scholarly journals Decision letter: TMEM95 is a sperm membrane protein essential for mammalian fertilization

2020 ◽  
Author(s):  
Polina V Lishko
eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Ismael Lamas-Toranzo ◽  
Julieta G Hamze ◽  
Enrica Bianchi ◽  
Beatriz Fernández-Fuertes ◽  
Serafín Pérez-Cerezales ◽  
...  

The fusion of gamete membranes during fertilization is an essential process for sexual reproduction. Despite its importance, only three proteins are known to be indispensable for sperm-egg membrane fusion: the sperm proteins IZUMO1 and SPACA6, and the egg protein JUNO. Here we demonstrate that another sperm protein, TMEM95, is necessary for sperm-egg interaction. TMEM95 ablation in mice caused complete male-specific infertility. Sperm lacking this protein were morphologically normal exhibited normal motility, and could penetrate the zona pellucida and bind to the oolemma. However, once bound to the oolemma, TMEM95-deficient sperm were unable to fuse with the egg membrane or penetrate into the ooplasm, and fertilization could only be achieved by mechanical injection of one sperm into the ooplasm, thereby bypassing membrane fusion. These data demonstrate that TMEM95 is essential for mammalian fertilization.


2020 ◽  
Author(s):  
Ismael Lamas-Toranzo ◽  
Julieta G Hamze ◽  
Enrica Bianchi ◽  
Beatriz Fernández-Fuertes ◽  
Serafín Pérez-Cerezales ◽  
...  

2020 ◽  
Vol 117 (17) ◽  
pp. 9393-9400 ◽  
Author(s):  
Yoshitaka Fujihara ◽  
Yonggang Lu ◽  
Taichi Noda ◽  
Asami Oji ◽  
Tamara Larasati ◽  
...  

Sperm–oocyte fusion is a critical event in mammalian fertilization, categorized by three indispensable proteins. Sperm membrane protein IZUMO1 and its counterpart oocyte membrane protein JUNO make a protein complex allowing sperm to interact with the oocyte, and subsequent sperm–oocyte fusion. Oocyte tetraspanin protein CD9 also contributes to sperm–oocyte fusion. However, the fusion process cannot be explained solely by these three essential factors. In this study, we focused on analyzing a testis-specific gene 4930451I11Rik and generated mutant mice using the CRISPR/Cas9 system. Although IZUMO1 remained in 4930451I11Rik knockout (KO) spermatozoa, the KO spermatozoa were unable to fuse with oocytes and the KO males were severely subfertile. 4930451I11Rik encodes two isoforms: a transmembrane (TM) form and a secreted form. Both CRISPR/Cas9-mediated TM deletion and transgenic (Tg) rescue with the TM form revealed that only the TM form plays a critical role in sperm–oocyte fusion. Thus, we renamed this TM form Fertilization Influencing Membrane Protein (FIMP). The mCherry-tagged FIMP TM form was localized to the sperm equatorial segment where the sperm–oocyte fusion event occurs. Thus, FIMP is a sperm-specific transmembrane protein that is necessary for the sperm–oocyte fusion process.


1990 ◽  
Vol 10 (2) ◽  
pp. 131-139
Author(s):  
Oyewole Adeyemo ◽  
E. O. Okegbile ◽  
O. O. Olorunsogo

For the development of immunological contraception, attention is being concentrated on the possibility of using a sperm membrane antigen. Boar sperm membrane was extracted with triton-X 100 and fractionated by Sephadex G-150 column chromatography. The glycosylated and nonglycosylated portions of protein peaks from the gel filtration were obtained by fractionating on concanavalin A-Sepharose and eluting the bound protein with 0.3 M methyl mannoside. A glycosylated fraction was found to induce sperm agglutinating antibodies in rabbit. The partially purified protein has a molecular weight of 30 kilodaltons, as determined by sodium dodecyl polyaccyrlamide gel electrophoresis. Further work is planned on the histochemical determination of the origin of this protein and species cross-activity of the antibody.


2009 ◽  
Vol 10 (1) ◽  
pp. 51 ◽  
Author(s):  
Jaime Antonio Cardozo ◽  
Patricia Grasa ◽  
María Teresa Muiño B. ◽  
José Álvaro Cebrián P.

<p>Este estudio se adelantó para evaluar el efecto de la adición de proteínas del plasma seminal de cordero en la criopreservación sobre la motilidad e integridad de la membrana espermática, y los cambios en el perfil electroforético de las proteínas de la membrana espermática inducidos por la criopreservación. Se usaron eyaculados de ocho corderos adultos de la raza rasa aragonesa, se les determinó su viabilidad y motilidad espermáticas y posteriormente se sometieron a un procedimiento de congelación. Las proteínas se separaron por el método de electroforesis en geles de acrilamida en dos dimensiones. Se obtuvo un mejoramiento significativo (<em>p </em>&lt; 0,05) en la calidad del semen congelado, cuando se adicionaron proteínas del plasma seminal. El análisis bidimensional comparativo entre el semen fresco y el congelado evidenció la pérdida de 8 puntos de proteína en el espermatozoide descongelado. La concentración de un punto de proteína de membrana espermática, de bajo peso molecular (punto 2), fue más alta (<em>p </em>&lt; 0,05) en el espermatozoide descongelado al que se adicionaron proteínas del plasma seminal. Se encontraron correlaciones entre algunos puntos de proteína y la motilidad y viabilidad espermáticas, lo cual sugiere que pueden jugar papeles importantes en el mantenimiento de la integridad y funcionalidad del espermatozoide. Se puede concluir que la adición de proteínas del plasma seminal en la congelación mejora la integridad del espermatozoide descongelado, y que la criopreservación del semen de cordero produce variaciones en la composición de las proteínas de membrana.  </p><p> </p><p><strong>Effect of seminal plasma proteins at freezing on ram sperm motility and viability</strong>  </p><p>The aim of the study was to evaluate the cryoprotective effect of seminal plasma proteins on ram sperm motility, membrane integrity and the changes in the profile of ram sperm membrane proteins induced by cryopreservation. Fresh ejaculates from 8 mature Rasa aragonesa rams were used. Sperm motility and cell viability was assessed. The freezing procedure was based on the method described by Fiser <em>et al</em>. (1987). Proteins extracted from fresh and frozen-thawed semen were subjected to the Two-dimensional polyacrilamide gel electrophoresis. A significant improvement in the quality of frozenthawed sperm was obtained after addition of seminal plasma proteins (<em>p </em>&lt; 0.05). Comparative two-dimensional polyacrilamide gel electrophoresis analysis between fresh and frozen semen, either with or without seminal plasma proteins in the cryopreservation medium, revealed that eight protein spots were lost in frozen-thawed sperm. The concentration of one sperm membrane protein spot of low Mr (spot 2) was higher (<em>p </em>&lt; 0.05) in proteinadded frozen sperm. Correlations found between certain protein spots sperm motility and viability suggests that these proteins could play important roles in the maintenance of sperm integrity and functionality. In conclusion, the addition of seminal plasma proteins to freezing extender improved frozen-thawed ram sperm integrity quality and cryopreservation of ram semen produced variations in the sperm membrane protein composition. </p>


2004 ◽  
Vol 82 (6) ◽  
pp. 383-388 ◽  
Author(s):  
Xiaoling Tang ◽  
Jianchao Zhang ◽  
Ying Cai ◽  
Shiying Miao ◽  
Shudong Zong ◽  
...  

2018 ◽  
Vol 98 (6) ◽  
pp. 776-783 ◽  
Author(s):  
Matthew R Marcello ◽  
Marina Druzhinina ◽  
Andrew Singson

1992 ◽  
Vol 119 (1) ◽  
pp. 55-68 ◽  
Author(s):  
S W L'Hernault ◽  
P M Arduengo

Spermatogenesis in the nematode Caenorhabditis elegans uses unusual organelles, called the fibrous body-membranous organelle (FB-MO) complexes, to prepackage and deliver macromolecules to spermatids during cytokinesis that accompanies the second meiotic division. Mutations in the spe-4 (spermatogenesis-defective) gene disrupt these organelles and prevent cytokinesis during spermatogenesis, but do not prevent completion of the meiotic nuclear divisions that normally accompany spermatid formation. We report an ultrastructural analysis of spe-4 mutant sperm where the normally close association of the FB's with the MO's and the double layered membrane surrounding the FB's are both defective. The internal membrane structure of the MO's is also disrupted in spe-4 mutant sperm. Although sperm morphogenesis in spe-4 mutants arrests prior to the formation of spermatids, meiosis can apparently be completed so that haploid nuclei reside in an arrested spermatocyte. We have cloned the spe-4 gene in order to understand its role during spermatogenesis and the molecular basis of how mutation of this gene disrupts this process. The spe-4 gene encodes an approximately 1.5-kb mRNA that is expressed during spermatogenesis, and the sequence of this gene suggests that it encodes an integral membrane protein. These data suggest that mutation of an integral membrane protein within FB-MO complexes disrupts morphogenesis and prevents formation of spermatids but does not affect completion of the meiotic nuclear divisions in C. elegans sperm.


Sign in / Sign up

Export Citation Format

Share Document