TABLE 2.

Stages of early embryogenesis in B. mori embryos incubated at 15°C.

Timing after egg activation (at 15°C)	PK1			Implant PK1 in K23 ♂			K23
	Stage	%	n	Stage	%	n	Stage	%	n
12 h	A	100	12	A	100	16	A	100	11
24 h	B	100	16	B	100	14	B-C	40–60	12
36 h	C-D	40–60	10	C-D	75–25	15	D-E	80–20	10
48 h	D-E	10–90	11	D-E	65–35	16	E-F	80–20	27
60 h	F	100	14	F	100	2	F	100	12
72 h	F	100	10	F	100	9	F	100	21

Embryonic development was analyzed at 12-h intervals during the first 72 h AEA. Each time point is characterized by developmental stages A-G described in Table 1. PK1, parthenogenetic eggs from PK1 ovaries; implant PK1 in K23 ♂, parthenogenetic PK1 eggs from ovarian implants that developed in K23 males; K23, fertilized eggs from endogenous K23 ovaries; n, number of embryos examined; %, percentage of occurrence of the embryonic developmental stage examined among all eggs in the sample. Stages of embryonic development were determined subjectively by two observers.