Smyth J R
Poult Sci. 1981 Nov;60(11):2371-3. doi: 10.3382/ps.0602371.
The multiple trait semilethal mutation previously described by McGibbon and Shackelford (1972) has reappeared among the F2 progeny of an outcross mating between two standard lines. The mutant phenotype is expressed by the simultaneous presence of syndactyly polydactyly, and ptilopody resulting from homozygosity for an autosomal recessive gene, psp. Less than 31% of the mutants hatched, with the rest dying during the last quarter of the incubation period. In this study no psp/psp chicks survived beyond 6 weeks of age.
先前由麦吉本和沙克尔福德（1972年）描述的多性状半致死突变，在两个标准品系的远交后代的F2子代中再次出现。突变表型由并趾多指和绒羽足同时出现表现出来，这是由于常染色体隐性基因psp的纯合性导致的。孵化出的突变体不到31%，其余的在孵化期的最后四分之一时间内死亡。在本研究中，没有psp/psp雏鸡存活超过6周龄。
