9 NEW CASES OF RECIPROCAL TRANSLOCATION IN THE DOMESTIC PIG (SUS-SCROFA-DOMESTICA L.)

Nine pigs with decreased litter size or sired by boars with decreased litter size were found to be reciprocal translocation carriers. Four L arge White animals (two females and two males) demonstrated translocat ions involving chromosomes 1 and 9 (1p-;9p+), 11 and 13 (11q+;13q-), 3 and 13 (3;13)(p1.5;q3.1), and 15 and 17 (15;17)(q1.3;q2.1). Two Large White x Pietrain terminal boars demonstrated translocations involving chromosomes 11 and 16 (11;16)(p1.4;q1.4), and 6 and 14 (6;14)(q2.7;q2 .1). The (9;15)(p2.4;q1.3) and (6;16)(q1.1;q1.1) translocations were f ound in a Large White x French Landrace boar, and in a commercial male line boar with decreased litter size, respectively. A Gascon breed bo ar with reduced prolificacy also had an abnormal karyotype, namely 38 XY, rcp(1;6)(q1.2;q2.2). Reduction in prolificacy was estimated accura tely in cases 3, 5, 6, 7, and 9 (35%, 30%, 35%, 41%, and 56%, respecti vely). Rcp(1;6)(q1.2;q2.2) and rcp(6;16)(q1.1;q1.1) seemed to have bee n of de novo origin.