PRODUCTION OF PIGLETS PRESELECTED FOR SEX FOLLOWING IN-VITRO FERTILIZATION WITH X-CHROMOSOME-BEARING AND Y-CHROMOSOME-BEARING SPERMATOZOA SORTED BY FLOW-CYTOMETRY

In vivo-matured porcine oocytes were fertilized in vitro with X and Y chromosome-bearing spermatozoa, and sorted for sex on the basis of DNA content by flow cytometry. Developmental competence of the sexed embr yos was determined through established pregnancies after embryo transf er. Spermatozoa were stained with Hoechst 33342 and sorted using a flo w cytometry cell sorter. Purity of sorting was 83% for Y spermatozoa a nd 92% for X spermatozoa. A total of 387 mature cumulus-oocyte-complex es (COG) was collected from 18 superovulated prepuberal gilts shortly before ovulation. In vitro fertilization with sorted spermatozoa was p erformed in 4 replicates. After 18 h of sperm- oocyte co-culture at 39 degrees C, the zygotes were placed into culture medium (NCSU-23) for another 24 h. The average cleavage rate was 56.2%. Ninety-two embryos produced from X-sorted sperm cells were transferred surgically into th e uterus of 2 recipients. Two gilts farrowed and delivered 6 and 4 hea lthy female piglets, respectively. Additionally, 2 gilts were insemina ted intratubally via surgical laparotomy with either X or Y sorted spe rmatozoa (2x10(5)) per oviduct. The 2 sows farrowed producing 15 pigle ts. Thirteen of the 15 piglets were of the predicted gender (85%). (C) 1997 by Elsevier Science Inc.