Journal of Reproduction and Development最新文献

{"title":"Evaluation of the clinical utility of poor-quality embryos using an extended in vitro embryo culture system.","authors":"Can Cheng, Shuoping Zhang, Yifan Gu, Fei Gong, Ge Lin, Lizhi Leng","doi":"10.1262/jrd.2026-032","DOIUrl":"10.1262/jrd.2026-032","url":null,"abstract":"<p><p>There is limited consensus among embryologists regarding the decision to freeze or discard borderline-quality blastocysts. This study aims to investigate the intrinsic developmental potential of blastocysts with poor inner cell mass (ICM) or trophectoderm (TE) quality using an in vitro three-dimensional (3D) culture system that excludes maternal factors. A total of 51 one-pronucleus (1PN)-derived blastocysts were obtained from couples undergoing assisted reproduction technology (ART). The embryos were categorized into three groups: 20 high-quality embryos, 17 embryos with poor ICM, and 14 embryos with poor TE. A 3D culture system was utilized to assess the post-implantation developmental potential of blastocysts with varying grades. Embryonic morphology and diameter were measured to evaluate growth characteristics, and immunofluorescence staining was performed to assess the differentiation of embryonic lineages. 35% of high-quality 1PN embryos developed into OCT4 + epiblast (EPI), GATA6 + hypoblast (HYP), and CK7 + TE, along with an amniotic cavity and yolk sac. Blastocysts with poor TE quality demonstrate reasonable developmental potential, whereas those with poor ICM quality are already compromised during implantation. This study provides valuable insights for ART and clinical management of low-quality blastocysts.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"813-818"},"PeriodicalIF":2.1,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13677168/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148345651","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 serum-free cryomedia for slow-freezing of chicken primordial germ cells.","authors":"Asma Khatun, Saori Harada, Satoru Ohira, Haruto Takeuchi, Haruto Shirahase, Natsumi Takahashi, Wataru Fujii, Sota Takamiya, Kazuhiro Rikimaru, Masaki Kato, Yoshiaki Nakamura","doi":"10.1262/jrd.2026-087","DOIUrl":"10.1262/jrd.2026-087","url":null,"abstract":"<p><p>The preservation of chicken genetic resources is important to both backup commercial breeds that support egg and meat production worldwide and conserve the genetic diversity of indigenous breeds, which is essential for managing breeding according to future demands. Because chicken embryos are attached to a large yolk, cryopreservation is technically impossible. In chickens, a unique developmental engineering approach based on the manipulation of primordial germ cells (PGCs), the embryonic precursor cells of gametes, has been developed. Cryobanking of PGCs is an innovative strategy for efficiently maintaining chicken genetic resources without breeding live birds. Cryomedia containing dimethyl sulfoxide or propylene glycol (PG) as permeable cryoprotectants, combined with serum as a non-permeable cryoprotectant, have been widely used for the cryopreservation of chicken PGCs. However, because the serum composition varies greatly, performance differences arise between lots. Consequently, there is a demand for serum-free cryomedia with specific known compositions. Here, we investigated the cryoprotective effects of ovalbumin and sericin, as alternatives to serum, on chicken PGCs. Two cryomedia were designed: PO comprising 7.5% PG and 5% ovalbumin and PS comprising 7.5% PG and 2% sericin. Following the culture of PGCs cryopreserved in these cryomedia, viability and cell doubling times recovered to levels comparable to those of an unfrozen control group at 6 and 2 d post-culture, respectively. When frozen-thawed PGCs were transplanted, their gonadal migration ability was significantly lower immediately after thawing, but recovered to levels comparable to those of the unfrozen control group after 4 d of culture. We successfully revived viable offspring from Hinai-dori, designated as a natural monument of Japan, from PGCs cryopreserved in these cryomedia. In conclusion, we developed two serum-free cryomedia that achieved > 60% recovery of viable PGCs after thawing while maintaining germline competency.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"838-847"},"PeriodicalIF":2.1,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148430648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A decrease in glucose supply promotes cell death in bovine corpus luteum.","authors":"Aoi Jimbo, Hiroki Hasegawa, Masamichi Yamashita, Takeshi Yamaguchi, Kiyoshi Okuda, Ryo Nishimura","doi":"10.1262/jrd.2026-052","DOIUrl":"10.1262/jrd.2026-052","url":null,"abstract":"<p><p>Glucose (GLU) is an essential energy source for mammalian cells, and its depletion induces various cellular responses, including apoptosis. The present study examined whether a decrease in GLU levels induces apoptotic cell death, which typically occurs during regression of the bovine corpus luteum (CL). To investigate the possible mechanisms of luteal cell death induced by low GLU levels, we examined the effect of GLU-free medium on the expression of apoptosis-regulating factors (FAS, BAX, BCL2, CASP8, and CASP3). Luteal cells cultured in GLU-free medium showed reduced viability, which was rescued by GLU supplementation in a dose-dependent manner. Culturing without GLU increased the expression of FAS and CASP3 mRNAs. Inhibiting glucose transporter 1 (GLUT1) with cytochalasin B or STF-31 in the presence of GLU also induced cell death. Based on these findings, a decrease in GLU supply, which is induced by a decrease in blood flow to the CL during luteolysis, may promote apoptosis by stimulating the expression of FAS and CASP3 in the bovine CL.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"848-852"},"PeriodicalIF":2.1,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13677196/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148536511","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":"Assessment of cumulus expansion capacity based on morphological characteristics and its effect on bovine in vitro-produced embryo development.","authors":"Tsumugi Yoshiyama, Masafumi Miwa, Miki Sakatani","doi":"10.1262/jrd.2026-028","DOIUrl":"10.1262/jrd.2026-028","url":null,"abstract":"<p><p>The quality of oocytes is crucial for embryonic development. The morphology of cumulus-oocyte complexes (COCs) and cumulus expansion are widely used indicators of oocyte quality; however, quantitative evidence is limited. We investigated the potential of assessing the quality of COCs based on their objective morphological characteristics and the impact of cumulus expansion on bovine in vitro-produced embryo development. COCs were graded before in vitro maturation (IVM) according to the International Embryo Technology Society (IETS) standards, and their morphological characteristics (area, perimeter, circularity, and solidity) were measured. The cumulus expansion rate and nuclear maturation were then evaluated after IVM. Decision tree models were developed based on COC morphology to classify COC grades and predict the cumulus expansion rate. In another experiment, COCs were divided into two groups based on a 100% cumulus expansion threshold, and embryonic development was assessed. The results revealed that the morphological characteristics of COCs were associated with the IETS grades and cumulus expansion rate but not with nuclear maturation. The predictive models for cumulus expansion capacity achieved an accuracy of 75.5%. COCs with greater cumulus expansion exhibited a significantly higher proportion of ≥ eight-cell-stage embryos on day 2 (14.0 ± 5.9%, P < 0.05). However, the blastocyst formation rate did not differ according to the extent of cumulus expansion. These findings indicate that an objective morphological assessment can predict cumulus expansion capacity and may provide a non-invasive and reproducible approach for selecting high-quality COCs before IVM, potentially indicating an association with the speed of early embryonic development.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"830-837"},"PeriodicalIF":2.1,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148430629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of dynamic changes in human sperm heat shock protein A2 in male infertility.","authors":"Akiko Natsume, Yasuhiko Ozaki, Yu Kitadate, Shotaro Hayashi, Yosuke Matsumoto, Tomoki Takeda, Shoichiro Iwatsuki, Seiji Mabuchi, Yukihiro Umemoto","doi":"10.1262/jrd.2026-023","DOIUrl":"10.1262/jrd.2026-023","url":null,"abstract":"<p><p>Male factors account for approximately 50% of infertility cases; however, the mechanisms underlying sperm dysfunction remain unclear. Heat shock protein A2 (HSPA2) is a biomarker associated with sperm fertilization; however, few studies have examined changes in its localization in vitro. This study investigated the in vitro localization dynamics of HSPA2 in sperm and its association with male infertility. Fertility status was determined according to the 2021 World Health Organization criteria. Semen samples were collected from 28 men with normal findings and 57 men with varicocele or oligozoospermia. Samples were subjected to density gradient centrifugation and the swim-up procedure, followed by a 24 h incubation. HSPA2 protein levels were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blotting, and localization patterns were evaluated using immunofluorescence staining. Western blot analysis showed that HSPA2 levels were significantly lower in samples from men with oligozoospermia (P < 0.01) and varicocele (P < 0.05) than in those from men with normal findings. Moreover, HSPA2 levels were correlated with total motile sperm counts and sperm motility. The percentage of sperm with HSPA2 localized in the acrosomal region immediately after sperm processing was lower (P < 0.01) and peaked later in samples from men with oligozoospermia and varicocele than in those from men with normal findings. These findings indicate that the reduced acrosomal localization of HSPA2 and delayed acrosomal localization dynamics after sperm processing represent a shared feature of male infertility rather than condition-specific differences and may be linked to impaired sperm function.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"740-746"},"PeriodicalIF":2.1,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13677204/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148251850","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 glucocorticoid system in bovine oviduct epithelial cells attenuates lipopolysaccharide induced inflammatory responses.","authors":"Omowumi Funmilayo Ademola, Sameera Premaratne, Yuki Muranishi, Hiroyuki Watanabe, Masafumi Tetsuka","doi":"10.1262/jrd.2026-049","DOIUrl":"10.1262/jrd.2026-049","url":null,"abstract":"<p><p>The bovine oviduct supports early reproductive events that require a balance between immune defense and tolerance. Glucocorticoids are well-known immune modulators; however, their presence, regulation, and functional relevance in the bovine oviduct remain poorly understood. This study investigated the presence and role of the corticosteroid system in the bovine oviduct and cultured bovine oviduct epithelial cells (BOECs). Bovine oviducts were collected during estrous cycle, fixed in 4% paraformaldehyde and processed for immunohistochemistry. BOECs were harvested from the ampulla and isthmus and cultured under sequential progesterone and estradiol treatment to mimic estrous cycles. On day 8, which equivalent to post‑ovulation day 1 in vivo, cells were treated with lipopolysaccharide (LPS; 1 μg/ml), cortisol (100 nM), cortisone (100 nM), or their combinations for 24 h. After culture, cells were harvested for gene analysis by RT-PCR, while spent media were collected for cortisol measurement by ELISA. Immunohistochemistry revealed predominant epithelial localization of NR3C1, NR3C2, HSD11B1, and HSD11B2 in both ampulla and isthmus. During 7-day preculture, expression of NR3C1 and HSD11B1 persisted, whereas that of NR3C2 and HSD11B2 declined sharply. LPS treatment on day 8 sharply upregulated TLR2, TNF, IL1B, IL6, CXCL8 and HSD11B1, whereas the concomitant treatment with cortisol suppressed all LPS-induced cytokines. BOECs were capable to convert added cortisone to cortisol, and LPS doubled this through up-regulating HSD11B1. Locally produced cortisol also suppressed LPS-induced cytokines. Collectively, these findings demonstrate that BOECs possess a functional glucocorticoid system, capable of producing cortisol from cortisone, which in turn suppresses LPS-induced inflammation.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"756-765"},"PeriodicalIF":2.1,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13677207/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148199345","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":"Involvement of cocaine- and amphetamine-regulated transcript neurons in glucoprivic suppression of pulsatile luteinizing hormone secretion in female rats.","authors":"Sena Matsuzaki, Safiullah Hazim, Yuna Toyohama, Koki Yamada, Shunsuke Seki, Kota Inamura, Yuki Otsuka, Marina Takizawa, Chisato Noda, Naoko Inoue, Hiroko Tsukamura, Yoshihisa Uenoyama","doi":"10.1262/jrd.2026-059","DOIUrl":"10.1262/jrd.2026-059","url":null,"abstract":"<p><p>Malnutrition often suppresses reproductive function by inhibiting the pulsatile secretion of gonadotropin-releasing hormone (GnRH)/gonadotropins in mammals. This study aimed to determine whether cocaine- and amphetamine-regulated transcript (CART) neurons mediate the suppression of GnRH/gonadotropin pulses under malnutrition, since CART neurons have been reported to project to kisspeptin/neurokinin B/dynorphin A neurons (also known as the GnRH pulse generator) and GnRH neurons in rats. Wistar-Imamichi female rats were ovariectomized (OVX), and some of these rats were immediately implanted with subcutaneous Silastic tubing containing estradiol-17β (OVX + low E2) to maintain a diestrous level of estrogen. Free-moving conscious OVX and OVX + low E2 rats were subjected to 1-h frequent blood sampling followed by brain sampling to examine whether acute glucoprivation by peripheral administration of 2-deoxy-D-glucose (2DG), a glucose utilization inhibitor, suppressed the secretion of luteinizing hormone (LH) and activated hypothalamic CART neurons. The other cohort of animals was subjected to 3-h frequent blood sampling to examine whether central CART administration suppresses pulsatile LH secretion. Peripheral 2DG administration suppressed LH secretion and activated CART neurons in the hypothalamic supraoptic nucleus (SON) and parvocellular paraventricular nucleus (PVN), but not in the magnocellular PVN-zona incerta-dorsomedial nucleus continuum and arcuate nucleus, in OVX and OVX + low E2 rats. In addition, central CART administration suppressed pulsatile LH secretion in OVX and OVX + low E2 rats. These results suggest the possible involvement of CART neurons in the SON and parvocellular PVN in malnutrition-induced suppression of pulsatile LH secretion in female rats.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"853-861"},"PeriodicalIF":2.1,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13677171/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148535843","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":"Somatic cell nuclear transfer as a complementary tool for genetic conservation of the Peruvian Paso horse.","authors":"Jenin V Cortez, Gleni T Segura Portocarrero, Nilton L Murga Valderrama, William Bardales, Ricardo Encina Ruiz, Carmen L Velásquez Castillo, Christopher G Grupen, Jorge L Maicelo Quintana","doi":"10.1262/jrd.2026-068","DOIUrl":"10.1262/jrd.2026-068","url":null,"abstract":"<p><p>The Peruvian Paso horse, a breed of national significance in Peru known for its unique gait, has been selectively bred for nearly 500 years and now faces potential risks due to reduced genetic diversity. To investigate the potential of somatic cell nuclear transfer to enhance genetic conservation strategies, a program was initiated to produce cloned Peruvian Paso foals. Skin biopsies from a highly awarded stallion with exceptional breed-defining traits were used as the source of donor somatic cells. Of the 15 cloned embryos reconstructed, seven blastocysts were produced, and five were transferred to five recipient mares. Three pregnancies ensued, two of which resulted in the birth of healthy foals at 333 and 347 days of gestation. Cloned foals were genetically and phenotypically identical to the donor animal, demonstrating the successful application of this approach to support genetic conservation in a protected horse breed.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"887-890"},"PeriodicalIF":2.1,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13677195/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148620540","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":"Spheroid granulosa cell supplementation improves granulosa cell-oocyte interactions and enhances in vitro growth of oocytes in cows.","authors":"Kota Ushiroshoji, Takuya Ui, Genya Ito, Ayaka Sugimoto, Asuka Kamio, Tomomi Tadokoro, Komei Shirasuna, Hisataka Iwata","doi":"10.1262/jrd.2026-050","DOIUrl":"10.1262/jrd.2026-050","url":null,"abstract":"<p><p>Oocytes develop through bidirectional communication with surrounding granulosa cells (GCs), and differences in the GC environment represent a major distinction between in vivo and in vitro oocyte growth systems. However, the influence of GC number and organization on oocyte growth and quality during in vitro culture remains unclear. In this study, oocyte-granulosa cell complexes (OGCs) derived from early antral follicles (0.5-0.7 mm) of cows were supplemented with spheroid granulosa cells (GC-S) derived from antral follicles (3-5 mm). GC-S were incorporated into OGCs during 14 days of incubation. Oocyte characteristics, maturation, and fertilization competence were evaluated, and the transcriptomic profiles of surrounding GCs were analyzed by RNA sequencing. GC-S supplementation increased transzonal projections and improved GC survival within OGCs, indicating enhanced GC-oocyte interactions. It also increased ATP content, oocyte diameter, and DNA methylation levels, reaching levels comparable to those observed in in vivo-grown oocytes. Furthermore, GC-S supplementation significantly improved oocyte maturation and fertilization rates, although these remained lower than those of in vivo counterparts. In contrast, lipid content, mitochondrial DNA copy number, and mitochondrial membrane potential were not affected and remained lower than those of in vivo-grown oocytes. RNA-seq analysis revealed that GC-S supplementation altered the expression of genes associated with focal adhesion and cytoskeleton-related pathways toward those observed in vivo. These results demonstrate that spheroid GC supplementation improves GC-oocyte interactions and partially restores in vivo-like characteristics of oocytes during in vitro growth.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"776-785"},"PeriodicalIF":2.1,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148295540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overconfluent culture promotes cell cycle synchronization in mouse embryonic stem cells for efficient cloned embryo production.","authors":"Dinh Quoc Pham, Shogo Matoba, Satoshi Funaya, Michiko Hirose, Fumio Ike, Ayako Isotani, Narumi Ogonuki, Masahito Ikawa, Nguyen VAN Thuan, Atsuo Ogura, Kimiko Inoue","doi":"10.1262/jrd.2026-069","DOIUrl":"10.1262/jrd.2026-069","url":null,"abstract":"<p><p>Mouse embryonic stem cell (ESC) cloning via nuclear transfer is a potential platform for direct generation of genetically modified mice. However, the low G1 cell population in ESCs hampers their broader use in nuclear transfer, as S-phase donors induce 1-cell arrest in reconstructed oocytes. This study aimed to enrich the G1-phase population of ESCs to improve ESC-based cloning efficiency. We demonstrated that EB3 ESCs derived from the 129/Ola strain and C57BL/6×129/Sv hybrid ESCs exhibited superior traits for nuclear transfer in terms of cleavage rate and blastocyst formation but showed reduced efficiency in development to term. Transcriptomic analyses revealed that this failure was likely due to aberrant imprinted gene expression in critical clusters, such as H19-Igf2 or Dlk1-Dio3. In contrast, although cloned offspring were successfully generated at a promising rate (approximately 6%) using EGR-R01 (BDF1×129/Sv) ESCs, early cleavage to the 2-cell embryo was inefficient. To address this, we induced cell cycle synchronization by culturing ESCs to overconfluency, which markedly increased the G1 proportion, as confirmed via FACS analysis. This alteration led to a significant improvement in first cleavage efficiency without compromising the developmental potential of ESC-derived cloned embryos to live birth. Overall, our study highlights the importance of both cell cycle synchronization and imprinting maintenance in improving ESC cloning efficiency to facilitate broad applications, including the direct generation of genetically modified mice.</p>","PeriodicalId":16942,"journal":{"name":"Journal of Reproduction and Development","volume":" ","pages":"819-829"},"PeriodicalIF":2.1,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13677205/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148411990","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}