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In the off-spring of crosses between Drosophila simulans and its island derivative Drosophila mauritiana, female hybrids are fertile but male hybrids are sterile. Recent studies have shown that a critical gene for gender determination in Drosophila known as the sex-lethal gene is highly misregulated in D. melanogaster and D. simulans hybrids ...
Hybrid sterility can be caused by different closely related species breeding and producing offspring. These animals are usually sterile due to the different numbers of chromosomes between the two parents. The imbalance results in offspring that is viable but not fertile, as is the case with the mule.
Hybrid between Varanus panoptes horni and Varanus gouldii flavirufus. Superfamily Lacertoidea. Family Teiidae. Hybrid between Aspidoscelis exsanguis and Aspidoscelis inornatus. Infraorder Alethinophidia. Family Pythonidae. Hybrids between the yellow ball python and the woma python. Hybrids between the ball python and the Borneo short-tailed python.
A mule is a sterile hybrid of a male donkey and a female horse.Mules are smaller than horses but stronger than donkeys, making them useful as pack animals.. In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different varieties, subspecies, species or genera through sexual reproduction.
Another simple way to establish a female line for hybrid seed production is to identify or create a line that is unable to produce viable pollen. Since a male-sterile line cannot self-pollinate, seed formation is dependent upon pollen from another male line. Cytoplasmic male sterility is also used in hybrid seed production.
Hybrid incompatibility occurs when the offspring of two closely related species are not viable or suffer from infertility. Charles Darwin posited that hybrid incompatibility is not a product of natural selection, stating that the phenomenon is an outcome of the hybridizing species diverging, rather than something that is directly acted upon by selective pressures. [4]
Rare, sterile hybrids form between D. pseudoobscura and D. persimilis, with sympatric D. pseudoobscura females discriminating against D. persimilis males; more so than allopatric populations. [42] Other Drosophila research on reinforcement has been from laboratory experiments and is discussed below.
Sterile F1 hybrids have given rise to allopolyploids in other taxa (e.g. Spartina and Senecio), but allopolyploids can also form via fertile intermediate hybrids (e.g. Tragopogon). In general, hybrid species can arise from two major types of hybrid speciation, defined by whether the speciation event is associated with genome duplication ...