title: A deleterious effect associated with UNH159 is attenuated in twin embryos of an inbred line of blue tilapia Oreochromis aureus.
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.
authors: Institute of Animal Science, Agricultural Research Organization, Bet-Dagan 50250, Israel. shiraka@agri.gov.il
authors: A
authors: A
authors: Shirak
authors: Y
authors: Y
authors: Palti
authors: O
authors: O
authors: Bern
authors: T D
authors: TD
authors: Kocher
authors: E
authors: E
authors: Gootwine
authors: E
authors: E
authors: Seroussi
authors: G
authors: G
authors: Hulata
authors: M
authors: M
authors: Ron
authors: R R
authors: RR
authors: Avtalion
mesh_terms: D000818:Animals; D005260:Female; D005796:Genes / Q000235:genetics; D008040:Genetic Linkage; D005838:Genotype; D007178:Inbreeding; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D017210:Tilapia / Q000235:genetics*; D014428:Twins, Conjoined / Q000473:pathology; D014430:Twins, Monozygotic / Q000235:genetics*