Journal of Reproduction and Development最新文献

{"title":"Identification of the optimal manipulation medium temperature for in vitro handling of oocytes and embryos during in vitro maturation, parthenogenesis, and in vitro culture in pigs.","authors":"So Yeon Nam, Su Bin Jung, Ha Rin Namkung, Ji Won Han, Jeong Min Lee, Young Jae Lee, Jung Im Yun, Eun Song Lee, Jeong Mook Lim, Seung Tae Lee","doi":"10.1262/jrd.2026-031","DOIUrl":"10.1262/jrd.2026-031","url":null,"abstract":"<p><p>Exposure of cumulus-oocyte complexes (COCs), mature oocytes, and preimplantation embryos to subphysiological temperatures during in vitro maturation (IVM), parthenogenesis (PG), and in vitro culture (IVC) has been shown to impair oocyte maturation, embryogenesis, and developmental competence. However, most previous studies have focused primarily on defining optimal embryo culture temperatures. Therefore, the present study aimed to establish optimal temperature conditions for in vitro manipulation, to minimize impairment of oocyte maturation, embryogenesis, and preimplantation development. All in vitro manipulation steps during the IVM, PG, and IVC processes were conducted using manipulation media maintained at defined temperatures (39°C, 38°C, 37°C, 35°C, 34°C, and 33°C) through the combined use of microscope warming plates and infrared irradiation. Oocyte maturation and the preimplantation developmental competence of embryos following parthenogenetic activation were subsequently evaluated. The use of infrared irradiation to control manipulation medium temperature precisely did not adversely affect oocyte maturation or embryonic developmental competence. Among the subphysiological temperature conditions examined (33°C-38°C), maintaining the in vitro manipulation media at 35°C throughout the IVM, PG, and IVC processes resulted in significantly reduced perivitelline space size, increased intra-ooplasmic glutathione levels, improved mitochondrial distribution normality, and enhanced preimplantation development compared with manipulation at 39°C, the physiological body temperature of pigs. Based on these results, we suggest that in vitro manipulation of immature COCs, oocytes, and embryos in pigs should be performed using manipulation media maintained at 35°C.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"691-699"},"PeriodicalIF":2.1,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13441541/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148015933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ovarian and follicular culture enables the production of fertile oocytes in C57BL/6 mice.","authors":"Kyota Yoshida, Minami Fukuzawa, Yayoi Obata","doi":"10.1262/jrd.2026-008","DOIUrl":"10.1262/jrd.2026-008","url":null,"abstract":"<p><p>In vitro experiments have become a powerful alternative to in vivo approaches for analyzing gene functions and molecular mechanisms. However, successful in vitro oogenesis using the C57BL/6 strain-widely used as a standard mouse model in mammalian studies-has not yet been reported. In this study, we established a 30-day culture system combining ovarian and follicular culture, and successfully produced fully competent oocytes from neonatal C57BL/6N ovaries, which contain only non-growing oocytes prior to primordial follicle formation. A key contributing factor to this success was the supplementation of dibutyryl cyclic AMP, a membrane-permeable analogue of endogenous cyclic AMP, which promoted follicular growth. This culture system provides a valuable tool for investigating the mechanisms underlying oogenesis.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"710-714"},"PeriodicalIF":2.1,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13441539/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147463561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monosodium glutamate protects DNA of freeze-dried somatic cells and improves development of somatic cell nuclear transfer embryos.","authors":"Kosuke Tanaka, Ai Namiki, Natsuki Ushigome, Kango Yamaji, Daiyu Ito, Sayaka Wakayama, Teruhiko Wakayama","doi":"10.1262/jrd.2026-036","DOIUrl":"10.1262/jrd.2026-036","url":null,"abstract":"<p><p>Freeze-dried (FD) somatic cells serve as a novel method for preserving animal genetic resources; however, the efficiency of cloned mice production from FD somatic cells remains low, owing to severe nuclear damage induced by the freeze-drying. In this study, we aimed to mitigate freeze-drying-induced damage by evaluating protectants that have been reported to exert protective effects during freeze-drying of microorganisms, and to identify those most effective for somatic cells. Results showed, that using Tris-EGTA as the basal medium for freeze-drying, together with monosodium glutamate (MSG) as a protective agent, significantly reduced DNA damage in FD somatic cells after injection into oocytes. Subsequent optimization of MSG concentration revealed that the addition of 3% MSG markedly increased the formation rate of premature chromosome condensation from 50.0% to 80.4% compared with the non-MSG condition. Moreover, the rate of normal chromosome segregation at the two-cell stage of cloned embryos increased from 0% to 20.0%. Furthermore, although no blastocysts were obtained in the absence of MSG, the addition of 3% MSG enabled the formation of morphologically good-quality blastocysts, albeit at a low frequency. These findings indicated that the addition of 3% MSG reduces DNA damage in FD somatic cells and improves the developmental competence of somatic cell nuclear transfer embryos, representing the first step toward the practical application of FD somatic cells as genetic resources.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"660-670"},"PeriodicalIF":2.1,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13461264/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147723215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond a single signal: How can bovine pregnancy be established without IFNT?","authors":"Toshihiro Sakurai, Hanako Bai, Kazuya Kusama, Kazuhiko Imakawa","doi":"10.1262/jrd.2026-051","DOIUrl":"10.1262/jrd.2026-051","url":null,"abstract":"<p><p>Interferon tau (IFNT) has been regarded as the dominant conceptus signal for maternal recognition of pregnancy (MRP) in ruminants. In cattle, IFNT is classically proposed to prevent luteolysis by suppressing uterine luteolytic pulses of prostaglandin F2α (PGF2α). IFNT also induces endometrial interferon-stimulated genes (ISGs) such as ISG15, MX dynamin-like GTPase 2 (MX2), and 2'-5'-oligoadenylate synthetase 1 (OAS1), thereby supporting uterine receptivity and an attachment-supportive immune milieu. A recent loss-of-function report using conceptuses lacking functional IFNT challenges this view by describing conceptus elongation and persistence of luteal function in a subset of recipients despite markedly reduced uterine ISG induction during the peri-implantation window. Here, we interpret this claim conservatively and specify experimental boundary conditions that currently limit generalization, including somatic cell nuclear transfer (SCNT), multi-embryo transfer, limited sample size, and the absence of direct physiological readouts of PGF2α pulsatility and the estrogen receptor 1 (ESR1) and oxytocin receptor (OXTR) axis. We then summarize possible buffering routes that could support early pregnancy when IFNT input is weakened, focusing on prostaglandin network rerouting toward luteoprotective outputs such as PGE2, extracellular vesicle (EV)-mediated communication, steroid-immune interactions, and corpus luteum (CL) gating of luteolytic sensitivity. Finally, we discuss how bovine endogenous retrovirus (BERV) long terminal repeats (LTRs) retaining interferon-responsive motifs, including interferon-stimulated response elements (ISREs), gamma-activated sequences (GAS), and ETS-family motifs, may act as enhancer substrates that amplify cytokine inputs in a cell-type and chromatin-dependent manner. Overall, we suggest that IFNT should be evaluated as a frequently dominant signal within a system that includes parallel buffering routes, such that the apparent requirement for IFNT can vary with conceptus load, uterine endocrine conditions, and ERV-derived regulatory architecture.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"612-617"},"PeriodicalIF":2.1,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13441456/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147839314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of a GnRH antagonist on antral follicular development and ovarian hemodynamics in cycling ewes.","authors":"Jakub Bartlewski, Maria Emilia Franco Oliveira, Pawel M Bartlewski","doi":"10.1262/jrd.225-109","DOIUrl":"10.1262/jrd.225-109","url":null,"abstract":"<p><p>Sixteen multiparous Santa Inês ewes underwent transrectal ovarian ultrasonography from days 6 to 17 (D6-17; D0 = ovulation). On D6, ewes received a single subcutaneous injection of Firmagon^® at a low dose (LD; n = 5; 215 µg/kg body weight [b.w.]) or a high dose (HD; n = 6; 235 µg/kg b.w.); controls (C; n = 5) received saline. Ovulations were detected in 100% of controls, but only in 20% of LD and 17% of HD animals. Mean daily numbers of large antral follicles (> 4.49 mm) decreased (P < 0.05) between D6 and D7 in HD group. Compared with controls, LD ewes had higher (P < 0.05) ovarian artery pulsatility index (PI; D16-17) and resistive index (RI; D17), but lower flow-propagation velocity (FPV; D17), whereas HD ewes exhibited higher PI (D15) and RI (D17), along with lower FPV (D8 and D15) and end-diastolic velocity (D17). Firmagon^® treatment was associated with a reduced number of large antral follicles and alterations in ovarian blood perfusion.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"80-85"},"PeriodicalIF":2.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13078924/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146202094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Current status and advances in bovine semen production technologies for artificial insemination in Japan.","authors":"Yousuke Naniwa, Masashi Kinukawa, Kyoko Uchiyama","doi":"10.1262/jrd.2025-141","DOIUrl":"10.1262/jrd.2025-141","url":null,"abstract":"<p><p>Artificial insemination (AI) is the predominant reproductive technology in Japanese cattle breeding, particularly for genetic improvement of dairy and beef cattle. This review outlines the historical development, current status, and recent advances in semen production technologies for AI in Japan and addresses the remaining challenges and future directions. The adoption of AI accelerated after the Act on Improvement and Increased Production of Livestock was implemented in 1950, with frozen semen replacing liquid semen by the mid-1960s. Advances in cryobiology and genomic selection have improved breeding efficiency; however, fertility issues persist. In dairy cattle, conception rates have declined primarily due to high milk yield, negative energy balance, and heat stress. In beef cattle, particularly Japanese Black cattle, conception rates remain stable overall, but subfertile sires still occur despite normal post-thaw semen quality. Studies on sperm motility, acrosomal integrity, and genomic variants have identified a single nucleotide polymorphism (SNP) marker linked to extreme subfertility in Japanese Black bulls. Japan has developed innovative technologies such as the two-layer semen straw (FCMax), which enhances post-thaw sperm function through in-straw dilution and supplementation. Field trials have suggested potential improvements in conception rates; however, large-scale validation studies are still ongoing. Furthermore, sexed semen technology has been widely adopted in Japan and achieved conception rates comparable to those of conventional semen. Emerging challenges include labor efficiency in large-scale farms, prompting interest in improved thawing protocols or liquid semen alternatives. Future priorities include integrating genomic tools, refining cryobiological techniques, and implementing practical innovations to sustain cattle reproduction in evolving production systems.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"39-47"},"PeriodicalIF":2.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13078927/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147276486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of a three-dimensional culture model of endometrium to study embryo-uterine interactions.","authors":"Nobuhiko Yamauchi","doi":"10.1262/jrd.2025-102","DOIUrl":"10.1262/jrd.2025-102","url":null,"abstract":"<p><p>Three-dimensional (3D) culture systems provide physiologically relevant models that better replicate in vivo cell architecture and function compared to the conventional two-dimensional cultures. In reproductive biology, 3D models of endometrial cells have emerged as powerful tools to investigate uterine physiology, embryo-maternal interactions, and implantation processes. Gel-based cultures using natural extracellular matrices such as collagen or Matrigel enable endometrial epithelial and stromal cells to form gland-like or fibroblast-like structures while maintaining hormone responsiveness and secretory activity. In addition, spheroid cultures recapitulate cell polarity, paracrine signaling, and tissue remodeling, offering insights into implantation biology and endometrial pathologies such as endometriosis. Our studies have demonstrated that bovine endometrial epithelial cells embedded in Matrigel exhibit enhanced glandular gene expression and that engineered hetero-spheroids provide stable models for studying interferon-induced matrix remodeling. Furthermore, co-culture of cultured endometrial explants with rat hatched blastocyst facilitates in vitro analysis of embryo attachment and uterine receptivity. Advances in organoid and microfluidic platforms extend these models by enabling long-term culture and dynamic hormonal regulation. Collectively, 3D culture approaches bridge the gap between in vitro experimentation and in vivo physiology, offering translational applications in reproductive medicine, livestock fertility management, and drug discovery.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"34-38"},"PeriodicalIF":2.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13078922/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145917929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large cyclic AMP-dependent increases in tyrosine-phosphorylated proteins are not absolutely necessary for the induction of full-type hyperactivation and penetration into eggs in ejaculated boar spermatozoa in vitro.","authors":"Ami Ueshiba, Riko Nakao, Riho Morikawa-Tomita, Hirohisa Kyogoku, Hiroshi Harayama","doi":"10.1262/jrd.2025-092","DOIUrl":"10.1262/jrd.2025-092","url":null,"abstract":"<p><p>Although it is well-known that sperm tyrosine-phosphorylated proteins increase in a cyclic AMP (cAMP)-dependent manner during capacitation, it remains unclear whether or not this reaction is involved directly in sperm fertilization-related events. This study aimed to examine the effects of pharmacological suppression of cAMP-dependent increases in tyrosine-phosphorylated proteins on the induction of full-type hyperactivation and penetration into eggs in boar spermatozoa. Ejaculated spermatozoa were treated with a cAMP analog (cBiMPS) and subsequently used for Western blotting, flagellar beating assays, and egg penetration assays. Marked increases in tyrosine-phosphorylated proteins and full-type hyperactivation were observed in spermatozoa treated with cBiMPS in the presence of CaCl₂. These spermatozoa effectively penetrated eggs. A spleen tyrosine kinase (SYK) inhibitor OXSI2 suppressed large cBiMPS-dependent increases in sperm tyrosine-phosphorylated proteins, in contrast to the ineffectiveness of SU6656 (a SRC family kinase inhibitor) and dasatinib (a c-ABL inhibitor). However, this suppression was not associated with changes in the state of full-type hyperactivation or the outcomes of egg penetration assays conducted in insemination medium without OXSI2. Conversely, adding OXSI2 to both the cBiMPS treatment medium and the sperm insemination medium suppressed increases in sperm tyrosine-phosphorylated proteins during insemination and significantly decreased the average number of spermatozoa that penetrated eggs. These results suggest that high SYK activation and large cAMP-dependent increases in tyrosine-phosphorylated proteins are not absolutely necessary for inducing full-type hyperactivation and penetration into eggs in boar spermatozoa in vitro, but may influence sperm functions associated with the outcomes of egg penetration assays.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"55-64"},"PeriodicalIF":2.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13078923/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146202041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Functional roles of NR4A transcription factors in GnRH regulation of gonadotropin gene expression and secretion in rat primary pituitary cells.","authors":"Ryota Terashima, Yuta Tomiyama, Shiro Kurusu, Mitsumori Kawaminami","doi":"10.1262/jrd.2025-100","DOIUrl":"10.1262/jrd.2025-100","url":null,"abstract":"<p><p>Gonadotropin-releasing hormone (GnRH) tightly regulates the synthesis and the release of gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), while the intracellular molecular mechanisms following GnRH signal for the regulation of transcription remain incompletely understood. In this study, we used primary culture of rat anterior pituitary cells to investigate the role of NR4A transcription factors (NR4A1, NR4A2, and NR4A3) in GnRH regulation of gonadotropin secretion. GnRH agonist stimulation rapidly and transiently increased Nr4a1, Nr4a2, and Nr4a3 expression within one hour, accompanied by a time-dependent increase in Fshb mRNA levels and the secretion of both FSH and LH. The knockdown of each Nr4a gene using siRNA significantly reduced Fshb expression under GnRH stimulation. Nr4a1 knockdown caused the most pronounced decrease in FSH secretion. Although Lhb and Cga mRNA levels were largely unaffected, LH secretion was consistently reduced following NR4A knockdown. These findings suggest that NR4A transcription factors act downstream of GnRH signaling to promote Fshb transcription and facilitate gonadotropin secretion, thereby modulating GnRH-dependent control of FSH and LH secretion.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"48-54"},"PeriodicalIF":2.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13078925/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145985102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Niacin improves developmental ability by increasing glutathione levels and promoting male pronuclear formation in porcine oocytes grown in vitro.","authors":"Takayuki Yamochi, Shu Hashimoto, Yoshiharu Morimoto","doi":"10.1262/jrd.2025-140","DOIUrl":"10.1262/jrd.2025-140","url":null,"abstract":"<p><p>We examined the effect of niacin, a water-soluble vitamin essential for the metabolism of carbohydrates, lipids, and other substrates, on the developmental potential of oocytes grown in vitro, as well as the number and activity of mitochondria and reduced glutathione (GSH) content in oocytes. Porcine oocytes were cultured in medium containing 0-10 mM niacin for 12 days. Subsequently, in vitro maturation was performed, followed by in vitro fertilization using intracytoplasmic sperm injection, and the ability to develop into blastocysts was examined. Niacin treatment (10 mM) increased the mitochondrial, GSH, and glutamate-cysteine ligase catalytic subunit contents in porcine oocytes grown in vitro. Furthermore, niacin treatment enhanced male pronuclear formation and blastocyst development rates in porcine oocytes grown in vitro. Niacin increased the mitochondrial content and GSH levels in porcine oocytes and enhanced the ability of oocytes to form male pronuclei, which in turn promoted embryonic development.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"73-79"},"PeriodicalIF":2.1,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13078926/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147276545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}