Mouse Sperm Lacking ADAM1b/ADAM2 Fertilin Can Fuse with the Egg Plasma Membrane and Effect Fertilization

Abstract

Fertilin, a heterodimeric protein complex composed of α (ADAM1) and β (ADAM2) subunits on the sperm surface, is believed to mediate adhesion and fusion between the sperm and egg plasma membranes. Here we have shown that mutant male mice lacking ADAM1b are fertile and that the loss of ADAM1b results in no significant defect in sperm functions such as migration from the uterus into oviduct, binding to egg zona pellucida, and fusion with zona pellucida-free eggs. ADAM1b-deficient epididymal sperm showed a severe reduction of ADAM2 on the cell surface, despite the normal presence of ADAM2 in testicular germ cells. The appearance of ADAM1b and ADAM2 on the sperm surface depended on formation and abundance of ADAM1b/ADAM2 fertilin in testicular germ cells. These results suggest that mouse ADAM1b/ADAM2 fertilin may play a crucial role not in the sperm/egg fusion but in the appearance of these two ADAMs on the sperm surface. Fertilin, a heterodimeric protein complex composed of α (ADAM1) and β (ADAM2) subunits on the sperm surface, is believed to mediate adhesion and fusion between the sperm and egg plasma membranes. Here we have shown that mutant male mice lacking ADAM1b are fertile and that the loss of ADAM1b results in no significant defect in sperm functions such as migration from the uterus into oviduct, binding to egg zona pellucida, and fusion with zona pellucida-free eggs. ADAM1b-deficient epididymal sperm showed a severe reduction of ADAM2 on the cell surface, despite the normal presence of ADAM2 in testicular germ cells. The appearance of ADAM1b and ADAM2 on the sperm surface depended on formation and abundance of ADAM1b/ADAM2 fertilin in testicular germ cells. These results suggest that mouse ADAM1b/ADAM2 fertilin may play a crucial role not in the sperm/egg fusion but in the appearance of these two ADAMs on the sperm surface. Members of the ADAM (adisintegrin and metalloprotease) 3The abbreviations used are: ADAM, a disintegrin and metalloprotease; ZP, zona pellucida; ER, endoplasmic reticulum; TGC, testicular germ cells. 3The abbreviations used are: ADAM, a disintegrin and metalloprotease; ZP, zona pellucida; ER, endoplasmic reticulum; TGC, testicular germ cells. family are multifunctional, transmembranous proteins consisting of pro-, metalloprotease, disintegrin, cysteine-rich, epidermal growth factor-like, transmembrane, and cytoplasmic tail domains (1Schlöndorff J. Blobel C.P. J. Cell Sci. 1999; 112: 3603-3617Crossref The ADAM proteins are in the of cell and of growth and in the such as and ADAM have in a of the of ADAMs have are of the ADAM family that are in the but are sperm to to and the zona the and to with the egg The of 1999; Fertilin, a heterodimeric protein complex composed of α (ADAM1) and β (ADAM2) subunits on the sperm surface, believed to mediate adhesion and fusion between the sperm and egg plasma the and disintegrin domains of and ADAM2 the that the of fusion proteins and the binding of J. J. Cell C.P. C.P. two of and are in the and ADAM1b is on the plasma of epididymal sperm The of J. a protein the endoplasmic of testicular germ ADAM2 and as 1999; have of mutant The loss of ADAM2 in male sperm of mice of from the uterus into the the and of binding to the egg J. The of these mutant sperm to the may a of on the sperm surface J. male mice and the mutant sperm showed the defect in the binding 1999; the loss of ADAM2 in in the of ADAM1b and in to on the sperm surface mouse sperm in adhesion to and fusion with the egg the of and ADAM1b/ADAM2 fertilin complex in are we have mice a in the male mice lacking ADAM1b are and ADAM1b-deficient epididymal sperm are normal in the migration into the oviduct, binding to the ZP, and fusion with the the normal presence of ADAM2 in TGC, ADAM2 proteins is on epididymal sperm of the ADAM1b-deficient the of the results on of mutant mice lacking we in the fertilin is the appearance of on the sperm surface, ADAM1b/ADAM2 fertilin is the appearance of ADAM1b and ADAM2 on the sperm of of the and of a mouse ADAM1b the the of the The with and into mouse and and as J. cell the from to and and into mouse male mice to mice to mutant mice of and to the the and of the of from mouse and from testicular as J. The and the membranes. The and a as J. ADAM1b J. and J. as ADAM2 and mouse from and J. and from from to mice with a in and a and as The cell in the and the on a in the and from a the of the and with and epididymal sperm in a consisting of and on and as in the in the presence of and and with the with and with proteins and the of the protein a a protein to the J. into mice with male mice of and formation of as J. The with a of the uterus in with and in with and with with from the of mice to and in a of a J. with epididymal sperm from mice in a of in of the sperm with the in a of in the with testicular to cells. The and male in the in with and as J. with and in a of with of sperm to a and in and the in The to of and in The of sperm to the egg with a as J. The used as and the of the a the of as The with with sperm in in the the the role of ADAM1b in we mutant mice lacking ADAM1b in cells. The to the the pro-, metalloprotease, disintegrin, and domains of ADAM1b with The of and mice the of of the of ADAM1b in protein of a protein to the of These the of ADAM1b in the of male and mice the of mice from and normal in and no significant in the and of and epididymal sperm and The of epididymal sperm normal in male mice normal and and in and we that ADAM1b is not in the the of mouse sperm with in epididymal the not and normal in mouse sperm significant in the sperm binding to in the fusion of sperm with between and mice and of of the the of mouse sperm to from the uterus into the the loss of ADAM1b no significant defect in sperm migration of ADAM1b-deficient mouse sperm from uterus into with and a sperm in the and the loss of ADAM1b formation of fertilin in and appearance of ADAM proteins on the sperm surface, we of and epididymal sperm proteins mice ADAM1b in TGC, the of ADAM1b in mice of that in mice and proteins in the are in of the protein in formation of heterodimeric protein between the of ADAM1b and ADAM2 fertilin and ADAM1b/ADAM2 fertilin and ADAM2 the loss of and ADAM1b/ADAM2 in and TGC, of proteins in ADAM1b-deficient from and epididymal sperm of and mice with and and to proteins a of of proteins in and TGC, formation of and ADAM1b/ADAM2 fertilin in and and ADAM1b/ADAM2 proteins from and mice with and ADAM2 and to of sperm ADAM1b and ADAM2 not in the sperm of mice the and proteins in and mouse that the protein to the and of in the sperm of and the of ADAM2 in between and mice epididymal sperm of mice showed the loss of ADAM2 as as of ADAM1b the loss of ADAM2 on mouse we of sperm from and mice two the not with the of ADAM2 in the sperm the protein in the but the and sperm a of the ADAM2 the and of ADAM2 are on mouse The cytoplasmic tail of ADAM2 on mouse sperm may a the is not The of the of ADAM2 on mouse sperm of that on mouse sperm mouse sperm a of protein from a mouse and ADAM1b-deficient mice and and to and the of ADAM2 The of protein to the of ADAM2 shown in of ADAM1b and ADAM2 on mouse sperm to a despite the normal of ADAM2 in of that in a of and on mouse sperm of the on mouse These suggest that the appearance of ADAM1b and ADAM2 on the sperm surface may on the formation and abundance of ADAM1b/ADAM2 fertilin in of ADAM1b and ADAM2 on the surface of and mouse of sperm proteins and and The of protein of ADAM1b and ADAM2 on mouse sperm to and of on mouse The of and on mouse sperm to on and mouse are as the sperm from of and not that ADAM1b and ADAM1b/ADAM2 fertilin are not the of sperm migration into the oviduct, and fusion between the sperm and egg have the of ADAM1b/ADAM2 fertilin formation in the appearance of these two ADAMs on the sperm surface and the between the abundance of ADAM proteins and sperm in mouse lacking on mouse sperm the that is crucial in the sperm binding to egg 1999; between the abundance of ADAM proteins and sperm functions in mouse lacking mutant formation in from and of sperm of and ADAM1b-deficient mice from and of and mice from The of protein on sperm is as of and mice from and from J. and of and ADAM1b-deficient mice from and of and mice from The of protein on sperm is as of and mice from J. and 1999; in a have that the loss of results in the of fertilin in and on epididymal despite the normal presence of ADAM1b/ADAM2 fertilin and in J. The of ADAM1b and ADAM2 on the sperm surface are normal in mice J. the mice ADAM1b/ADAM2 fertilin in and a of ADAM2 on epididymal the is normal on mouse sperm and the formation of the and ADAM1b/ADAM2 in is the appearance of and ADAM1b and ADAM2 on the sperm surface, is with the that the loss and ADAM1b/ADAM2 in to the of ADAM1b and in to on the sperm surface J. The of the sperm surface in and of ADAM1b and ADAM2 in may in is that mouse sperm are to mouse mouse sperm no defect and the mouse sperm the as mouse sperm a of sperm/egg fusion in mouse sperm of the and of ADAM2 are on mouse sperm and are that may the presence of ADAM2 on the surface of mouse ADAM2 is the sperm surface a protein complex with a of ADAM1b ADAM2 of sperm the of the and of ADAM1b testicular of mice on and the and not and the to the cysteine-rich, epidermal growth and cytoplasmic tail domains of ADAM1b is that ADAM2 in may of on the sperm surface the complex formation with ADAM2 on mouse sperm may the loss of ADAM1b and ADAM1b/ADAM2 mouse sperm are normal and but the mice lacking the with and the of sperm in binding egg and in from the uterus into is between and ADAM2 between ADAM1b and ADAM2 in The defect of mouse sperm in the binding may the of on the sperm surface of a of fertilin in mouse on the cell surface. the of the the sperm surface fertilin to that the loss of in mice may in from a of protein the of and on the sperm surface is and mouse sperm may not from the uterus into The mouse sperm into the 1999; is ADAM1b ADAM2 ADAM1b/ADAM2 fertilin functions in the sperm mouse sperm are of into the despite the loss severe reduction of these two ADAM proteins mutant sperm lacking are of a in sperm migration into the fertilin fertilin in on the sperm surface as a protein complex the fusion between sperm and egg plasma J. J. Cell C.P. the role of complex not to have shown that in the sperm fertilin no crucial role in of the egg as ADAM to sperm/egg binding and fusion fertilin is protein complex is in the appearance of on the sperm surface that functions in sperm/egg binding J. 1999; of ADAM1b/ADAM2 fertilin to the mouse sperm fertilin is a protein complex to sperm the of to that the of is on epididymal sperm of mice J. the in the is ADAM1b/ADAM2 fertilin may the appearance of on the sperm surface. Members of the ADAM (adisintegrin and metalloprotease) 3The abbreviations used are: ADAM, a disintegrin and metalloprotease; ZP, zona pellucida; ER, endoplasmic reticulum; TGC, testicular germ cells. 3The abbreviations used are: ADAM, a disintegrin and metalloprotease; ZP, zona pellucida; ER, endoplasmic reticulum; TGC, testicular germ cells. family are multifunctional, transmembranous proteins consisting of pro-, metalloprotease, disintegrin, cysteine-rich, epidermal growth factor-like, transmembrane, and cytoplasmic tail domains (1Schlöndorff J. Blobel C.P. J. Cell Sci. 1999; 112: 3603-3617Crossref The ADAM proteins are in the of cell and of growth and in the such as and ADAM have in a of the of ADAMs have are of the ADAM family that are in the but are sperm to to and the zona the and to with the egg The of 1999; Fertilin, a heterodimeric protein complex composed of α (ADAM1) and β (ADAM2) subunits on the sperm surface, believed to mediate adhesion and fusion between the sperm and egg plasma the and disintegrin domains of and ADAM2 the that the of fusion proteins and the binding of J. J. Cell C.P. C.P. two of and are in the and ADAM1b is on the plasma of epididymal sperm The of J. a protein the endoplasmic of testicular germ ADAM2 and as 1999; have of mutant The loss of ADAM2 in male sperm of mice of from the uterus into the the and of binding to the egg J. The of these mutant sperm to the may a of on the sperm surface J. male mice and the mutant sperm showed the defect in the binding 1999; the loss of ADAM2 in in the of ADAM1b and in to on the sperm surface mouse sperm in adhesion to and fusion with the egg the of and ADAM1b/ADAM2 fertilin complex in are we have mice a in the male mice lacking ADAM1b are and ADAM1b-deficient epididymal sperm are normal in the migration into the oviduct, binding to the ZP, and fusion with the the normal presence of ADAM2 in TGC, ADAM2 proteins is on epididymal sperm of the ADAM1b-deficient the of the results on of mutant mice lacking we in the fertilin is the appearance of on the sperm surface, ADAM1b/ADAM2 fertilin is the appearance of ADAM1b and ADAM2 on the sperm surface. of of the and of a mouse ADAM1b the the of the The with and into mouse and and as J. cell the from to and and into mouse male mice to mice to mutant mice of and to the the and of the of from mouse and from testicular as J. The and the membranes. The and a as J. ADAM1b J. and J. as ADAM2 and mouse from and J. and from from to mice with a in and a and as The cell in the and the on a in the and from a the of the and with and epididymal sperm in a consisting of and on and as in the in the presence of and and with the with and with proteins and the of the protein a a protein to the J. into mice with male mice of and formation of as J. The with a of the uterus in with and in with and with with from the of mice to and in a of a J. with epididymal sperm from mice in a of in of the sperm with the in a of in the with testicular to cells. The and male in the in with and as J. with and in a of with of sperm to a and in and the in The to of and in The of sperm to the egg with a as J. The used as and the of the a the of as The with with sperm in in the the of of the and of a mouse ADAM1b the the of the The with and into mouse and and as J. cell the from to and and into mouse male mice to mice to mutant mice of and to the the and of the of from mouse and from testicular as J. The and the membranes. The and a as J. ADAM1b J. and J. as ADAM2 and mouse from and J. and from from to mice with a in and a and as The cell in the and the on a in the and from a the of the and with and epididymal sperm in a consisting of and on and as in the in the presence of and and with the with and with proteins and the of the protein a a protein to the J. into mice with male mice of and formation of as J. The with a of the uterus in with and in with and with with from the of mice to and in a of a J. with epididymal sperm from mice in a of in of the sperm with the in a of in the with testicular to cells. The and male in the in with and as J. with and in a of with of sperm to a and in and the in The to of and in The of sperm to the egg with a as J. The used as and the of the a the of as The with with sperm in in the the the role of ADAM1b in we mutant mice lacking ADAM1b in cells. The to the the pro-, metalloprotease, disintegrin, and domains of ADAM1b with The of and mice the of of the of ADAM1b in protein of a protein to the of These the of ADAM1b in the of male and mice the of mice from and normal in and no significant in the and of and epididymal sperm and The of epididymal sperm normal in male mice normal and and in and we that ADAM1b is not in the the of mouse sperm with in epididymal the not and normal in mouse sperm significant in the sperm binding to in the fusion of sperm with between and mice and of of the the of mouse sperm to from the uterus into the the loss of ADAM1b no significant defect in sperm the loss of ADAM1b formation of fertilin in and appearance of ADAM proteins on the sperm surface, we of and epididymal sperm proteins mice ADAM1b in TGC, the of ADAM1b in mice of that in mice and proteins in the are in of the protein in formation of heterodimeric protein between the of ADAM1b and ADAM2 fertilin and ADAM1b/ADAM2 fertilin and ADAM2 the loss of and ADAM1b/ADAM2 in and TGC, of proteins in ADAM1b-deficient from and epididymal sperm of and mice with and and to proteins a of of proteins in and TGC, formation of and ADAM1b/ADAM2 fertilin in and and ADAM1b/ADAM2 proteins from and mice with and ADAM2 and to of sperm ADAM1b and ADAM2 not in the sperm of mice the and proteins in and mouse that the protein to the and of in the sperm of and the of ADAM2 in between and mice epididymal sperm of mice showed the loss of ADAM2 as as of ADAM1b the loss of ADAM2 on mouse we of sperm from and mice two the not with the of ADAM2 in the sperm the protein in the but the and sperm a of the ADAM2 the and of ADAM2 are on mouse The cytoplasmic tail of ADAM2 on mouse sperm may a the is not The of the of ADAM2 on mouse sperm of that on mouse sperm mouse sperm a of protein from a mouse and ADAM1b-deficient mice and and to and the of ADAM2 The of protein to the of ADAM2 shown in of ADAM1b and ADAM2 on mouse sperm to a despite the normal of ADAM2 in of that in a of and on mouse sperm of the on mouse These suggest that the appearance of ADAM1b and ADAM2 on the sperm surface may on the formation and abundance of ADAM1b/ADAM2 fertilin in of ADAM1b and ADAM2 on the surface of and mouse of sperm proteins and and The of protein of ADAM1b and ADAM2 on mouse sperm to and of on mouse The of and on mouse sperm to on and mouse are as the sperm from of and not the role of ADAM1b in we mutant mice lacking ADAM1b in cells. The to the the pro-, metalloprotease, disintegrin, and domains of ADAM1b with The of and mice the of of the of ADAM1b in protein of a protein to the of These the of ADAM1b in the of male and mice the of mice from and normal in and no significant in the and of and epididymal sperm and The of epididymal sperm normal in male mice normal and and in and we that ADAM1b is not in the the of mouse sperm with in epididymal the not and normal in mouse sperm significant in the sperm binding to in the fusion of sperm with between and mice and of of the the of mouse sperm to from the uterus into the the loss of ADAM1b no significant defect in sperm the loss of ADAM1b formation of fertilin in and appearance of ADAM proteins on the sperm surface, we of and epididymal sperm proteins mice ADAM1b in TGC, the of ADAM1b in mice of that in mice and proteins in the are in of the protein in formation of heterodimeric protein between the of ADAM1b and ADAM2 fertilin and ADAM1b/ADAM2 fertilin and ADAM2 the loss of and ADAM1b/ADAM2 in and TGC, the of ADAM2 in between and mice epididymal sperm of mice showed the loss of ADAM2 as as of ADAM1b the loss of ADAM2 on mouse we of sperm from and mice two the not with the of ADAM2 in the sperm the protein in the but the and sperm a of the ADAM2 the and of ADAM2 are on mouse The cytoplasmic tail of ADAM2 on mouse sperm may a the is not The of the of ADAM2 on mouse sperm of that on mouse sperm shown in of ADAM1b and ADAM2 on mouse sperm to a despite the normal of ADAM2 in of that in a of and on mouse sperm of the on mouse These suggest that the appearance of ADAM1b and ADAM2 on the sperm surface may on the formation and abundance of ADAM1b/ADAM2 fertilin in that ADAM1b and ADAM1b/ADAM2 fertilin are not the of sperm migration into the oviduct, and fusion between the sperm and egg have the of ADAM1b/ADAM2 fertilin formation in the appearance of these two ADAMs on the sperm surface and the between the abundance of ADAM proteins and sperm in mouse lacking on mouse sperm the that is crucial in the sperm binding to egg 1999; between the abundance of ADAM proteins and sperm functions in mouse lacking mutant formation in from and of sperm of and ADAM1b-deficient mice from and of and mice from The of protein on sperm is as of and mice from and from J. and of and ADAM1b-deficient mice from and of and mice from The of protein on sperm is as of and mice from J. and 1999; in a have that the loss of results in the of fertilin in and on epididymal despite the normal presence of ADAM1b/ADAM2 fertilin and in J. The of ADAM1b and ADAM2 on the sperm surface are normal in mice J. the mice ADAM1b/ADAM2 fertilin in and a of ADAM2 on epididymal the is normal on mouse sperm and the formation of the and ADAM1b/ADAM2 in is the appearance of and ADAM1b and ADAM2 on the sperm surface, is with the that the loss and ADAM1b/ADAM2 in to the of ADAM1b and in to on the sperm surface J. The of the sperm surface in and of ADAM1b and ADAM2 in may in is that mouse sperm are to mouse mouse sperm no defect and the mouse sperm the as mouse sperm a of sperm/egg fusion in mouse sperm of the and of ADAM2 are on mouse sperm and are that may the presence of ADAM2 on the surface of mouse ADAM2 is the sperm surface a protein complex with a of ADAM1b ADAM2 of sperm the of the and of ADAM1b testicular of mice on and the and not and the to the cysteine-rich, epidermal growth and cytoplasmic tail domains of ADAM1b is that ADAM2 in may of on the sperm surface the complex formation with ADAM2 on mouse sperm may the loss of ADAM1b and ADAM1b/ADAM2 mouse sperm are normal and but the mice lacking the with and the of sperm in binding egg and in from the uterus into is between and ADAM2 between ADAM1b and ADAM2 in The defect of mouse sperm in the binding may the of on the sperm surface of a of fertilin in mouse on the cell surface. the of the the sperm surface fertilin to that the loss of in mice may in from a of protein the of and on the sperm surface is and mouse sperm may not from the uterus into The mouse sperm into the 1999; is ADAM1b ADAM2 ADAM1b/ADAM2 fertilin functions in the sperm mouse sperm are of into the despite the loss severe reduction of these two ADAM proteins mutant sperm lacking are of a in sperm migration into the fertilin fertilin in on the sperm surface as a protein complex the fusion between sperm and egg plasma J. J. Cell C.P. the role of complex not to have shown that in the sperm fertilin no crucial role in of the egg as ADAM to sperm/egg binding and fusion fertilin is protein complex is in the appearance of on the sperm surface that functions in sperm/egg binding J. 1999; of ADAM1b/ADAM2 fertilin to the mouse sperm fertilin is a protein complex to sperm the of to that the of is on epididymal sperm of mice J. the in the is ADAM1b/ADAM2 fertilin may the appearance of on the sperm surface. that ADAM1b and ADAM1b/ADAM2 fertilin are not the of sperm migration into the oviduct, and fusion between the sperm and egg have the of ADAM1b/ADAM2 fertilin formation in the appearance of these two ADAMs on the sperm surface and the between the abundance of ADAM proteins and sperm in mouse lacking on mouse sperm the that is crucial in the sperm binding to egg 1999; have that the loss of results in the of fertilin in and on epididymal despite the normal presence of ADAM1b/ADAM2 fertilin and in J. The of ADAM1b and ADAM2 on the sperm surface are normal in mice J. the mice ADAM1b/ADAM2 fertilin in and a of ADAM2 on epididymal the is normal on mouse sperm and the formation of the and ADAM1b/ADAM2 in is the appearance of and ADAM1b and ADAM2 on the sperm surface, is with the that the loss and ADAM1b/ADAM2 in to the of ADAM1b and in to on the sperm surface J. The of the sperm surface in and of ADAM1b and ADAM2 in may in is that mouse sperm are to mouse mouse sperm no defect and the mouse sperm the as mouse sperm a of sperm/egg fusion in mouse sperm of the and of ADAM2 are on mouse sperm and are that may the presence of ADAM2 on the surface of mouse ADAM2 is the sperm surface a protein complex with a of ADAM1b ADAM2 of sperm the of the and of ADAM1b testicular of mice on and the and not and the to the cysteine-rich, epidermal growth and cytoplasmic tail domains of ADAM1b is that ADAM2 in may of on the sperm surface the complex formation with ADAM2 on mouse sperm may the loss of ADAM1b and ADAM1b/ADAM2 mouse sperm are normal and but the mice lacking the with and the of sperm in binding egg and in from the uterus into is between and ADAM2 between ADAM1b and ADAM2 in The defect of mouse sperm in the binding may the of on the sperm surface of a of fertilin in mouse on the cell surface. the of the the sperm surface fertilin to that the loss of in mice may in from a of protein the of and on the sperm surface is and mouse sperm may not from the uterus into The mouse sperm into the 1999; is ADAM1b ADAM2 ADAM1b/ADAM2 fertilin functions in the sperm mouse sperm are of into the despite the loss severe reduction of these two ADAM proteins mutant sperm lacking are of a in sperm migration into the fertilin fertilin in on the sperm surface as a protein complex the fusion between sperm and egg plasma J. J. Cell C.P. the role of complex not to have shown that in the sperm fertilin no crucial role in of the egg as ADAM to sperm/egg binding and fusion fertilin is protein complex is in the appearance of on the sperm surface that functions in sperm/egg binding J. 1999; of ADAM1b/ADAM2 fertilin to the mouse sperm fertilin is a protein complex to sperm the of to that the of is on epididymal sperm of mice J. the in the is ADAM1b/ADAM2 fertilin may the appearance of on the sperm surface. and and and and of and the of a