Page 179 - Linear Models for the Prediction of Animal Breeding Values 3rd Edition
P. 179

m
                                      m
                       m
        where (1 − r )r  = (1 − r)r for r  = r or (1 − r), F  is the inbreeding coefficient at
                    o  o              o              d
                                  m
        the MQTL of the dam and h  is the diagonal element of D for the paternal MQTL
                                  o
                                                          m
        of individual o. Therefore, if the dam is not inbred, h  = 2(1 − r)r with marker
                                                          o
                                                                    2
                        m
                                                               m
        information or h = 0.5 with no marker information and h  = s  if the dam is
                        o                                      o    v
        unknown.
            Equation 10.13 may be written as:
                  n
            G -1  = å qqh  -1
              v      j  j  j
                  j=1
        where n is the number of individuals in the pedigree, q  is the column of Q and h  is
                                                        j                      j
        the jth diagonal element of H. Since Q = (1 − P′), the jth element of q  (i.e. the dia-
                                                                      j
        gonal element) is unity and q  has at most only two other non-zero elements. If the
                                  j
                                                                     p
                                                 p
                                        p
                                                                m
                              p
        sire of o is known, j = i , element i  = −(1 − r ) and element i  = −r . Similarly, if
                              o         s        o              s    o
                                                                                m
        the dam is known, then for j = i , element i  = −(1 − r ) and element i  = −r .
                                                           m
                                                 p
                                      m
                                                                          m
                                      o          d         o              d     o
        Therefore, the contribution corresponding to the paternal and maternal MQTL
        alleles of an individual to  G  can easily be calculated from parent and marker
                                  −1
                                   v
        information.
            Fernando and Grossman (1989) gave the following rules for obtaining G . First,
                                                                           −1
                                                                           v
        calculate the diagonals of H using Eqns 10.14 and 10.15 and its inverse. Second, set
        G   to zero and for each offspring o, with sire s and dam d, add the following to the
          −1
          v
        indicated elements of G :
                             −1
                             v
            If the sire is known, add:
                 p  2  − 1               p p
                                         s s
            (1 − r o ) h p to diagonal element  i i  ;
                     i o
                                  p p
                                         p p
             (1    p ) h p to elemeents ii  and ii ;
                      −
                      1
            −− r  o               s o    o s
                     i o
                 p  p  − 1          p m    m m p
                  )
                 o
                                   s s
                                           s s
            (1 − rr o  h p  to elements i i  and i i ;
                       i o
              p 2  −  1               m m
                                      s s
            (r o )  h p to diagonal element  i i ;
                  i o
            −  p  h p to elemeents ii  and i i
                              m p
                                      p m
                  −
                  1
               o              s o     o s
              r
                 i o
        If the dam is known, add:
                 m  2  −  1                p p
                                          d d
            (1 − r o  ) h m to diagonal element  i i  ;
                     i o
                                   p m
                                           m p
             (1   m ) h m to elemeents ii  and i i ;
                      −
                      1
            −− r  o                d o     o d
                      i o
                 m  m  − 1           p m    m m p
                  )
                                            d d
                 o
                                    d d
            (1 − rr o  h m  to elements i i  and i i ;
                       i o
              m 2  − 1                 m m
                                       d d
              o  )  h m to diagonal element  i i ;
            (r
                  i o
            −  m  h m to elemeents ii  and ii
                               m m
                                       m m
                  −
                  1
               o
              r
                  i o          d o     o d
        And always add:
                            p
                                               m
                         p
            h p to element  ii and  h m to element  i , i m
                          ,
             - 1
                                  - 1
             i o         o  o     i o          o  o
        Use of Genetic Markers in Breeding Value Prediction                  163
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