What everyone needs to be doing is thinking about these traits in terms of their evolutionary history and the advantages they may confer. There are a huge number of species which form either colonies of clones (I'm thinking heather) or exist in groups of individual plants - either way they are presumably going to be in close proximity to others of their kind. If one plant can tell others around that it's being munched on, its neighbours can prepare for that eventuality or what have you. The precise effect doesn't matter but there's an obvious advantage, it's just down to working out how/what happens.
The problem there is that the group size is no where near large enough. If you want to actually determine if a value (m/f ratio) is being affected by the environment you need to be doing some sort of statistical analysis. The exact analysis method would be dependent on the number of/type of environmental factors you were controlling but it's a bit more complex than dividing 25 by 50.
So how is this not an example of environment being capable of determining sex? As DP and I have both said, as females are capable of producing pollen it seems fairly apparent that the genes responsible for a 'male' phenotype are present in both males and females, as we would expect if the plant evolved from a monoecious ancestor fairly recently.
Infinitesimal said:epigenetics allow for suppressed ancestral traits to be expressed through modifying the gene function through said chemical tags...
for instance, since birds evolved from dinosaurs... scientist postulate that using epigenetics it may be possible to reverse engineer species using their modern day living descendants... for instance using epigenetic to cause an emu to express traits that were present in its prehistoric ancestors because the descendants still maintain the basic genetic information and frame work of their ancestors...
No they don't; I have a feeling you may be confusing some of the ancestral traits we see in animal embryonic development or something with epigenetics. Epigenetics is likely involved but it's not a well understood field, don't make out like you know what you're talking about.
No they don't; environment and genes have both changed. The proteins expressed by cells today have had an extra x million years to mutate. This includes both the epigenetic switches you speak of and the receptors that would be needed to recognize them and the enzyme pathways involved in processing them.
Infinitesimal said:blocking the ethylene likely triggers the expression of latent monoecious traits buried in the cannabis genome... or at least maybe?
Now that language is better Sorry to be an arse, people asserting 'facts' about brand new fields of biology that are far from being understood in relation to our understanding of other mechanisms within a cell. When you talk about epigenetics you have to remember that the term itself is as vague as can be. Talking about the epigenome is rather like talking about the proteome - the term itself simply mean above genetics so covers the changes in phenotypes which can occur without a change in genotype (as you said) however the way this is done varies massively and adds a layer of complexity to genetics which is just damn frightening to think about (I do). So let's look at a couple of ways in which genome expression is controlled briefly:
DNA Methylation - CpG islands in promotor regions of DNA are methylated by proteins. This prevents the binding of protein complexes required for the initiation of transcription and also leads to:
Histone Modification - Acetylation, phosphorylation, ubiquitination and the reverse reactions are possible on numerous sites of the histone depending on the constituent subunits. These can make some regions of DNA more or less accessible to transcription associated proteins or perhaps changes the affinity of said proteins for binding. Who knows? The point is that the number of modification variants means that every single nucleosome is likely to be completely unique in terms of it's modified structure.
siRNA - small interfering RNA, small single stranded pieces of RNA complimentary to sections of a specific mRNA or multiple RNAs. Double stranded RNA is recognized by RNAses for degredation so prevents expression unless a) [mRNA]>[siRNA] b) Somehow RNAase cannot detect it? c) The double stranded RNA has some other function we don't know about.
So say we have a defined pathway for the synthesis of a protein that forces a plant to be male (hypothetical here; obviously it's way more complex ), how readily to transcription factors bind to that gene? This can be varied greatly (almost in an analogue fashion due to histone modification and DNA methylation) which can lead to varying levels of the transcription of that gene into mRNA. We then have alternative splicing - how much of the 'male protein' mRNA is actually going to make it out and how many of those splice variants produce a completely different protein? At the same time and outside of the nucleus whilst these splice variants are floating around trying to find a ribosome, siRNA is present. How many siRNAs are capable of blocking these mRNA splice variants? And then of course we have to consider that each of these genes responsible for the synthesis of these siRNAs (genes don't just code proteins remember) are affected by exactly the same mechanisms described above. It gets so messy, convoluted and complex that you begin to loose hope of ever understanding how it all works.
don't make out like you know what you're talking about.
That's fine your threads sometimes make me feel stupidAnd DP, you bugger, made me feel really old.
DNA Methylation - CpG islands in promotor regions of DNA are methylated by proteins. This prevents the binding of protein complexes required for the initiation of transcription and also leads to:
Histone Modification - Acetylation, phosphorylation, ubiquitination and the reverse reactions are possible on numerous sites of the histone depending on the constituent subunits. These can make some regions of DNA more or less accessible to transcription associated proteins or perhaps changes the affinity of said proteins for binding. Who knows? The point is that the number of modification variants means that every single nucleosome is likely to be completely unique in terms of it's modified structure.
siRNA - small interfering RNA, small single stranded pieces of RNA complimentary to sections of a specific mRNA or multiple RNAs. Double stranded RNA is recognized by RNAses for degredation so prevents expression unless a) [mRNA]>[siRNA] b) Somehow RNAase cannot detect it? c) The double stranded RNA has some other function we don't know about.
So say we have a defined pathway for the synthesis of a protein that forces a plant to be male (hypothetical here; obviously it's way more complex ), how readily do transcription factors bind to that gene? This can be varied greatly (almost in an analogue fashion due to histone modification and DNA methylation) which can lead to varying levels of the transcription of that gene into mRNA. We then have alternative splicing - how much of the 'male protein' mRNA is actually going to make it out and how many of those splice variants produce a completely different protein? At the same time and outside of the nucleus whilst these splice variants are floating around trying to find a ribosome, siRNA is present. How many siRNAs are capable of blocking these mRNA splice variants? And then of course we have to consider that each of these genes responsible for the synthesis of these siRNAs (genes don't just code proteins remember) are affected by exactly the same mechanisms described above. It gets so messy, convoluted and complex that you begin to loose hope of ever understanding how it all works.
further more... please explain... as I think I have given an understandable basic explanation to the sexual controls of the cannabis plant and anyone refuting it should at least be able to do the same.
With that in mind,
What is the mode of action... what is happening inside the seed when you lower the temps, increase the humidity, decrease the wind, or whatever else... that is supposedly creating more or less males or females?
Peace,
Infi
DemonPigeon said:is it me or can you feel a BioChem storm brewing? I'm going to put sandbags around my alleles and battern down the gametes.
GMT said:you're talking about sexual expression and complaining about determination. 2 separate things. Determination is genotype, expression is phenotype. Phenotype doesn't determine inheritance, genotype does.
Infinitesimal said:LOL, just how does a plant prepare to get munched on? hehehe... can you feel the plants pain... can you feel their PAIN MAN?
Infinitesimal said:lol, it was just a HYPOTHETICAL example... to make a point, not a scientific study to prove anything... you can extrapolate those numbers and the number of rooms to any scale you like and the results will be the same... its probabilities and luck of the draw... your shortsightedness is YOUR weakness
Infinitesimal said:the effects you are seeing are do to changes in the epigenome either environmentally or chemically stressing the plant using epigenetic triggers... which doesn't effect the DNA of which X and Y chromosomes are a part of.
Infinitesimal said:but embryonic development had nothing to do with what I was saying.
but the fact is after doing human genome studies we know that there are not enough genes in our DNA to account the variety of phenotypes... the differences between us are epigenetic... and epigenetic changes can be reversed by moving the chemical tags and turning the gene on or off
Infinitesimal said:"mutate" you mean inherited... recombinant genetic pairing (in cannabis as in humans) results in "mutated" offspring... "mutated" meaning genetically different from either parent...
Infinitesimal said:and if epigenetics doesn't allow for expression of latent ancestral traits then how do you explain the fact... that we share so much of our DNA with chimps but they resemble our primate ancestors so much more than we do... why is that?
are they expressing latent ancestral traits that have been suppressed in us Epigenetically?
Epigenetics is dynamic and can undo and redo modifications to the structure, using the chemical tags can turn on or off expression...
those are all processes used in Epigenetic research that and PCR among others... I don't think Epigenetics is that vague; new sort of... relatively so, not well understood by many sure...
ah ha, "completely unique in terms of it's MODIFIED structure"...
Atavism
I don't know how any of that pertains to the intersex traits observed in cannabis???
I just graduated from a Biochemistry and Neuroscience degree and filed 30,000 words worth of dissertations on the role of epigenetics and de novo mutation in various diseases... As I keep saying, I don't mean to be an arse, just don't like seeing people asserting things that no one knows. If you were talking about 'Astral Weed' or 'God' I would be doing exactly the samemaybe take your own advise ay?
Riddle me this....
Interesting paper...
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1691578/pdf/15058400.pdf
sex determination and the evolution of diocey from monoecy
[URL=https://www.icmag.com/ic/picture.php?albumid=42494&pictureid=1070306&thumb=5]View Image[/url]
Well I'm not too sure, if 'male' genes are present outside of the Y chromosome then it's rather pointless making that distinction as the difference would be entirely within the phenotypes and protein expression profiles of the plants. Saying that, the Y chromosome being a giant promoter/regulatory region is a wild guess so probably completely wrong Otherwise yeah, my bad, 3am posts are never the most thought out >.<
!
Since we know the genes for producing male flowers, exist outside of the Y, then when we have 2 X's, we would also see male flowers on female plants without the X suppressing those genes or the male being needed to stimulate them. Therefore we can say with certainty, that in the absence of any chemical alteration (whether that be natural stresses or artificial external chemical additions) the X either stimulates the production of female flowers, the X silences the male flowers, the Y stimulates the male flowers and is stronger than the x's supression, or the Y silences the female flowers or some combination of the above. To say that describing the Y as a regulator is a mistake, I feel to be a mistake in itself. TO say that male is phenotype rather than genotype is a mistake also. A female only parentage gives rise to genetically female plants. A male female parentage generates male and female offspring. This is clearly genetic and not phenotype expression.
To say that describing the Y as a regulator is a mistake, I feel to be a mistake in itself.
TO say that male is phenotype rather than genotype is a mistake also.
yesWell, if we can force a female to produce pollen, does this not mean that the genes responsible for the sex phenotype are present in both males and females?
no. a female does not silence the production of female flowers, a male does not silence the production of pollen, a pretty important distinction for both growers of buds and breeders of seeds.In this case both 'males' and 'females' are technically both male and female in genotype.
yesEither way, we know that females are capable of producing pollen sacs. Regardless of whether the pollen contains X or Y chromosomes, this will still lead to the production of fertile offspring,
lol maleized, technically if you are using that term in the way we use feminized, then no as maleized would only produce male seeds and what you are describing can only ever produce female seeds.capable of a repeated 'maleized' female x female crossings correct?
if one can breed and one cannot without the use of chemicals, if one fills half your room with males and the other fills all your room with females, if one is genetically different from the other, how can that be considered irrelevant?If this is the case, then this is what I mean by the distinction being somewhat irrelephant. Obviously in nature this isn't going to be a successful survival mechanism (thus why we see Y chromosome males I guess?).
lol maleized, technically if you are using that term in the way we use feminized, then no as maleized would only produce male seeds and what you are describing can only ever produce female seeds.
no. a female does not silence the production of female flowers, a male does not silence the production of pollen, a pretty important distinction for both growers of buds and breeders of seeds.
if one can breed and one cannot without the use of chemicals, if one fills half your room with males and the other fills all your room with females, if one is genetically different from the other, how can that be considered irrelevant?