only mammals have antibodies?

[wenxian]

i was told that only mammals have(can produce by their own) antibody...
then how abt other animals like reptile,bird n fish??
without antibody,how can those animals protect themselves against diseases??

[JHamm]

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1317265/

While it is clear that all birds have the typical vertebrate adaptive immune system and can produce antibodies

It seems like you were told some hooey.

[Andy Resnick]

Plants have an immune system as well:

http://www.nature.com/nature/journal/v444/n7117/full/nature05286.html

[Ygggdrasil]

Plants have an immune system as well:

http://www.nature.com/nature/journal/v444/n7117/full/nature05286.html

But do plants use antibodies as part of their immune system? I thought plants had only an innate immune system and lacked an adaptive immune system.

[Andy Resnick]

But do plants use antibodies as part of their immune system? I thought plants had only an innate immune system and lacked an adaptive immune system.

Good question- I'm not an expert. The Nature article states "Plants, unlike mammals, lack mobile defender cells and a somatic adaptive immune system." I couldn't decipher all the pathways discussed.

http://www.stanford.edu/class/mi104/Plant%20immunity.pdf

I'm thinking about the 'systemic acquired resistance', if that is a reasonable analog.

[atyy]

I think antibodies (immunoglobulins) are restricted to vertebrates.

Plants have other defences. In addition to the mechanisms described Andy Resnick's link, plants have an anti-virus system.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC157182/pdf/1070679.pdf
http://en.wikipedia.org/wiki/RNA_interference

The wikipedia article says that RNA interference may have an anti-virus purpose not only in plants, but also in invetebrates such as flies and worms.

[Pythagorean]

it would make sense that they are restricted to vertebrates. Antibodies are white blood cells, which are derived form bone marrow cells. Anything non animals would probably be a case of convergent evolution, wouldn't it?

I guess a non-vertebrate (chordate) could have the same cells, I'm not really sure at what point in the "dividing line" the cells actually originated.

[atyy]

it would make sense that they are restricted to vertebrates. Antibodies are white blood cells, which are derived form bone marrow cells. Anything non animals would probably be a case of convergent evolution, wouldn't it?

I guess a non-vertebrate (chordate) could have the same cells, I'm not really sure at what point in the "dividing line" the cells actually originated.

Wow, yes - there are invertebrates with antibodies. Googling turns up http://www.scripps.edu/newsandviews/e_20040830/wilson.html: "Sharks are the most primitive animals known to have antibodies"!

[Pythagorean]

aren't sharks vertebrates?

[bobze]

aren't sharks vertebrates?

Yes they belong to the phylum chordata> subphylum vertebrata.

Vertebrates are chordates (notochords) with back"bones" that persist through life. In sharks, skates and rays however this is composed of cartilage, not bone.

[atyy]

aren't sharks vertebrates?

Ooops, yes. So in fact antibodies are restricted to vertebrates.

[feathermoon]

I was just reading about certain proteins that exist in the human eye which are potent antibacterials. I'm sure there are plenty of options in nature for fighting off illnesses besides antibodies. Really interesting stuff!

[bobze]

I was just reading about certain proteins that exist in the human eye which are potent antibacterials. I'm sure there are plenty of options in nature for fighting off illnesses besides antibodies. Really interesting stuff!

In deed, the most potent antimicrobials actually come from microbes themselves (a couple billion years of microbe on microbe violence--They have developed biological ways to kill each other that make our technology for harm and genocide look paltry! :wink:). Antibiotics for example!

[Mech_Engineer]

I hear alligator blood may be a source of new super-antibiotics:

http://news.nationalgeographic.com/news/2008/04/080407-alligator-blood.html

Chemists in Louisiana found that blood from the American alligator can successfully destroy 23 strains of bacteria, including strains known to be resistant to antibiotics.

In addition, the blood was able to deplete and destroy a significant amount of HIV, the virus that causes AIDS.

Study co-author Lancia Darville at Louisiana State University in Baton Rouge believes that peptides—fragments of proteins—within alligator blood help the animals stave off fatal infections.

[lpetrich]

There are two kinds of immune system: innate and adaptive. The innate sort of immune system is the most widespread one, while only jawed vertebrates have an adaptive immune system.

Origin of the Metazoan Immune System: Identification of the Molecules and Their Functions in Sponges (http://icb.oxfordjournals.org/content/43/2/281.short)
The plant immune system : Article : Nature (http://www.nature.com/nature/journal/v444/n7117/full/nature05286.html)
Both innate.