Achondroplasia in Calves*

Brandt, G.W.

doi:10.1093/oxfordjournals.jhered.a105033

Cited by 9 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Heterozygous forms appear to be perfectly normal and survive. Achondroplasia in man is currently regarded as the expression of a dominant factor (4, 5) ° In the "bulldog" calf, the condition is inherited as a dominant or semidominant (6) while other forms in cattle are recessive in character (7)(8)(9)(10). In the dog (3), the condition of achondroplastic extremities is inherited as a single factor dominant character while the localized chondrodystrophic deformity of the tail of the bulldog, or "screwtail," is recessive to the normal long straight tail of the bassethound.…”

Section: Discussionmentioning

confidence: 99%

Hereditary Achondroplasia in the Rabbit

Pearce¹,

Brown²

1945

Journal of Experimental Medicine

View full text Add to dashboard Cite

The hereditary nature of achondroplastic dwarfism (chondrodystrophia foetalis) in the rabbit was pointed out in the first paper of this series in which the physical appearance of the animals was described (1). The second paper was devoted to the pathologic features of the condition (2). In the present report, the results of genetic studies are described, the circumstances of the original cases are considered with particular reference to certain disease complexes carried in their parental lines which might have a bearing on the abnormality and, finally, the condition is briefly discussed in relation to achondroplasia in other animal species. Materials and MethodsSince achondroplasia in the rabbit is invariably lethal, the animals either being born dead or dying within a few hours of birth, and since transmitters of the condition have so far been identified only by breeding tests, genetic studies were necessarily carried out with such animals. Identified transmitters were mated with unrelated animals, including examples of pure breeds, to form an F, generation, and these animals in turn were tested for transmission of the condition. Those found to be transmitters were then interbred to form an F2 generation.The proportion of achondroplastic and normal animals in the progeny derived from these various breeding experiments has been determined. A selected number of transmitters, both male and female, have been compared from the standpoint of the character of their progeny. Special attention has also been paid to the occurrence of negative litters obtained from transmitting parents, that is, litters in which the expected achondroplastic dwarfs were not observed. Results of Genetic StudiesThe number of achondroplastic dwarfs so far observed is 228; they occurred among 788 total births contained in 132 litters. The incidence of the condition is 28.93 per cent. On the basis of a simple recessive unit factor, one-fourth, or 197 animals, would be expected to show the condition. There is no significant deviation between the observed distribution of achondroplastic dwarfs and normal litter mates and the expected distribution on the basis of genetic principles as shown by the X ~ test of homogeneity (N = 1, P = 0.05+).Of the total number of the progeny, 227 animals contained in 43 litters were derived from F~ matings, their Fx parents being outcrossed hybrids and of this number, 59, or 25.99 per cent, were achondroplastic dwarfs. There

show abstract

Section: Discussionmentioning

confidence: 99%