Table 1. Genotyping Table.

	Clone
Embryo number	5A5	5C7	5D6	5G1	5H8	5I7	6E6	6F7	7D7	5I2	Nb of different clones integrated
59	x	x			x			x	x		5
60		x						x			2
61	x	x	x	x	x			x	x		7
62		x	x								2
63					x						1
64				x							1
65											0
66		x			x			x			3
67											0
68	x	x		x	x			x	x		6
69									x		1
70		x							x		2
71	x			x							2
72	x	x						x	x		4
91	x	x							x		3
92					x			x	x		3
93	x	x	x	x	x			x	x		7
94				x	x			x	x		4
177	x	x	x						x		4
178		x	x								2
179					x				x		2
180	x	x	x	x	x			x	x		7
181					x			x	x		3
182											0
183					x				x		2
184	x								x		2
185	x				x				x		3
186	x	x			x			x	x		5
187	x	x	x	x	x			x	x		7
188											0
189	x										1
190	x	x	x		x			x	x		6
191	x		x					x	x		4
192	x	x									2
193	x	x	x	x	x				x		6
194					x				x		2
195											0
196	x							x	x		3
197		x		x				x	x		4
198		x	x		x			x	x		5
199					x			x			2
200	x				x			x	x		4
201			x					x	x		3
	20	20	12	10	21	0	0	21	25	0

Example of a genotyping table. Pool B clones are displayed horizontally and embryo numbers vertically. X indicates that the embryo integrated the corresponding clone. Embryo numbers in bold face indicate LacZ positive animals. Candidate clones were identified by first looking for a repetition of a specific staining pattern among embryos injected with a pool of sequences. Within the subset of embryos that displayed the same pattern, we looked for common integrated clones. These fragments were the candidate enhancers to be injected individually for confirmation.