Genetically defective?

[dave partington]

Keep it going. I love watching Dave talk to anyone about genetics. I just hope he [Dave] doesn't say anything out of line. He knows I have a small list of trigger words or phrases that make me want to rip my hair out.

Let me tell you about my stripe motley widestripe cubed vanishing pattern tessera LavamelShatterCoralStrawberryUltraHo's ... :sidestep:
So what are the parents het for?
Yew no I likes the DaveBait... it's why you keep getting the Bosley Hair Implants. Mutual appreciations, Hot Mess, &c. :noevil:

This is great info. It would be awesome if we could get some other people to experiment with incubating lavender clutches at lower temps and see if they see reduced issues with kinks. It would probably be especially useful to try repeating the exact same pairings that previously produced a fair number of kinks and see what happens...but I know generally people try to avoid repeating those pairings.

I know I've seen various speculations in various places (but don't really know if they all originated from the same person and how much evidence there is or isn't to back it up) that maybe we incubate our N. American colubrids at temps that are too high. So, based on those speculations, it would make sense that incubating low & slow would produce healthier babies with fewer issues. The idea that babies incubated at 84 might *look* fully developed, but either have issues because they aren't fully developed on the inside and/or just didn't quite develop right makes perfect sense as a possibility.

However, I'm having a hard time lining that up with what I know of weather patterns here in N. America. Don't most places where corns & other colubrids live get temps upwards of 80 degrees during the months that the eggs would be incubating in the wild? Sure, the female can lay her eggs in sheltered places, so they won't be totally subjected to the extremes of the temperature range, but when there is a heat wave and the temps don't even drop below 80 at night... those eggs are probably gonna get pretty hot. What happens then? No corn snake babies that year?

When you figure in the cost of aspen+mice+time (over the course of a year), running an experiment just to see what happens can become a rather costly endeavor.

The geographical range of corns is quite extensive. In places where the soil temperature is above 68 for more than 7 months of the year, the organic material tends to break down rather quickly, resulting in sandy/quartz-based/more mineral-based soils. In places where the soil temperature is below 68, the amount of organic compounds tend to increase. Not sure what (if anything) this has to do with the topic. Microclimates may be something worth considering as well. Such as how USDA Zone 9 runs up the barrier islands on the east coast, but mainland and inland, the zone can drop to 6 or 7.
Even which side of a mountain range the eggs are laid on can make a difference. There are numerous instances of eggs of reptiles in general, being laid late in the year, or an early winter sets in, and those babies either stay in the egg over-winter, or hatch but do not emerge from the nest until the following Spring. Probably a good thing they stay offline and illiterate or they'd be extinct by now.

I guess if one works with a single simple recessive and breeds that to a classic and then breeds those sib X sibs then the punnett squares deliver as they are supposed to. I'm guessing Reginald didn't have any classics 100% het amel, lavender, lava, ultra-or-amel, dilute, charcoal, stripe, palmetto, caramel, anery & hypo back when he was playing with his pencil ruler & protractor.

 

[fyrefocks]

Let me tell you about my stripe motley widestripe cubed vanishing pattern tessera LavamelShatterCoralStrawberryUltraHo's ... :sidestep:
So what are the parents het for?
Yew no I likes the DaveBait... it's why you keep getting the Bosley Hair Implants. Mutual appreciations, Hot Mess, &c. :noevil:

The breeding was caramel diffused het motley/stripe, amel X diffused het motley/stripe amel, caramel, hypo.

Last year the one surviving baby was a sulfur and I put down a fire so I know the hets are there.

 

[DuxorW]

I guess if one works with a single simple recessive and breeds that to a classic and then breeds those sib X sibs then the punnett squares deliver as they are supposed to. I'm guessing Reginald didn't have any classics 100% het amel, lavender, lava, ultra-or-amel, dilute, charcoal, stripe, palmetto, caramel, anery & hypo back when he was playing with his pencil ruler & protractor.

You would still get the expected ratios of offspring if you have enough eggs

 

[kc261]

Yeah, I know it can be costly, and in other ways too, like if one only wants to have a few clutches a year, then you are using up one of those clutches on an experiment instead of something else you might have wanted to do. But if people are doing lavender clutches anyway, and decide to incubate them lower... very little cost there, and we might learn something.

I really don't know about the climate/incubation temps stuff. There's probably a bazillion factors and I don't even begin to know half of them. But what little I do know was making me wonder, so I thought it was worth posting so someone intelligent could respond with stuff like micro climates and whether or not they are on the rain shadow side of a mountain or not... Of course I could turn around and argue that corns survive and therefore presumably reproduce across their entire range, not just the certain microclimates or left sides of the mountains... so it still leaves me scratching my head, but that's ok. Probably a good thing (see next paragraph).

I totally agree it's a good thing they don't get literate and start reading online. Soon they'd know things like, um, oh, I dunno. Like they are supposed to have a pre-lay shed before they lay eggs and then they'd all start doing it instead of only most of them and then what would we have left to keep us scratching our heads?

 

[crackerhead]

Okay. I know I'm probably going to catch poop for this but here goes. Given that I breed corns strictly because I LOVE genetics and they provide a means to get my "fix" in a legal manner, I do a lot of experimental breeding. By that I mean, I test theories such as do snake tan. The answer is a definitive/statistical "Yes" and I have several year's data and fun tests to back that statement up.
So when it comes to incubation induced deformities I have tested many theories over the years. Kinks have been a favorite of mine because I have a love/hate thing for the Lavender gene. It's an odd mutation among all of the ones out there. Just take a gander at Scaleless Lavender to get an inkling of what I mean. The explanation of how that gene works visually falls into the same category as why do Bluebirds appear blue. So surely a person attracted to the genetics of corns would be fascinated with the Lavender gene and all it's components. One of those seems to be a propensity towards kinks. So is it the gene or some external factor? I'd say in the case of Lavender the answer is both, either separately or in conjunction. I can tell you without hesitation that kinks increase dramatically when incubation temps rise about 85F for all morphs. Lavender and Bloodred/Diffused seem to be more prone to exhibiting kinks at the lower end of the high temp mark (83F +/- 2). The fun fact here is that Lavenders AND Bloodred/Diffused also exhibit saddle patch abnormalities. The mismatch/cojoined saddles are increased with higher temps in both as well. High temps have also been show to produce smaller neonates (incomplete yolk absorption) and compacted spines.
Varying the temps during the incubation period has differing effects too. Heat spikes at different times during the development process produce results depending on what is developing at that time in the animal. Like a heat spike in the last couple of days of incubation has less of a dramatic effect than say early on when neural tube formation is occurring. Color saturation is affected by long slow incubation periods (120+/- 5 days). Most color in corns happens in the last 10 to 15 days of incubation. Hence the little white fetuses we see when we open DIEs. I open every last one regardless of the reason for failure. I've learned a lot that way, gruesome as that might seem to some.
I play with chickens and quail genetics too because it is faster from egg to hatch and can be done all year long. And I can tell you that they are also affected by high incubations temps in much the same way corns are (reptiles and birds are very similar in sooo many ways). Yolks don't get fully absorbed, feet deformities, spine deformities are just a few of the things one can expect to find.
So lower your temps and learn to be more patient. Your hatchlings will benefit in the long run.

Terri

 

[vetusvates]

As a side note...I wish I could find the scientific paper that I, or someone, posted several years ago.
Concurs with Terri's post, and ideas alluded to at the beginning of this thread.
It was strictly comparing hatchlings as products of short (high temp) versus long (lower temp) incubations. LowER temp hatchlings were larger, longer, more robust and "seemed" more uniformly healthy.
The article was very interesting.

 

[fyrefocks]

As a side note...I wish I could find the scientific paper that I, or someone, posted several years ago.
Concurs with Terri's post, and ideas alluded to at the beginning of this thread.
It was strictly comparing hatchlings as products of short (high temp) versus long (lower temp) incubations. LowER temp hatchlings were larger, longer, more robust and "seemed" more uniformly healthy.

That seems to be the general consensus, however, I always cooked at 86 prior to this year. I mean, obviously the 90 issue happened, but otherwise always 86. I get good sized babies that average around 7.5 grams, with the largest babies being over 10 grams. I never have babies trailing yolk, and it's always absorbed. And the obvious temp spike from last year aside, I've never produced a deformed baby before. I also don't usually have trouble getting them to eat.

I know everyone means well, but cooking at 86 is my thing and it works.

 

[vetusvates]

Oh, I wasn't challenging your own personal methods Nate. No, no, no.
If it ain't broke---don't fix it, I say.

I was just recalling an academic paper.

When I think about black rat or texas rat snake eggs I have found in the wild, that may very well have fluctuated 20± degrees over the course of the summer months (or even a summer day),
I have to consider that likely none of the wise parents involved have read any scientific papers.

 

[Rich Z]

So lower your temps and learn to be more patient. Your hatchlings will benefit in the long run.

Terri

As a side note...I wish I could find the scientific paper that I, or someone, posted several years ago.
Concurs with Terri's post, and ideas alluded to at the beginning of this thread.
It was strictly comparing hatchlings as products of short (high temp) versus long (lower temp) incubations. LowER temp hatchlings were larger, longer, more robust and "seemed" more uniformly healthy.
The article was very interesting.

Absolutely!

I kept my incubation temps pretty much at room temperatures (82 to 84 with a day/night fluctuation) and I think the trick is to allow the babies the luxury of wanting to escape the egg because they exhausted their food supply instead of exhausting their oxygen supply. Honestly i am just guessing at the "oxygen supply" thing. But SOMETHING forces them to yank the escape cord early when incubating temps are high!

 

[Rich Z]

That seems to be the general consensus, however, I always cooked at 86 prior to this year. I mean, obviously the 90 issue happened, but otherwise always 86. I get good sized babies that average around 7.5 grams, with the largest babies being over 10 grams. I never have babies trailing yolk, and it's always absorbed. And the obvious temp spike from last year aside, I've never produced a deformed baby before. I also don't usually have trouble getting them to eat.

I know everyone means well, but cooking at 86 is my thing and it works.

How many days does it take, as an average, for your babies to pip?

 

[DuxorW]

Thanks for all that informative info Terri. It is what I expected to be the case as a developmental biologist, but there is only one way to find out and that is with experiments. I know of a few genes in mice that increase the odds of sporadic kinks when certain environmental conditions are met. I see no reason for you to "catch poop"

 

[DuxorW]

"Informative info".....I need to buy that edit button.

 

[fyrefocks]

Rich, I get noses by day 55, usually. But they will sometimes stay in the egg for up to 3 days. I try to not helicopter over them, or poke around and take pics. They take their sweet time emerging and I rarely ever see even an umbilical chord by the time they come out.

 

[vetusvates]

Now I'll probably get pooped on. Probably not, though....lol...
Regarding the original topic (I do drift back to those on occasion), Nate, I think it is very responsible and very noble to put your thinking and disclosure on the line regarding the past clutch.

But....since it was a heat thing, with that first calamity, IMHO stating or not stating that historical event would be totally up to you. More recent successes underline the fact that it was only a temperature problem.



BTW, this study is not the study I am looking for, but similar. The one I'm looking for seems like was by a friend of a member of the forum or something, and specifically about Panterophis guttatus.
But it was on this forum. I just can't find it.

 

[crackerhead]

Interesting thing to note: When I starting breeding corns back in the Stone Ages I incubated at much higher temps. Pipping was consistently 54 days and the neonates were big fully developed animals. I had no experience with non-absorbed yolks or refusal of meals. It wasn't until I move away from breeding dominant genes and the most common morphs that I started to have "issues" at the higher temps. Frustration with hatchlings not doing as well as when I started out is why I began experimenting.
I always have said that recessive genes are recessive for a reason and large gene pools are the best/safest way to go. Nanci mentioned the article she read about the smaller "island" type gene pools being stronger. I totally see how that would work in Nature but in a captive breeding pool where merciful/foolish humans play god it is doomed to fail. Animals that would never in a billion years make it in the rough and tumble world are being line breed and force fed to produce aesthetically pleasing creatures that don't function as they should. It's my experience that the more recessive genes homozygous in an animal the fussier they become. We all know the heartbreak of losing the only target morph (those 1/64 odds ones, etc.) in an F2 clutch. Plus we are only looking at the outside of the snakes we produce. That's is part of why corn snakes are so much fun to play with genetically. I won't elaborate here but they don't all look/function the same on the inside either when they are sporting all those recessives.

Terri

 

[vetusvates]

Good points re the 'bigger picture'.

 

[DuxorW]

It makes sense that recessive genes would cause other problems especially when several are combined in the same animal. Most proteins involved in development have more than one function. Recessive mutations are usually those that produce no functional protein, so a homozygous recessive animal may be entirely missing a protein that has other functions besides affecting the color/pattern, although they may be very minor. An animal het for a recessive appears normal because the other (wildtype) allele is able to produce functional protein and 50% is enough. Dominant alleles are usually those that produce protein that is hyperactive or "gain-of-function" rather than loss-of-function.

Less commonly, alleles that produce no functional protein are dominant. This occurs when 50% of normal protein levels are not enough. This is called "haploinsufficient." Think accidentally halving the baking powder in a cake recipe.