Electronic supplementary material (table S1 and figures S1-S7)

Table S1. Primers for making ISH probes.

Gene name Forward primer (5' → 3') Reverse primer (5' → 3') Product length (bp)

Bat_Hoxd9 TACGAGGTGGCAAGGATT TTCCAGGTCTCAGTCAAGG 629

Bat_Hoxd10 AGTAGATGTCGCTGTTGTCCGC AAGGGACCTCGGCAGAAATG 602

Bat_Hoxd11 TTCTTCCCACGGTCAACT GCAGCACCAGGATCACAT 607

Bat_Hoxd12 TTTCGTCCAATCGTCTGA CCTTGGAGTCGTCCTTGA 587

Bat_Hoxd13 ACATGGTGTCCACCTTCG AAAGTCAGGTTGGGTAGCA 590

Bat_Tbx3 TCCTCAACCTGAACACCAT AGATCCCGGATACAGAAACC 543

Bat_Fam5c GCGGAACCTGGGCTACAT AAGCATTGCCACGGAACA 630

Mouse_Hoxd9 GCCAGGATTCTGAACCTTACA GAGGCTGGATAGGGTGAGAC 511

Mouse_Hoxd10 CCGAGTCTTGTCCTGTTG GGTTTGTTTCCGCCTTGC 705

Mouse_Hoxd11 CTCGGATGCTCAACCTCAC ACAGTGACTCATGCCCAAAG 556

Mouse_Hoxd12 TGAGCCCGTCCTCCTATT CCACTTGCACTGCCATGTTC 599

Mouse_Hoxd13 CACTTCGGCAACGGTTACTA CCTTCACCCTTCGATTCTG 607

Mouse_Tbx3 GAAGTCAGGAAGGCGAATG TGGGCAAAGCAGTTGAAGG 609

Mouse_Fam5c CTGGGAAACAAATGGAAGA CAAGATTTTGGGTTGTGCT 493

Figure S1. Alcian blue staining of bat and mouse autopods. Orientation of limbs as in figure 1. F:

forelimb; H: hindlimb; S16E: early stage 16; S17M: middle stage 17; S19L: late stage 19. Scale

bars, 500 μm.

Figure S2. Hoxd10 expression in the fore- (F) and hindlimbs (H) of embryonic bats and mice

visualized by ISH. Orientation of limbs as in figure 1. Scale bars, 200 μm in (A-L) and 500 μm in

(M-X).

Figure S3. Hoxd11 expression in the fore- (F) and hindlimbs (H) of embryonic bats and mice

visualized by ISH. Orientation of limbs as in figure 1. Scale bars, 200 μm in (A-L) and 500 μm in

(M-X).

Figure S4. Hoxd12 expression in the fore- (F) and hindlimbs (H) of embryonic bats and mice

visualized by ISH. Orientation of limbs as in figure 1. Scale bars, 200 μm in (A-L) and 500 μm in

(M-X).

Figure S5. Hoxd13 expression in the fore- (F) and hindlimbs (H) of embryonic bats and mice

visualized by ISH. Orientation of limbs as in figure 1. Scale bars, 500 μm.

Figure S6. Tbx3 expression in the fore- (F) and hindlimbs (H) of embryonic bats and mice

visualized by ISH. Orientation of limbs as in figure 1. Scale bars, 200 μm in (A-L) and 500 μm in

(M-X).

Figure S7. Fam5c expression in the fore- (F) and hindlimbs (H) of embryonic bats visualized by

ISH. Orientation of limbs as in figure 1. Scale bars, 200 μm in (A-H) and 500 μm in (I-P).