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E Ntemou, P Kadam, D Van Saen, J Wistuba, R T Mitchell, S Schlatt, E Goossens
STUDY QUESTION: Can full spermatogenesis be achieved after xenotransplantation of prepubertal primate testis tissue to the mouse, in testis or subcutaneously? SUMMARY ANSWER: Intratesticular xenotransplantation supported the differentiation of immature germ cells from marmoset (Callithrix jacchus) into spermatids and spermatozoa at 4 and 9 months post-transplantation, while in subcutaneous transplants, spermatogenic arrest was observed at 4 months and none of the transplants survived at 9 months...
February 12, 2019: Human Reproduction
P H Vogt, B Besikoglu, M Bettendorf, P Frank-Herrmann, J Zimmer, U Bender, S Knauer-Fischer, D Choukair, P Sinn, Y-F C Lau, P H Heidemann, T Strowitzki
STUDY QUESTION: Which Y genes mapped to the 'Gonadoblastoma Y (GBY)' locus on human Y chromosome are expressed in germ cells of individuals with some Differences of Sexual Development (DSD) and a Y chromosome in their karyotype (DSD-XY groups)? SUMMARY ANSWER: The GBY candidate genes DDX3Y and TSPY are expressed in the germ cells of DSD-XY patients from distinct etiologies: patients with mixed gonadal dysgenesis (MGD) and sex chromosome mosaics (45,X0/46,XY; 46,XX/46,XY); patients with complete androgen insensitivity (CAIS), patients with complete gonadal dysgenesis (CGD; e...
February 12, 2019: Human Reproduction
Chaofeng Hao, Jinrong Yin, Manli Sun, Qinhu Wang, Jie Liang, Zhuyun Bian, Huiquan Liu, Jin-Rong Xu
Ascospores are the primary inoculum in Fusarium graminearum. Interestingly, 70 of its genes have premature stop codons (PSC) and require A-to-I editing during sexual reproduction to encode full-length proteins, including the ortholog of yeast Ama1, a meiosis-specific activator of APC/C. In this study, we characterized the function of FgAMA1 and its PSC editing. FgAMA1 was specifically expressed during sexual reproduction. The Fgama1 mutant was normal in growth and perithecium formation but defective in ascospogenesis...
February 11, 2019: Molecular Microbiology
Qianting Zhang, Shu-Yan Ji, Kiran Busayavalasa, Chao Yu
Segregation of homologous chromosomes in meiosis I is tightly regulated by their physical links, or crossovers (COs), generated from DNA double-strand breaks (DSBs) through meiotic homologous recombination. In budding yeast, three ZMM (Zip1/2/3/4, Mer3, Msh4/5) proteins, Zip2, Zip4, and Spo16, form a "ZZS" complex, functioning to promote meiotic recombination via a DSB repair pathway. Here, we identified the mammalian ortholog of Spo16, termed SPO16, which interacts with the mammalian ortholog of Zip2 (SHOC1/MZIP2), and whose functions are evolutionarily conserved to promote the formation of COs...
January 2019: Science Advances
Pilar Ferré-Pujol, Xuan Khanh Nguyen, Tomoki Nagahara, Thi Tra Mi Bui, Takuya Wakai, Hiroaki Funahashi
We examined the effect of the timing of removing cumulus cells surrounding porcine oocytes from small follicles (SFs, < 3 mm in diameter) and medium follicles (MFs; 3-6 mm in diameter) on the meiotic and developmental competence of the oocytes. Cumulus-oocyte complexes (COCs) were collected from SFs and MFs, and the oocytes were denuded at 0, 20, and 44 h after the start of in vitro maturation (IVM), and the meiotic progression of the oocytes was assessed at the end of the IVM period. The incidence of mature oocytes was significantly affected by both the origin of the COCs and the time when the oocytes were denuded...
February 9, 2019: Journal of Reproduction and Development
Joo Bin Lee, Min Gu Lee, Tao Lin, Hyeon Yeong Shin, Jae Eun Lee, Jung Won Kang, Dong-Il Jin
Objective: The main goal of this study was to provide a morphological indicator that could be used to select high-quality oocytes of appropriate meiotic and developmental capabilities in pig. The higher quality of immature oocytes, the higher success rates of IVM and IVF. Thus, prior to the IVM culture, it is important to characterize oocytes morphologically and biochemically in order to assess their quality. Two of the largest indicators of oocyte quality are the presence of cumulus cells and status of chromatin...
January 2, 2019: Asian-Australasian Journal of Animal Sciences
Wezley C Griffin, Michael A Trakselis
There are several DNA helicases involved in seemingly overlapping aspects of homologous and homoeologous recombination. Mutations of many of these helicases are directly implicated in genetic diseases including cancer, rapid aging, and infertility. MCM8/9 are recent additions to the catalog of helicases involved in recombination, and so far, the evidence is sparse, making assignment of function difficult. Mutations in MCM8/9 correlate principally with primary ovarian failure/insufficiency (POF/POI) and infertility indicating a meiotic defect...
February 5, 2019: DNA Repair
Benedetta Iussig, Roberta Maggiulli, Gemma Fabozzi, Sara Bertelle, Alberto Vaiarelli, Danilo Cimadomo, Filippo Maria Ubaldi, Laura Rienzi
The term "cryopreservation" refers to the process of cooling cells and tissues and storing them at subzero temperatures in order to stop all biologic activity and preserve their viability and physiologic competences for future use. Cooling to subzero temperatures is not a physiological condition for human cells; this is probably due to the high content of water in the living matter, whose conversion to ice crystals may be associated with severe and irreversible damages. Among reproductive cells and tissues, metaphase II oocytes are notably vulnerable to cryopreservation, mainly because of their large size, low surface area to volume ratio, relatively high water content and presence of the meiotic spindle...
February 10, 2019: Acta Obstetricia et Gynecologica Scandinavica
Dmitriy Li, Marianne Roca, Raif Yuecel, Alexander Lorenz
Schizosaccharomyces pombe, also known as fission yeast, is an established model for studying chromosome biological processes. Over the years, research employing fission yeast has made important contributions to our knowledge about chromosome segregation during meiosis, as well as meiotic recombination and its regulation. Quantification of meiotic recombination frequency is not a straightforward undertaking, either requiring viable progeny for a genetic plating assay, or relying on laborious Southern blot analysis of recombination intermediates...
February 9, 2019: Chromosoma
Ken-Ichi Sato, Alexander A Tokmakov
Studies on the egg plasma membrane-associated tyrosine kinase Src have shed light on the identity of the molecular machinery that is responsible for gamete interaction and possibly fusion in African clawed frog Xenopus laevis. Here we describe our protocol for identifying and analyzing molecular and cellular machinery that contributes to a variety of biological processes in the course of oogenesis, oocyte maturation, egg fertilization, and early embryogenesis in Xenopus. Our current special interest is to evaluate the hypothesis that the oocyte/egg membrane microdomain (MD)-associated uroplakin III-Src system is responsible for mediating sperm-egg membrane interaction/fusion signal to the oocyte/egg cytoplasm to initiate embryonic and zygotic development in this species...
2019: Methods in Molecular Biology
Yao Wang, Hanben Wang, Yu Zhang, Zhenhai Du, Wei Si, Suixing Fan, Dongdong Qin, Mei Wang, Yanchao Duan, Lufan Li, Yuying Jiao, Yuanyuan Li, Qiujun Wang, Qinghua Shi, Xin Wu, Wei Xie
Chromatin organization undergoes drastic reconfiguration during gametogenesis. However, the molecular reprogramming of three-dimensional chromatin structure in this process remains poorly understood for mammals, including primates. Here, we examined three-dimensional chromatin architecture during spermatogenesis in rhesus monkey using low-input Hi-C. Interestingly, we found that topologically associating domains (TADs) undergo dissolution and reestablishment in spermatogenesis. Strikingly, pachytene spermatocytes, where synapsis occurs, are strongly depleted for TADs despite their active transcription state but uniquely show highly refined local compartments that alternate between transcribing and non-transcribing regions (refined-A/B)...
February 7, 2019: Molecular Cell
Rui Xia, Chengjie Chen, Suresh Pokhrel, Wuqiang Ma, Kun Huang, Parth Patel, Fuxi Wang, Jing Xu, Zhongchi Liu, Jianguo Li, Blake C Meyers
Small RNAs are key regulators in plant growth and development. One subclass, phased siRNAs (phasiRNAs) require a trigger microRNA for their biogenesis. In grasses, two pathways yield abundant phasiRNAs during anther development; miR2275 triggers one class, 24-nt phasiRNAs, coincident with meiosis, while a second class of 21-nt phasiRNAs are present in premeiotic anthers. Here we report that the 24-nt phasiRNA pathway is widely present in flowering plants, indicating that 24-nt reproductive phasiRNAs likely originated with the evolutionary emergence of anthers...
February 7, 2019: Nature Communications
Victor Spangenberg, Marine Arakelyan, Eduard Galoyan, Mark Pankin, Ruzanna Petrosyan, Ilona Stepanyan, Tatiana Grishaeva, Felix Danielyan, Oxana Kolomiets
According to the synthesis of 30 years of multidisciplinary studies, parthenogenetic species of rock lizards of genus Darevskia were formed as a result of different combination patterns of interspecific hybridization of the four bisexual parental species: Darevskia raddei , D. mixta , D. valentini , and D. portschinskii . In particular, D. portschinskii and D. raddei are considered as the parental species for the parthenogenetic species D. rostombekowi . Here for the first time, we present the result of comparative immunocytochemical study of primary spermatocyte nuclei spreads from the leptotene to diplotene stages of meiotic prophase I in two species: D...
2019: PeerJ
Mehmet E Karasu, Nora Bouftas, Scott Keeney, Katja Wassmann
Meiosis poses unique challenges because two rounds of chromosome segregation must be executed without intervening DNA replication. Mammalian cells express numerous temporally regulated cyclins, but how these proteins collaborate to control meiosis remains poorly understood. Here, we show that female mice genetically ablated for cyclin B3 are viable-indicating that the protein is dispensable for mitotic divisions-but are sterile. Mutant oocytes appear normal until metaphase I but then display a highly penetrant failure to transition to anaphase I...
February 5, 2019: Journal of Cell Biology
Xuexia Liu, Qian Li, Wenjuan Wang, Fujun Liu
The energy required for normal sperm function is mainly generated by glycolysis and oxidative phosphorylation. Testis‑specific glycolytic enzymes are expressed in germ cells and present in mature spermatozoa. The objective of the present study was to investigate the association between aberrant expression of glycolytic enzymes and human sperm quality. In silico analysis of glyceraldehyde‑3‑phosphate dehydrogenase, testis‑specific (GAPDHS), phosphoglycerate kinase 2 (PGK2) and lactate dehydrogenase (LDHC) identified that they were exclusively expressed in post‑meiotic germ cells and this was validated in human testes using immunohistochemistry...
February 1, 2019: Molecular Medicine Reports
Yan Wang, Yanyan Chen, Juan Chen, Lijun Wang, Leitong Nie, Juanjuan Long, Haishuang Chang, Jian Wu, Chenhui Huang, Ming Lei
During meiotic prophase I, telomeres attach to and move on the nuclear envelope (NE), regulating chromosome movement to promote homologous pairing. Meiosis-specific proteins TERB1, TERB2 and MAJIN play a key role in this process. Here, we report the crystal structures of human TERB1-TERB2 and TERB2-MAJIN subcomplexes. Specific disruption of the TERB1-TERB2 or the TERB2-MAJIN interaction in the mouse Terb2 gene abolishes the telomere attachment to the NE and causes aberrant homologous pairing and disordered synapsis...
February 4, 2019: Nature Communications
Baolu Shi, Jiangyang Xue, Hao Yin, Rui Guo, Mengcheng Luo, Lan Ye, Qinghua Shi, Xiaoyan Huang, Mingxi Liu, Jiahao Sha, P Jeremy Wang
Meiotic recombination permits exchange of genetic material between homologous chromosomes. The replication protein A (RPA) complex, the predominant ssDNA-binding complex, is required for nearly all aspects of DNA metabolism, but its role in mammalian meiotic recombination remains unknown due to the embryonic lethality of RPA mutant mice. RPA is a heterotrimer of RPA1, RPA2, and RPA3. We find that loss of RPA1, the largest subunit, leads to disappearance of RPA2 and RPA3, resulting in the absence of the RPA complex...
February 4, 2019: PLoS Genetics
Jacinta H Martin, R John Aitken, Elizabeth G Bromfield, Shenae L Cafe, Jessie M Sutherland, Emily R Frost, Brett Nixon, Tessa Lord
Diabetes is associated with poor oocyte quality and the dysregulation of ovarian function and is thus a leading contributor to the increasing prevalence of female reproductive pathologies. Accordingly, it is well-established that insulin fulfils a key role in the regulation of several facets of female reproduction. What remains less certain is whether proinsulin C-peptide, which has recently been implicated in cellular signaling cascades, holds any functional role in the female germline. In the present study, we examined the expression of insulin, C-peptide and its purported receptor; GPR146, within the mouse ovary and oocyte...
January 30, 2019: Biology of Reproduction
Qian-Qian Sha, Jue Zhang, Heng-Yu Fan
In mammals, maternal-to-zygotic transition (MZT), or oocyte-to-embryo transition, begins with oocyte meiotic resumption due to the sequential translational activation and destabilization of dormant maternal transcripts stored in the ooplasm. It then continues with the elimination of maternal transcripts during oocyte maturation and fertilization and ends with the full transcriptional activation of the zygotic genome during embryonic development. A hallmark of MZT in mammals is its reliance on translation and the utilization of stored RNAs and proteins, rather than de novo transcription of genes, to sustain meiotic maturation and early development...
January 31, 2019: Biology of Reproduction
Alexandre P Marand, Hainan Zhao, Wenli Zhang, Zixian Zeng, Chao Fang, Jiming Jiang
Recombination plays an integral role in the creation novel genetic variation in sexually reproducing species. Despite this importance, the determinants and evolution of crossover hotspots have remained poorly understood in plants. Here we present a comparative analysis of two rice (Oryza sativa) historical recombination maps from two subspecies (indica and japonica) using 150 resequenced genomes. Fine-scale recombination rates and crossover hotspots were validated by comparison with a consensus genetic map and empirically derived crossovers, respectively...
January 31, 2019: Plant Cell
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