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PILE-O LAVAS & LAVA CINDERS !!
- Thread starter Walter Smith
- Start date
ghosthousecorns
Well-known member
Nice! I am definitely going to have to pair her with one of my cinder males.
Mitchell Mulks
New member
I love this thread!
Well, I have to say this is the coolest thread I've read here in a long time. Major Kudos to Dusty for piecing all of this together!!!!!!!!! It's been a long time since I took Genetics in college, but I remembered plenty for this to make sense to me. It's really funny, but I didn't read this thread until today, as I wanted to take it all in in one sitting. I kept working out the Punnett squares on paper in front of me as I read along, and even drew out the crossover events that would lead to a het cinder female being able to produce both sexes (this is of course without the suppressor). I spent an hour or so tonight making the Punnett squares for all six situations that would involve a suppressor on the W chromosome of a female. Basically I just included Punnett squares for the info that Nanci provided everyone on Page 15 of this thread, and then drew a few conclusions. Most of you kept saying you wanted some visual assistance, so here it is.
Btw, in a future post I'll post scanned photos of how crossing-over during meiosis allows het cinder females to produce both sexes; and also how the suppressor makes cinder behave sex-linked.
Well, I have to say this is the coolest thread I've read here in a long time. Major Kudos to Dusty for piecing all of this together!!!!!!!!! It's been a long time since I took Genetics in college, but I remembered plenty for this to make sense to me. It's really funny, but I didn't read this thread until today, as I wanted to take it all in in one sitting. I kept working out the Punnett squares on paper in front of me as I read along, and even drew out the crossover events that would lead to a het cinder female being able to produce both sexes (this is of course without the suppressor). I spent an hour or so tonight making the Punnett squares for all six situations that would involve a suppressor on the W chromosome of a female. Basically I just included Punnett squares for the info that Nanci provided everyone on Page 15 of this thread, and then drew a few conclusions. Most of you kept saying you wanted some visual assistance, so here it is.
Btw, in a future post I'll post scanned photos of how crossing-over during meiosis allows het cinder females to produce both sexes; and also how the suppressor makes cinder behave sex-linked.
Walter Smith
CRAZY BOUT' CORNS !!
I would love for you to post a picture of amber cinders and lavender cinders in the photo gallery
I would be interested in seeing these as well. Post away !!
Walter
:crazy02:BOUT' CORNS !!
DuxorW
Derailer of Threads
Lol....Dusty.....
Thanks for posting this. I got started on some figures explaining the basics of meiosis and crossing over, linkage of non sex-linked genes, and how suppression of crossing over makes cinder behaved sex-linked. But, time got away from me. I'd be happy to look over anything that you want to post if you want a second pair of eyes.
I wish had known about this before this breeding season as I probably could have gotten enough data for a small journal article. This is actually more significant scientifically than people might think. Maybe next year!
DuxorW
Derailer of Threads
Also, did you mean to have the "suppressor" on all the females in your post? I'd argue the females that are ideal are the ones without the suppressor at all. It will also be interesting to see if there are ever any females with both cinder and suppressor on their W chromosomes. I suspect this will never happen but is perhaps vanishingly possible.
DuxorW
Derailer of Threads
I don't know if you saw them but Carol posted a pic of a hatchling lavender cinder in her personal forum. That's the first one I've ever seen. I'd love to see an adult.
Mitchell Mulks
New member
I agree with you 100% that the females you want are the ones without a suppressor. However, seeing as how the presence of a suppressor supports linkage between sex and cinder I thought it'd be best to show all the examples with a suppressor present.
Walter Smith
CRAZY BOUT' CORNS !!
Yeah, I saw those. I would really like to see these Amber Cinders though.
Walter
:crazy02:BOUT' CORNS !!
Walter Smith
CRAZY BOUT' CORNS !!
Well, that's why I'm anxious to see what they look like. I have a VERY good shot at producing some next season, also with other poss. genes involved
Walter
:crazy02:BOUT' CORNS !!
martin-bernstein
Anything Lava!
So jealous! Love these! Nice job.
DuxorW
Derailer of Threads
So I've been thinking about this a lot lately. Obviously my first theory was on the right track (Z/W linkage) but then had to be modified because cinder was only behaving sex-linked in certain females. I admit I was writing pretty casually about this and said some things here and there that are not entirely accurate. My second idea just introduced the idea of crossover suppression but left some unanswered questions, such as why that was happening in some females and not others.
In humans, there are regions of the X and Y chromosomes called pseudoautosomal regions (PARs). Basically these are regions where the X and Y share sequences. During meiosis, the X and Y pair at these regions and crossover occurs. This appears to be necessary for the X and Y to segregate properly into separate sperm (ie, to prevent a sperm from being XY or from lacking a sex chromosome entirely). Pseudoautosomal regions exist in birds and presumably other animals using the ZW system that have heteromorphic sex chromosomes.
Where is this going? Genes that are located outside of the PAR regions exhibit sex-linked inheritance, either because crossover cannot occur at that region or because the gene is only present on the X chromosome and has no locus on the Y. But genes located in the PAR regions don't exhibit sex-linked inheritance. Rather, they are inherited as if they are not on a sex chromosome at all. PARs can vary within the population and there are some PAR variants that exist in only 2-4% of the human population.
Thus, if PARs can vary, that gives a plausible explanation for the bizarre inheritance of cinder. There could be W chromosome variants where cinder is not located within a PAR so cannot cross over, and other W chromosomes where cinder is within a PAR and thus has no problem crossing over with the other allele on the Z. This explains why we have never seen the situation of a female het cinder only producing female cinders: presumably there is no way to get cinder onto a W chromosome that can't cross over with the Z at the cinder locus. This is because any female cinder can trace her W chromosome back to the original female cinder, and those W chromosomes can cross over as evidence by that fact that het cinder daughters of female cinders do no display sex-linked inheritance of cinder. So any het cinder female with cinder on her W had to get it from a homo cinder female, since W is always inherited from the mother.
In the wild, an upper keys corn is geographically isolated from something like a Carolina corn. Heteromorphic sex chromosomes evolve more rapidly than autosomes, so it is not surprising that there would be variation in the structure of the W chromosome in different localities that could prevent crossover at certain regions of the ZW chromosomes.
I'm not saying this scenario is correct, it is just an explanation that is plausible. But the moral of the story is still the same: in cinder projects it is best to use a cinder female or the het cinder daughter of a cinder female, as you will be guaranteed to not have sex-linked inheritance. If your female got her cinder allele from dad, you may get lucky with her W chromosome. Or maybe not.
In humans, there are regions of the X and Y chromosomes called pseudoautosomal regions (PARs). Basically these are regions where the X and Y share sequences. During meiosis, the X and Y pair at these regions and crossover occurs. This appears to be necessary for the X and Y to segregate properly into separate sperm (ie, to prevent a sperm from being XY or from lacking a sex chromosome entirely). Pseudoautosomal regions exist in birds and presumably other animals using the ZW system that have heteromorphic sex chromosomes.
Where is this going? Genes that are located outside of the PAR regions exhibit sex-linked inheritance, either because crossover cannot occur at that region or because the gene is only present on the X chromosome and has no locus on the Y. But genes located in the PAR regions don't exhibit sex-linked inheritance. Rather, they are inherited as if they are not on a sex chromosome at all. PARs can vary within the population and there are some PAR variants that exist in only 2-4% of the human population.
Thus, if PARs can vary, that gives a plausible explanation for the bizarre inheritance of cinder. There could be W chromosome variants where cinder is not located within a PAR so cannot cross over, and other W chromosomes where cinder is within a PAR and thus has no problem crossing over with the other allele on the Z. This explains why we have never seen the situation of a female het cinder only producing female cinders: presumably there is no way to get cinder onto a W chromosome that can't cross over with the Z at the cinder locus. This is because any female cinder can trace her W chromosome back to the original female cinder, and those W chromosomes can cross over as evidence by that fact that het cinder daughters of female cinders do no display sex-linked inheritance of cinder. So any het cinder female with cinder on her W had to get it from a homo cinder female, since W is always inherited from the mother.
In the wild, an upper keys corn is geographically isolated from something like a Carolina corn. Heteromorphic sex chromosomes evolve more rapidly than autosomes, so it is not surprising that there would be variation in the structure of the W chromosome in different localities that could prevent crossover at certain regions of the ZW chromosomes.
I'm not saying this scenario is correct, it is just an explanation that is plausible. But the moral of the story is still the same: in cinder projects it is best to use a cinder female or the het cinder daughter of a cinder female, as you will be guaranteed to not have sex-linked inheritance. If your female got her cinder allele from dad, you may get lucky with her W chromosome. Or maybe not.
DuxorW
Derailer of Threads
Not to beat this horse to death some more, but thought Jen might be interested in this. Jen, I was doing a little research and saw that Medusa is from silver queen lines, which descend from Miami stock. I am thinking that upper keys W chromosomes may recombine just fine at the cinder locus. Which makes sense because of the original upper keys cinder female. Due to their proximity geographically, Miamis would be expected to be closely related to upper keys corns. More so than a Carolina. I saw that Zephyr fathered het cinder daughters from multiple females, but the ones that could produce male and female cinders were produced by Zephyr x Medusa. So maybe Miami W chromosomes also have no problem crossing over.
ghosthousecorns
Well-known member
Dux, I have been thinking about that. since I just purchased a (male cinder, female poss het) pair from Heather that were from Shane's cinder/ terrazzo pairing, and it seems he got some female cinders in that clutch too. And terrazzo also originated in the keys. So it seems like for best chance of getting cinder females, use snakes at least from Southern Florida, if not the keys themselves?
I'm excited to combine the old school cinder with the Boyd line terrazzo and see what happens!
I'm excited to combine the old school cinder with the Boyd line terrazzo and see what happens!
DuxorW
Derailer of Threads
Also interesting that the only female cinder we know Walter produced came from this pairing. Upper Keys het cinder Dame!