Claude Robert

Claude Robert
Laval University | ULAVAL · Centre de Recherche en Biologie de la Reproduction (CRBR)

PhD

About

167
Publications
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Publications

Publications (167)
Preprint
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Background Most of the resources that support the early development of the embryo are stored in the oocyte. Clearing of maternal resources and activation of the embryonic genome to produce its own mRNA transcripts marks the maternal-to-embryo transition. Dependence on stored mRNA can last from a few hours to several days, depending on animal specie...
Article
Full-text available
Communications are crucial to ovarian follicle development and to ovulation, and while both folliculogenesis and oogenesis are distinct processes, they share highly interdependent signaling pathways. Signals from distant organs such as the brain must be processed and compartments within the follicle have to be synchronized. The hypothalamic–pituita...
Article
Numerous field observations and previous reports have described a breed effect on embryonic survival to cryopreservation. Embryos collected from Jersey cows show a poor survival rate compared to Holstein embryos due to their rich intracellular lipid content. Less well documented in the scientific literature, but also reported from field observation...
Article
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Genetic improvement programs have resulted in spectacular productivity gains for most animal species in recent years. The introduction of quantitative genetics and the use of statistical models have played a fundamental role in achieving these advances. For the honeybee (Apis mellifera), genetic improvement programs are still rare worldwide. Indeed...
Article
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Genetic selection has led to spectacular advances in animal production in many domestic species. However, it is still little applied to honey bees (Apis mellifera), whose complex genetic and reproductive characteristics are a challenge to model statistically. Advances in informatics now enable creation of a statistical model consistent with honey b...
Article
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Background Assisted reproductive technologies (ART) are widely used to treat fertility issues in humans and for the production of embryos in mammalian livestock. The use of these techniques, however, is not without consequence as they are often associated with inauspicious pre- and postnatal outcomes including premature birth, intrauterine growth r...
Article
Full-text available
Background: Aberrant DNA methylation patterns of genes required for development are common in in vitro produced embryos. In this regard, we previously identified altered DNA methylation patterns of in vivo developed blastocysts from embryos which spent different stages of development in vitro, indicating carryover effects of suboptimal culture con...
Article
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Cryopreservation is known for its marked deleterious effects on embryonic health. Bovine compact morulae were vitrified or slow-frozen, and post-warm morulae were cultured to the expanded blastocyst stage. Blastocysts developed from vitrified and slow-frozen morulae were subjected to microarray analysis and compared with blastocysts developed from...
Article
Full-text available
Mitochondria are powerhouse organelles involved in several vital functions in cells, mainly maintaining balance between ATP synthesis and oxidative stress during early development in mammalian embryos. It has been shown that impaired mitochondrial function in bovine model might reach failure in oocyte and embryo developmental competence. In this re...
Article
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Early embryonic loss is a large contributor to infertility in cattle. Moreover, bovine becomes an interesting model to study human preimplantation embryo development due to their similar developmental process. Although genetic factors are known to affect early embryonic development, the discovery of such factors has been a serious challenge. Microa...
Article
Suboptimal culture condition before minor or major genome activation is believed to affect the quality and the transcriptome landscape of the resulting blastocysts. Thus, we hypothesised that exposure of bovine embryos to suboptimal culture condition before minor embryonic genome activation could affect the genome methylation patterns of the result...
Article
The EmbryoGENE Network (2008–2013) has assembled data from more than 764 DNA arrays covering the entire transcriptome of bovine oocytes, embryos, and somatic cells, such as granulosa and cumulus cells. The data were obtained using the same extraction-amplification-hybridization-analysis protocols enabling normalization and statistical analysis acro...
Article
Full-text available
Local translation at the synapse plays key roles in neuron development and activity-dependent synaptic plasticity. mRNAs are translocated from the neuronal soma to the distant synapses as compacted ribonucleoparticles referred to as RNA granules. These contain many RNA-binding proteins, including the Fragile X Mental Retardation Protein (FMRP), the...
Data
FXR1P and FXR2P are also present in granules as detected by immunogold labelling (arrow heads for FXR1P; 15 nm and FXR2P; 5 nm) on LR-White resin embedded thin sections. (TIF)
Data
Cargoes are formed by progressive coalescence of smaller puncta as observed by time-lapse video microscopy. A) Presented here is the second boxed area in Fig 8A in the main text (Top left) showing the movements of 5 independent granules. B) Individual trajectories versus time of each of these granules. (TIF)
Data
Normalized spectrum counts for proteins identified by mass-spectrometry in granules and polyribosomes-enriched preparations. For each protein, individual spectrum counts normalized to the total spectrum counts are presented and ordered from the highest (red) to the lowest (green) values in granules preparations. A value of 0 indicates that the prot...
Data
Gene Ontology analysis to reveal functional categories enriched in proteins identified in granules (listed in Fig 5 and S1 Table). Analyses were performed using the DAVID bioinformatics resources with the granule list as input. GOTERM categories: biological processes, cellular components and molecular functions with a significant Benjamini’s adjust...
Data
Gene Ontology analysis to reveal functional categories enriched in proteins identified in polyribosomes (listed in S1 Table). Analysis was performed using the DAVID bioinformatics resources with the granule list as input. GOTERM categories: biological processes, cellular components and molecular functions with a significant Benjamini’s adjusted pva...
Data
List of mRNA detected in granules. For each transcript, probe and gene ID are provided. Enrichment is calculated as the logarithm (base 2) of the ratio in average probe intensity (log2FC) in granules as compared to polyribosomes preparation. Transcripts corresponding to probes displaying an enrichment equals or above 1 (FC>1; log2(FC)>0) with a sig...
Data
Gene Ontology analysis to reveal functional categories enriched in mRNA of the granules. Analysis was performed using DAVID bioinformatics resources with the list of transcripts with FC>1 and pval<0.002 (mRNA as abundant or more abundant in granules than polyribosomes, see S3 Table). GOTERM categories (biological processes, cellular components and...
Data
Titration assay to determine the steady state levels of FMRP in polyribosomes and granules. Ten and 20 μg of proteins from purified polyribosomes (P) and granules (G) were analysed in parallel by immunoblotting with IgY#C10, and the membrane exposed for different times to X ray films. Densitometric analyses enable to calculate that the ratio of 2 f...
Data
Frequency distribution of gold-FMRP in 100 independent granules after immunogold-labelling on LR-White resin embedded sections. (TIF)
Data
Isolation of polyribosome and RNA granule populations. A) Schematic diagram of the steps used for the purification of polyribosomes and granules. B) Isopycnic centrifugation on Metrizamide gradients reveals that granules and polyribosomes have identical density properties. (TIF)
Article
Aim: There is a growing concern about the potential adverse effects of high dose folic acid (FA) supplementation before and during pregnancy. FA metabolism generates S-adenosyl methionine (SAM) which is an important cofactor of epigenetic programming. We sought to assess the impact of a large dose of SAM on early embryo development. Materials & m...
Conference Paper
Full-text available
[Conference abstract] The works explains the biology of RNA accumulation, its regulation and functions during mammalian oogenesis. It also discusses the role of RNA accumulation to obtain competent oocytes, as well as methods to study this process. Citation: Sirard, M.A., Macaulay, A., Labrecque, R., Orozco-Lucero, E., Khan, D. and Robert, C., 201...
Article
Full-text available
Reproduction depends on the generation of healthy oocytes. Improving therapeutic strategies to prolong or rescue fertility depends on identifying the inter- and intracellular mechanisms that direct oocyte development under physiological conditions. Growth and proliferation of multiple cell types is regulated by the Hippo signaling pathway, whose ch...
Article
Monozygotic (MZ) twins are of great interest to elucidate the contributions of pre- and postnatal environmental factors on epigenetics in the expression of complex traits and diseases. Progeny testing recently revealed that MZ twin bulls do not necessarily lead to identical genetic merit estimates (i.e. breeding values). Therefore, to explain diffe...
Article
Full-text available
Some embryos exhibit better survival potential to cryopreservation than others. The cause of such a phenotype is still unclear and may be due to cell damage during cryopreservation, resulting from overaccumulation and composition of lipids. In cattle embryos, in vitro culture conditions have been shown to impact the number of lipid droplets within...
Article
Full-text available
So far, the characteristics of a good quality egg have been elusive, similar to the nature of the physiological, cellular, and molecular cues leading to its production both in vivo and in vitro. Current understanding highlights a strong and complex interdependence between the follicular cells and the gamete. Secreted factors induce cellular respons...
Article
Full-text available
The decapping scavenger enzyme DcpS is known for its role in hydrolyzing the cap structure following mRNA degradation. Recently, we discovered a new function in miRNA degradation activation for the ortholog of DcpS in C. elegans. Here we show that human DcpS conserves its role in miRNA turnover. In human cells, DcpS is a nucleocytoplasmic shuttling...
Article
Full-text available
Early embryonic loss and altered gene expression in in vitro produced blastocysts are believed to be partly caused by aberrant DNA methylation. However, specific embryonic stage which is sensitive to in vitro culture conditions to alter the DNA methylation profile of the resulting blastocysts remained unclear. Therefore, the aim of this study was t...
Article
Full-text available
Thyroid hormones (THs) have been shown to improve in vitro embryo production in cattle by increasing blastocyst formation rate, and the average cell number of blastocysts and by significantly decreasing apoptosis rate. To better understand those genetic aspects that may underlie enhanced early embryo development in the presence of THs, we character...
Article
Full-text available
The prevalence of bone deformities, particularly linked with mineral deficiency, is an important issue for fish production. Juvenile triploid rainbow trout (Oncorhynchus mykiss) were fed a low-phosphorus (P) diet for 27 weeks (60 to 630 g body mass). At study termination, 24.9% of the fish fed the low-P diet displayed homogeneous biconcave vertebra...
Article
Mitochondria in maturing oocytes and early embryos change shape from the usual mature form seen in other cells to an immature form that has very limited capacity for energy production from glucose and oxidative phosphorylation (OXPHOS). With the high demand for energy in these cells and limited capacity for OXPHOS, it is unclear how these cells mee...
Article
Microarrays represent a significant advantage when studying gene expression in early embryo because they allow for a speedy study of a large number of genes even if the sample of interest contains small quantities of genetic material. Here we describe the protocols developed by the EmbryoGENE Network to study the bovine transcriptome in early embry...
Article
Now recognised as part of the cellular transcriptome, the function of long non-coding (lnc) RNA remains unclear. Previously, we found that some lncRNA molecules in bovine embryos are highly responsive to culture conditions. In view of a recent demonstration that lncRNA may play a role in regulating important functions, such as maintenance of plurip...
Chapter
This chapter covers the current and emerging reproductive technologies that are destined to increase the rate of genetic improvement, with a focus on dairy herds. Topics discussed include breeding soundness evaluation (BSE), estimation of sire fertility, sperm attributes, sperm sorting, improving male fertility through integration of the omics, art...
Article
Full-text available
Background Genome-wide profiling of single-nucleotide polymorphisms is receiving increasing attention as a method of pre-implantation genetic diagnosis in humans and of commercial genotyping of pre-transfer embryos in cattle. However, the very small quantity of genomic DNA in biopsy material from early embryos poses daunting technical challenges. A...
Article
Full-text available
Even after several decades of quiescent storage in the ovary, the female germ cell is capable of reinitiating transcription to build the reserves that are essential to support early embryonic development. In the current model of mammalian oogenesis, there exists bilateral communication between the gamete and the surrounding cells that is limited to...
Article
Introduction: Oocytes must effectively grow, accumulate reserves, and mature prior to fertilization. Errors in any of these processes affecting nuclear, cytoplasmic, or molecular maturation of the oocyte will result in poor embryonic development. Materials and methods: Immunofluorescence, direct fluorescent staining, and autoradiography were combin...
Article
Mitochondria play an important role during early development in mammalian embryos. It has been shown that properly controlled follicular preparation increases the likelihood of in-vitro-produced bovine embryos reaching the blastocyst stage and that competent embryos exhibit heightened expression of genes associated with mitochondrial function. We h...
Article
Rainbow trout (Oncorhynchus mykiss) is an important production species as well as one of the most studied fish models, particularly regarding nutritional physiology. Due to negative environmental impacts linked with rainbow trout farm effluents, significant restrictions have been established in numerous regions to reduce dietary phosphorus (P) outp...
Article
Full-text available
Although the oocyte is the largest cell in the body and an unavoidable phase in life, its physiology is still poorly understood, and other cell types provide little insight into its unique nature. Even basic cellular functions in the oocyte such as energy metabolism are not yet fully understood. It is known that the mitochondria of the female gamet...
Article
Full-text available
Physiology of the adult can be modified by alterations in prenatal development driven by the maternal environment. Developmental programming, which can be established before the embryo implants in the uterus, can affect females differently than males. The mechanism by which sex-specific developmental programming is established is not known. Here we...
Article
Full-text available
BACKGROUND: Oocytes and early embryos contain minute amounts of DNA, RNA and proteins, making the study of early mammalian development highly challenging. The study of the embryo epigenome, in particular the DNA methylome, has been made accessible thanks to the possibility of amplifying specific sequences according to their initial methylation stat...
Article
Mammalian embryos that rapidly reach the two-cell stage in culture have a higher probability of becoming viable blastocysts. Our goal was to separate two-cell bovine embryos based on their zygotic cleavage timing, and to assess their global mRNA levels. Following in vitro fertilization, all embryos that cleaved by 29.5 hpi (early) were cultured sep...
Article
Mitochondria play an important role during early mammalian embryo development through their diverse cellular functions, in particular creating balance between production of ATP by electron transport chain and oxidative stress. Embryonic mitochondria are inherited maternally and independently of the nuclear genome. They show limited activity during...
Article
Competence of the bovine embryo to establish pregnancy can be enhanced by treatment with colony stimulating factor 2 (CSF2) from Days 5 to 7 post-insemination. The mechanism is unknown but could involve developmental reprogramming. Here, we questioned whether treatment with CSF2 from Days 5 to 7 alters growth, interferon-τ (IFNT) secretion, and the...
Article
Full-text available
Gap junctional communication (GJC) plays a primordial role in oocyte maturation and meiotic resumption in mammals by directing the transfer of numerous molecules between cumulus cells and the oocyte. Gap junctions are made of connexins (Cx), proteins that regulate GJC in numerous ways. Understanding the dynamic regulation of connexin arrangements d...
Article
Full-text available
The past decade of life sciences research has been driven by progress in genomics. Many voices are already proclaiming the post-genomics era, in which phenomena other than sequence polymorphism influence gene expression and also explain complex phenotypes. One of these burgeoning fields is the study of the epigenome. Although the mechanisms by whic...