Multiplex polymerase chain reaction (PCR) assays were designed that incorporated primer pairs for the sex determining region on the Y chromosome, Sry, and one or two control sequences. A triplex and a duplex assay were created involving Sry and Dax, a single copy X chromosome gene which is involved in the female sex determination pathway. The third sequence in the triplex assay was a repetitive Y chromosome sequence, YR. A minimum of 2.5 x 10-3 to 2.5 x 10 -4 m g/ m L of male DNA and 2.5 x 10-5 m g/ m L of female DNA was required if a single multiplex PCR was performed. To demonstrate that sex determination of preimplantation porcine embryos is possible, morulae were collected 5 d post insemination from pregnant mare serum gonadotrophin (PMSG)/human chorionic gonadotrophin (hCG)-treated 60--70 kg prepubertal gilts. Embryos were biopsied using a micromanipulator and cells were placed into individual microcentrifuge tubes for further analysis. Embryos were then cultured to the blastocyst stage. A total of 315 embryos were sexed via the PCR assay with a resultant female/male (%) ratio of 73/27. When 94 embryos from heavier gilts (90--100 kg) were sexed in a similar assay, the resultant female/male ratio was 60/40. Attempts were made to correlate these results with karyotypes. Five transfers of sexed embryos into synchronized recipients were attempted. None of these resulted in pregnancies; although return to estrus was delayed by two to eight days, in four out of the five recipients. Our findings suggest that PCR amplification of the Sry gene can be a reliable method for sexing porcine embryos. It does appear that embryo quality is critical for both the PCR assay and subsequent successful culture. (Abstract shortened by UMI.)
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.20617 |
| Date | January 1998 |
| Creators | Watt, Heather Lynn. |
| Contributors | Downey, B. R. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Animal Science.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001609859, proquestno: MQ44330, Theses scanned by UMI/ProQuest. |
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