The Israeli Journal of Aquaculture - Bamidgeh 53(1), 2001, 15-22

FULL-SIB MATING CAN REDUCE DELETERIOUS EFFECTS
ASSOCIATED WITH RESIDUAL SPERM INHERITANCE
IN GYNOGENOTES

Andrey Shirak and Ramy R. Avtalion

Laboratory of Fish Immunology and Genetics, Faculty of Life Sciences, Bar Ilan University, Ramat Gan 52900, Israel

(Received 5.10.00, Accepted 2.5.01)

Abstract

Fertilization of Oreochromis aureus eggs with UV-irradiated sperm from the closely related species O. niloticus, followed by diploidy restoration, produced offspring with lower embryo viability and higher skeletal deformation rates than siblings generated with sperm from a genetically distant species (Tilapia zillii). Results showed that: (a) deleterious effects due to O. niloticus sperm accumulate in gynogenetic fish over generations; (b) such effects are eliminated when using T. zillii sperm to fertilize eggs from gynogenetic mothers produced by full-sib matings. These results suggest that: (a) deleterious effects are associated with residual male DNA fragments which may be passed on to descendent offspring; (b) such fragments are significantly purged following full-sib mating. These findings suggest that biparental reproduction may play an important role in the control of genome integrality by purging supernumerary chromosome fragments.

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