Table I.

List of sperm proteins with a putative epididymis-derived origin in both human and mouse species.

Human sperm proteins with putative extra-testicular acquisition (from Castillo et al., 2018)			Mouse proteomics data
Predicted organ of origin	Accession number	Gene name	Testis	Epididymal sperm	Epididymis	Epididymosomes
Epididymis	Q9UKQ2	ADAM28	–	×	×	×
Epididymis	Q9H2U9	ADAM7	–	×	×	×
Epididymis	Q8IUA0	WFDC8	–	×	×	–
Epididymis	Q5GAN3	RNASE13	–	×	×	–
Epididymis	P30613	PKLR	–	×	–	×
Epididymis	P56851	EDDM3B	–	×	–	–
Epididymis	Q7RTZ1	OVCH2	–	×	–	–
Epididymis	Q08648	SPAG11B	–	×	–	–
Epididymis	Q075Z2	BSPH1	–	×	–	–
Epididymis	Q3B820	FAM161A	–	×	–	–
Epididymis/seminal vesicles	O14975	SLC27A2	–	×	×	–
Epididymis/seminal vesicles	P22748	CA4	–	×	–	×
Epididymis/seminal vesicles/prostate	P05787	KRT8	–	×	×	×
Epididymis/seminal vesicles/prostate	P05783	KRT18	–	×	×	×
Epididymis/seminal vesicles/ prostate	P08727	KRT19	–	×	×	×
Epididymis/seminal vesicles/prostate	P12830	CDH1	–	×	×	×
Epididymis/seminal vesicles/prostate	P09668	CTSH	–	×	×	–
Epididymis/seminal vesicles/prostate	E7ET76	GGT1	–	×	×	×
Epididymis/seminal vesicles/prostate	Q8IW92	GLB1L2	–	×	×	–
Epididymis/seminal vesicles/prostate	P02788	LTF	–	×	–	×
Epididymis/seminal vesicles/prostate	O95994	AGR2	–	×	×	–
Epididymis/seminal vesicles/prostate	O14493	CLDN4	–	×	–	–
Epididymis/seminal vesicles/prostate	Q96BQ1	FAM3D	–	×	–	–
Epididymis/seminal vesicles/prostate	Q9Y584	TIMM22	–	×	–	–
Epididymis/seminal vesicles/prostate	P06280	GLA	–	×	–	–

The subset of human sperm proteins with a predicted acquisition after testicular maturation published by Castillo et al. (2018) was complemented by integrating published mouse proteomic datasets (see an extended version in Supplementary Table SI). Proteins whose epididymis-derived origin has been experimentally validated in this study are indicated in bold.

×, Protein detection, –, Protein absence.