Antibody:	anti-neuregulin beta (sc-1793)
Detection system:	Biotinylated secondary antibody/[Strept]avidin coupled to horseradish peroxidase
Assay notes:	Embryos were fixed in 70% ethanol/ 1% acetic acid.

Structure	Level	Pattern	Image	Note
TS19: gonad	Weak	Single cells	4a	There is faint staining in a few cells.

Structure	Level	Pattern	Image	Note
TS20: testis	Present	Single cells	4b	Expression is in the somatic cells of the testicular tubules.

Structure	Level	Pattern	Image	Note
TS20: ovary	Weak	Single cells	4f	There is weak staining in a portion of the somatic cells.

Structure	Level	Pattern	Image	Note
TS21: male reproductive system	Present	Single cells	4c	The number of positive cells is greater than at 12.5 dpc.

Structure	Level	Pattern	Image	Note
TS21: male reproductive system	Present	Single cells	4d	The number of positive cells is less than it was at 13.0 dpc.

Structure	Level	Pattern	Image	Note
TS21: female reproductive system	Present	Single cells	4g	There is weak expression in a portion of the cells in the somatic gonad.

Structure	Level	Pattern	Image	Note
TS22: male reproductive system	Weak	Single cells	4e	A few cells show weak staining.

Structure	Level	Pattern	Image	Note
TS22: female reproductive system	Absent		4h	No significant signal is seen in the genital ridge.