done, the genes within the cytoplasm are slightly altered. This approached cannot
be used when the species are too far apart. Some cases of heterosis are observed, in
which the first hybrid generation shows superior traits to the parents, although the
reason for this is not clearly understood. The only way to learn which mixtures
produce stronger hybrids is to actually make them. The techniques described in this
section are illustrated in Fig. 4.1 (Thomas 1980; Oshiro 1990).
Fig. 4.1 Basic techniques of chromosome manipulation
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4 Fish Breeding and Biotechnology
be used when the species are too far apart. Some cases of heterosis are observed, in
which the first hybrid generation shows superior traits to the parents, although the
reason for this is not clearly understood. The only way to learn which mixtures
produce stronger hybrids is to actually make them. The techniques described in this
section are illustrated in Fig. 4.1 (Thomas 1980; Oshiro 1990).
Fig. 4.1 Basic techniques of chromosome manipulation
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4 Fish Breeding and Biotechnology