scholarly journals The Transformation of the Centrosome into the Basal Body: Similarities and Dissimilarities between Somatic and Male Germ Cells and Their Relevance for Male Fertility

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2266
Author(s):  
Constanza Tapia Contreras ◽  
Sigrid Hoyer-Fender
Keyword(s):  
Germ Cells ◽  
Basal Body ◽  
Male Fertility ◽  
Round Spermatid ◽  
Clinical Diagnostics ◽  
The Body ◽  
Microtubule Organizing Center ◽  
Male Germ Cells ◽  
Sperm Tail ◽  
Acrosomal Vesicle

The sperm flagellum is essential for the transport of the genetic material toward the oocyte and thus the transmission of the genetic information to the next generation. During the haploid phase of spermatogenesis, i.e., spermiogenesis, a morphological and molecular restructuring of the male germ cell, the round spermatid, takes place that includes the silencing and compaction of the nucleus, the formation of the acrosomal vesicle from the Golgi apparatus, the formation of the sperm tail, and, finally, the shedding of excessive cytoplasm. Sperm tail formation starts in the round spermatid stage when the pair of centrioles moves toward the posterior pole of the nucleus. The sperm tail, eventually, becomes located opposed to the acrosomal vesicle, which develops at the anterior pole of the nucleus. The centriole pair tightly attaches to the nucleus, forming a nuclear membrane indentation. An articular structure is formed around the centriole pair known as the connecting piece, situated in the neck region and linking the sperm head to the tail, also named the head-to-tail coupling apparatus or, in short, HTCA. Finally, the sperm tail grows out from the distal centriole that is now transformed into the basal body of the flagellum. However, a centriole pair is found in nearly all cells of the body. In somatic cells, it accumulates a large mass of proteins, the pericentriolar material (PCM), that together constitute the centrosome, which is the main microtubule-organizing center of the cell, essential not only for the structuring of the cytoskeleton and the overall cellular organization but also for mitotic spindle formation and chromosome segregation. However, in post-mitotic (G1 or G0) cells, the centrosome is transformed into the basal body. In this case, one of the centrioles, which is always the oldest or mother centriole, grows the axoneme of a cilium. Most cells of the body carry a single cilium known as the primary cilium that serves as an antenna sensing the cell’s environment. Besides, specialized cells develop multiple motile cilia differing in substructure from the immotile primary cilia that are essential in moving fluids or cargos over the cellular surface. Impairment of cilia formation causes numerous severe syndromes that are collectively subsumed as ciliopathies. This comparative overview serves to illustrate the molecular mechanisms of basal body formation, their similarities, and dissimilarities, in somatic versus male germ cells, by discussing the involved proteins/genes and their expression, localization, and function. The review, thus, aimed to provide a deeper knowledge of the molecular players that is essential for the expansion of clinical diagnostics and treatment of male fertility disorders.

scholarly journals Advanced bioengineering of male germ stem cells to preserve fertility

2021 ◽  
Vol 12 ◽  
pp. 204173142110605
Author(s):  
Hossein Eyni ◽  
Sadegh Ghorbani ◽  
Hojjatollah Nazari ◽  
Marziyeh Hajialyani ◽  
Sajad Razavi Bazaz ◽  
...  
Keyword(s):  
Fertility Preservation ◽  
Germ Cells ◽  
Male Fertility ◽  
Round Spermatid ◽  
The Body ◽  
Testicular Sperm Extraction ◽  
Male Germ Cells ◽  
Vitro Fertilization ◽  
In Vitro Spermatogenesis

In modern life, several factors such as genetics, exposure to toxins, and aging have resulted in significant levels of male infertility, estimated to be approximately 18% worldwide. In response, substantial progress has been made to improve in vitro fertilization treatments (e.g. microsurgical testicular sperm extraction (m-TESE), intra-cytoplasmic sperm injection (ICSI), and round spermatid injection (ROSI)). Mimicking the structure of testicular natural extracellular matrices (ECM) outside of the body is one clear route toward complete in vitro spermatogenesis and male fertility preservation. Here, a new wave of technological innovations is underway applying regenerative medicine strategies to cell-tissue culture on natural or synthetic scaffolds supplemented with bioactive factors. The emergence of advanced bioengineered systems suggests new hope for male fertility preservation through development of functional male germ cells. To date, few studies aimed at in vitro spermatogenesis have resulted in relevant numbers of mature gametes. However, a substantial body of knowledge on conditions that are required to maintain and mature male germ cells in vitro is now in place. This review focuses on advanced bioengineering methods such as microfluidic systems, bio-fabricated scaffolds, and 3D organ culture applied to the germline for fertility preservation through in vitro spermatogenesis.

Evidence of male germ cell redifferentiation into female germ cells in planarian regeneration

Development ◽  
1982 ◽  
Vol 70 (1) ◽  
pp. 29-36
Author(s):  
V. Gremigni ◽  
M. Nigro ◽  
I. Puccinelli
Keyword(s):  
Germ Cells ◽  
Somatic Cells ◽  
The Body ◽  
Diploid Male ◽  
Female Gonad ◽  
Anterior Portion ◽  
Male Germ Cells ◽  
Blastema Formation ◽  
Planarian Regeneration ◽  
Undifferentiated Cells

The source and fate of blastema cells are important and still unresolved problems in planarian regeneration. In the present investigation we have attempted to obtain new evidence of cell dedifferentiation-redifferentiation by using a polyploid biotype of Dugesia lugubris s.1. This biotype is provided with a natural karyological marker which allows the discrimination of triploid embryonic and somatic cells from diploid male germ cells and from hexaploid female germ cells. Thanks to this cell mosaic we previously demonstrated that male germ cells take part in blastema formation and are then capable of redifferentiating into somatic cells. In the present investigation sexually mature specimens were transected behind the ovaries and the posterior stumps containing testes were allowed to regenerate the anterior portion of the body. Along with the usual hexaploid oocytes, a small percentage (3.2%) of tetraploid oocytes were produced from regenerated specimens provided with new ovaries. By contrast only hexaploid oocytes were produced from control untransected specimens. The tetraploid oocytes are interpreted as original diploid male germ cells which following the transection take part in blastema formation and then during regeneration redifferentiate into female germ cells thus doubling their chromosome number as usual for undifferentiated cells entering the female gonad in this biotype.

377 SPERMATOZOA RETRIEVED FROM MALE MICE FROZEN FOR 15 YEARS CAN PRODUCE NORMAL OFFSPRING

2007 ◽  
Vol 19 (1) ◽  
pp. 304
Author(s):  
N. Ogonuki ◽  
K. Mochida ◽  
H. Miki ◽  
K. Inoue ◽  
T. Iwaki ◽  
...  
Keyword(s):  
Germ Cells ◽  
Mammalian Species ◽  
The Body ◽  
Freezing And Thawing ◽  
Abdominal Incision ◽  
Closely Related Species ◽  
Male Germ Cells ◽  
Testicular Spermatozoa ◽  
One Year ◽  
Normal Offspring

Cryopreservation of male germ cells is a strategy to conserve animal species and strains of animals valuable to biomedical research. However, to minimize damage that may occur during freezing and thawing, complex cryopreservation protocols that have been optimized for the stage and species of male germ cells are usually employed. Recently, we have found that mouse male germ cells can be cryopreserved at -80�C by freezing the whole epididymides and testes without cryoprotectant for at least one year (Ogonuki et al. 2006 Reprod. Fertil. Dev. 18, 286 abst). This study was undertaken to determine whether mouse male germ cells retrieved from the bodies of mice frozen at -20�C for 15 years could produce normal offspring by microinsemination. Mature males of BALB/c-nude and C3H/He (8 weeks of age) were euthanized by overdose of pentobarbital on February 20 and March 8, 1991, respectively, and kept in a -20�C freezer. The frozen body was thawed about 15 years after freezing (February 2006) by putting it in a water bath until the outer surface of the body was softened. The body was then removed from the water, and the testes were isolated through an abdominal incision. Testicular spermatozoa were collected from the testes and microinseminated into B6D2F1 oocytes. Within 24 h after sperm injection, over 80% of oocytes developed into 2-cell embryos. Apparently normal pups were born after embryo transfer in both strains of mice at rates of 21% (17/81) and 12% (12/97) per transfer, respectively. Two pups from the BALB/c-nude group died shortly after Caesarian section due to respiratory failure, but others grew normally and were proven to be fertile when they matured (at least 19 mice out of 20 mice tested). We further mated these F1 offspring and confirmed that the nude gene was safely propagated. The present study demonstrates that spermatozoa can retain their fertilizing ability in frozen whole bodies for longer than we anticipated. If spermatozoa of extinct mammalian species (e.g. woolly mammoth) can be retrieved from animal bodies that were kept frozen in permanent frost, live animals might be restored by injecting them into oocytes from females of closely related species.

scholarly journals The Golgi Glycoprotein MGAT4D is an Intrinsic Protector of Testicular Germ Cells From Mild Heat Stress

2019 ◽  
Author(s):  
Ayodele Akintayo ◽  
Meng Liang ◽  
Boris Bartholdy ◽  
Frank Batista ◽  
Jennifer Aguilan ◽  
...  
Keyword(s):  
Heat Stress ◽  
Germ Cell ◽  
Germ Cells ◽  
The Body ◽  
Wild Type ◽  
Tgfβ Signaling ◽  
Male Germ Cells ◽  
Mild Heat ◽  
Intrinsic Mechanism ◽  
Shock Response

AbstractMale germ cells are sensitive to heat stress and testes must be maintained outside the body for optimal fertility. However, no germ cell intrinsic mechanism that protects from heat has been reported. Here, we identify the germ cell specific Golgi glycoprotein MGAT4D as a protector of male germ cells from heat stress. Mgat4d is highly expressed in spermatocytes and spermatids. Unexpectedly, when the Mgat4d gene was inactivated globally or conditionally in spermatogonia, or mis-expressed in spermatogonia, spermatocytes or spermatids, neither spermatogenesis nor fertility were affected. On the other hand, when males were subjected to mild heat stress of the testis (43°C for 25 min), germ cells with inactivated Mgat4d were markedly more sensitive to the effects of heat stress, and transgenic mice expressing Mgat4d were partially protected from heat stress. Germ cells lacking Mgat4d generally mounted a similar heat shock response to control germ cells, but could not maintain that response. Several pathways activated by heat stress in wild type were induced to a lesser extent in Mgat4d[−/−] heat-stressed germ cells (NFκB response, TNF and TGFβ signaling, Hif1α and Myc genes). Thus, the Golgi glycoprotein MGAT4D is a novel, intrinsic protector of male germ cells from heat stress.

scholarly journals Chromatin-Associated Protein Sugp2 Involved in mRNA Alternative Splicing During Mouse Spermatogenesis

2021 ◽  
Vol 8 ◽  
Author(s):  
Junfeng Zhan ◽  
Jianbo Li ◽  
Yuerong Wu ◽  
Panfeng Wu ◽  
Ziqi Yu ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Germ Cells ◽  
Regulatory Network ◽  
Male Fertility ◽  
Metal Ion ◽  
Control Group ◽  
Splicing Regulation ◽  
Male Germ Cells ◽  
Meiotic Progression ◽  
Candidate Protein

Mammalian spermatogenesis is a highly ordered process that is determined by chromatin-associated moderators which still remain poorly understood. Through a multi-control group proteomics strategy, we confirmed that Sugp2 was a chromatin-associated candidate protein, and its signal arose along spermatogenesis. The expression results showed that Sugp2, which is mainly expressed in the testis, had two transcripts, encoding one protein. During spermatogenesis, Sugp2 was enriched in the nucleus of male germ cells. With the depletion of Sugp2 by CRISPER-Cas9 technology, we found that Sugp2 controlled a network of genes on metal ion and ATP binding, suggesting that alternative splicing regulation by Sugp2 is involved in cellular ion and energy metabolism during spermatogenesis, while it had a little effect on meiotic progression and male fertility. Collectively, these data demonstrated that, as a chromatin-associated protein, Sugp2 mediated the alternative splicing regulatory network during spermatogenesis.

scholarly journals GPR62 constitutively activates cAMP signaling but is dispensable for male fertility in mice

Reproduction ◽  
2017 ◽  
Vol 154 (6) ◽  
pp. 755-764 ◽  
Author(s):  
Tomoyuki Muroi ◽  
Yuri Matsushima ◽  
Ryota Kanamori ◽  
Hikari Inoue ◽  
Wataru Fujii ◽  
...  
Keyword(s):  
Germ Cells ◽  
Male Fertility ◽  
Camp Signaling ◽  
Constitutive Activity ◽  
Male Germ Cells ◽  
Camp Pathway ◽  
Functional Features ◽  
And Behavior ◽  
Orphan Gpcrs ◽  
G Protein Coupled

G-protein-coupled receptors (GPCRs) participate in diverse physiological functions and are promising targets for drug discovery. However, there are still over 140 orphan GPCRs whose functions remain to be elucidated.Gpr62is one of the orphan GPCRs that is expressed in the rat and human brain. In this study, we found thatGpr62is also expressed in male germ cells in mice, and its expression increases along with sperm differentiation. GPR62 lacks the BBXXB and DRY motifs, which are conserved across many GPCRs, and it was able to induce cAMP signaling in the absence of a ligand. These structural and functional features are conserved among mammals, and the mutant analysis of GPR62 has revealed that lacking of these motifs is involved in the constitutive activity. We also found that GPR62 can homooligomerize, but it is not sufficient for its constitutive activity. We further investigated its physiological function by usingGpr62knockout (Gpr62−/−) mice.Gpr62−/−mice were born normally and did not show any abnormality in growth and behavior. In addition, both male and femaleGp62−/−mice were fertile, and the differentiation and motility of spermatozoa were normal. We also found thatGpr61, the gene most similar toGpr62in the GPCR family shows a constitutive activity and an expression pattern similar to those ofGpr62. Our results suggest that GPR62 constitutively activates the cAMP pathway in male germ cells but is dispensable for male fertility, which is probably due to its functional redundancy with GPR61.

scholarly journals The Male Fertility Gene Atlas: a web tool for collecting and integrating OMICS data in the context of male infertility

2020 ◽  
Vol 35 (9) ◽  
pp. 1983-1990 ◽  
Author(s):  
Henrike Krenz ◽  
Jörg Gromoll ◽  
Thomas Darde ◽  
Frederic Chalmel ◽  
Martin Dugas ◽  
...  
Keyword(s):  
Male Infertility ◽  
Clinical Research ◽  
Germ Cells ◽  
Male Fertility ◽  
Literature Search ◽  
Research Unit ◽  
Male Germ Cells ◽  
Raw Data ◽  
Fertility Gene ◽  
Clinical Research Unit

Abstract STUDY QUESTION How can one design and implement a system that provides a comprehensive overview of research results in the field of epi-/genetics of male infertility and germ cells? SUMMARY ANSWER Working at the interface of literature search engines and raw data repositories, the newly developed Male Fertility Gene Atlas (MFGA) provides a system that can represent aggregated results from scientific publications in a standardized way and perform advanced searches, for example based on the conditions (phenotypes) and genes related to male infertility. WHAT IS KNOWN ALREADY PubMed and Google Scholar are established search engines for research literature. Additionally, repositories like Gene Expression Omnibus and Sequence Read Archive provide access to raw data. Selected processed data can be accessed by visualization tools like the ReproGenomics Viewer. STUDY DESIGN, SIZE, DURATION The MFGA was developed in a time frame of 18 months under a rapid prototyping approach. PARTICIPANTS/MATERIALS, SETTING, METHODS In the context of the Clinical Research Unit ‘Male Germ Cells’ (CRU326), a group of around 50 domain experts in the fields of male infertility and germ cells helped to develop the requirements engineering and feedback loops. They provided a set of 39 representative and heterogeneous publications to establish a basis for the system requirements. MAIN RESULTS AND THE ROLE OF CHANCE The MFGA is freely available online at https://mfga.uni-muenster.de. To date, it contains 115 data sets corresponding to 54 manually curated publications and provides an advanced search function based on study conditions, meta-information and genes, whereby it returns the publications’ exact tables and figures that fit the search request as well as a list of the most frequently investigated genes in the result set. Currently, study data for 31 different tissue types, 32 different cell types and 20 conditions are available. Also, ∼8000 and ∼1000 distinct genes have been found to be mentioned in at least 10 and 15 of the publications, respectively. LARGE SCALE DATA Not applicable because no novel data were produced. LIMITATIONS, REASONS FOR CAUTION For the most part, the content of the system currently includes the selected publications from the development process. However, a structured process for the prospective literature search and inclusion into the MFGA has been defined and is currently implemented. WIDER IMPLICATIONS OF THE FINDINGS The technical implementation of the MFGA allows for accommodating a wide range of heterogeneous data from aggregated research results. This implementation can be transferred to other diseases to establish comparable systems and generally support research in the medical field. STUDY FUNDING/COMPETING INTEREST(S) This work was carried out within the frame of the German Research Foundation (DFG) Clinical Research Unit ‘Male Germ Cells: from Genes to Function’ (CRU326). The authors declare no conflicts of interest.

scholarly journals 322 DIFFERENTIAL DEVELOPMENT OF RABBIT EMBRYOS FOLLOWING MICROINSEMINATION USING SPERM AND SPERMATIDS

2005 ◽  
Vol 17 (2) ◽  
pp. 312
Author(s):  
N. Ogonuki ◽  
K. Inoue ◽  
H. Miki ◽  
Y. Hirose ◽  
H. Okada ◽  
...  
Keyword(s):  
Embryo Development ◽  
Germ Cells ◽  
Round Spermatid ◽  
Nuclear Staining ◽  
Male Germ Cells ◽  
Average Cell ◽  
Mouse Oocytes ◽  
Round Spermatid Injection ◽  
Rabbit Embryos

Microinsemination is a technique that delivers male germ cells directly into the ooplasm. The efficiency of fertilization and subsequent embryo development after microinsemination varies with species and the male germ cells used. This study examined the developmental ability of rabbit embryos in vitro and in vivo following microinsemination using haploid male germ cells at different stages. First, we injected rabbit spermatozoa, elongated spermatids, and round spermatids into mouse oocytes to assess their oocyte-activating capacity. Mouse oocytes are a good experimental model for assessing the oocyte-activating capacity of male germ cells from different species. The majority of mouse oocytes were activated irrespective of the stage of rabbit male germ cells injected (77, 61, and 73% for spermatozoa, elongated spermatids, and round spermatids, respectively). By contrast, these male germ cells activated homologous rabbit oocytes at rates of 100, 59, and 29%, respectively. After 120 h in culture, 69, 55, and 13% of these activated rabbit oocytes (pronuclear eggs) developed into blastocysts, respectively. The rate of embryo development into blastocysts following round spermatid injection was significantly improved when oocytes were activated by an electric pulse shortly before microinsemination. The total number of cells was counted in embryos that reached the morula/blastocyst stages in culture using nuclear-staining with propidium iodide. The average cell number of embryos derived from elongated (89 ± 41; mean ± SD) or round spermatid (98 ± 34) injection was significantly lower than that of control embryos (in vivo fertilization) (211 ± 44) (P < 0.01). After 24 h in culture, some four- to eight-cell-stage embryos were transferred into the oviducts of pseudopregnant females. Normal pups were born from embryos involving sperm (4 offspring/16 transfers; 25%) and elongated spermatid (3/26; 12%) injection, but none from those involving round spermatid injection (0/68). These findings indicate that rabbit male germ cells acquire the ability to activate oocytes and to support subsequent embryo development as they undergo spermiogenesis. Immaturity of the nuclear genome or difficulty in coordinating the behavior of the male and female chromosomes might compromise embryo development.

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