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Scientific Reports Mar 2024Egg specific gravity is of relevance for fish recruitment since the ability to float influences egg and larvae development, dispersal and connectivity between fishing...
Egg specific gravity is of relevance for fish recruitment since the ability to float influences egg and larvae development, dispersal and connectivity between fishing grounds. Using zootechnics, histological approaches, optical and electronic transmission microscopy, this study describes the morphogenetic mechanism of adhesion of the oil-drop covering layer (OCL) to the oil droplet (OD) in embryos of Merluccius merluccius under physical conditions reflecting the marine environment. The herein described primordial (p)OCL is a substructure of the inner yolk syncytial layer which contains egg organella aimed to mobilize lipidic reserves from the oil drop (OD) towards the embryo blood. It is shown that the timely OD-OCL assembly is a critical morphogenetic process for embryo and larvae survival. Such assembly depends on egg buoyance because of its influence on the embryo capacity to rotate within the perivitelline space. Therefore, oil droplet adhesion (ODA) eggs are capable to complete their development while oil droplet non-adhesion eggs (ODNA) dye soon after hatching. We show that gravity-dependent egg buoyance categories exhibit different ODA/ODNA ratios (0-77%) and that relationship diminishes under incubation systems such as sprayers, that do not assure a dynamic seawater surface mixing to avoid egg desiccation. As an adaptive trait, egg gravity strongly depends on oceanic properties such as current dynamics, turbulence, oxygen, rainfall, and salinity, whose rapid changes would likely challenge the sustainability of fisheries recruitment.
Topics: Animals; Egg Yolk; Embryo, Nonmammalian; Embryonic Development; Eggs
PubMed: 38519522
DOI: 10.1038/s41598-024-57429-9 -
Scientific Reports Nov 2019After sperm-oocyte fusion, cortical granules (CGs) located in oocyte cortex undergo exocytosis and their content is released into the perivitelline space to avoid...
After sperm-oocyte fusion, cortical granules (CGs) located in oocyte cortex undergo exocytosis and their content is released into the perivitelline space to avoid polyspermy. Thus, cortical granule exocytosis (CGE) is a key process for fertilization success. We have demonstrated that alpha-SNAP -and its functional partner NSF- mediate fusion of CGs with the plasma membrane in mouse oocytes. Here, we examined at cellular and ultrastructural level oocytes from hyh (hydrocephalus with hop gait) mice, which present a missense mutation in the Napa gene that results in the substitution of methionine for isoleucine at position 105 (M105I) of alpha-SNAP. Mutated alpha-SNAP was mislocalized in hyh oocytes while NSF expression increased during oocyte maturation. Staining of CGs showed that 9.8% of hyh oocytes had abnormal localization of CGs and oval shape. Functional tests showed that CGE was impaired in hyh oocytes. Interestingly, in vitro fertilization assays showed a decreased fertilization rate for hyh oocytes. Furthermore, fertilized hyh oocytes presented an increased polyspermy rate compared to wild type ones. At ultrastructural level, hyh oocytes showed small mitochondria and a striking accumulation and secretion of degradative structures. Our findings demonstrate the negative effects of alpha-SNAP M105 mutation on oocyte biology and further confirm the relevance of alpha-SNAP in female fertility.
Topics: Amino Acid Substitution; Animals; Female; Fertility; Fertilization; Homozygote; Infertility, Female; Isoleucine; Male; Metaphase; Methionine; Mice; Mice, Transgenic; Mutation, Missense; Oocytes; Oogenesis; Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins
PubMed: 31758001
DOI: 10.1038/s41598-019-53574-8 -
Journal of Assisted Reproduction and... Oct 2016Crotamine is capable of penetrating cells and embryos and transfecting cells with exogenous DNA. However, no studies are available regarding its uptake by...
PURPOSE
Crotamine is capable of penetrating cells and embryos and transfecting cells with exogenous DNA. However, no studies are available regarding its uptake by parthenogenetic (PA) embryos or its use for transfection in in vitro fertilized (IVF) embryos. This study aimed to determine the translocation kinetics of crotamine into PA and IVF bovine embryos and assess its effect over in vitro development of PA embryos. Moreover, crotamine-DNA complexes were used to test the transfection ability of crotamine in bovine IVF zygotes.
METHODS
PA and IVF embryos were exposed to labeled crotamine for four interval times. Embryo toxicity was assayed over PA embryos after 24 h of exposure to crotamine. Additionally, IVF embryos were exposed to or injected with a complex formed by crotamine and pCX-EGFP plasmid.
RESULTS
Confocal images revealed that crotamine was uptaken by PA and IVF embryos as soon as 1 h after exposure. Crotamine exposure did not affect two to eight cells and blastocyst rates or blastocyst cell number (p > 0.05) of PA embryos. Regarding transfection, exposure or injection into the perivitelline space with crotamine-DNA complex did not result in transgene-expressing embryos. Nevertheless, intracytoplasmic injection of plasmid alone showed higher expression rates than did injection with crotamine-DNA complex at days 4 and 7 (p < 0.05).
CONCLUSIONS
Crotamine is able to translocate through zona pellucida (ZP) of PA and IVF embryos within 1 h of exposure without impairing in vitro development. However, the use of crotamine does not improve exogenous DNA expression in cattle embryos, probably due to the tight complexation of DNA with crotamine.
Topics: Animals; Blastocyst; Cattle; Cell-Penetrating Peptides; Crotalid Venoms; Embryo Culture Techniques; Embryo, Mammalian; Female; Fertilization in Vitro; Parthenogenesis; Zygote
PubMed: 27515309
DOI: 10.1007/s10815-016-0772-7 -
PloS One 2015Our center's quality improvement optimization process on many occasions anecdotally suggested that oocyte assessments might enhance embryo assessment in predicting...
CONTEXT
Our center's quality improvement optimization process on many occasions anecdotally suggested that oocyte assessments might enhance embryo assessment in predicting pregnancy chances with in vitro fertilization (IVF).
OBJECTIVE
To prospectively compare a morphologic oocyte grading system to standard day-3 morphologic embryo assessment.
DESIGN, SETTING, PATIENTS
We prospectively investigated in a private academically-affiliated infertility center 94 consecutive IVF cycles based on 6 criteria for oocyte quality: morphology, cytoplasm, perivitelline space (PVS), zona pellucida (ZP), polar body (PB) and oocyte size, each assigned a value of -1 (worst), 0 (average) or +1 (best), so establishing an average total oocyte score (TOS). Embryo assessment utilized grade and cell numbers of each embryo on day-3 after oocyte retrieval. Clinical pregnancy was defined by presence of at least one intrauterine gestational sac.
INTERVENTIONS
Standard IVF cycles in infertile women.
MAIN OUTCOME MEASURES
Predictability of pregnancy based on oocyte and embryo-grading systems.
RESULTS
Average age for all patients was 36.5 ± 7.3 years; mean oocyte yield was 7.97± 5.76; Patient specific total oocyte score (PTOS) was -1.05 ± 2.24. PTOS, adjusted for patient age, was directly related to odds of increased embryo cell numbers (OR 1.12, P = 0.025), embryo grade (OR 1.19, P < 0.001) and clinical pregnancy [OR 1.58 (95%CI 1.23 to 2.02), P < 0.001]. Restricting the analysis to day three embryos of high quality (8-cell/ good grades), TOS was still predictive of clinical pregnancy (OR 2.08 (95%CI 1.26 to 3.44, P = 0.004). Among the 69 patients with embryos of Grade 4 or better available for transfer 23 achieved Clinical Pregnancy. When the analysis was restricted to the 69 transfers with good quality embryos (≥ Grade 4) the Oocyte Scoring System (TOS) (AUC±SE 0.863±0.044, oocyte score) provided significantly greater predictive value for clinical pregnancy compared to the embryo grade alone (AUC 0.646 ± 0.072, embryo grade) p = 0.015.
CONCLUSIONS
Oocyte-scoring, thus, provides useful clinical information especially in good prognosis patients with large numbers of high quality embryos. This finding appears of particular importance at a time when many IVF centers are committing sizable investments to closed incubation systems with time-lapse photography, which are exclusively meant to define embryo morphology.
Topics: Adult; Embryo, Mammalian; Female; Fertilization in Vitro; Humans; Oocytes; Pregnancy; Treatment Outcome
PubMed: 26630267
DOI: 10.1371/journal.pone.0143632 -
BioMed Research International 2015Farnesyl pyrophosphate synthase (FPPS) plays a vital role in the mevalonate pathway and has been shown to be involved in hypertrophy and cardiovascular diseases....
Farnesyl pyrophosphate synthase (FPPS) plays a vital role in the mevalonate pathway and has been shown to be involved in hypertrophy and cardiovascular diseases. Lentivirus-mediated RNA interference (RNAi) to knock down a gene of interest has become a promising new tool for the establishment of transgenic animals. The interfering fragment, named pLVT202, was chosen from cardiomyocytes tested in vitro and was microinjected into the perivitelline space of zygotes from C57BL/6J mice via a lentivirus vehicle; 20 were identified as carrying copies of the transgene using the polymerase chain reaction (PCR). Real-time PCR and western blotting analysis showed that FPPS was downregulated in multiple tissues in the transgenic mice. The transgenic mouse model provides a novel means of studying the gene function of FPPS.
Topics: Animals; Cells, Cultured; Geranyltranstransferase; Lentivirus; Mice; Mice, Inbred C57BL; Mice, Transgenic; Myocytes, Cardiac; Plasmids; RNA Interference
PubMed: 25688370
DOI: 10.1155/2015/914026