Mammalian chimaeras / Anne McLaren.

  • McLaren, Anne.
Date:
[1976]
Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Mammalian chimaeras / Anne McLaren. Source: Wellcome Collection.

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    Making chimaeras 13 i » I о /\ •••: ч • •ф« ^ Fig. 6. Diagram to show the essential steps involved in making aggregation chimaeras (on the left) and injection chimaeras (on the right). For both, the pro¬ cedures represented in the outer columns are carried out in vitro. may be done with glass needles, forceps or hair loops. Mintz, Gearhart & Guymont (1973) describe the use of phytohaemagglutinin to facilitate aggre¬ gation at room temperature. Once stuck, embryos continue to aggregate until a single large morula has been formed. This process has been filmed by time-lapse cinematography (Mulnard, 1971). The embryos are maintained in culture for 24-48 hours, to allow aggregation to be completed and to check that no blastomeres are extruded. They are then transferred to the uterus of a pseudopregnant foster- mother, days post coitum {p.c.). Mintz uses special culture dishes, with a medium containing serum; Whitten uses tubes, in an atmosphere of 5 % carbon dioxide, 5% oxygen and 90% nitrogen; and Mulnard places his embryos in drops of medium in capillary tubes immersed in oil, with the gas phase provided by bubbles in the capillary tube. Other published studies are based on the culture system of Brinster, with drops of modified Krebs- Ringer bicarbonate under mineral oil. The essential steps of the procedure are presented in Fig. 6, and details of some of the culture media in Table 1. In our laboratory (Bowman & McLaren, 1970), blastocysts formed after zona removal and aggregation showed as 2-2