ISSN:
1365-2761
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
Abstract. S, a dominant, lethal, atitosomal gene, was discovered in Auburn University's population of Surotherodon aureus (=Tilapia auera). When present in the heterozygous state (S+). the S gene produces the saddleback phenotype. Saddlebacks are missing part of or all of the dorsal fin. Some fish thai are missing most of or the entire dorsal fin have additional fin disorders and are missing various combinations of the pectoral, pelvic, and anal fins. Each fin disorder is associated with gross skeletal anomalies. Viability in saddlebacks is reduced by 67% during the first three months of life. Those that survive are less resistant to stress and subsequent infection than normal fish. When challenged by Saprolcegnia sp., saddlebacks were far more susceptible to infection (P〈0.01). When present in the homozygous state (SS), the gene causes death in fry prior to swim-up. Thus, a single S gene reduces viability by 67%, and two S genes reduce viability by 100%. The S gene did not affect early growth or dressing percentage. Because it is a dominant gene, the S gene can be eliminated from any population in one generation by culling all saddlebacks.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2761.1983.tb00051.x
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