151 EVALUATION OF REFERENCE GENE TRANSCRIPT STABILITY DURING EARLY PRE-IMPLANTATION DEVELOPMENT AND IN SPERMATOGONIAL CELLS IN THE CAT

2012 ◽  
Vol 24 (1) ◽  
pp. 187 ◽  
Author(s):  
M. N. Biancardi ◽  
C. E. Pope ◽  
R. H. Powell ◽  
J. Galiguis ◽  
C. Dumas ◽  
...  

Differences in the stability of commonly used reference genes have been discovered between species and among different tissue types. These inconsistencies underscore the importance of validation and selection of an appropriate reference for normalization of gene expression to an endogenous control in RT-qPCR experiments. Three different reference transcripts (GAPDH, RPS19 and 18S rRNA) of 3 different functional categories were selected for evaluation during pre-implantation embryonic development and in spermatogonial cells in the domestic cat. Amplification efficiency was done by standard curve analysis with 5-fold template dilutions. For pre-implantation analysis, transcripts were assayed at 4 developmental stages: 2- to 6-cell (2–6C), 8- to 16-cell (8–16C), morula (M) and blastocyst (BL). Embryos were from pools of 4 to 10 in vitro matured and fertilized domestic cat embryos. For spermatogonia, isolates of 20 000 to 30 000 cells were assayed from single testis isolates following a collagenase and trypsin with DNase digestion and Percoll gradient separation. Total mRNA was isolated using the Cells-to-cDNA II Kit, with a minimum of 2 biological replicates for each sample type. The RNA quantitation was done by RiboGreen analysis and 47 ng of RNA was used for cDNA synthesis. Transcript abundance was detected in 2 technical replicates per sample by SYBR Green chemistry and data were analysed with NormFinder and one-way ANOVA. Each transcript showed varying levels of expression throughout development and among embryonic stages and in spermatogonial cells. The GADPH and 18S rRNA transcripts were expressed at higher levels in BL than in 2–6C and 8–16C, respectively. Contrarily, transcript levels of RSP19 were lower in BL compared with levels at 2–6C. Even though differences were observed among embryonic stages, analysis with NormFinder indicated that the most stable reference gene throughout early pre-implantation development was RPS19. When each stage was analysed separately, 18S rRNA was the most stable at 2–6C, whereas RPS19 was found to be the most stable at 8–16C, M and BL stages. In spermatogonial samples, GAPDH was the most stably expressed gene. Our results support the selection of an appropriate reference gene based on the needs of the experimental design. We conclude from these findings that when gene expression throughout the duration of early embryonic development is examined, RPS19 is the preferred selection. If gene expression is analysed within discrete time points of development only, it is appropriate to select 18S rRNA at the 2–6C stage and RPS19 for 8–16C, M and BL stage embryos. For spermatogonial samples, if comparing only different biological replicates, GAPDH should be selected for normalization of expression; however if the purpose of the experiment is to assay genes that are also expressed in BL, the most stably expressed reference gene is RPS19.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shauna Kehoe ◽  
Katarina Jewgenow ◽  
Paul R. Johnston ◽  
Susan Mbedi ◽  
Beate C. Braun

AbstractIn vitro growth (IVG) of dormant primordial ovarian follicles aims to produce mature competent oocytes for assisted reproduction. Success is dependent on optimal in vitro conditions complemented with an understanding of oocyte and ovarian follicle development in vivo. Complete IVG has not been achieved in any other mammalian species besides mice. Furthermore, ovarian folliculogenesis remains sparsely understood overall. Here, gene expression patterns were characterised by RNA-sequencing in primordial (PrF), primary (PF), and secondary (SF) ovarian follicles from Felis catus (domestic cat) ovaries. Two major transitions were investigated: PrF-PF and PF-SF. Transcriptional analysis revealed a higher proportion in gene expression changes during the PrF-PF transition. Key influencing factors during this transition included the interaction between the extracellular matrix (ECM) and matrix metalloproteinase (MMPs) along with nuclear components such as, histone HIST1H1T (H1.6). Conserved signalling factors and expression patterns previously described during mammalian ovarian folliculogenesis were observed. Species-specific features during domestic cat ovarian folliculogenesis were also found. The signalling pathway terms “PI3K-Akt”, “transforming growth factor-β receptor”, “ErbB”, and “HIF-1” from the functional annotation analysis were studied. Some results highlighted mechanistic cues potentially involved in PrF development in the domestic cat. Overall, this study provides an insight into regulatory factors and pathways during preantral ovarian folliculogenesis in domestic cat.


2021 ◽  
Author(s):  
Zhongyi Yang ◽  
Rui Zhang ◽  
Zhichun Zhou

Abstract Background Quantitative real-time PCR (qRT-PCR) is a reliable and high-throughput technique for gene expression studies, but its accuracy depends on the expression stability of reference genes. Schima superba is a strong resistance and fast-growing timber specie. However, so far, reliable reference gene identifications have not been reported in S. superba. In this study, we screened and verified the stably expressed reference genes in different tissues of S. superba.Results Nineteen candidate reference genes were selected and evaluated for their expression stability in different tissues. Three software programs (geNorm, NormFinder, and BestKeeper) were used to evaluate the reference gene transcript stabilities, and comprehensive stability ranking was generated by the geometric mean method. Our results identified that SsuACT was the most stable reference gene, SsuACT + SsuRIB was the best reference genes combination for different tissues. Finally, the stable and less stable reference genes were verified using the SsuSND1 expression in different tissues.Conclusions This is the first report to verify the appropriate reference genes for normalizing gene expression in S. superba for different tissues, which will facilitate future elucidation of gene regulations in this species, and useful references for relative species.


2010 ◽  
Vol 44 (1) ◽  
pp. 59-70 ◽  
Author(s):  
Cynthia Shannon Weickert ◽  
Donna Sheedy ◽  
Debora A. Rothmond ◽  
Irina Dedova ◽  
Samantha Fung ◽  
...  

2016 ◽  
Vol 28 (2) ◽  
pp. 207
Author(s):  
J. Galiguis ◽  
C. E. Pope ◽  
C. Dumas ◽  
G. Wang ◽  
R. A. MacLean ◽  
...  

As precursors to germline stem cells and gametes, there are many potential applications for primordial germ cells (PGC). Primordial germ cell-like cells have been generated from mouse embryonic stem cells and induced pluripotent stem cells, which subsequently were used to produce functional spermatozoa, oocytes, and healthy offspring (Hayashi et al. 2012 Science 338(6109), 971–975). Applying this approach to generate sperm and oocytes of endangered species is an appealing prospect. Detection of molecular markers associated with PGC is essential to optimizing the process of PGC induction. In the current study, in vitro-derived domestic cat embryos were assessed at various developmental stages to characterise the expression of markers related to the specification process of cat PGC. In vivo-matured, IVF oocytes were cultured until Days 7, 9, and 12 post-insemination. Then, embryos were assessed by RT-qPCR to determine relative transcript abundance of the pluripotency markers NANOG, POU5F1, and SOX2; the epiblast marker DNMT3B; the primitive endoderm marker GATA4; the PGC marker PRDM14; and the germ cell marker VASA; RPS19 was used as the internal reference gene. To validate the qPCR results, fibroblasts served as the negative control cells, whereas spermatogonial stem cells (SSC) served as the positive control cells for GATA4, PRDM14, and VASA. Total mRNA were isolated using the Cells-to-cDNA™ II Kit (Ambion/Thermo Fisher Scientific, Waltham, MA, USA) from either pools of 2 to 6 embryos or ~25 000 fibroblasts/SSC. A minimum of 2 biological replicates for each sample type was analysed, with transcript abundance detected in 2 technical replicates by SYBR Green chemistry. Student’s t-tests were performed on the ΔCts for statistical analysis. PRDM14, specific to the germ cell lineage, was detected as early as Day 7, suggesting the presence of PGC precursor cells. Compared with their levels at Day 7, PRDM14 expression was 0.34-fold lower in SSC (P < 0.05), whereas expression of VASA and GATA4 were 1964-fold and 144-fold higher, respectively (P < 0.05). This seems to emphasise the relative importance of PRDM14 in pre-germ cell stages. In general, all genes analysed were up-regulated from Day 7 to Day 9. This up-regulation was statistically significant for SOX2 and GATA4 (P < 0.05). Relative to that at Day 9, all transcripts were relatively less abundant at Day 12 (P < 0.05 for NANOG, POU5F1, SOX2, DNMT3B, and PRDM14). The data suggest that PGC specification takes place near Day 9, with peak specification activity concluding by Day 12. Although much needs be explored about PGC specification in the cat before applying induction and in vitro germ cell production techniques, these findings represent the first step towards a new potential strategy for preserving endangered and threatened felids.


2015 ◽  
Vol 27 (1) ◽  
pp. 196
Author(s):  
L. N. Moro ◽  
D. Veraguas ◽  
L. Rodriguez-Alvarez ◽  
M. I. Hiriart ◽  
C. Buemo ◽  
...  

The cheetah (Ch, Acinonyx jubatus) is a species considered globally endangered and cloning is one of the assisted reproductive techniques that can help to preserve it and to study early embryo development. However, the production of cloned felid embryos remains inefficient, probably because of the difficulty to control the process of nuclear reprogramming and obtain adequate gene expression. Embryo aggregation has been demonstrated to improve the cloning efficiency in several species and to normalise cdx2 in the mouse by lowering its expression (Balbach et al. 2010), but it has not been evaluated in felids before. To better understand the effect of interspecific somatic-cell nuclear transfer (iSCNT) and embryo aggregation in nuclear reprogramming, we analysed the expression of oct4, sox2, nanog, and cdx2 in cheetah blastocysts generated by iSCNT, domestic cat blastocysts (Dc) generated by SCNT, and IVF blastocysts as control. To achieve this, domestic cat oocytes were in vitro matured and zona-free SCNT or iSCNT was performed, as previously described (Moro et al. 2014, Reprod. Fertil. Dev.). Zona-free reconstructed embryos were then cultured individually (1X) or two embryo were cultured together (2X) in microwells, in synthetic oviductal fluid (SOF) medium. The experimental groups were Dc1X, Dc2X, Ch1X, Ch2X, and IVF. After 8 days of in vitro culture the blastocysts obtained were stored in RNA-later at –20°C. For gene expression analysis, blastocysts were pooled as follows: Dc1X, 4 replicates of 3 blastocysts each; Dc2X, 4 replicates of 3 blastocysts each; Ch1X, 2 replicates of 2 blastocysts and 1 replicate of 1 blastocyst; Ch2X, 4 replicates of 3 blastocysts each; IVF 3 replicates of 3 blastocysts each. Embryos were treated with a Cells-to-cDNA TM II kit (Life Technologies, Carlsbad, CA, USA) lyses buffer and treated with DNase I (0.04 U μL–1) for genomic DNA digestion. Gene expression analysis was performed by real-time qPCR using the standard curve method. In all qPCRs, GAPDH was used as an internal control. The statistical analysis was performed using a non-parametric Kruskal–Wallis test (P < 0.05). We observed that Dc1X blastocysts overexpressed the 4 genes evaluated respect to the IVF control. However, the gene expression of the aggregated group (Dc2X) was lower for all the genes, achieving the same levels of nanog and sox2 as the IVF blastocysts. The expression of oct4 and cdx2 were also closer to the expression levels of the control in the Dc2X group than in the Dc1X group. With respect to interspecific embryos, the amount of oct4 and cdx2 was also significantly reduced in the Ch2X blastocysts respect to Ch1X blastocysts. Both cheetah groups showed significantly lower expression of oct4, cdx2, and nanog than the IVF control. In conclusion, transcription of pluripotent and early differentiation factors in cheetah embryos was not as efficient as in the domestic cat embryos, probably caused by interspecific transfer. Our study demonstrated for the first time that defects in gene expression of domestic cat embryos can be corrected by embryo aggregation, providing a simple strategy to improve felid cloning.


2014 ◽  
Vol 26 (1) ◽  
pp. 175 ◽  
Author(s):  
M. D. Snyder ◽  
J. H. Pryor ◽  
M. D. Peoples ◽  
G. L. Williamson ◽  
M. C. Golding ◽  
...  

During early bovine embryogenesis, the regular establishment of DNA methylation and histone modification patterns is essential for proper gene expression and continuation of embryonic development. Epigenome patterns established during this period, if improperly maintained, can lead to developmental anomalies and may partially explain the lower pregnancy rates of in vitro-produced embryos. We hypothesised that the suppression of translation of the genes euchromatic histone-lysine N-methyltransferase 2 (EHMT2), DNA methyltransferase 3A (DNMT3A), absent, small, or homeotic-like (ASH2L), and SET domain, bifurcated 1 (SETDB1) would provide insightful information on the importance of these genes during early embryonic development in an in vitro setting. In order to define the roles of these genes, small interfering RNA (siRNA) targeting the gene of interest were synthesised and target verified in bovine cell culture using quantitative real-time RT-PCR (RT-qPCR). We acquired matured bovine oocytes from commercial suppliers, followed by IVF by standard laboratory procedures. Eighteen hours post IVF, cumulus cells were removed and zygotes separated into 3 different treatment groups: non-injected controls (CNTL), non-targeting siRNA injected controls (siNULL), and injection with siRNA targeting the gene of interest (si “gene target”). Each siRNA was mixed with a green fluorescent dextran at a concentration of 20 μM and ~100 pL injected cytoplasmically. The green fluorescent dextran was used to give visual confirmation that zygotes were indeed injected. Post-injection, fluorescent embryos were separated and cultured in Bovine Evolve (Zentih Biotech) medium supplemented with 4 mg mL–1 of BSA (Probumin, Millipore). Cleavage rates were monitored on Day 2, and only cleaved embryos were cultured further. On Day 8 post-IVF, embryos were morphologically examined and numbers of blastocysts recorded. Mean development rates between siNULL and targeting siRNA were compared using a t-test statistic. Over the course of these experiments the mean blastocyst rate for CNTL zygotes was 34.5% ± 2.6 s.e.m. (n = 1647). None of the zygotes injected with siEHMT2 (n = 1184) or siSETDB1 (n = 361) reached the blastocyst stage and these rates differed from the siNULL rate (21.0% ± 2.5 s.e.m., n = 1587; P < 0.05). Morphologically, embryos from both groups developed to the morula stage before they exhibited fragmentation. Injection of siDNMT3A also resulted in significant loss of viability at the 8-cell stage and few zygotes injected (n = 1057) developed to blastocyst (2.1% ± 0.5 s.e.m.; P < 0.001). Inhibiting gene expression of ASH2L showed little variation in blastocyst rate from our siNULL embryos (31.3% ± 2.0 s.e.m., n = 466 v. 34.8% ± 1.9 s.e.m., n = 418, respectively, P > 0.2). It is unknown at this time if inhibition of ASH2L translation will have effects later in development. Ongoing experiments analysing DNA methylation and histone modifications through immunocytochemistry and global gene expression via RT-qPCR will further explore the establishment and maintenance of these genes in the embryonic epigenome.


2019 ◽  
Vol 31 (1) ◽  
pp. 134
Author(s):  
D. Veraguas ◽  
C. Aguilera ◽  
D. Echeverry ◽  
D. Saez-Ruiz ◽  
F. O. Castro ◽  
...  

The kodkod is considered a vulnerable species by the International Union for Conservation of Nature. Phylogenetically, the kodkod is classified in the Leopardus genus, which has only 36 chromosome pairs compared with the domestic cat, which has 38. The proposed hypothesis was that domestic cat oocytes are capable of reprogramming somatic cells from kodkod after interspecies somatic cell NT (SCNT), allowing the in vitro embryo development up to blastocyst stage. Five experimental groups were made based on the technology and culture system: (1) cat embryos generated by IVF (IVF), (2) cat embryos generated by SCNT (Ca1x), (3) aggregated cat embryos generated by SCNT (Ca2x), (4) kodkod embryos generated by interspecies SCNT (K1x), and (5) aggregated kodkod embryos generated by interspecies SCNT (K2x). Interspecies SCNT was performed using a zona-free method. Reconstructed embryos were activated by 2 electrical pulses of 140 kV cm−1 for 40 µs and then incubated for 5h in 10μg mL−1 of cycloheximide and 5μg mL−1 of cytochalasin B. Embryos were cultured in SOF media using the well of the well system in a 5% O2, 5% CO2, and 90% N2 atmosphere at 38.5°C for 8 days. The morulae and blastocysts rates were estimated, and diameter of cloned blastocysts was measured. The relative expression of OCT4, SOX2, and NANOG was evaluated in blastocysts by RT-qPCR using the standard curve method; SDHA was used for normalization. The Kruskal-Wallis test was used to evaluate the developmental parameters and gene expression. The t-test was used to evaluate blastocyst diameter. Statistical differences were considered at P&lt;0.05. The number of replicates was IVF=10, Ca1x=8, Ca2x=6, K1x=3, and K2x=8. The morulae rate was lower when clone embryos were cultured individually (IVF=97/153, 63.4%; Ca2x=28/51, 54.9%; K2x=63/110, 57.3%; Ca1x=48/126, 38.1%; K1x=22/87, 25.3%; P&lt;0.05). In the domestic cat, blastocysts rate was higher in IVF (58/153, 37.9%) and Ca2x (28/51, 29.4%) groups than in the Ca1x group (21/126, 16.7%; P&lt;0.05). No blastocysts were generated in the K1x group (0/87), whereas 5.5% of blastocysts were obtained from the K2x (6/110; 5.5%); this was not statistically different compared with the K1x group (P&gt;0.05). No differences were found in blastocyst diameter between the Ca1x (220.4µm) and Ca2x (251.2µm) groups (P&gt;0.05). However, the diameter of the blastocysts from the K2x group (172.8µm) tended to be lower than that of the blastocysts from the Ca2x group (P=0.05). Regarding gene expression, only 1 of the 6 kodkod blastocysts expressed OCT4, and none expressed SOX2 and NANOG. On the other hand, the relative expression of OCT4 tended to decrease in blastocysts from the Ca1x and Ca2x groups compared with the IVF group (P=0.09), but no differences were found in the expression of SOX2 and NANOG among groups (P&gt;0.05). In conclusion, after interspecies SCNT, domestic cat oocytes support the development of kodkod embryos until the morula stage. However, the embryo aggregation did not significantly improve the blastocyst rate and gene expression.


Genes ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 372
Author(s):  
Aleksandra Dunislawska ◽  
Anna Slawinska ◽  
Maria Siwek

The selection of a suitable reference gene assures a reliable gene expression analysis when using the qPCR method. Normalization of the reaction is based on the basic metabolism genes. These genes show a constant, unregulated expression in all cells and function throughout their lifetime. In the current study, seven reference gene candidates were screened using RT-qPCR, to determine the best-matched pair of reference genes in the chicken DT40 cell line. The DT40 was derived from bursal lymphoma cells that were subjected to RAV-1 bird retroviral infection. It is a simplified in vitro model that allows tracking the direct interaction of stimulants on the lymphoid population and profiling of the hepatocellular B cell transcriptome. The reference gene analysis was carried out using statistical tools integrating four independent methods—geNorm, Best Keeper, NormFinder, delta Ct and RefFinder. Based on the selected reference genes, the relative gene expression analysis was done using the ddCt method. Complete relative gene expression study on a panel of the target genes revealed that proper selection of reference genes depending on the tissue eliminate decreases in data quality. The SDHA and RPL4 genes constitute stable internal controls as reference genes when analyzing gene expression in the DT40 cell line.


Author(s):  
Daniel Veraguas-Davila ◽  
Maria Francisca Cordero ◽  
Soledad Saez ◽  
Darling Saez-Ruiz ◽  
Alejandro Gonzalez ◽  
...  

2009 ◽  
Vol 106 (17) ◽  
pp. 7028-7033 ◽  
Author(s):  
Zhe Ji ◽  
Ju Youn Lee ◽  
Zhenhua Pan ◽  
Bingjun Jiang ◽  
Bin Tian

The 3′ untranslated regions (3′ UTRs) of mRNAs containcis-acting elements for posttranscriptional regulation of gene expression. Here, we report that mouse genes tend to express mRNAs with longer 3′ UTRs as embryonic development progresses. This global regulation is controlled by alternative polyadenylation and coordinates with initiation of organogenesis and aspects of embryonic development, including morphogenesis, differentiation, and proliferation. Using myogenesis of C2C12 myoblast cells as a model, we recapitulated this process in vitro and found that 3′ UTR lengthening is likely caused by weakening of mRNA polyadenylation activity. Because alternative 3′ UTR sequences are typically longer and have higher AU content than constitutive ones, our results suggest that lengthening of 3′ UTR can significantly augment posttranscriptional control of gene expression during embryonic development, such as microRNA-mediated regulation.


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