Search

In vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) are 2 major assisted reproductive techniques (ARTs) used widely to treat infertility. Recently, spermatogonia! transplantation emerged as a new ART to restore fertility to young patients with cancer after cancer therapy. To examine the influence of germ cell manipulation on behavior of offspring, we produced [F.sub.1] offspring by a combination of two ARTs, spermatogonial transplantation and ICSI. When these animals were compared with [F.sub.1] offspring produced by ICSI using fresh wild-type sperm, not only spermatogonial transplantation- ICSI mice but also ICSI-only control mice exhibited behavioral abnormalities, which persisted in the [F.sub.2] generation. Furthermore, although these [F.sub.1] offspring appeared normal, [F.sub.2] offspring produced by IVF using [F.sub.1] sperm and wild- type oocytes showed various types of congenital abnormalities, including anophthalmia, hydrocephalus, and missing limbs. Therefore, ARTs can induce morphological and functional defects in mice, some of which become evident only after germline transmission., Introduction Since its first report in 1978, in vitro fertilization (IVF) has been used in assisted reproductive techniques (ARTs) in humans (1). IVF is often used when a woman's fallopian [...]

We report a case of argyrophilic grain disease (AGD) with unique clinical and pathological presentations. A 52‐year‐old man presented with spastic quadriparesis, bulbar palsy, and mild cognitive decline. His condition deteriorated rapidly and he died of pneumonia three years from onset. Pathologically, neuronal degeneration was involved severely in the amygdala, ambient gyrus, midbrain tegmentum, and reticular formation. The neurons of the temporal lobe, cingulate gyrus, brainstem, and spinal gray matter were also lost moderately. There was diffuse 4‐repeat tau‐pathology with argyrophilic grains. There were pretangles, globose‐type neurofibrillary tangles, and coiled bodies in the cerebral cortices, basal ganglia, thalami, brainstem, and the spinal cord except for the cerebellar cortices. There was no pathologic mutation in MAPT. [ABSTRACT FROM AUTHOR]

The leading cause of death for patients with Duchenne muscular dystrophy (DMD), a progressive muscle disease, is heart failure. Prostaglandin (PG) D2, a physiologically active fatty acid, is synthesized from the precursor PGH2 by hematopoietic prostaglandin D synthase (HPGDS). Using a DMD animal model (mdx mice), we previously found that HPGDS expression is increased not only in injured muscle but also in the heart. Moreover, HPGDS inhibitors can slow the progression of muscle injury and cardiomyopathy. However, the location of HPGDS in the heart is still unknown. Thus, this study investigated HPGDS expression in autopsy myocardial samples from DMD patients. We confirmed the presence of fibrosis, a characteristic phenotype of DMD, in the autopsy myocardial sections. Additionally, HPGDS was expressed in mast cells, pericytes, and myeloid cells of the myocardial specimens but not in the myocardium. Compared with the non-DMD group, the DMD group showed increased HPGDS expression in mast cells and pericytes. Our findings confirm the possibility of using HPGDS inhibitor therapy to suppress PGD2 production to treat skeletal muscle disorders and cardiomyopathy. It thus provides significant insights for developing therapeutic drugs for DMD. [ABSTRACT FROM AUTHOR]

Spinocerebellar ataxia type 8 (SCA8) is a neurodegenerative condition that presents with several neurological symptoms, such as cerebellar ataxia, parkinsonism, and cognitive impairment. It is caused by a CTA/CTG repeat expansion on chromosome 13q21 (ataxin 8 opposite strand [ATXN8OS]). However, the pathological significance of this expansion remains unclear. Moreover, abnormal CTA/CTG repeat expansions in ATXN8OS have also been reported in other neurodegenerative diseases, including progressive supranuclear palsy. In this study, we analyzed all available autopsy cases in Japan to investigate common pathological features and profiles of tau pathology in each case. Severe neuronal loss in the substantia nigra and prominent loss of Purkinje cells, atrophy of the molecular layer, and proliferation of Bergmann glia in the cerebellum were common features. Regarding tauopathy, one case presented with progressive supranuclear palsy‐like 4‐repeat tauopathy in addition to mild Alzheimer‐type 3‐ and 4‐repeat tauopathy. Another case showed 3‐ and 4‐repeat tauopathy accentuated in the brainstem. The other two cases lacked tauopathy after extensive immunohistochemical studies. The present study confirmed common pathological features of SCA8 as degeneration of the substantia nigra in addition to the cerebellum. Our study also confirmed unique tauopathy in two of four cases, indicating the necessity to further collect autopsy cases. [ABSTRACT FROM AUTHOR]

Spermatogenesis is one of the most complex and longest processes of sequential cell proliferation and differentiation in the body, taking more than a month from spermatogonial stem cells, through meiosis, to sperm formation (1,2). The whole process, therefore, has never been reproduced in vitro in mammals (3-5), nor in any other species with a very few exceptions in some particular types of fish (6,7). Here we show that neonatal mouse testes which contain only gonocytes or primitive spermatogonia as germ cells can produce spermatids and sperm in vitro with serum-free culture media. Spermatogenesis was maintained over 2 months in tissue fragments positioned at the gas-liquid interphase. The obtained spermatids and sperm resulted in healthy and reproductively competent offspring through microinsemination. In addition, neonatal testis tissues were cryopreserved and, after thawing, showed complete spermatogenesis in vitro. Our organ culture method could be applicable through further refinements to a variety of mammalian species, which will serve as a platform for future clinical application as well as mechanistic understanding of spermatogenesis., Studies on in vitro spermatogenesis date back to organ culture experiments about a century ago (8). In 1937, it was reported that spermatogenesis proceeded up to the pachytene stage of [...]

Cloning mammals by means of somatic cell nuclear transfer (SCNT) is highly inefficient because of erroneous reprogramming of the donor genome. Reprogramming errors appear to arise randomly, but the nature of nonrandom, SCNT-specific errors remains elusive. We found that Xist, a noncoding RNA that inactivates one of the two X chromosomes in females, was ectopically expressed from the active X (Xa) chromosome in cloned mouse embryos of both sexes. Deletion of Xist on Xa showed normal global gene expression and resulted in about an eight- to ninefold increase in cloning efficiency. We also identified an Xist-independent mechanism that specifically down-regulated a subset of X-linked genes through somatic-type repressive histone blocks. Thus, we have identified nonrandom reprogramming errors in mouse cloning that can be altered to improve the efficiency of SCNT methods. 10.1126/science.1194174

Microinjection of spermatozoa or spermatids into oocytes is a major choice for infertility treatment. However, the use of premeiotic spermatocytes has never been considered because of its technical problems. Here, we show that the efficiency of spermatocyte injection in mice can be improved greatly by reducing the size of the recipient oocytes. Live imaging showed that the underlying mechanism involves reduced premature separation of the spermatocyte's meiotic chromosomes, which produced much greater (19% vs. 1%) birth rates in smaller oocytes. Application of this technique to spermatocyte arrest caused by STX2 deficiency, an azoospermia factor also found in humans, resulted in the production of live offspring. Thus, the microinjection of primary spermatocytes into oocytes may be a potential treatment for overcoming a form of nonobstructive azoospermia caused by meiotic failure. Synopsis: Mouse primary spermatocytes can complete meiosis following injection into meiotic oocytes, but with severe chromosome segregation errors. Reduction of the cytoplasm of the oocytes prevents these chromosomal errors and enables efficient production of spermatocyte‐derived offspring. Spermatocyte chromosomes within oocytes show premature separation at MI and seem to be defective in activating spindle assembly checkpoint.The predominant error pattern is predivision of sister chromatids, which can be suppressed by reduction of the ooplasm.This technology enabled the production of offspring from azoospermic male mice lacking Stx2, an azoospermic factor in humans. [ABSTRACT FROM AUTHOR]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2007.09.041 Byline: Kazuo Yamagata (a), Taiga Yamazaki (a), Hiromi Miki (b), Narumi Ogonuki (b), Kimiko Inoue (a)(b), Atsuo Ogura (a)(b), Tadashi Baba (a) Keywords: Mouse; DNA methylation; Germ cell lineage; Somatic cell cloning; Centric/pericentric region; Epigenetics Abstract: Germ cells have unique features strikingly distinguishable from somatic cells. The functional divergence between these two cell lineages has been postulated to result from epigenetic mechanisms. Here we show that the chromosomal centric and pericentric (C/P) regions in male and female germline cells are specifically DNA-hypomethylated, despite the hypermethylation status in somatic cells. In multipotent germline stem cells, the C/P region was initially hypomethylated and then shifted to the hypermethylation status during differentiation into somatic lineage in vitro. Moreover, the somatic-type hypermethylation pattern was maintained in the somatic cell-derived nuclear transfer embryos throughout preimplantation development. These results imply that the identity of germ cell lineage may be warranted by the hypomethylation status of the C/P region as an epigenetic signature. Author Affiliation: (a) Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba Science City, Ibaraki 305-8572, Japan (b) RIKEN, Bioresource Center, Tsukuba Science City, Ibaraki 305-0074, Japan Article History: Received 14 June 2007; Revised 20 September 2007; Accepted 21 September 2007

Germline cells that can form different embryonic stem (ES) as well as embryonic germ (EG) cells are obtained only from embryonic tissues, hence tests were conducted to obtain such cells from other sources. Researchers conducted tests to obtain similar ES-like cells from neonatal mouse testis and these cells were similar to the ES/EG cells except that in their genomic imprinting pattern.

Spermatogenesis is a highly specialized process of cellular differentiation to produce spermatozoa. This differentiation process accompanies morphological changes that are controlled by a number of genes expressed in a stage-specific manner during spermatogenesis. Here we show that in mice, the absence of a testis-specific, cytoplasmic polyadenylate [poly(A)] polymerase, TPAP, results in the arrest of spermiogenesis. TPAP-deficient mice display impaired expression of haploid-specific genes that are required for the morphogenesis of germ cells. The TPAP deficiency also causes incomplete elongation of poly(A) tails of particular transcription factor messenger RNAs. Although the overall cellular level of the transcription factor TAF10 is unaffected, TAF10 is insufficiently transported into the nucleus of germ cells. We propose that TPAP governs germ cell morphogenesis by modulating specific transcription factors at posttranscriptional and posttranslational levels., Poly(A) tails of eukaryotic mRNAs are implicated in various aspects of mRNA metabolism, including transport into the cytoplasm, stability, and translational control (1, 2). Thus, the control of poly(A) tail [...]

Here we investigated the pathogenesis of deletion mutant mitochondrial (mt)DNA by generating mice with mutant mtDNA carrying a 4696-basepair deletion ([DELTA]mtDNA4696), and by using cytochrome c oxidase (COX) electron micrographs to identify COX activity at the individual mitochondrial level. All mitochondria in tissues with [DELTA]mtDNA4696 showed normal COX activity until [DELTA]mtDNA4696 accumulated predominantly; this prevented mice from expressing disease phenotypes. Moreover, we did not observe coexistence of COX-positive and -negative mitochondria within single cells. These results indicate the occurrence of inter-mitochondrial complementation through exchange of genetic contents between exogenously introduced mitochondria with [DELTA]mtDNA4696 and host mitochondria with normal mtDNA. This complementation shows a mitochondria-specific mechanism for avoiding expression of deletion-mutant mtDNA, and opens the possibility of a gene therapy in which mitochondria possessing full-length DNA are introduced., Author(s): Kazuto Nakada [1, 2, 3, 6]; Kimiko Inoue [1, 5, 6]; Tomoko Ono [1]; Kotoyo Isobe [1]; Atsuo Ogura [5]; Yu-Ichi Goto [4]; Ikuya Nonaka [3]; Jun-Ichi Hayashi (corresponding [...]

● Report of filaminopathy in a female patient with a mutation in Filamin C. ● The patient developed arrhythmogenic hypertrophic cardiomyopathy at age 6. ● Myofibrillar myopathy with respiratory failure and scoliosis were noted. ● Gastric polyp, urinary bladder tumor, and breast cancer were observed. ● This case showcases the clinical spectrum of filaminopathy. We report a case of a patient presenting with arrhythmogenic cardiomyopathy, myofibrillar myopathy, and multiorgan tumors. A 41-year-old woman with a history of hypertrophic cardiomyopathy, diagnosed at 6 years of age, developed scoliosis after puberty. Following spinal surgery to address the scoliosis, she developed recurrent severe arrhythmia and heart failure. She developed hypoventilation at age 29 years. Proximal dominant weakness and mild elevation of serum creatine kinase indicated possible myopathy. Myofibrillar myopathy was diagnosed by muscle biopsy at age 30 year. Acute abdomen was repeatedly reported from age 33 years, eventually leading to a diagnosis of gastric polyp and erosive ulcer. A urinary bladder tumor was found at age 35 years, and breast cancer was diagnosed at age 40 years. Whole exome sequencing detected a heterozygous missense mutation in Filamin C. Recent evidences suggest that filamins are associated with tumors, and this case further highlights the clinical spectrum of filaminopathy. [ABSTRACT FROM AUTHOR]

During natural fertilization, mammalian spermatozoa must pass through the zona pellucida before reaching the plasma membrane of the oocyte. It is assumed that this step involves partial lysis of the zona by sperm acrosomal enzymes, but there has been no unequivocal evidence to support this view. Here we present evidence that acrosin, an acrosomal serine protease, plays an essential role in spermpenetration of the zona. We generated acrosin-knockout (KO) hamsters, using an in vivo transfection CRISPR/Cas9 system. Homozygous mutant males were completely sterile. Acrosin-KO spermatozoa ascended the female genital tract and reached ovulated oocytes in the oviduct ampulla, but never fertilized them. In vitro fertilization (IVF) experiments revealed that mutant spermatozoa attached to the zona, but failed to penetrate it. When the zona pellucida was removed before IVF, all oocytes were fertilized. This indicates that in hamsters, acrosin plays an indispensable role in allowing fertilizing spermatozoa to penetrate the zona. This study also suggests that the KO hamster system would be a useful model for identifying new gene functions or analyzing human and animal disorders because of its technical facility and reproducibility. [ABSTRACT FROM AUTHOR]

Exclusion of paternal mitochondria in fertilized mammalian eggs is very stringent and ensures strictly maternal mtDNA inheritance. In this study, to examine whether elimination was specific to sperm mitochondria, we microinjected spermatid or liver mitochondria into mouse embryos. Congenic B6-[mt.sup.spr] strain mice, which are different from C57BL/6J (B6) strain mice (Mus musculus domesticus) only in possessing M. spretus mtDNA, were used as mitochondrial donors. B6-[mt.sup.spr] mice and a quantitative PCR method enabled selective estimation of the amount of M. spretus mtDNA introduced even in the presence of host M. m. domesticus mtDNA and monitoring subsequent changes of its amount during embryogenesis. Results showed that M. spretus mtDNA in spermatid mitochondria was not eliminated by the blastocyst stage, probably due to the introduction of a larger amount of spermatid mtDNA than of sperm mtDNA into embryos on fertilization. However, spermatid-derived M. spretus mtDNA was eliminated by the time of birth, whereas liver-derived M. spretus mtDNA was still present in most newborn mice, even though its amount introduced was significantly less than that of spermatid mtDNA. These observations suggest that mitochondria from spermatids but not from liver have specific factors that ensure their selective elimination and resultant elimination of mtDNA in them, and that the occurrence of elimination is not limited to early stage embryos, but continues throughout embryogenesis.