However, the process of ancestral
introgression with subsequent natural selection may help explain unexpected shifts in local snail-schistosome relationships (e.g., the changing compatibility of Bulinus nyassanus snails in Lake Malawi with S.
This has been reported previously and
introgression produced by cattle/bison crossbreeding is suggested as one of the explanation for this result (Cai et al., 2011; Hassanin et al., 2012).
The Boran cattle, a humped breed reflecting indicine
introgression, carry genes adaptive to harsh environment and heat tolerance developed by a long-term natural selection, display high resistance to heat and ticks and good productivity on poor forage and low amounts of water, whereas, Sheko and Abigar are found in humid and forest areas where burden of tsetse flies is high [27].
Introgression is the signal of past hybridization, and an ability to successfully hybridize might be of fundamental importance to the future of a species, while climates and environments continue to change (Grant and Grant 1993, Allendorf et al.
Moreover, in hybridizing populations, different markers representing different genomic components [allozymes, nuclear DNA (nDNA), and mtDNA] appear to vary in an uncoordinated way, leading to biased estimates of different levels of genetic
introgression (Riginos & Cunningham 2005, Vainola & Strelkov 2011).
This decrease might be an effect of the location sampled each year (derived from differences of sampling years) or may indicate that the
introgression of farm shrimp alleles into the wild has probably been limited.
(1.) Judith Rhymer and Daniel Simberloff, "Extinction by Hybridization and
Introgression," Annual Review of Ecology and Systematics, Vol.
Keywords: Rice;
Introgression lines; Grain shape; Quantitative trait locus; Genetic background
However, while some specific features in wolves were shown to be the result of
introgression from domestic dog (such as the black coat, white claws and spur on the hind legs, Galaverni et al.
In
introgression breeding, discrimination of different genomes and chromosome locus identification is carried out by this method.
These findings indicate that multiple domestication events have occurred in river buffalo, leading to independent expansion of some maternal lineages with minimum
introgression from wild populations.