TY - JOUR
T1 - Seipin deficiency increases chromocenter fragmentation and disrupts acrosome formation leading to male infertility
AU - El Zowalaty, A. E.
AU - Baumann, C.
AU - Li, R.
AU - Chen, W.
AU - De La Fuente, R.
AU - Ye, X.
N1 - Funding Information:
Acknowledgements. We thank the Department of Pathology in the College of Veterinary Medicine, University of Georgia, for access to the imaging system; Dr James N. Moore in the Department of Large Animal Medicine for access to the ABI 7900 Realtime PCR machine; Dr Qien Yang at Northwest Plateau Institute of Biology, The Chinese Academy of Sciences, for insightful suggestions; the Office of the Vice President for Research, Interdisciplinary Toxicology Program, and Department of Physiology and Pharmacology at the University of Georgia, the National Institutes of Health (NIH R15HD066301 and NIH R01HD065939 (co-funded by ORWH and NICHD) to XYand NIH 2R01HD042740 to RDLF); and the Georgia Cancer Coalition (to RDLF) for financial support.
Publisher Copyright:
© 2015 Macmillan Publishers Limited All rights reserved.
PY - 2015/7/1
Y1 - 2015/7/1
N2 - The Berardinelli-Seip congenital lipodystrophy type 2 (Bscl2, seipin) gene is involved in adipogenesis. Bscl2-/- males were infertile but had normal mating behavior. Both Bscl2-/- cauda epididymis sperm count and sperm motility were ∼ 20 × less than control. Bscl2-/- seminiferous tubules had relatively normal presence of spermatogonia and spermatocytes but had reduced spermatids and sperm. Spatiotemporal expression analyses in Bscl2+/+ testes demonstrated prominent Bscl2 transcriptional activity in spermatocytes with a plateau reached around postnatal day 28. Seipin protein localization was most abundant in postmeiotic spermatids, suggesting translational repression of Bscl2 mRNA in spermatocytes. In situ end-labeling plus detected increased spermatid apoptosis in Bscl2-/- testis and annexin V detected increased percentage of positive Bscl2-/- round spermatids compared with control. Immunofluorescence of marker proteins synaptonemal complex proteins 3 and 1 (SYCP3 and SYCP1), and H3K9me3 (histone H3 trimethylated at lysine 9) in germ cell spreads detected normal meiotic chromosome pairing and homologous chromosome synapsis in Bscl2-/- spermatocytes, but significantly increased percentages of round spermatids with chromocenter fragmentation and late spermatids and sperm with chromatin vacuoles, indicating defective chromatin condensation in Bscl2-/- spermatids. Bscl2-/- late spermatids were disorganized within the seminiferous epithelium, despite normal appearance of Sertoli cells detected by vimentin immunofluorescence. Peanut agglutinin staining revealed various abnormalities of acrosomes in Bscl2-/- late spermatids, including the absence, irregular-shaped, and fragmented acrosomes, indicating defective acrosome formation in Bscl2-/- late spermatids, which may affect late spermatid orientation in the seminiferous epithelium. Mitotracker strongly stained the midpiece of control sperm but only very weakly labeled the midpiece of Bscl2-/- sperm, indicating defective mitochondrial activity that most likely contributed to reduced Bscl2-/- sperm motility. These data demonstrate novel roles of seipin in spermatid chromatin integrity, acrosome formation, and mitochondrial activity. Increased spermatid apoptosis, increased chromocenter fragmentation, defective chromatin condensation, abnormal acrosome formation, and defective mitochondrial activity contributed to decreased sperm production and defective sperm that resulted in Bscl2-/- male infertility.
AB - The Berardinelli-Seip congenital lipodystrophy type 2 (Bscl2, seipin) gene is involved in adipogenesis. Bscl2-/- males were infertile but had normal mating behavior. Both Bscl2-/- cauda epididymis sperm count and sperm motility were ∼ 20 × less than control. Bscl2-/- seminiferous tubules had relatively normal presence of spermatogonia and spermatocytes but had reduced spermatids and sperm. Spatiotemporal expression analyses in Bscl2+/+ testes demonstrated prominent Bscl2 transcriptional activity in spermatocytes with a plateau reached around postnatal day 28. Seipin protein localization was most abundant in postmeiotic spermatids, suggesting translational repression of Bscl2 mRNA in spermatocytes. In situ end-labeling plus detected increased spermatid apoptosis in Bscl2-/- testis and annexin V detected increased percentage of positive Bscl2-/- round spermatids compared with control. Immunofluorescence of marker proteins synaptonemal complex proteins 3 and 1 (SYCP3 and SYCP1), and H3K9me3 (histone H3 trimethylated at lysine 9) in germ cell spreads detected normal meiotic chromosome pairing and homologous chromosome synapsis in Bscl2-/- spermatocytes, but significantly increased percentages of round spermatids with chromocenter fragmentation and late spermatids and sperm with chromatin vacuoles, indicating defective chromatin condensation in Bscl2-/- spermatids. Bscl2-/- late spermatids were disorganized within the seminiferous epithelium, despite normal appearance of Sertoli cells detected by vimentin immunofluorescence. Peanut agglutinin staining revealed various abnormalities of acrosomes in Bscl2-/- late spermatids, including the absence, irregular-shaped, and fragmented acrosomes, indicating defective acrosome formation in Bscl2-/- late spermatids, which may affect late spermatid orientation in the seminiferous epithelium. Mitotracker strongly stained the midpiece of control sperm but only very weakly labeled the midpiece of Bscl2-/- sperm, indicating defective mitochondrial activity that most likely contributed to reduced Bscl2-/- sperm motility. These data demonstrate novel roles of seipin in spermatid chromatin integrity, acrosome formation, and mitochondrial activity. Increased spermatid apoptosis, increased chromocenter fragmentation, defective chromatin condensation, abnormal acrosome formation, and defective mitochondrial activity contributed to decreased sperm production and defective sperm that resulted in Bscl2-/- male infertility.
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U2 - 10.1038/cddis.2015.188
DO - 10.1038/cddis.2015.188
M3 - Article
C2 - 26181198
AN - SCOPUS:84949882290
SN - 2041-4889
VL - 6
JO - Cell Death and Disease
JF - Cell Death and Disease
IS - 7
M1 - e1817
ER -
