TY - JOUR
T1 - Adenylate kinase 9 is essential for sperm function and male fertility in mammals
AU - Callaghan, Elena O.
AU - Navarrete-Lopez, Paula
AU - Štiavnická, Miriama
AU - Sánchez, José M.
AU - Maroto, Maria
AU - Pericuesta, Eva
AU - Fernández-González, Raul
AU - Meara, Ciara O.
AU - Eivers, Bernard
AU - Kelleher, Margaret M.
AU - Evans, Ross D.
AU - Mapel, Xena M.
AU - Lloret-Villas, Audald
AU - Pausch, Hubert
AU - Balastegui-Alarcón, Miriam
AU - Avilés, Manuel
AU - Sanchez-Rodriguez, Ana
AU - Roldan, Eduardo R.S.
AU - McDonald, Michael
AU - Kenny, David A.
AU - Fair, Sean
AU - Gutiérrez-Adán, Alfonso
AU - Lonergan, Patrick
N1 - Publisher Copyright:
© 2023 the Author(s). Published by PNAS.
PY - 2023
Y1 - 2023
N2 - Despite passing routine laboratory tests for semen quality, bulls used in artificial insemination exhibit significant variation in fertility. Routine analysis of fertility data identified a dairy bull with extreme subfertility (10% pregnancy rate). To characterize the subfertility phenotype, a range of in vitro, in vivo, and molecular assays were carried out. Sperm from the subfertile bull exhibited reduced motility and severely reduced caffeine-induced hyperactivation compared to controls. Ability to penetrate the zona pellucida, cleavage rate, cleavage kinetics, and blastocyst yield after IVF or AI were significantly lower than in control bulls. Whole-genome sequencing from semen and RNA sequencing of testis tissue revealed a critical mutation in adenylate kinase 9 (AK9) that impaired splicing, leading to a premature termination codon and a severely truncated protein. Mice deficient in AK9 were generated to further investigate the function of the gene; knockout males were phenotypically indistinguishable from their wild-type littermates but produced immotile sperm that were incapable of normal fertilization. These sperm exhibited numerous abnormalities, including a low ATP concentration and reduced motility. RNA-seq analysis of their testis revealed differential gene expression of components of the axoneme and sperm flagellum as well as steroid metabolic processes. Sperm ultrastructural analysis showed a high percentage of sperm with abnormal flagella. Combined bovine and murine data indicate the essential metabolic role of AK9 in sperm motility and/or hyperactivation, which in turn affects sperm binding and penetration of the zona pellucida. Thus, AK9 has been found to be directly implicated in impaired male fertility in mammals.
AB - Despite passing routine laboratory tests for semen quality, bulls used in artificial insemination exhibit significant variation in fertility. Routine analysis of fertility data identified a dairy bull with extreme subfertility (10% pregnancy rate). To characterize the subfertility phenotype, a range of in vitro, in vivo, and molecular assays were carried out. Sperm from the subfertile bull exhibited reduced motility and severely reduced caffeine-induced hyperactivation compared to controls. Ability to penetrate the zona pellucida, cleavage rate, cleavage kinetics, and blastocyst yield after IVF or AI were significantly lower than in control bulls. Whole-genome sequencing from semen and RNA sequencing of testis tissue revealed a critical mutation in adenylate kinase 9 (AK9) that impaired splicing, leading to a premature termination codon and a severely truncated protein. Mice deficient in AK9 were generated to further investigate the function of the gene; knockout males were phenotypically indistinguishable from their wild-type littermates but produced immotile sperm that were incapable of normal fertilization. These sperm exhibited numerous abnormalities, including a low ATP concentration and reduced motility. RNA-seq analysis of their testis revealed differential gene expression of components of the axoneme and sperm flagellum as well as steroid metabolic processes. Sperm ultrastructural analysis showed a high percentage of sperm with abnormal flagella. Combined bovine and murine data indicate the essential metabolic role of AK9 in sperm motility and/or hyperactivation, which in turn affects sperm binding and penetration of the zona pellucida. Thus, AK9 has been found to be directly implicated in impaired male fertility in mammals.
KW - bovine
KW - mutation
KW - sperm
UR - http://www.scopus.com/inward/record.url?scp=85174740796&partnerID=8YFLogxK
U2 - 10.1073/pnas.2305712120
DO - 10.1073/pnas.2305712120
M3 - Article
C2 - 37812723
AN - SCOPUS:85174740796
SN - 0027-8424
VL - 120
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 42
M1 - e2305712120
ER -