A deleterious effect associated with UNH159 is attenuated in twin embryos of an inbred line of blue tilapia Oreochromis aureus

Authors

A. Shirak, Agricultural Research OrganizationFollow
Yniv Palti, USDA-ARSFollow
O. Bern, Bar-Ilan University, Ramat Gan
Thomas D. Kocher, University of MarylandFollow
Elisha Gootwine, Agricultural Research OrganizationFollow
Eyal Seroussi, Agricultural Research OrganizationFollow
Gideon Hulata, Agricultural Research OrganizationFollow
Micha Ron, Agricultural Research OrganizationFollow
Ramy R. Avtalion, Bar-Ilan University, Ramat GanFollow

Document Type

Article

Date of this Version

2012

Citation

Journal of Fish Biology (2012); doi:10.1111/j.1095-8649.2012.03474.x

Abstract

Offspring of a highly inbred gynogenetic line of Oreochromis aureus displayed 12-fold increase in twinning rate compared to the outbred population. Asymmetric conjoined twins, which consist of a normal embryo attached to a malformed-atrophic twin, were frequently encountered in both gynogenetic (90·7%) and outbred (38·2%) embryos. The monozygotic origin of these twins was determined using five microsatellite markers. Progeny of heterozygous parents for the microsatellite UNH159 were separated into sub-sets of twins and normal full-sibs. Consistent with previous reports, the normal embryo sub-set exhibited elimination of both types of homozygotes for the UNH159 genetic marker at 2–8 days after fertilization. Unexpectedly, this elimination was less frequent in twins. The UNH159 marker as well as RNA-binding motif protein, X-linked (rbmx), SRY-box containing gene 3 (sox3) and alpha-thalassemia/mental retardation syndrome X-linked (atrx) genes were mapped to linkage group 2. These gene orthologues are all located on the mammalian X chromosome and atrx is necessary for the X-chromosome inactivation.