
%0 Journal Article
%A Stephenson, SK 
%T Some aspects of gene dosage in <I>N</I>- type sheep
%J Australian Journal of Agricultural Research
%D 1956/10/01
%V 7
%N 5
%P 447-468
%K 
%R https://doi.org/10.1071/AR9560447
%U https://www.publish.csiro.au/paper/AR9560447 
%X The dominant and recessive mimic genes N and nr produce increased birthcoat hairiness in New Zealand Romney lambs. This hairiness has been studied in lambs of different genotypes by three different methods. It has been found: (i) that in individual lambs there is a gradient in hairiness from the shoulder patch to the britch; (ii) increases in hairiness with increasing dosage of the N and nr genes conform to this gradient; (iii) with any single increase in N-gene dosage there is a differential rate of increase in hairiness on different positions. These results are explained on the hypothesis that the primary gene action is linear, but the gradient is modified by a threshold and possibly by a ceiling effect in the production of birthcoat medullation. 
