Unser Haushund: Eine Spitzmaus im Wolfspelz? - Wolf-Ekkehard ...

81Aus F. Vogel und A. G. Motulski: Human Genetics (1979/1982/1986, p. 317; redrawn by Roland Slowik 2013):"Diagrammatic structure of a polypeptide chain in normals and heterozygotes. a The individual is homozygous. It produces onlynormal polypeptides. b The individual is heterozygous. Normal and abnormal polypeptides are formed in equal amounts. Thepolypeptide chain cannot be properly assembled.” (Siehe http://www.weloennig.de/AesIV2.B.3.html, dort weitereAusführungen.)"The polypeptide cannot be properly assembled” oder als andere Möglichkeit:vielleicht nicht mehr in adäquaten Mengen im heterozygoten Organismus. Sieheweiter auch die Ausführungen zur ektopischen Genexpression oben.9.8 Blaue AugenMelaninproduktion ist stark reduziert ("reduction of melanin production" or"low concentrations of melanin" "[almost] absence of pigmentation"). Zunächstzum Menschen (Literaturhinweise in dem im Folgenden zitierten Artikel 138 :"In humans, the inheritance pattern followed by blue eyes is considered similar to that of a recessivetrait […]. Scientists tracked down a genetic mutation that leads to blue eyes. "Originally, we all hadbrown eyes," said Eiberg. Eiberg and colleagues showed in a study published in Human Genetics that amutation in the 86th intron of the HERC2 gene, which is hypothesized to interact with the OCA2gene promoter, reduced expression of OCA2 with subsequent reduction in melanin production.[…] Eiberg stated, "A genetic mutation affecting the OCA2 gene in our chromosomes resulted in thecreation of a 'switch,' which literally 'turned off' the ability to produce brown eyes."George M. Strain zum Haushund (2011, Schriftbild von ihm, aber Farbe vonmir 139 ):"Blue eyes, resulting from an absence of pigment in the iris, is common with pigment-associateddeafness but is not, in and of itself, an indication of deafness or the presence of a deafness gene;however, in several breeds dogs (Dalmatian, English Setter, English Cocker Spaniel, Bull Terrier) withblue eyes are statistically more likely to be deaf.”138 http://en.wikipedia.org/wiki/Eye_color. Vielleicht ein wichtiger Punkt zur Ergänzung aus diesem Artikel: "The genetic switch is located in the gene adjacent toOCA2 and rather than completely turning off the gene, the switch limits its action, which reduces the production of melanin in the iris. In effect, the turned-downswitch diluted brown eyes to blue. If the OCA2 gene had been completely shut down, our hair, eyes and skin would be melanin-less, a condition known as albinism.”Hinweis auf blaue Augen bei Cuscus, Sclater's Lemur, Katzen und Hunden im selben Beitrag: "Blue eyes are rare in mammals; one example is the quite recentlydiscoveredBlue-eyed Spotted Cuscus (Spilocuscus wilsoni). The trait is hitherto known only from a single primate other than humans – Sclater's Lemur (Eulemurflavifrons) of Madagascar. While some cats and dogs have blue eyes, this is usually due to another mutation which is associated with deafness [trifft abergenerell nicht auf die Sibirian Huskies zu, kann aber auch dort vorkommen.] But in cats alone, there are four identified gene mutations that produce blue eyes,some of which are associated with congenital neurological disorders. The mutation found in the Siamese cats is associated with strabismus (crossed eyes). Themutation found in blue-eyed solid white cats (where the coat color is caused by the gene for "epistatic white") is associated with deafness. However, there arephenotypically identical, but genotypically different, blue-eyed white cats (where the coat color is caused by the gene for white spotting) where the coat color is notstrongly associated with deafness. In the blue-eyed Ojos Azules breed, there may be other neurological defects. Blue-eyed non-white cats of unknown genotype alsooccur at random in the cat population."139 Vgl. http://www.dogousa.org/message_boards/topic.asp?TOPIC_ID=14991&whichpage=6