fun with nifs!!!

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Fun With Nifs!!!. What Are and what do they do???. Nifs. Survive without food?. Legumes like Nitrogen Fixation. . Then, why do Nitrogen Fixing bacteria exist?. To give plants the nitrogen needed to develop and grow to many of our favorite vegetables. . - PowerPoint PPT Presentation

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Page 1: Fun With Nifs!!!
Page 2: Fun With Nifs!!!

What Are and what do they do???

Page 3: Fun With Nifs!!!

Survive without food?

Page 4: Fun With Nifs!!!

Legumes like Nitrogen Fixation.

Page 5: Fun With Nifs!!!

Then, why do Nitrogen Fixing bacteria exist?

• To give plants the nitrogen needed to develop and grow to many of our favorite vegetables.

Page 6: Fun With Nifs!!!

Nitrogen fixating bacteria has specific genes, Nitrogen Fixing genes (Nifs)

Page 7: Fun With Nifs!!!

There are many kinds of Nif Genes!

Such as NifA, NifD, NifK…

Page 8: Fun With Nifs!!!

Where are Nifs found?

• In some kinds of bacteria. Example : Anabaena and Azotobacter.

Page 9: Fun With Nifs!!!

Nitrogen Fixation is done through a Nitrogenase complex…

Page 10: Fun With Nifs!!!

But due to the complexity of the cofactor, there are three kinds…

Page 11: Fun With Nifs!!!

Most Nitrogen fixing bacteria has 1 of the 3,

yet, Anabaena has ALL 3 kinds!!!

Page 12: Fun With Nifs!!!

Then… How did Anabaena acquire those different Nitrogen Fixing

genes?

Page 13: Fun With Nifs!!!

• First, let us look at the genes of Azotobacter Vinelandii (which is not a cyanobacterium) that contains Nifs and alternatives, Anfs and Vnfs.

• Then, Let us compare its genes to genes of Anabaena.

Page 14: Fun With Nifs!!!

• Do you think there is a similarity between their Nifs? How about between Vnfs or Anfs of Azobacter and Nifs of Anabaena?

• Considering that they are all Nitrogen Fixing genes, one would expect one of two possibilities…

Page 15: Fun With Nifs!!!

All Anabaena genes evolved from the same ancestor, while Azotobacter is different…

Page 16: Fun With Nifs!!!

Or…All Nif genes in Anabaena evolved from the same ancestor, while Vnf evolved from same ancestor as for Vnf in Azotobacter

Page 17: Fun With Nifs!!!

How do we compare them?

• To understand where it all came from, a TREE must be constructed to compare Azotobacter gene sequence with Cyanobacter gene sequence.

• By Run-Phylip, or Make-Tree

Page 18: Fun With Nifs!!!

Go to biolingua…

• Bring genes of Azotobacter to biolingua.• BLAST them against Cyanobacteria• Add them together, then ALIGN.• Finally, make a tree.

• Giving the following actual results…

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So, how did Anabaena acquire those different Nitrogen Fixing

genes?

• Anabaena genes and Azotobacter genes can share the same ancestors:

Maybe.• Anabaena genes and Azotobacter genes don’t

share the same ancestors: Most likely the case.

Page 24: Fun With Nifs!!!

• In order to answer this complex question, further research must be done on this topic to provide enough supporting evidence.

Page 25: Fun With Nifs!!!

Special Thanks to…• Dr. Teresa Thiel

Associate Dean, College of Arts and Sciences Professor of Biology Department of Biology University of Missouri-St. Louis

…And…• Dr. Jeff Elhai

Dept. of Biology and Center for the Study of Biological ComplexityVirginia Commonwealth University