[-Thursday, February 22, 2007-]
Particle Bombardment of Plant Transformation
A plant cell is different from an animal cell. It has a cell wall which makes it even more difficult for us to insert our constructed transgene into the cell. However, we can remove the cell wall from the plant cells using certain enzymes and the plant cell without a cell wall is called a protoplast. But, it is very difficult to maintain a protoplast in an isotonic solution as the solution has to be changed at a regular interval if not the protoplast will die. Another big difference from animal cell is that all plant cells are pluripotent that is the plant cell can differentiate into different parts of the plant whereas in animal cell not all of them have such a potential. A plant cell may be already differentiated at a certain stage of life but with ajustment in environmental factors, the plant cell can be undifferentiated, thus become pluripotent again.
The only animal cell which is pluripotent is our embroynic stem cell. That's why embroynic stem cells is so impt in research for cure of human diseases.
Outsider may have the mentality that we can clone ourselves so that we may be able to use their organs as ours when we suffered organ failure. That is totally wrong. Why? How sure are you that it is not our clones taking our own organs to save themselves when they suffered organ failure themselves?
Back to plant transformation. I will be talking the 2 methods used in our Biotechnology Practical 2 for Particle Bombardment on plants.
1st method is the Helios Gene Gun.
2nd is the Biolistic PDS 1000.
Both use small Gold (999 de gold okay..) microcarriers (microscopic gold pellets) which are coated with our DNA transgenes. We make use of hyperpressure to fire these gold microcarriers into the plant tissue, hopefully that the gold will remained inside to allow plant transformation. Transcient expression can be observed after a few days whereas a stable genetic line is mostly obtained by the Biolistic PDS 1000.
Helios Gene Gun
It is a compact hand-held "hair-dryer look alike" equip. It looks like a gun hold by the aliens in Mars Attack to me. It is easy to use in outfield but the success rate is low. When i heard the TA said "outfield", i told the rest, if we bring this to outfield, i think all the soldiers will shoot us cos we are goin to transform them using this gun. LoLx!! Btw, our DNA transgene allows the cells to give a blue color substrate when it digests X-Gluc. So the plant will express blue dots if the expt had succeeded.
Now imagine if i use this gene gun to shoot u and throw u into a pool of X-Gluc. U will come out a "Blue Dots" alien!! In theory, this is feasible but in practical this is not. It seems that animal cells will be destroyed by the pressure of the gene gun instead. So lucky u.. I mean U!! U noe who U are!! Ya!! U.
R-O-N
ps: very scary lo.. especially wen u see the person everyhow point the gun at u.. WAH!! Stunned man! Faster run away sia..
Biolistic PDS 1000
This is a larger equip which is really quite big. Dun ever tink of bringing it out to the field. The differences between a Biolistic PDS 1000 and a Gene gun are the gold microcarriers used are bigger ($_$), it is conducted under vaccum, the pressure used is higher and the transforming rate is higher with more stable genetic line obtained.
Actually this is the part of the practical which is more fun and there's more hands on. We actually had to load the compartments which had the Gold microcarriers/DNA transgene on the flying disk first so that it will dry up b4 we load it into the PDS. So every group (2 ppl) had 1 ppl doing and my grp is the last. So i asked my lab partner who go and load the tingy. She replied "wo men yi qi load." Den everyone laughed and someone sang the "xiao fu qi" song. I regretted asking tis question.. In the end we 2 loaded the ting together, but was more like i do lo. After that, we were taught how to use that machine, need to remember the steps such as vaccumming the inside chamber, increase the pressure slowly until the rupture disk broke off due to the pressure met. Very easy to handle la i must say.
So that's all for that practical. Oh ya.. Niu Mei!! My lab partner looks like you when we first met!! LoLx!! I tot how come u can so fast come study in NUS.
ps: my TA (duno from where one like arabic or indian la, dun even noe wad is he babbling about lo..) cannot make it leh.. I ask him what's the difference between indeterminate organ and determinate organ, he can only "har har har??" I spell out to him he still blur blur. Den i showed him the lecture notes den he still duno. Den like try to smoke me lidat. I say this he say yayaya!! Dots.. Den my lab partner oso asked him someting about the haploid plants does it mean that it only consist of 1n chromosomes? Wah.. he gave up and said "im not good in plants biology." Arbish!!
Haploid plants are plants which are grown using only a set of parent chromosome (either mother or father). Eg. A normal embryo consists of 2 sets (2n) of chromosomes, one from the father (sperm 1n) and one from the mother (egg 1n). Its the same for plants. However, we are able to use only 1 set of chromosome to create a full grown plant. I duno the exact mechanism, maybe they replicate 1 more set of chromosome from the one we have at first. However, such plants appeared smaller compared to the normal plants. That's y i tink my lab partner is trying to ask why is it smaller den normal? Is it bcos it is only 1n? Too bad.. the TA duno. Den we 2 tou tou xiao wen we turned away from the TA. LoLx!! We very bad hor.. xD
"Never ask why i love you, just accept that i do." || 1:08 PM
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