Sperm MMP‐2 is indispensable for fast electrical block to polyspermy at fertilization in Xenopus tropicalis

Abstract

Sperm matrix metalloproteinase-2 (MMP-2) is necessary for frog fertilization.Monospermy is ensured by a fast, electrical block to polyspermy mediated by a positive fertilization potential. To determine the role of the MMP-2 hemopexin domain (HPX) in a fast block to polyspermy during fertilization of the frog, Xenopus tropicalis, we prepared mutant frogs deficient in mmp2 gene using the transcription activator-like effector nuclease method. mmp2 ΔHPX (−/−) sperm without MMP-2 protein were able to fertilize wild-type (WT; +/+) eggs. However, polyspermy occurred in some eggs. The mutant sperm generated a normal fertilization potential amounting to 10 mV, and were able to fertilize eggs at 10 mV, at which WT sperm never fertilized. Sensitivity during voltage-dependent fertilization decreased in mutant sperm. This study demonstrates for the first time that the genetic alteration of the MMP-2 molecule in sperm causes polyspermy during fertilization of a monospermic species. Our findings provide reliable evidence that sperm MMP-2 is indispensable for the fast, electrical block to polyspermy during Xenopus fertilization.

Involvement of Matrix Metalloproteinases in COVID-19: Molecular Targets, Mechanisms, and Insights for Therapeutic Interventions

“…MMPs are implicated in many biological processes, including embryonic development, cell proliferation, migration, and differentiation, angiogenesis, remodeling of ECM, tissue invasion and vascularization, and apoptosis [ 16 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ]. The imbalance between metalloproteinases and their inhibitors leads to the progression of inflammatory and autoimmune diseases.…”