Effect of bovine feeding system (pasture or concentrate) on the oxidative and sensory shelf life of whole milk powder.

Correlating volatile compounds with the sensory attributes of whole milk powder (WMP) is fundamental for appreciating the effect of lipid oxidation (LO) on sensory perception. LO compounds can adversely affect the sensory perception of WMP by imparting rancid, metallic, and painty notes. Whole milk powders derived from milk produced by cows maintained on a pasture diet (grass and grass-clover mix) versus a nonpasture diet [total mixed ration (TMR); concentrates and silage] were stored at room temperature 21°C (ambient storage) and 37°C (accelerated storage) and analyzed for volatile compounds and sensory attributes every 2 mo for a total of 6 mo. Thirteen volatile compounds originating from LO were chosen to track the volatile profile of the WMP during storage. Color, composition, total fatty acid, and free fatty acid profiling were also carried out. Significant variations in the concentrations of 14 fatty acids were observed in WMP based on diet. Concentrations of free fatty acids increased in all sample types during storage. Similar trends in sensory attributes were observed with an increase in painty attributes, corresponding to an increase in hexanal. Buttery/toffee attributes were found to be more closely correlated with TMR WMP. Those WMP derived from pasture diets were found to be more susceptible to LO from a volatile perspective, particularly in relation to aldehyde development, which is likely due to increased concentrations of conjugated linoleic acid and α-linolenic acid found in these samples.

Ultrastructure and intercellular contact-mediated communication in cultured human early stage follicles exposed to mTORC1 inhibitor.

The reproductive lifespan of a woman is determined by the gradual recruitment of quiescent follicles into the growing pool. In humans, ovarian tissue removal from its in vivo environment induces spontaneous activation of resting follicles. Similarly, pharmacological activation of the PI3K/Akt pathway leads to accelerated follicle recruitment, but has been associated with follicular damage. Recent findings demonstrate that everolimus (EVE), an mTORC1 inhibitor, limits primordial follicle activation. However, its potential benefit regarding growing follicle integrity remains unexplored. Ovarian cortical fragments were exposed to ± EVE for 24 h and cultured for an additional 5 days. After 0, 1 and 6 days of culture, fragments were either processed for ultrastructural analysis or subjected to follicular isolation for gene expression and immunofluorescence assessments. Data from transmission electron microscopy showed that growing follicles displayed similar ultrastructural features irrespective of the conditions and maintained close contacts between germinal and stromal compartments. Establishment of intra-follicular communication was confirmed by detection of a gap junction component, Cx43, in both groups throughout culture, whereas transzonal projections, which physically link granulosa cells to oocyte, formed later in EVE-treated follicles. Importantly, levels of GJA1 mRNA, encoding for the Cx43 protein, significantly increased from Day 0 to Day 1 in the EVE group, but not in the control group. Given that EVE-treated follicles were smaller than controls, these findings suggest that EVE might facilitate the establishment of appropriate intercellular communications without impairing follicle ultrastructure. Therefore, mTORC1 inhibitors might represent an attractive tool to delay the culture-induced primordial follicle activation while maintaining follicles in a functionally integrated state.

Both in vivo FSH depletion and follicular exposure to Gonadotrophin-releasing hormone analogues in vitro are not effective to prevent follicular depletion during chemotherapy in mice.

STUDY QUESTION: Does fertility preservation using gonadotrophin-releasing hormone (GnRH) analogues during chemotherapy act through a direct effect on the ovary or through inhibition of FSH secretion? SUMMARY ANSWER: The absence of FSH in vivo and the direct exposition of ovarian follicles to GnRH analogues in vitro did not prevent chemotherapy-induced ovarian damage. WHAT IS KNOWN ALREADY: The potential mechanisms of action of GnRH analogues in protecting ovaries against chemotherapy damage remain poorly understood. We previously showed that GnRH analogues have a limited inhibitory effect on gonadotropin secretion and follicular growth in mice. STUDY DESIGN SIZE, DURATION: Mouse models were developed to independently evaluate (i) the indirect effect of FSH depletion on chemotherapy-induced ovarian damage using Fshb-deficient (-/-) mice to mimic the profound inhibition of FSH secretion during GnRH analogues treatment and (ii) the direct in vitro effect of GnRH agonist and antagonist in follicles exposed to chemotherapy using a follicular culture system. PARTICIPANTS/MATERIALS, SETTING, METHODS: To assess the indirect effect of GnRH analogues through FSH inhibition, Fshb-/- mice were treated with 1 IU pregnant mare serum gonadotropin (control group) or saline (study group) for 7 days and with cyclophosphamide (200 mg/kg) on Day 5. Ovaries were collected 48 h post-cyclophosphamide to evaluate ovarian reserve, cellular apoptosis and proliferation. To evaluate the direct effects of GnRH analogues on growing follicles, isolated preantral follicles from prepubertal mice were cultured in vitro for 13 days with 1 µM GnRH analogues and 20 µM of 4-hydroperoxycyclophosphamide or not at Day 4. Oocytes were matured by adding epidermal growth factor (EGF)/hCG on Day 12. Follicular development, follicular survival, oocyte maturation rates, cAMP production, and steroidogenesis were evaluated. To assess the direct GnRH analogues effects on follicular reserve, whole neonatal ovaries were cultured in vitro under the same conditions for 2 days. Ovaries were processed 24 h post-chemotherapy for ovarian reserve, cellular apoptosis and proliferation analysis. MAIN RESULTS AND THE ROLE OF CHANCE: Cyclophosphamide induced a significant follicular loss of more than 50% in Fshb-/- mice regardless of previous treatment with gonadotropins and no difference was observed in cell proliferation or apoptosis. In vitro experiments on growing follicles showed that 4-hydroperoxycyclophosphamide significantly decreased preantral follicle survival and maturation rates (55% and 37%, respectively) and delayed follicular development, regardless of the presence of GnRH analogues. Chemotherapy reduced granulosa cell numbers in all groups, while no change in cAMP production/106 granulosa cells was observed. Similarly, 4-hydroperoxycyclophosphamide induced apoptosis and significant follicular loss in cultured neonatal ovaries irrespective of GnRH analogues exposure. LIMITATIONS REASONS FOR CAUTION: As ovarian GnRH receptors expression differs in humans and mice, further studies are needed to validate our results in human ovaries. WIDER IMPLICATIONS OF THE FINDINGS: Our findings demonstrate that ovarian damage occurred even in the absence of FSH, suggesting that inhibition of the pituitary-gonadal axis is not involved in ovarian protection during GnRH analogues treatment. Using in vitro models, no evidence for direct protective effect of GnRH analogues against cyclophosphamide metabolite damage was observed. At present, clinical efficiency of GnRH analogues to prevent chemotherapy-induced ovarian damage remains highly debated and these experimental results reinforced the question as they did not bring evidence of direct or indirect mechanisms of protection. LARGE SCALE DATA: N/A. STUDY FUNDING AND COMPETING INTEREST(S): This work was supported by the Belgian FNRS, 'Le Fonds Emile DEFAY', and 'La Fondation Rose et Jean Hoguet'. Authors have no conflict of interest to declare.

The endoplasmic reticulum stress marker CHOP predicts survival in malignant mesothelioma.

BACKGROUND: Mesothelioma is an incurable cancer originating from the mesothelial cells that line the pleural, peritoneal and pericardial cavities. These cells synthesise large quantities of surface glycoproteins, rendering them dependent upon efficient endoplasmic reticulum (ER) function. When faced with elevated levels of secretory protein load, cells are said to experience ER stress, which has been implicated in the pathogenesis of many human diseases including cancer. METHOD: We set out to measure markers of ER stress in malignant mesothelioma and to determine whether ER stress signalling correlates with clinical parameters. RESULTS: We observed that expression of the ER stress-responsive transcription factor C/EBP homologous protein (CHOP) correlated with patient survival and remained an independent prognostic variable in pairwise comparisons with all clinical variables tested. The most parsimonious multivariate model in our study comprised only performance status and CHOP staining. In contrast, expression of the ER stress-responsive phosphatase growth arrest and DNA damage 34 (GADD34) correlated with the degree of mesothelial differentiation, being lost progressively in biphasic and sarcomatoid mesotheliomas. CONCLUSION: Our findings suggest that staining for CHOP provides prognostic information that may be useful in the stratification of patients with mesothelioma. Staining for GADD34 may prove useful in classification of mesothelioma histopathology.

Temperature dependency of Clostridium botulinum C and D toxin production from anaerobically enriched bovine gastrointestinal samples.

AIMS: To determine whether Clostridium botulinum neurotoxin (BoNT) production in anaerobic culture was affected by temperature and could influence the sandwich ELISA (sELISA) detection of group III toxins in pre-enriched gastrointestinal (GI) contents from clinically suspect cattle botulism cases. METHODS AND RESULTS: Bovine post-mortem GI samples taken from 124 and 96 animals with suspect and nonsuspect botulism, respectively, were pre-enriched anaerobically at 30 and 37°C prior to testing by sELISA. After enrichment at 37°C, BoNT was demonstrated in all clinically suspect bovine botulism cases that had been identified by the mouse bioassay, and enrichment by both temperatures enabled BoNT detection in a number of mouse bioassay-negative suspect cases. CONCLUSIONS: Culture temperature does influence the production of group III BoNT, and incubation at both 30 and 37°C is required for optimum detection. SIGNIFICANCE AND IMPACT OF THE STUDY: The in vitro assay defined in this study has the potential of improving the confirmation rate of clinically suspect cattle botulism cases whilst reducing the use of the costly and ethically sensitive mouse bioassay, the current diagnostic gold standard for BoNT testing.

Diagnosis of botulism types C and D in cattle by a monoclonal antibody-based sandwich ELISA.

This study was undertaken to evaluate two monoclonal antibody-based sandwich ELISAs (sELISAs) for the detection of Clostridium botulinum neurotoxins (BoNTs) types C and D from culture-enriched intestinal content samples from cattle. To validate the diagnostic significance of the presence of cultivable, toxin-producing C botulinum in the intestines of cattle, samples from both suspect and non-suspect botulism cases were examined. BoNT was detected by both sELISAs in a greater number of suspect animals than by direct testing of uncultured samples by mouse bioassay. One sELISA detected two BoNT C and one BoNT Group III mosaic isoform in three animals that were missed by the other, and both sELISAs failed to identify samples from two mouse bioassay-positive BoNT C animals. BoNT D was also detected in one non-suspect sample by one of the sELISAs.

Culture enrichment assists the diagnosis of cattle botulism by a monoclonal antibody based sandwich ELISA.

Monoclonal antibodies (MAbs) obtained from a mouse immunised with Clostridium botulinum type D toxoid were developed into a sandwich ELISA (sELISA) format that was able to detect type D toxin and types C and D toxin complexes. The sELISA was examined for its potential to replace the mouse bioassay as an alternative in vitro assay for the diagnosis of cattle botulism. Its application directly to intestinal samples collected from suspect cattle botulism cases and prepared for testing for the standard mouse bioassay showed poor correlation and sensitivity with the mouse bioassay results. However, anaerobic pre-enrichment of the samples after heat treatment at 80 degrees C for 10 min to activate any residual C. botulinum spores greatly improved the sELISA detection rate of the toxin by increasing the sample toxin levels. All of the mouse bioassay positive cattle cases tested were detected by the sELISA from the heated and pre-enriched samples tested after 24h incubation. Toxin was detected by sELISA and subsequently confirmed by mouse bioassay in samples from an additional 3 cases that had been originally mouse bioassay negative. The results indicate that the application of this procedure for screening intestinal samples for C. botulinum strains that produce types C and D toxins from suspect cattle botulism cases would improve the diagnostic rate as well as significantly reduce the number of mice involved in diagnosis.

Incomplete seating of the liner with the Trident acetabular system: a cause for concern?

We reviewed the initial post-operative radiographs of the Trident acetabulum and identified a problem with seating of the metal-backed ceramic liner. We identified 117 hips in 113 patients who had undergone primary total hip replacement using the Trident shell with a metal-backed alumina liner. Of these, 19 (16.4%) were noted to have incomplete seating of the liner, as judged by plain anteroposterior and lateral radiographs. One case of complete liner dissociation necessitating early revision was not included in the prevalence figures. One mis-seated liner was revised in the early post-operative period and two that were initially incompletely seated were found on follow-up radiographs to have become correctly seated. There may be technical issues with regard to the implanting of this prosthesis of which surgeons should be aware. However, there is the distinct possibility that the Trident shell deforms upon implantation, thereby preventing complete seating of the liner.

Impaction bone grafting in revision hip surgery.

We retrospectively reviewed the use of impaction bone grafting with cement for the fixation of femoral and acetabular components in revision hip arthroplasty. Seventy hips formed the basis of the study, with a mean follow-up time of 37 months. Sixty-eight percent of the femurs showed severe bone loss (Endoklinik grades 3 and 4). The mean Harris hip and Merle D'Aubigne Postel scores were 84 and 15.4, respectively. Massive subsidence occurred in only one femoral revision (>10 mm) and cup migration >5 mm in 6 cases. Loosening was seen in 1 revision for sepsis but none for aseptic loosening. Five complications were identified that were related to the surgical technique. We therefore support the use of this technique in revision surgery in patients with extensive bone loss.

Development of a sandwich ELISA and comparison with PCR for the detection of F11 and F165 fimbriated Escherichia coli isolates from septicaemic disease in farm animals.

The P fimbriae F11 and F165 that have been demonstrated on Escherichia coli septicaemic strains in poultry and calves, respectively, possess a nearly identical major subunit that demonstrates a serological cross-reaction. A polyclonal antibody-based sandwich ELISA (sELISA) that was specific for both F11 and F165 fimbriated strains was compared with a PCR method to detect F11/F165 fimbriated strains, in a collection of E. coli strains isolated from diseased animals. Of 298 isolates tested, 36 were positive by PCR of which only 14 were sELISA positive. There were no sELISA positive but PCR negative results. The 36 PCR positive isolates comprised 11 avian strains of which 10 were sELISA positive, 20 bovine strains of which 4 were sELISA positive and 3 ovine strains, 1 porcine strain and 1 equine strain all of which were sELISA negative. The F11/F165 incidence of 10.7% in 103 poultry and 18.3% in 109 bovine isolates demonstrates a moderate level of these factors in E. coli septicaemic cases in Northern Ireland.

Factors controlling the loss of immunoreactive somatic histone H1 from blastomere nuclei in oocyte cytoplasm: a potential marker of nuclear reprogramming.

Nuclei of differentiated cells can acquire totipotency following transfer into the cytoplasm of oocytes. While the molecular basis of this nuclear reprogramming remains unknown, the developmental potential of nuclear-transfer embryos is influenced by the cell-cycle stage of both donor and recipient. As somatic H1 becomes immunologically undetectable on bovine embryonic nuclei following transfer into ooplasm and reappears during development of the reconstructed embryo, suggesting that it may act as a marker of nuclear reprogramming, we investigated the link between cell-cycle state and depletion of immunoreactive H1 following nuclear transplantation. Blastomere nuclei at M-, G1-, or G2-phase were introduced into ooplasts at metaphase II, telophase II, or interphase, and the reconstructed embryos were processed for immunofluorescent detection of somatic histone H1. Immunoreactivity was lost more quickly from donor nuclei at metaphase than at G1 or G2. Regardless of the stage of the donor nucleus, immunoreactivity was lost most rapidly when the recipient cytoplast was at metaphase and most slowly when the recipient was at interphase. When the recipient oocyte was not enucleated, however, immunoreactive H1 remained in the donor nucleus. The phosphorylation inhibitors 6-DMAP, roscovitine, and H89 inhibited the depletion of immunoreactive H1 from G2, but not G1, donor nuclei. In addition, immunoreactive H1 was depleted from mouse blastomere nuclei following transfer into bovine oocytes. Finally, expression of the developmentally regulated gene, eIF-1A, but not of Gapdh, was extinguished in metaphase recipients but not in interphase recipients. These results indicate that evolutionarily conserved cell-cycle-regulated activities, nuclear elements, and phosphorylation-linked events participate in the depletion of immunoreactive histone H1 from blastomere nuclei transferred in oocyte cytoplasm and that this is linked to changes in gene expression in the transferred nucleus.

The treatment of impending and existing pathological femoral fractures using the long gamma nail.

The subtrochanteric region of the femur accounts for one-third of all pathological fractures requiring surgical intervention. The large forces occurring in this region and the possible non-occurrence of bony consolidation constitute a difficult problem to the trauma surgeon. The medical records and X-rays of 25 consecutive patients treated with the long gamma nail (LGN) for pathological (impending or existing) fractures of the femur were analysed retrospectively. Our results in the use of the LGN for pathological fractures of the femur have been good. We recommend an aggressive approach to the early stabilisation of impending fractures and the use of distal locking.

High-mobility group proteins 14 and 17 maintain the timing of early embryonic development in the mouse.

The high-mobility group (HMG) proteins 14 and 17 are abundant chromosomal proteins that bind to nucleosomes and enhance transcription. We report that both mRNA species and both proteins are present throughout oogenesis and preimplantation development of the mouse. When antisense oligonucleotides targeting each mRNA species are injected into one-cell embryos, the proteins become depleted at the two- and four-cell stages and reaccumulate at the eight-cell stage. One-cell embryos injected with antisense oligonucleotides targeting both HMG-14 and HMG-17 cleave to the two-cell stage. Subsequent cleavages, however, are delayed compared with control-injected embryos. Nevertheless, these embryos ultimately reach the blastocyst stage. Similarly, injection into the nuclei of two-cell embryos of a peptide corresponding to the common nucleosome-binding domain of HMG-14 and HMG-17 delays progression to the four-cell stage. Furthermore, both RNA and protein synthesis is transiently reduced in antisense-injected embryos compared with injected controls. These results identify HMG-14 and HMG-17 as constitutive components of mouse oocyte and embryonic chromatin and establish a link between the structure of embryonic chromatin and the normal progression of embryonic development.

The long gamma nail: a DGH experience.

Subtrochanteric fractures constitute a difficult problem for the trauma surgeon. The long Gamma nail (LGN) represents an efficient technique in the management of these fractures. A retrospective analysis of 51 LGN with an average follow up of 16 weeks is presented. The average age of the patients was 72 years and the mean time to union was 11 weeks. The incidence of peroperative, early local and late local complications was 8, 8 and 4%, respectively or 20% in total. The thirty-day mortality was 8%. Our results in the use of the LGN have been good. Its introduction provides the trauma surgeon with a tool for allowing earlier mobilisation, decreasing operative time, surgical trauma, blood loss and wound problems. The LGN is a device by which most complex fractures in the proximal femur can be managed with a single implant.

Effects of hydrosalpingeal fluid on murine embryo development and implantation.

PURPOSE: Our purpose was to evaluate the effects of various concentrations of hydrosalpingeal fluid (HSF) on the preimplantation development and implantation of murine embryos. METHODS: One-cell mouse embryos were cultured in KSOM culture medium with 0.1, 1.0, 10, or 50% HSF, without and with lactate supplementation. Late-stage embryos were transferred into the uteri of pseudopregnant CD-1 females to determine implantation rates. The embryo transfer technique used was developed by our group and its effectiveness was evaluated during this experiment. RESULTS: Blastocyst development in the 0.1, 1.0, 10, and 50% group was 45, 55.0, 12.5, and 17.5%, respectively, with lactate supplementation, and 35.0, 52.5, 12.5, and 5.0%, respectively, without lactate supplementation, while in the KSOM (control) group it was 63.8%. Blastocyst development was reduced compared to controls in the 10% HSF and 50% HSF groups. Implantation rates for the 0.1 and 1.0% groups with lactate supplementation were 43.0 and 25.0%, respectively, and those with lactate supplementation were 50.6 and 61.8%, respectively, while in the KSOM group the implantation rate was 65.5%. None of the implantation rates were significantly different. CONCLUSIONS: Hydrosalpingeal fluid has a concentration-dependent inhibitory effect on in vitro murine embryo development, but it has minimal effects on implantation rates.

Developmentally regulated loss and reappearance of immunoreactive somatic histone H1 on chromatin of bovine morula-stage nuclei following transplantation into oocytes.

One difference between chromatin of bovine oocytes and blastomeres is that somatic subtypes of histone H1 are undetectable in oocytes and are assembled onto embryonic chromatin during the fourth cell cycle. We investigated whether this chromatin modification is reversed when nuclei containing somatic H1 are transplanted into ooplasts. Donor nuclei obtained from morula-stage bovine embryos were fused to ooplasts at different times before and after parthenogenetic activation of the ooplasts. After fusion, immunoreactive H1 became undetectable, and the loss occurred more rapidly when fusion was performed near the time of ooplast activation compared with several hours after activation, when the host oocytes were at a stage corresponding to interphase. Although the loss of immunoreactive H1 occurred independently of DNA replication and transcription, exposure of reconstructed oocytes to cycloheximide or 6-dymethylaminopurine (6-DMAP) delayed the loss of immunoreactive H1 from transplanted nuclei. During further development of nuclear-transplant embryos, somatic H1 remained undetectable at the 2- and 4-cell stages, and it reappeared on the chromatin at the 8- to 16-cell stage, as previously observed in unmanipulated embryos. We conclude that factors in oocyte cytoplasm are able to modify morula chromatin so that somatic H1 becomes undetectable, and that the amount or activity of these factors declines over time in activated ooplasts.

Production of steroids from human cumulus cells treated with different concentrations of gonadotropins during culture in vitro.

OBJECTIVE: To evaluate the output of E2 and progesterone produced by cumulus cells, derived from mature and immature oocytes, in culture medium. DESIGN: Prospective randomized study. SETTING: McGill Reproductive Center, Royal Victoria Hospital, McGill University, Montreal, Quebec, Canada. PATIENT(S): Twenty-one women, <38 years of age and with normal menstrual cycles, who were undergoing intracytoplasmic sperm injection for assisted reproduction. INTERVENTION(S): Culture medium with or without fetal bovine serum (FBS) supplemented with either a physiologic (75 mIU/mL) or a supraphysiologic (7,500 mIU/mL) concentration of gonadotropins. MAIN OUTCOME MEASURE(S): Comparison of steroid levels in culture medium. RESULT(S): Estradiol secretion was significantly increased in the culture medium with FBS supplemented with both concentrations of FSH alone compared with control. However, E2 secretion was inhibited by both concentrations of FSH with LH. The level of E2 was undetectable in the medium without FBS even after supplementation with both concentrations of FSH alone, hCG alone, and FSH with LH. Progesterone production was increased in the medium with FBS supplemented with FSH alone, hCG alone, and FSH with LH compared with control. There was no difference in progesterone levels in the culture medium without FBS supplemented with both concentrations of FSH alone and hCG alone compared with control. However, progesterone secretion was increased in the medium without FBS supplemented with a physiologic concentration of FSH with LH. CONCLUSION(S): Culture medium with FBS supplemented with a physiologic and a supraphysiologic concentration of FSH stimulates E2 secretion from cumulus cells derived from mature and immature oocytes. This suggests that it may be not necessary to add E2 to the culture medium for maturation in vitro of immature human oocytes retrieved from patients undergoing stimulated cycles.

Linker histone transitions during mammalian oogenesis and embryogenesis.

A unique characteristic of the oocyte is that, although it is a differentiated cell, it can to give rise to a population of undifferentiated embryonic cells. This transition from a differentiated to a totipotential condition is thought to be mediated in part by changes in chromatin composition or configuration. In many non-mammalian organisms, oocytes contain unique subtypes of the linker histone H1, which are replaced in early embryos by the so-called somatic histone H1 subtypes. We review evidence that such histone H1 subtype switches also occur in mammals. Immunologically detectable somatic H1 is present in mitotically proliferating oogonia but gradually becomes undetectable after the oocytes enter meiosis. Immunoreactive somatic H1 remains undetectable throughout oogenesis and the early cell cycles after fertilization. Following activation of the embryonic genome, it is assembled onto chromatin. In contrast to the absence of immunoreactive protein, mRNAs encoding each of the five mammalian somatic H1 subtypes are present in growing oocytes and newly fertilized embryos, indicating that post-transcriptional mechanisms regulate expression of these genes. This maternal mRNA is degraded at the late 2-cell stage, and embryonically encoded mRNAs accumulate after embryos reach the 4-cell stage. During the period when somatic H1 is not detectable, oocytes and embryos contain mRNA encoding a sixth subtype, histone H1(0) which accumulates in differentiated somatic cells, and the nuclei can be stained with an H1(0)-specific antibody. We propose that the linker histone composition of the oocyte lineage resembles that of other mammalian cells, namely, that the somatic H1 subtypes predominate in mitotically active oogonia, that histone H1(0) becomes prominent in differentiated oocytes, and that following fertilization and transcriptional activation of the embryonic somatic H1 genes, the somatic H1 subtypes are reassembled onto chromatin of the embryonic cells. Potential functions of these linker histone subtype switches are discussed, including stabilization by H1(0) of the differentiated state of the oocytes, protection of the oocyte chromatin from factors that remodel sperm chromatin after fertilization, and restoration by the incorporation of the somatic H1 subtypes of the totipotential state of embryonic nuclei.