Sometimes,even recombination occurs

• Most of these people who have recombined mitochondrial DNA are so sick that they probably will not have offspring. Apparently, these changes to their DNA and the recombination will result in their never entering the human population at large.
• The maternal inheritance will continue to be the rule.

When I try to study mitochondrial inheritance in tomatoes, it is like trying to study an extensive root system, so many leads and dead ends. The more interesting factors include male sterile associations, and the additions of pollen derived mitochondrial particles.

Trying to find all the exceptions to the rule about maternally inherited traits is too time consuming for me, so for the time being, I place a great link on cross-breeding work keeping the female line on a pedestal, so to speak.

Tom Wagner

[Patrina_Pepperina]

Originally Posted by Tom Wagner

Trying to find all the exceptions to the rule about maternally inherited traits is too time consuming for me, so for the time being, I place a great link on cross-breeding work keeping the female line on a pedestal, so to speak.

Tom Wagner

It's quite intriguing - what could mommy be hiding in her inner sanctuary I wonder? Do recessives lurk in mitochondrial or chloroplast DNA too?

Patrina

[Tom Wagner]

I had a 12 page response to your questions, Patrina, and was doing a Preview Post, but lost in all including my Word document that had tons of select, copy, and paste info in it.

Maybe I will get around to making a truncated version of it later.

Computer crashes have knocked out more of my potential responses on TVille than I care to admit.

Tom

[dice]

[Lost document issues with Word]

Try EditPad. There is a free version, and a
commercial version with a 30-day free trial.
It lacks most of Word's fancy formatting features,
but as a result there is a lot less code for something
to go wrong with, and it doesn't have Notepad's
limits on document size.

http://www.editpadpro.com/editpadlite.html

PSPad seems to be popular, too (entirely free):

Edit: access permissions for downloads at whoever
hosts PSPad's home page seemed to be broken at
the moment. This URL works, though:

http://www.snapfiles.com/download/dlspad.html

[Original URL, presently useless]
http://www.pspad.com/en/

Unless you are editing a document intended to be
printed, a "word processor" is usually mass overkill,
like using the Starship Enterprise to run down to
the corner store for a quart of milk. A text editor
is often a more practical choice for a document
that you want to post online somewhere, insert
in email, etc.

[Patrina_Pepperina]

Originally Posted by Tom Wagner

I had a 12 page response to your questions, Patrina, and was doing a Preview Post, but lost in all including my Word document that had tons of select, copy, and paste info in it.

Maybe I will get around to making a truncated version of it later.

Computer crashes have knocked out more of my potential responses on TVille than I care to admit.

Tom

Arrrggghhhh, I know how THAT feels..... all the effort and time spent on preparing a message which just disappears in a nano second or something, and when it happens I always swear I won't do a long post again without highlighting and copying the whole text before I go anywhere near those 2 buttons sitting innocently under all the smilies

Well, let me say thanks for your potential response Tom

Patrina

[Rena]

Originally Posted by Tom Wagner

I remember my attractive lab partner was from England and we took turns looking at microscope slides of meiosis and cytoplasm and I suppose I was a bit mitofondaer. I let our relationship "slide" however.

Tom Wagner

I just found this thread as I am gearing up to do some crosses. I had to read it twice but I did get it!!