Colors, Patterns and Genetics.. planning for results
We now know that every sheep pulls its exterior appearance
from 3 sets of genes inherited from each parent: 6 genes.
is dominant over Moorit... and the pattern Solid is recessive. So
based solely on the appearance of the black lamb we can conclusively
say that it carries: 1 black gene and 2 solid genes. We
can also say that it carries the gene "no spotting" since
spotting is recessive and requires two spotting genes to express.
Without knowing about its breeding, we can't guess if it carries
moorit, or if it carries spotting.
Moorit lamb, on the other hand, definitely carries 2 recessive
moorit genes and 2 recessive solid genes. Again, we can't speak
to the spotting gene without knowing the sheep's pedigree.
Without knowing the ancestry of these sheep, we decide to breed
them. We get twins. One twin is black, one twin is moorit. Both
are, of course, solid, but one twin shows spotting. Now we can say
conclusively that both parents carry moorit, both parents carry
spotting. We can say conclusively of our new black lamb that she
carries moorit, and may carry spotting (remember, if both parents
carried the gene for no spotting, she may not have the gene for
spotting). About her solid moorit brother with spotting we can say
with absolute certainty he carries 2 moorit genes, 2 solid genes,
and 2 spotting genes. He is, in short, absolutely reliable genetically.
If he's bred to a sheep with any other pattern, that pattern will
express itself (solid is recessive). If he is bred to a black sheep,
the offspring will be black. And if he is bred to a sheep carrying
spotting, there is a 50/50 chance his offspring will be spotted.
does our little white lamb hide under those lovely ringlets? Since
she carries a pattern gene from each parent, and white is dominant,
she hides a pattern in there. She may carry two white pattern genes...
in which case she will always have white lambs no matter what she's
bred to. She also carries two color genes, and she may, or may not,
We breed our white lamb to our black ram above
and she has twins, one white and one black. About the white lamb
we can say with certainty that he carries the color black, and the
patterns white and solid. About the black lamb we can say with certainty
that he carries the color black, and the pattern solid.
If we breed our white lamb again next year to the solid
moorit ram lamb we created above what can we say if one
of her lambs is moorit? Well.. we know she carries moorit. We can
also say of her previous offspring that they carry moorit as well.
however, she had a Grey Moorit lamb. Now we know she carries
the patterns white and grey, since grey would be dominant over solid.
Her lamb, who is a grey moorit will carry the genes grey and solid...
and two moorit.
Which means that if we bred her, our Grey Moorit back
to her father, we have a 50/50 chance of producing either another
Grey Moorit, or a Solid Moorit. If we bred her to the black ram,
we would have a 50/50 chance of showing either the pattern Grey,
or the pattern Solid, but a 100% chance of showing black.
we bred our white lamb to our solid black ram and got... a
black badgerface. Again, we won't know for certain if either our
black ram or our white ewe is carrying moorit, but we do now know
our white lamb carries badgerface as her second pattern.
the same would hold true is we got a Black Mouflon.
Farms looking for specific colors and patterns can either use pedigrees
to hazard a best guess at what their lamb is likely to be carrying...
or buy proven sheep whose offspring give some clue as to the genes
they're carrying. Part of the fun of Icelandic Sheep is the "surprise
packages" every spring.
Let's see if you can predict the outcome of a few breedings:
have a Moorit Mouflon ewe carrying spotting. You breed
her to a White Ram you know carries black, grey, and spotting. What
might you see come spring?
Well... the pattern White is dominant over Mouflon, effectively
covering color. So you could simply have a white lamb carrying mouflon
(or possibly another pattern). You could also find yourself with
a co-expressed Black Grey Mouflon. If the ram is carrying moorit
you could also find yourself with a moorit in a co-expressed Grey
Mouflon. In short.. your lambs could be anywhere from snowy
white to chocolate topped to black topped, with spotting or without!
No wonder my new shepherd was overwhelmed!
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