13/17染色体易位纯合子猪(2n=36)与正常核型家猪(2n=38)的杂交试验

Crossbreeding Experiment of Homozygous Pigs for the 13/17 Robertsonian Translocation (2n=36)×Normal Karyotype Domestic Pigs (2n=38)

用13/17染色体易位杂合子猪互交获得的1头13/17染色体易位纯合子公猪[2n=36,XY,rob(13/17)]与4头正常核型母猪(2n=38,XX)交配,结果4头母猪全部妊娠并正常分娩.其产仔数分别为13,16,12,11,产活仔数分别为12,13,12,11;窝断奶头数分别为12,13,9,10.经核型鉴定,其后代全部为13/17易位杂合子[2n=37,XX或XY,rob(13/17)].此结果表明,13/17易位染色体的遗传完全符合孟德尔的遗传规律,13/17易位纯合子公猪具有正常的繁殖力.本杂交试验所产活仔48头,其性别比例为35?:13?,接近3:1的比例,经X^2检验不符合1:1的理论比率(X^2=10.08,P<0.01).此外,本杂交试验所产仔猪生长发育正常,并具有一定的杂合优势,这一结果为13/17易位纯合子猪的进一步推广应用,尤其是作为商品猪生产的杂交父本提供了可靠依据.

The homozygous pigs for the 13/17 Robertsonian is a new genetic type inthe domestic pig which obtained from mating the male and female heterozygous pigs of13/17 Robertsonian translocation. At the present study, 4 normal sows (2n = 38, XX)were mated with 1 homozygous boar for 13/17 Robertsonian translocation [2n = 36,XY, rob (13/17)]. Four sows were pregnant and farrowed normally. The litter sizes atbirth were 13, 16, 12, 11 respectively. The live litter sizes at 1 day of age were 12, 13, 12, 11 respectively; 12, 13, 9, 10 at weaning. All of the offsprings were heterozygousfor the 13/17 Robertsonian translocation by karyotype analysis. [2n = 37, XX or XY,rob (13/17)]. The results suggested that the 13/17 translocation chromosomes weretransmitted according to the Mendelian law, and homozygous boar for the 13/17Robertsonian translocation has a normal fertility. The sexual ratio of the 48 piglets fromthe present crossbreeding was about 3: 1 (35?: 13?), which, after X^2 test, was not co-incident with the theoretical ratio of 1: 1 (X^2= 10.08, P<0.01). In addition, all of thepiglets grew and developed normally, and they also showed some hybrid vigour. The re-sult has offered a reliable basis for the further application of homozygous pigs for the13/17 Robertsonian translocation, especially as a sire for crossbreeding to produce com-mercial pigs.