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Sex-linked traits

Toshiro

Toshiro

scoffindustries.be
Hiya peeps,
Thursday I received my copy of CMG.
I've been reading and enjoying it :)

But I came at a chapter "Sex-linked traits"
Where the difference of certain traits controlled by genes is discussed.
Females passing W-chromosones to daughters, Z-chromosenes to sons.
Males passing Z-chromosones to daughters and sons.
"Whichever allele is present in a female will be expressed, even if it acts recessive in males."
etc. etc. etc.

Which traits are these?
Can all traits be sex-linked?
Or are there just a few?
 
Erm it's the other way around- first only one pair of chromosomes controls the sex.

Female eggs will always contain W Chromosome, it is the male's sperm that can contain other Z or W- which is kind of funny, considering that in the past men used to blame women for not birthing any sons when in truth it was their fault :crazy02:

In regards to what other traits are linked to it... well, you have behavior differences, sex organs, hormones, reaction to a member of the opposite sex- et cetera.
I don't think it has anything to do with morphs though.
 
Birds can have sex-linked colors. There is a breed of chicken that has red males and white females so the babies can be sexed by sight. I can also think of one pigeon color, ash-red, which only appears in males.

I've heard talk of sex-linked color tendencies in corns- such as male lavs tend to be brighter, pinker, oranger than females.
 
Possibly... but it's distinct enough... also, is it really a universal truth that males will be darker/brighter?
I don't think so... but I could be wrong

At any rate, in snakes at least, it has little effect on their looks per se
 
there are a couple of mutations that are sexlinked in canaries. Twould make common sence since most birds are dismorphic from male to female. like in some tropical freshwater fish
 
From my observations, some [color] morphs tend to be 'sex-influenced' rather than 'sex-linked', where males sometimes tend to be brighter than females, such as with lavenders. However, there still seems to be some inconsistencies with this theory.
 
the term "linked" can be interpreted in many ways and can include any number of relationships between two factors.:shrugs:
 
All sexual animals carry sex-linked traits. These traits are what separate males from females. The traits that are visually obvious can play a large role in reproduction. Look at the peacock, for instance, with males displaying their beautiful plumage. As for snakes, I don't think that visual traits have much to do with this. Then again, I don't really have a clue.
 
In general most not all of the top colored animals in a clutch are males. Male corns are deeper colored than females of the same clutch most of the time . I'm only taking about the higher end of the clutch, not the normal to advarge looking animals. Once in while you get a female that is a screamer. That is the animal you are looking for . That will intern produce a good number of fantastc looking young male or female but again the most of top end will be males but you will get some nice females out of the top end bunch.
 
The fact that there's a difference between females and males does not necessarily indicate that the difference lies directly in that pair of chromosomes- but rather indirectly.

I am -pretty- positive that many organs simply are responsive to testosterone- and because males have it in higher concentrations, the change or effect is more visible than in females-It is quite possible that feathers for instance are identical in general principle in a female and male birds, however, they react to high levels of testosterone, so in the males it'll be more visible.

At any rate, in snakes the difference is inferior when compared to the difference between a potent bloodline to a lesser one- the difference between males and females in most snakes is far from being obvious.
 
no. males have a slightly larger head than a female and in colubrids the males grow much bigger than females. Also males have longer tails than females
 
Kokopelli said:
the term "linked" can be interpreted in many ways and can include any number of relationships between two factors.:shrugs:
Click to expand...

Sex-linkage denotes alleles on sex chromosomes. There's not really much of way to misinterpret that. There are traits that are sex-limited (only expressed in one sex) and sex-influenced (expressed differentially between the sexes, but can occur in both). These may be confused with sex-linked, but linkage itself is pretty clear.

There is a role of sex-linkage in sexual dimorphism (and plumage color). There's a large body of literature on these topics. I certainly don't know all that much about the specifics, but there's info out there. Here's one article I pulled up on my first search on google:
"The quantitative genetics of sexual dimorphism: assessing the importance of sex-linkage"
http://www.nature.com/hdy/journal/v97/n5/full/6800895a.html
 
Bah, I just got the cornsnake morphgude by Charles Pritzel- and only now it hits me that "sex-linked" is a a term with a very solid definition. I wasn't aware of that, as I use Hebrew mostly, and our professional/official terms are different.

I just thought the word "link" was used, which can be any number of things- so doi! :smash:

Anyways, beyond that, I am trying to find out which cell is the variable one, the male's or the female's in transferring genes. Does the mother always contribute Z or does the male always contribute it?

Sorry people, it didn't strike me as an obvious official term, my mistake and sincere apology
 
Kokopelli said:
Bah, I just got the cornsnake morphgude by Charles Pritzel- and only now it hits me that "sex-linked" is a a term with a very solid definition. I wasn't aware of that, as I use Hebrew mostly, and our professional/official terms are different.

I just thought the word "link" was used, which can be any number of things- so doi! :smash:

Anyways, beyond that, I am trying to find out which cell is the variable one, the male's or the female's in transferring genes. Does the mother always contribute Z or does the male always contribute it?

Sorry people, it didn't strike me as an obvious official term, my mistake and sincere apology
Click to expand...

No problem, You come from a different country.
 
jamay said:
Generally speaking, this may be true, but there are exceptions. Female hognoses get bigger than the males. I realize this isn't your point though.
Click to expand...

Is this in the wildor in captivity or both?

I know in many captive snakes, and especially on care sheets it'll show females as growing larger even if in the wild it is not the case, but in captivity that is common as most people don't worry too much about male weight, whereas, females need to have the girth to give birth.
 
Jcapicy said:
Is this in the wildor in captivity or both?

I know in many captive snakes, and especially on care sheets it'll show females as growing larger even if in the wild it is not the case, but in captivity that is common as most people don't worry too much about male weight, whereas, females need to have the girth to give birth.
Click to expand...

I would also think that the main different between captivity and wild as far as female size would be strongly related to the food availability.

but here's a thought:

If we're talking about natural conditions, it's true that female oviparous snakes (pythons excluded) tend to be smaller than the males. In captivity often enough, as you did mention, these females can be just as large a the males sometimes even larger. This indicates that sex and maximum size is not necessarily correlated for these animals, but perhaps correlates with an environmental factor. If such, then the size difference would not be inheritable. Heterodon and Coluber would examples of exception to this generality.

With "livebearers", on the other hand, the females tend to be larger. This could be an evolutionary advantage if the gestation time is considered. This may also be correlated to the amount of time the female needs to survive without feeding... or not. Also, here, the food for the developing embryo is supplied by the mother rather than the yolk of oviparous species, a larger size may again be an advantage. To my knowledge, generally speaking, even in captivity the males of these species can very rarely reach the possible maximum size of females.

Current phylogeny classification places both pythons and boas in the boidae. Perhaps the answer to the large female size of python's lies somewhere in common ancestry?

Maybe this is all wrong and the true evolutionary advantage is in the smaller size of the males :grin01: ...

What do you think?
 
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