Categories: Limbs / fins / digit / tail phene

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal recessive

Disease-related: yes

Key variant known: no

Species-specific symbol: dp-1

History: O'Hare et al. (2019): "The dp-1 mutation originated within a Single Comb White Leghorn commercial stock, was acquired by researchers at the University of California in 1941, and later incorporated into a congenic inbred line (a.k.a. UCD-Dp-1.003) in the late 1980s to early 1990s."

Mapping: Robb et al. (2011) mapped this trait to a 720kb region on chromosome GGA 1 (189,805,428 - 190,525,761). O'Hare et al. (2019) narrowed this to a region of 586kb. By sequencing this region in the UCD-Dp-1.003 congenic line, O'Hare et al. (2019) eventually narrowed the candidate region to a 5kb region that includes the genes MRE11 and GPR83, which they proposed as "high-priority candidates for the dp-1 mutation".

Molecular basis: As O'Hare et al. (2019) ruefully noted, "despite the advances of genomics and allied fields, this work affirms what other such research has shown, that finding the exact sequence element responsible for even a simply-inherited trait (single-gene autosomal recessive pattern) is not [necessarily] easily accomplished".

Clinical features: "Homozygotes (-/-) display moderate preaxial polydactly, dwarfing, some with exposed vicscera, occasional cleft palate, and shortened upper beak" Robb et al. (2011)