|Here is a simple
Genomic pedigree chart. 2 separate
chromosome segments are shown for each ancestor. (During meiosis , they
divide-recombination). The earliest generation, are all one color for
illustrative purposes. Dairy cattle
have 30 chromosomes, including the X
and Y. On average each chromosome
carries millions of base pairs, and thousands of genes.
|1)For the first segment, the sire has inherited ½ from each
piece. In the second segment, the
majority was inherited from one piece (both of these are an example of a
crossover). The individual has
received portions of the first segment that are traced back to the
|2) The dam has
inherited most of one segment from one portion of her sire’s piece, and a
mixture (double crossover) from her dam’s piece. The individual has segments that can be
traced to all grandparents.
example…. Say the light green
segment from the paternal grand dam was one that was high milk
production; the offspring, inheriting
a large segment from her, could mean that through this recombination, this
animal would have a higher PTA for milk that a full sib.