. 2016 Jul;55(4):400–405.

Table 1.

Summary of study groups

	n	No. (%) of donors with copulatory plugs	No. (%) of donors fertilized	No. of fertilized embryos	No. of injectable blastocysts	No. of blastocysts injected	No. of pups born	No. of chimeras born	No. of female chimeras born	No. of male chimeras born	No. of male chimeras with % chimerism by coat color
	n	No. (%) of donors with copulatory plugs	No. (%) of donors fertilized	No. of fertilized embryos	No. of injectable blastocysts	No. of blastocysts injected	No. of pups born	No. of chimeras born	No. of female chimeras born	No. of male chimeras born	100%	70% to 100%	40% to 70%	40% or less
4-wk-old BALB/c, superovulated donors	33	33 (100.0)	25 (75.8)	374	218	209	29	9	2	7	0	4	2	11
12 wk-old BALB/c, nonsuperovulated donors	21	21 (100.0)	18 (85.7)	149	120	112	74	52	3	49	2	42	6	9
4-wk-old albino B6, superovulated donors	36	32 (88.9)	34 (94.4)	651	418	253	47	26	9	17	0	10	2	14

Fertilized donors are female mice with fertilized embryos (at any stage) isolated at time of euthanasia. Numbers of fertilized embryos include 2-cell, 4-cell, 8-cell, morula, and blastocyst stage embryos. Numbers of injectable blastocysts are those blastocysts with an intact zona pellucida. Numbers of blastocysts injected indicates those blastocysts that underwent ES cell injection and were transferred into pseudopregnant recipient mice