Project description:We reported a kind of new haploid embryonic stem cell, human haploid androgenetic embryonic stem cell, which kept the sperm characteristic epigenetic modification patterns for imprinting genes. In this study, two human haploid androgenetic embryonic stem cell lines (ha-AGHESC) and two human haploid parthenogenetic embryonic stem cell lines (ha-PGHESC) with somatic control and diploid HESC control, were processed with RNA-sequencing (RNA-seq) and whole genome bisulfite sequencing (WGBS). We showed that the reconstructed semi-clone HESCs were similar to the diploid HESC in transcriptome and the methylome especially related to the known human imprinting genes. The raw data of WGBS and bulk RNA-seq are deposited at Genome Sequence Archive (GSA) of Human with accession number HRA004100.
Project description:Many insects possess a hyper-elongated intromittent organ with a diameter of only a few micrometers. Using morphological and theoretical approaches, we investigated the biomechanics of sperm transfer through such organs by calculating (1) how far and how fast sperm could fill in the penis by capillary action, (2) how much capillary pressure is generated in the penis, and (3) how much pressure is needed to pump sperm out of the penis. The results enabled us to propose the following hypotheses: (1) penile filling basically occurs by capillary action, and (2) sperm transport to females occurs by contracting the sperm pump muscles or by active propulsion of spermatozoa. Potential experimental approaches to test these hypotheses are discussed.
Project description:In this study, the transcriptional state and distribution of RNA polymerase II, pre-mRNA splicing machinery elements, and rRNA transcripts were investigated in the sperm cells of Hyacinthus orientalis L. during in vitro pollen tube growth. During the second pollen mitosis, no nascent transcripts were observed in the area of the dividing generative cell, whereas the splicing factors were present and their pools were divided between newly formed sperm cells. Just after their origin, the sperm cells were shown to synthesize new RNA, although at a markedly lower level than the vegetative nucleus. The occurrence of RNA synthesis was accompanied by the presence of RNA polymerase II and a rich pool of splicing machinery elements. Differences in the spatial pattern of pre-mRNA splicing factors localization reflect different levels of RNA synthesis in the vegetative nucleus and sperm nuclei. In the vegetative nucleus, they were localized homogenously, whereas in the sperm nuclei a mainly speckled pattern of small nuclear RNA with a trimethylguanosine cap (TMG snRNA) and SC35 protein distribution was observed. As pollen tube growth proceeded, inhibition of RNA synthesis in the sperm nuclei was observed, which was accompanied by a gradual elimination of the splicing factors. In addition, analysis of rRNA localization indicated that the sperm nuclei are likely to synthesize some pool of rRNA at the later steps of pollen tube. It is proposed that the described changes in the nuclear activity of H. orientalis sperm cells reflect their maturation process during pollen tube growth, and that mature sperm cells do not carry into the zygote the nascent transcripts or the splicing machinery elements.
Project description:The mechanism underlying the potential risk associated with in vitro fertilization and embryo transfer (IVF?ET) has been previously investigated but remains to be fully elucidated. As the placenta is a critical organ that sustains and protects the fetus, this is an important area of research. The aim of the present study was to determine the difference in trophoblast cell function in the first trimester between naturally conceived pregnancies and pregnancies achieved via IVF?ET therapy. A total of 20 placental villi in first trimester samples were obtained through fetal bud aspiration from patients undergoing IVF?ET due to oviductal factors between January 2016 and August 2018. In addition, a further 20 placental villi were obtained from those who naturally conceived and had normal pregnancies but were undergoing artificial abortion; these patients were recruited as the controls. Reverse transcription?quantitative (RT?q)PCR and semi?quantitative immunohistochemical methods were used to detect the mRNA and protein expression of ??fetoprotein (AFP), vascular endothelial growth factor (VEGF), transferrin (TF), tubulin ?1 class VI (TUBB1), metallothionein 1G (MT1G), BCL2, glial cells missing transcription factor 1 (GCM1), epidermal growth factor (EGF) receptor (EGFR), PTEN and leukocyte associated immunoglobulin like receptor 2 (LAIR2) in villi from both groups. Differentially expressed genes were analyzed using Search Tool for the Retrieval of Interacting Genes, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was conducted. The RT?qPCR data revealed that the mRNA expression levels of AFP, VEGF and TF were significantly higher in the IVF?ET group than in the control group (P<0.05), and those of TUBB1, MT1G, BCL2, GCM1, EGFR, PTEN and LAIR2 were significantly lower (P<0.05). These gene products were expressed in the placental villus tissues, either in the cytoplasm, or in the membrane of syncytiotrophoblast and cytotrophoblast cells. The immunohistochemistry results were in line with those observed using RT?qPCR. KEGG pathway analysis indicated that the trophoblast cell function of the IVF?ET group in the first trimester was different from naturally conceived pregnancies with regard to proliferation, invasion, apoptosis and vascular development. The IVF?ET process may trigger adaptive placental responses, and these compensatory mechanisms could be a risk for certain diseases later in life.
Project description:Gibberellin, a plant growth regulator, is widely used to increase the shelf life and quality of fruits and vegetables. In this study, human semen samples were exposed to different concentrations of gibberellin, which reduced spermatozoa motility in vitro. Gibberellin exposure also increased levels of reactive oxygen species and the protein levels of apoptosis markers in human sperm. Gibberellin inhibited the activity of Na+/K+-adenosine triphosphatase (ATPase) and Ca2+-ATPase, which maintain the stability of ions inside and outside the membranes of spermatozoa. Moreover, gibberellin exposure suppressed adenosine triphosphate production and reduced the protein levels of adenosine triphosphate synthases, which may have induced the protein expression of adenosine 5'-monophosphate-activated protein kinase (AMPK) and its phosphorylated form. These results suggest that gibberellin reduces human sperm motility in vitro by increasing reactive oxygen species levels and reducing ATPase activity, which may upregulate AMPK and consequently reduce the fertilization potential of spermatozoa.
Project description:The haematopoietic system plays an essential role in our health and survival. It is comprised of a range of mature blood and immune cell types, including oxygen-carrying erythrocytes, platelet-producing megakaryocytes and infection-fighting myeloid and lymphoid cells. Self-renewing multipotent haematopoietic stem cells (HSCs) and a range of intermediate haematopoietic progenitor cell types differentiate into these mature cell types to continuously support haematopoietic system homeostasis throughout life. This process of haematopoiesis is tightly regulated in vivo and primarily takes place in the bone marrow. Over the years, a range of in vitro culture systems have been developed, either to expand haematopoietic stem and progenitor cells or to differentiate them into the various haematopoietic lineages, based on the use of recombinant cytokines, co-culture systems and/or small molecules. These approaches provide important tractable models to study human haematopoiesis in vitro. Additionally, haematopoietic cell culture systems are being developed and clinical tested as a source of cell products for transplantation and transfusion medicine. This review discusses the in vitro culture protocols for human HSC expansion and differentiation, and summarises the key factors involved in these biological processes.