Dog domestication 개의 가축화

B20 Dog domestication, micro-evolutionary consequences, relatives and interspecies hybrids

​

Genomic data:

• Number of chromosomes is the same in Canis species group: 2n = 78 (39 pairs).
• No chromosome polymorphism across Canis species.
• Interspecies (Wolf × Dog) hybridization is successful! Offspring are fertile!
• New breeds were created by this method (Czech Wolfhound, Nordic breeds). Saarloose wolfhound, and wolamute. ​

---

Domestication:

• from the wolf: very early, >15 000 years B.C. or earlier, first species that domesticated by mankind
• many consequences of domestication: number of breeds, inbreeding, changes in temperament, appearance etc..
• Mitochondrion DNA research has revealed: maternal wolf ancestry, proved also the very early domestication (dog = domestic wolf).
• Long evolution: early and new types, highly variable breeds were developed, many new mutations were fixed.
•  Socialization to mankind.
•  Feral dogs are not typical and common​

---

there is extreme diversity between dogs breeds : selective breeding and natural adaptation to various habitats

• Size & body mass (1-100kg): Toy, small, medium, large breeds
• Coat colors & quality: Short-, long-, wire- haired, smooth/curled coat etc.
• Appearance & conformation
• Head shape  Long, brachycephalic, round-headed, square- headed etc.
• Ear shape & length  Erect, lopped, cropped (illegal, in some countries)
• Tail length & shape (e.g. curled in pugs)
• Temperament, senses, instinct
• Relationship with humans (companionship, some breeds are better suited to certain lifestyles)​

---

Coat color inheritance of the dog

•  A (agouti signaling protein, ASIP): Ay-, As-, A+-, at-, aa, fawn/sable (yellow), saddle, wild agouti, black and tan, recessive black. DNA-test.
•  B (black, tyrosinase related protein, TYRP1 gene, dominant): B-, bb, black, brown (chocolate or liver). DNA-test.
•  K (beta-defensin gene, CBD103): colours: dominant black (KB), brindle (kbr) and agouti fawn (kyky). DNA-test.
•  E (extension, non-extension, MC1R, melanocortin receptor): Em, Eg, E-, ee, masking, gizzle, full colour, yellow or red. DNA-test.
•  C (colour, thyrosinase): C-, cch-,ce, cb-,ca, full colour, chinchilla, albinos (extreme albino dilution, blue and pink eyed).
•  D (dense, dilute melanophilin gene, MLPH recessive): D-, dd, diluted colours: grey or blue, cream or buff. DNA-test.
•  M (merle, incomplete dominant, retrotranspozon): M-, mm, MM: subvital, Mm: blue and sable merle, harlequin Dane. DNA-test.
•  S (solid and spotted, microphthalmia-associated transcription factor gene or MITF): S-, si-, sp-, sw-, Irish, piebald and extreme white spotted, variations of expression.
•  T (ticking): T-, tt, colour spotting (Dalmatian).
• G (grey): G-, gg, progressive silvering or greying (roan).
• A (agouti, agouti signalling protein, ASIP): polymorphic alleles, dominance hierarchy: Ay > As > aw or a+> at > a. Colours: DNA-test.
• - Ay, fawn/sable (yellowish, reddish, darker tips),
• - As: saddle or blanket;
• - aw or a+: wild, wolf colour, pale grey, banded; – at: black and tan, tan points;
• - aa: only recessive black (Shetland Sheepdog and German Shepherd).​

---

Hair quality and texture inheritance of the dog

•  W (wire hair, R-spondin-2 gene, RSPO2): – W-, dominant wire hair + beard vs. ww, normal.
•  R (wavy, curly, keratin-71, KRT71 gene): – R-, dominant normal vs.– rr, recessive curly coat.
•  L (long, FGF5, fibroblast-growth faktor ):– L-, dominant short vs.– ll, recessive, long hair.
• L – W – R epistatic interactions and combinations: – L-: Basset hound (short) – L-, W-: Australian terrier (short wired)– rr-, W-: Airedale terrier (curly wired)
• – ll: Golden retriever (long)
• – ll, W-: bearded collie (long with beard)
• – ll, rr: spanish water spaniel (long and curly)
• – ll, rr, W-: bichon frisé (long, curly, beard)

---

Hairlessness of dogs

Hairlessness (alopecia, breed standard) in dogs: – Dominant (Hr, Mexican Xoloitzcuintli,

Peruvian, Inca orchid, Bolivian Khala dogs, American Hairless terrier).

– Recessive (hr), Chinese crested dogs and Manchurian Hairless dog.

– Hr/Hr homozygote is lethal! – FOXI3 gene mutation.​

---

Dogs Relatives & interspecies hybrids:

• Genus canis:
• C. lupinus- grey wolf, largest wild dog
• C. rufus – red wolf
• C. latrans- coyote
• C. aureus – golden jakal
• C. simensis