In other species: goat , sheep

Categories: Reproductive system phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 601918 (gene) , 618014 (trait)

Mendelian trait/disorder: no

Mode of inheritance: Multifactorial

Disease-related: no

Key variant known: yes

Year key variant first reported: 2019

Inheritance: Torrecilha et al. (2020): "The trait [average litter size] heritability was estimated at 43.1%, from which approximately 15% was accountable by the GDF9 locus alone. Therefore, markers flanking GDF9 explained approximately 6.5% of the variance in ALS."

Molecular basis: A GWAS for average litter size (ALS) in Entlebucher Mountain dogs conducted by Torrecilha et al. (2020) highlighted the GDF9 gene, mutations in which are central to fecundity in sheep. Further investigation "revealed two missense substitutions in GDF9, one of which (g.11:21147009G>A) affected a highly conserved nucleotide in vertebrates. The derived allele A was validated in 111 dogs and shown to be associated with decreased ALS (-0.75 ± 0.22 puppies per litter). The variant was further predicted to cause a proline to serine substitution. The affected residue was immediately followed by a six-residue deletion that is fixed in the canine species but absent in non-canids. We further confirmed that the deletion is prevalent in the Canidae family by sequencing three species of wild canids. Since canids uniquely ovulate oocytes at the prophase stage of the first meiotic division, requiring maturation in the oviduct, we conjecture that the amino acid substitution and the six-residue deletion of GDF9 may serve as a model for insights into the dynamics of oocyte maturation in canids."

Breed: Entlebucher Mountain Dog (Dog) (VBO_0200503).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).

Associated gene: