Mhlanga-Mutangadura Tendai, Hansen Liz, Katz Martin L
Canine Genetics Laboratory, Department of Pathobiology and Integrative Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA.
Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO 65211, USA.
Vet Sci. 2025 Sep 20;12(9):916. doi: 10.3390/vetsci12090916.
Every dog breed has characteristic physical features that have been fixed through numerous generations of selective breeding. For the Grand Basset Griffon Vendéen (GBGV) breed, short-leggedness has been established as the breed standard. Although breeders have been consistent in only breeding dogs that meet this standard, occasionally litters have included dogs that are significantly taller. In many dog breeds short leg length is associated with insertion of an retrogene () at specific sites on either chromosome 12 () and/or 18 (). A study was undertaken to determine whether genotype is the basis of the height difference. Of 47 GBGVs that were evaluated, 41 had leg lengths within the breed standard and 6 were significantly taller. None of the dogs had the insertion. The short-legged dogs were either homozygous or heterozygous for the insertion. All six long-legged dogs were homozygous for the non-insertion allele. This indicates that selective breeding based on phenotype alone has not been sufficient to fix short-leggedness in the breed due to retention of the non-insertion allele. The finding that one copy of the insertion is sufficient to confer short-leggedness indicates that expression of the retrogene during development is likely to inhibit growth of the limbs.
每一个犬种都有其独特的身体特征，这些特征通过多代的选择性育种得以固定。对于大贝吉格里芬凡丁犬（GBGV）品种来说，短腿已被确立为该品种的标准。尽管育种者一直只繁育符合这一标准的犬只，但偶尔也会有一窝犬中出现明显更高的犬只。在许多犬种中，短腿长度与逆转录基因（）插入12号染色体（）和/或18号染色体（）上的特定位置有关。一项研究旨在确定基因型是否是身高差异的基础。在评估的47只GBGV中，41只的腿长在品种标准范围内，6只明显更高。所有犬只均无该插入。短腿犬对于该插入要么是纯合子要么是杂合子。所有六只长腿犬对于非插入等位基因都是纯合子。这表明仅基于表型的选择性育种不足以在该品种中固定短腿特征，因为非插入等位基因得以保留。插入一份拷贝就足以导致短腿这一发现表明，逆转录基因在发育过程中的表达可能会抑制四肢的生长。
