Lack of acrosome formation in Hrb-deficient mice.
The sperm acrosome is essential for sperm-egg fusion and is often defective in men with nonobstructive infertility. Here we report that male mice with a null mutation in Hrb are infertile and display round-headed spermatozoa that lack an acrosome. In wild-type spermatids, Hrb is associated with the cytosolic surface of proacrosomic transport vesicles that fuse to create a single large acrosomic vesicle at step 3 of spermiogenesis. Although proacrosomic vesicles form in spermatids that lack Hrb, the vesicles are unable to fuse, blocking acrosome development at step 2. We conclude that Hrb is required for docking and/or fusion of proacrosomic vesicles during acrosome biogenesis.
Kang-Decker
N
N
Department of Pediatrics and Adolescent Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
Mantchev
G T
GT
Juneja
S C
SC
McNiven
M A
MA
van Deursen
J M
JM
D000177:Acrosome / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure*; D033965:Adaptor Protein Complex alpha Subunits; D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000378:metabolism; D002352:Carrier Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro; D018390:Gene Targeting; D006056:Golgi Apparatus / Q000737:chemistry; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D016253:Microscopy, Immunoelectron; D009154:Mutation; D028861:Nuclear Pore Complex Proteins / Q000032:analysis / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D010750:Phosphoproteins / Q000032:analysis / Q000378:metabolism; D016601:RNA-Binding Proteins; D013076:Sperm Count; D013081:Sperm Motility; D013084:Sperm-Ovum Interactions; D013087:Spermatids / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure; D013091:Spermatogenesis; D013094:Spermatozoa / Q000502:physiology / Q000648:ultrastructure; D022161:Transport Vesicles / Q000737:chemistry / Q000502:physiology*
C119724:AGFG1 protein, human; D033965:Adaptor Protein Complex alpha Subunits; D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; C440904:Agfg1 protein, mouse; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; C082729:Eps15 protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D028861:Nuclear Pore Complex Proteins; D010750:Phosphoproteins; D016601:RNA-Binding Proteins