4 Aryl hydrocarbon receptor targets are upregulated in porcine blastocyst-stage embryos that were cultured invitro: A transcriptional analysis

Invitro-produced (IVP) porcine embryos are developmentally delayed compared with those derived invivo. Thus, efforts have been made to modify the current medium for IVP of porcine embryos in an attempt to shift the abundance of target transcripts towards the invivo level. The objective of the current study was to identify differences in mRNA abundance that may account for reduced developmental competence in IVP embryos and to determine whether alterations to maturation and culture media directed the transcriptional profiles of IVP embryos towards an invivo state. Following AI of gilts, an oviduct and tip of the uterine horn were flushed on Day 2 to recover 4-cell stage embryos; these were cultured for 4 days in MU3, generating IVM and invitro-cultured (IVC) blastocyst-stage embryos. On Day 6, the gilts were killed, and the contralateral horns were flushed to obtain invivo-derived (IVV) blastocyst-stage embryos. The third group of blastocyst-stage embryos, referred to as invitro-matured and cultured (IVMC), were created by aspirating cumulus–oocyte complexes from slaughterhouse-derived ovaries, maturing and fertilizing invitro, and culturing for 6 days in MU3. Total RNA was extracted from pools of 10 blastocyst-stage embryos with 3 replicates per group. First- and second-strand cDNA was synthesised and sequenced by using the Illumina platform (Illumina Inc.). After removal of adapters and reads that mapped to porcine rRNA genes and the PhiX genome, reads were mapped to the Sus scrofa genome by using STAR (version 2.7.1a) with default options. Pairwise comparisons were performed to test for differential expression of genes by using the Bioconductor package DESEqn 2. Transcripts were differentially abundant (false discovery rate <0.05) between IVV and IVC embryos (2,450), between IVV and IVMC embryos (3,045), and between IVC and IVMC embryos (262). Pathways related to cell cycle were downregulated in IVC and IVMC compared with IVV embryos, and pathways related to amino acid transport in metabolism were upregulated in IVC and IVMC compared with IVV embryos. Of particular interest, message for cytochrome P450 family 1 subfamily A member 1 (CYP1A1) was only present in the IVC (956 reads) and IVMC (381 reads) embryos but not in the IVV embryos (0 reads). The aryl hydrocarbon receptor (AHR) promotes transcription of CYP1A1, which encodes a monooxygenase involved in xenobiotic metabolism. Moreover, abundance of 12 other AHR targets was increased in IVC and IVMC embryos (false discovery rate <0.05) compared with IVV embryos. Thus, production of porcine embryos invitro may activate AHR, resulting in altered transcriptional profiles and reduced competence. This research was funded by USDA-NIFA (2019-67011-29543).

A novel swine sex-linked marker and its application across different mammalian species

Advances in genome editing tools have reduced barriers to the creation of animal models. Due to their anatomical and physiological similarities to humans, there has been a growing need for pig models to study human diseases, for xenotransplantation and translational research. The ability to determine the sex of genetically modified embryos, cells or fetuses is beneficial for every project involving the production of transgenic animals. This strategy can improve the time-efficiency and lower the production costs. Additionally, sex assessment is very useful for wildlife studies to understand population behavior and structure. Thus, we developed a simple and fast PCR-based protocol for sex determination in pigs by using a unique primer set to amplify either the DDX3X or DDX3Y gene. The sex was 100% correctly assigned when tail genomic DNA, Day-35 fetus and hair samples from pigs were used. For both blastocysts and oocytes (84.6% and 96.5% of efficacy, respectively) the unidentified samples were potentially due to a limitation in sample size. Our assay also worked for domestic sheep (Ovis aries), American bison (Bison bison) and European cattle (Bos taurus) samples and by in silico analysis we confirmed X-Y amplicon length polymorphisms for the DDX3 gene in 12 other mammalian species. This PCR protocol for determining sex in pig tissues and cells showed to be simple, specific, highly reproducible and less time consuming as well as an important tool for other livestock species and wildlife studies.

Changes in the influence of lymphoma- and HIV-specific factors on outcomes in AIDS-related non-Hodgkin lymphoma

BACKGROUND

We undertook the present analysis to examine the shifting influence of prognostic factors in HIV-positive patients diagnosed with aggressive non-Hodgkin lymphoma (NHL) over the last two decades.

PATIENTS AND METHODS

We carried out a pooled analysis from an existing database of patients with AIDS-related lymphoma. Individual patient data had been obtained prior from prospective phase II or III clinical trials carried out between 1990 until 2010 in North America and Europe that studied chemo(immuno)therapy in HIV-positive patients diagnosed with AIDS-related lymphomas. Studies had been identified by a systematic review. We analyzed patient-level data for 1546 patients with AIDS-related lymphomas using logistic regression and Cox proportional hazard models to identify the association of patient-, lymphoma-, and HIV-specific variables with the outcomes complete response (CR), progression-free survival, and overall survival (OS) in different eras: pre-cART (1989-1995), early cART (1996-2000), recent cART (2001-2004), and contemporary cART era (2005-2010).

RESULTS

Outcomes for patients with AIDS-related diffuse large B-cell lymphoma and Burkitt lymphoma improved significantly over time, irrespective of baseline CD4 count or age-adjusted International Prognostic Index (IPI) risk category. Two-year OS was best in the contemporary era: 67% and 75% compared with 24% and 37% in the pre-cART era (P < 0.001). While the age-adjusted IPI was a significant predictor of outcome in all time periods, the influence of other factors waxed and waned. Individual HIV-related factors such as low CD4 counts (<50/mm(3)) and prior history of AIDS were no longer associated with poor outcomes in the contemporary era.

CONCLUSIONS

Our results demonstrate a significant improvement of CR rate and survival for all patients with AIDS-related lymphomas. Effective HIV-directed therapies reduce the impact of HIV-related prognostic factors on outcomes and allow curative antilymphoma therapy for the majority of patients with aggressive NHL.

2 THE IN VIVO DEVELOPMENTAL POTENTIAL OF PORCINE SKIN-DERIVED PROGENITORS

Skin-derived progenitors (SKP) are capable of generating both neural and mesodermal progeny in vitro: neurons, Schwann cells, adipocytes, osteocytes and chondrocytes, thus exhibiting characteristics similar to embryonic neural crest stem cells. SKP show distinct transcriptional profiles when compared with neurospheres/neural stem cells in the central nervous system (CNS) and skin-derived fibroblasts, indicating a novel type of multipotent stem cell derived from the dermis of the skin. However, it remains unclear whether SKP cells can produce ectoderm and mesoderm lineages or other germ layers in vivo, although oocyte-like structures can be induced from porcine SKP in vitro. Embryonic chimeras are a well-established tool for investigating cell lineage determination and cell potency through normal embryonic development. Thus the purpose of this study was to investigate the in vivo developmental potential of porcine SKP by chimera production. Porcine SKP cells and fibroblasts were isolated from the back skin of Day 35 to 50 GFP transgenic fetuses. Individual cells or clusters of male GFP transgenic SKP and skin-derived GFP-expressing fibroblasts were injected into pre-compact in vitro-fertilized (IVF) embryos, respectively and then transferred into corresponding surrogates 24 h post-injection. Additional injected embryos were cultured in PZM3 medium for another 2 days until the blastocyst stage and subsequently stained with Hoechst 33342. Interestingly, in some of the chimeras the injected SKP cells migrated and dispersed into different locations of the host blastocysts, whereas in others they remained as a cluster of cells within the chimeric blastocysts. In contrast, the fibroblast cells were not observed to spread around the host blastocysts. Two chimeric fetuses were recovered at the middle of gestation and a litter of viable piglets was born. Genomic DNA was extracted from various tissues of chimeric piglets and subjected to PCR amplification. Two chimeric fetuses and 2 out of 6 piglets carried the GFP transgene in SKP-derived chimeras, but GFP was not present in the fibroblast-derived chimeric fetuses (n = 6). Surprisingly, the GFP transgene was present in various tissues of two SKP-derived chimeric piglets, including lung, heart, liver, artery, kidney, brain, skin, muscle, gut, ovary, pancreas and stomach, thus representing the 3 germ layers (ectoderm, mesoderm and endoderm). In addition, SRY was detected in several tissues of the two GFP-positive female chimeric piglets, confirming the chimerism of these piglets. Therefore, it appears that porcine SKP can contribute to various cell types of the 3 germ layers and have a broader developmental potency than previously expected. Alternatively, pre-compact (4-cell and 8-cell stage) embryos may provide a unique environment for reprogramming skin-derived progenitors into a more primitive state by the process of embryonic compaction. This study was funded by NIH National Center for Research Resources (R01RR013438) and Food for the 21st Century at the University of Missouri.

Birth of piglets from in vitro-produced, zona-intact porcine embryos vitrified in a closed system

As the importance of swine models in biomedical research increases, it is essential to develop low-cost, high-throughput systems to cryopreserve swine germplasm for maintenance of these models. However, porcine embryos are exceedingly sensitive to low temperature and successful cryopreservation is generally limited to the use of vitrification in open systems that allow direct contact of the embryos with liquid nitrogen (LN(2)). This creates a high risk of pathogen transmission. Therefore, cryopreservation of porcine embryos in a "closed" system is of very high importance. In this study, in vitro-produced (IVP) porcine embryos were used to investigate cryosurvival and developmental potential of embryos cryopreserved in a closed system. Optimal centrifugal forces to completely disassociate intracellular lipids from blastomeres were investigated using Day-4 embryos. Cryosurvival of delipidated embryos was investigated by vitrifying the embryos immediately after centrifugation, or after development to blastocysts. In this study, centrifugation for 30 min at 13,000 g was adequate to completely delipidate the embryos; furthermore, these embryos were able to survive cryopreservation at a rate comparable to those centrifuged for only 12 min. When delipidated embryos were vitrified at the blastocyst stage, there was no difference in survival between embryos vitrified using OPS and 0.25 mL straws. Some embryos vitrified by each method developed to term. These experiments demonstrated that porcine embryos can be cryopreserved in a closed system after externalizing their intracellular lipids. This has important implications for banking swine models of human health and disease.

334 CONSTRUCTION OF A GENETICALLY ENGINEERED PIG EXPRESSING GREEN FLUORESCENT PROTEIN (GFP)-LABELLED PROTEASOMES

Proteasomes are large protein complexes involved in protein degradation in eukaryotes and undergo dynamic redistribution between cellular compartments. Characterising the cellular localization of proteasomes at various stages of development and in response to stimuli is of interest. We hypothesised that porcine proteasomes could be visualised in vivo via a ubiquitously expressed transgene fusion comprising a proteasomal subunit and green florescent protein (GFP). The full-length sequence for porcine PSMA-1 was first constructed in silico from public data and was used to retrieve a GenBank expressed sequence tag (EST) sequence that appeared to be full length (accession CO946059; kind gift from R. S. Prather). Primers were designed to remove the stop codon and create homology for cloning with InFusion (Clontech, Palo Alto, CA, USA). The amplimer was inserted into pCAG-CreGFP (Addgene plasmid 13776) in place of the Cre coding region. The resulting plasmid (pKW14) was screened via restriction digest and sequenced for confirmation. This plasmid was confirmed functional in porcine fetal fibroblasts. After removal of the plasmid backbones, pKW14, a G418 resistance cassette (NEO), and the chicken egg white matrix attachment region were co-electroporated into male fetal fibroblasts (10 μg of total DNA, 5:2:2 ratio, respectively). Cells were grown in DMEM with 10% fetal bovine serum (FBS) and selection was initiated 36 h after transfection. Following 12 days of selection at 400 mg L–1 G418, colonies were screened by epifluorescence. Positive colonies were harvested and confirmed transgenic for all 3 input DNAs. Positive colonies were randomly pooled as sets of 3 independent integration events. Embryos were reconstructed via SCNT and transferred to 2 recipients. The fusion rates were 70 and 78%, respectively, with transfer numbers of 120 and 125 fused couplets being transferred into synchronized recipients on Day 0 of heat. Both recipients became pregnant and delivered 2 piglets each on Day 114 by Caesarean section. One live piglet was produced from each litter. Of the 2 live-born piglets, 1 survived beyond Day 3 and continues to be healthy. Transgenic status was verified by PCR. Expression was confirmed by epifluorescence of GFP-labelled proteasomes. This founder will be used to establish a model to evaluated cellular localization of proteasomes in vivo and in culture.

58 HISTONE DEACETYLASES INHIBITOR, SCRIPTAID, IS BENEFICIAL TO THE REPROGRAMMING OF SOMATIC NUCLEI FOLLOWING NUCLEAR TRANSFER

Somatic cell nuclear transfer (SCNT) is a promising technology with potential applications in both agriculture and regenerative medicine. The reprogramming of differentiated somatic nuclei into totipotent embryonic state following NT is not efficient and the mechanism is currently unknown. However, accumulating evidence suggests that faulty epigenetic reprogramming is likely to be the major cause of low success rates observed in all mammals produced through SCNT. It has been demonstrated that increased histone acetylation in reconstructed embryos by applying histone deacetylases inhibitor (HDACi) such as trychostatin A (TSA) significantly enhanced the developmental competence in several species in vitro and in vivo. However TSA has been known to be teratogenic. Compared with TSA, Scriptaid is a low toxic but more efficient HDACi (Su GH et al. 2000 Cancer Res. 60, 3137–3142). The objectives of this study were: 1) to investigate and optimize the application Scriptaid to the NT using Landrace fetal fibroblast cells (FFCs) as donor; 2) investigate the effect of increased histone acetylation on the developmental competence of reconstructed embryos from NIH mini inbred FFCs in vitro and in vivo. The reconstructed embryos were treated with Scriptaid at different concentrations (0 nm, 250 nm, 500 nm and 1000 nm) after activation for 14 to 16 h. IVF embryos without treatment were produced as an additional control. Developmental rates to the 2-cell and blastocyst stage were determined. Developmental potential was determined by transferring Day 1 NT zygotes to the oviducts of surrogates on the day of, or one day after, the onset of estrus. Experiments were repeated at least 3 times and data were analyzed with chi-square tests using SAS 6.12 program (SAS institute, Inc., Cary, NC, USA). The percentage blastocyst of cloned embryos using Landrace FFCs as donors treated with 500 nm Scriptaid was the highest and was significantly higher than untreated group (25% v. 11%, P < 0.05). Percent cleaved was not different among four treatment groups. We used 500 nm Scriptaid for 14 to 16 h after activation for all subsequent experiments. Developmental rate to the blastocyst stage was significantly increased in cloned embryos derived from NIH mini inbred FFCs after treating with Scriptaid (21% v. 9%, P < 0.05), while the blastocyst rate in IVF group was 30%. Embryo transfer (ET) results showed that 5/6 (Transferred embryos No. were 190, 109, 154, 174, 152, and 190, respectively) surrogates (83%) became pregnant resulting in 2 healthy piglets from 2 litters (recipients received 190 and 154 embryos, respectively) in the Scriptaid treatment group, while no pregnancies were obtained in the untreated group from 5 ET (Embryos transferred No. are 140, 163, 161, 151 and 151, respectively). These results suggest that 500 nm Scriptaid treatment following activation increase both the in vitro and in vivo development of porcine SCNT embryos from NIH mini inbred FFCs and the hyperacetylation might actually improve reprogramming of the somatic nuclei after NT. Funding from the National Institutes of Health National Center for Research Resources RR018877.

Novel, starch-like polysaccharides are synthesized by an unbound form of granule-bound starch synthase in glycogen-accumulating mutants of Chlamydomonas reinhardtii

In vascular plants, mutations leading to a defect in debranching enzyme lead to the simultaneous synthesis of glycogen-like material and normal starch. In Chlamydomonas reinhardtii comparable defects lead to the replacement of starch by phytoglycogen. Therefore, debranching was proposed to define a mandatory step for starch biosynthesis. We now report the characterization of small amounts of an insoluble, amylose-like material found in the mutant algae. This novel, starch-like material was shown to be entirely dependent on the presence of granule-bound starch synthase (GBSSI), the enzyme responsible for amylose synthesis in plants. However, enzyme activity assays, solubilization of proteins from the granule, and western blots all failed to detect GBSSI within the insoluble polysaccharide matrix. The glycogen-like polysaccharides produced in the absence of GBSSI were proved to be qualitatively and quantitatively identical to those produced in its presence. Therefore, we propose that GBSSI requires the presence of crystalline amylopectin for granule binding and that the synthesis of amylose-like material can proceed at low levels without the binding of GBSSI to the polysaccharide matrix. Our results confirm that amylopectin synthesis is completely blocked in debranching-enzyme-defective mutants of C. reinhardtii.

Analysis of starch structure using fluorophore-assisted carbohydrate electrophoresis

The analysis of the fine structure of starches is important to the investigation of linkages between starch structure and function and to the investigation of the properties and roles of starch biosynthetic, modifying and degradation enzymes. Fluorophore-assisted carbohydrate electrophoresis has recently been introduced as a method for the analysis of the oligosaccharide populations released by the enzymatic digestion of starches, which has advantages in resolution and sensitivity over previously used methods, and provides the capacity for the facile analysis of oligosaccharide populations on either a molar or mass basis. The use of fluorophore-assisted carbohydrate electrophoresis for the analysis of oligosaccharides is reviewed with particular reference to the choice of label, efficiency of labeling and separation techniques. Examples of separations using slab gel electrophoresis, DNA sequencer analysis and capillary electrophoresis are presented and we conclude that on the basis of resolution and reproducibility, capillary electrophoresis is the method of choice for the separation of oligosaccharides of degree of polymerization from 1 to 100. Examples of isoamylase-debranched starches and glycogens analyzed by capillary electrophoresis are presented. The capillary electrophoresis analysis of starch structure through the analysis of oligosaccharides released by the debranching of limit dextrins derived from starches and glycogens is introduced as a useful diagnostic of starch structure. The potential for future development of novel diagnostics for starch structure using fluorophore-assisted carbohydrate electrophoresis is discussed.

Differential expression and properties of starch branching enzyme isoforms in developing wheat endosperm

Three forms of starch branching enzyme (BE) from developing hexaploid wheat (Triticum aestivum) endosperm have been partially purified and characterized. Immunological cross-reactivities indicate that two forms (WBE-IAD, 88 kD, and WBE-IB, 87 kD) are related to the maize BE I class and that WBE-II (88 kD) is related to maize BE II. Comparison of the N-terminal sequences from WBE-IAD and WBE-II with maize and rice BEs confirms these relationships. Evidence is presented from the analysis of nullisomic-tetrasomic wheat lines demonstrating that WBE-IB is located on chromosome 7B and that the WBE-IAD fraction contains polypeptides that are encoded on chromosomes 7A and 7D. The wheat endosperm BE classes are differentially expressed during endosperm development. WBE-II is expressed at a constant level throughout mid and late endosperm development. In contrast, WBE-IAD and WBE-IB are preferentially expressed in late endosperm development. Differences are also observed in the kinetic characteristics of the enzymes. The WBE-I isoforms have a 2- to 5-fold higher affinity for amylose than does WBE-II, and the WBE-I isoforms are activated up to 5-fold by phosphorylated intermediates and inorganic phosphate, whereas WBE-II is activated only 50%. The potential implications of this activation of BE I for starch biosynthesis are discussed.