Ionophore application for artificial oocyte activation and its potential effect on morphokinetics: a sibling oocyte study

Purpose To evaluate whether ionophore application at the oocyte stage changes the morphokinetics of the associated embryos in cases of artificial oocyte activation. Methods In a prospective sibling oocyte approach, 78 ICSI patients with suspected fertilization problems had half of their MII-oocytes treated with a ready-to-use ionophore (calcimycin) immediately following ICSI (study group). Untreated ICSI eggs served as the control group. Primary analyses focused on morphokinetic behavior and the presence of irregular cleavages. The rates of fertilization, utilization, pregnancy, and live birth rate were also evaluated. Results Ionophore-treated oocytes showed a significantly earlier formation of pronuclei (t2PNa) and a better synchronized third cell cycle (s3) (P < .05). The rate of irregular cleavage was unaffected (P > .05). Ionophore treatment significantly improved the overall rates of fertilization (P < .01) and blastocyst utilization (P < .05). Conclusion Ionophore application does not negatively affect cleavage timing nor is it associated with irregular cleavage.

P–131 Significance of the phenomenon of blastomere exclusion from compaction: Its relation to irregular cleavage, blastocyst development rate, and pregnancy rate

Study question When does blastomere exclusion from compaction increase and what effect does it have on the embryo? Summary answer More blastomere were excluded from compaction in embryos with irregular cleavage, resulting in lower blastocyst development rates, but no decrease in pregnancy rates at transfer. What is known already It has been reported that many of the chromosome analysis results of blastomere excluded from compaction were aneuploid, and pointed out that this exclusion may be related to the repair of blastocyst euploidy, but the effect of the number of excluded blastomere has not been reported. Study design, size, duration This is a retrospective study of 578 embryos that developed into morula with time-lapse monitoring by EmbryoScope (Vitrolife) in 2018–2019. Participants/materials, setting, methods The target embryos were classified into two groups: embryos with normal first and second cleavage (normal cleavage group) and embryos with irregular cleavage (dynamics of one cell dividing into three or more cells), called “direct cleavage”, at either cleavage (DC group), and the number of blastomere excluded from compaction during morula formation was recorded and compared. The blastocyst development rate and single blastocyst transfer pregnancy rates of the two groups were compared. Main results and the role of chance There are 286 in the normal cleavage group and 292 in the DC group. The mean number of excluded blastomere was 0.76 and 3.55, respectively, which was significantly higher in the DC group (P &lt; 0.01). Good blastocyst (Gardner classification 4 or higher) development rate was 84.5% (239/283) and 65.8% (181/275), respectively, and high grade blastocyst (Gardner classification BB or higher) development rate was 43.9% (105/239) and 14.9% (27/181) of them, both significantly higher in the normal cleavage group (P &lt; 0.01). The single blastocyst transfer pregnancy rates were 31.6% (25/79) and 32.4% (11/34), and the miscarriage rates were 24.0% (6/25) and 27.3% (3/11), respectively, neither was there a significant difference between the two groups. So, direct cleavage increased the number of blastomere excluded from compaction, decreased the rate of morula to good blastocyst development and reduced blastocyst grade, but did not affect blastocyst transfer pregnancy rate and miscarriage rate. Limitations, reasons for caution Please note that all target embryos must have developed into morula or larger (embryos that did not develop into morula will not be included in the study). Wider implications of the findings: Severe chromosomal aberrant blastomeres formed by direct cleavage were excluded from compaction, and the blastocyst development rate decreased due to a decrease in the amount of viable cells, but it is suggested that this blastomere exclusion mechanism is not related to euploidy after blastocyst development. Trial registration number Not applicable

Russoite, NH4ClAs23+O3(H2O)0.5, a new phylloarsenite mineral from Solfatara Di Pozzuoli, Napoli, Italy

The new mineral russoite (IMA2015-105), NH4ClAs23+O3(H2O)0.5, was found at the Solfatara di Pozzuoli, Pozzuoli, Napoli, Italy, as a fumarolic phase associated with alacránite, dimorphite, realgar, mascagnite, salammoniac and an amorphous arsenic sulfide. It occurs as hexagonal plates up to ~300 µm in diameter and 15 µm thick, in rosette-like intergrowths. On the basis of powder X-ray diffraction measurements and chemical analysis, the mineral was recognised to be identical to the corresponding synthetic phase NH4ClAs2O3(H2O)0.5. Crystals are transparent and colourless, with vitreous lustre and white streak. Tenacity is brittle and fracture is irregular. Cleavage is perfect on {001}. The measured density is 2.89(1) g/cm3; the calculated density is 2.911 g/cm3. The empirical formula, (based on 4.5 anions per formula unit) is [(NH4)0.94,K0.06]Σ1.00(Cl0.91,Br0.01)Σ0.92As2.02O3(H2O)0.5. Russoite is hexagonal, space group P622, with a = 5.2411(7), c = 12.5948(25) Å, V = 299.62(8) Å3 and Z = 2. The eight strongest X-ray powder diffraction lines are [dobs Å(I)(hkl)]: 12.63(19)(001), 6.32(100)(002), 4.547(75)(100), 4.218(47)(003), 3.094(45)(103), 2.627(46)(110), 2.428(31)(112) and 1.820(28)(115). The structure, was refined to R = 0.0518 for 311 reflections with I > 2σ(I) and shows a different location of the ammonium cation and water molecules with respect to that reported for the synthetic analogue. The mineral belongs to a small group of phylloarsenite minerals (lucabindiite, torrecillasite and gajardoite). It contains electrically neutral As2O3 layers, topologically identical to those found in lucabindiite and gajardoite between which are ammonium cations and outside of which Cl– anions. Water molecules and additional ammonium cations are located in a layer between two levels of chloride anions.

Juansilvaite, Na5Al3[AsO3(OH)]4[AsO2(OH)2]2(SO4)2·4H2O, a new arsenate-sulfate from the Torrecillas mine, Iquique Province, Chile

The new mineral juansilvaite (IMA2015-080), Na5Al3[AsO3(OH)]4[AsO2(OH)2]2(SO4)2·4H2O, was foOptically, juansilvaiteund at the Torrecillas mine, Iquique Province, Chile, where it occurs as asecondary alteration phase in association with anhydrite, canutite, halite, sulfur and a mahnertite-like phase. Juansilvaite occurs as bright pink blades up to ∼0.5 mm long grouped in tightly intergrown radial aggregates and also as opaque dull pale pink rounded aggregates. Blades areflattened on {001}, elongated on [100] and exhibit the forms {001}, {111} and {201}. Crystals are transparent, with vitreous lustre and white streak. The Mohs hardness is ∼2½, tenacity is brittle and fracture is irregular. Cleavage is very good on {001}. The measured density is3.01(2) g cm–3 and the calculated density is 3.005 g cm–3. Optically, juansilvaite is biaxial (+) with α= 1.575(1), β = 1.597(1), γ= 1.623(1) and 2V = 86(1)° (measured in white light). Dispersion is r < v, slight, andthe orientation is X = b; Z ^ c = 27° in the obtuse angle β. The pleochroism is X > Y ≈ Z in shades of pale pink. The mineral is slowly soluble in dilute HCl at room temperature. The empirical formula, determined from electron-microprobeanalyses, is Na4.95Al2.28Fe0.503+Mn0.213+Cu0.04As5.92S1.83O36H17.37. Juansilvaite is monoclinic, C2/c, a = 18.1775(13), b = 8.6285(5), c= 18.5138(13) Å, β = 90.389(6)°, V = 2903.7(3) Å3 and Z = 4. The eight strongest powder X-ray diffraction lines are [dobs Å(I)(hkl)]: 9.25(100)(002), 7.20(34)(111), 4.545(34)(400), 3.988(39)(114), 3.363(42)(314), 3.145(66)(512,420), 2.960(68)(422,422) and 2,804(33)(131,423). The structure of juansilvaite (R1 = 3.82% for 2040 Fo > 4σF reflections) contains layers made up of alternating corner-linked Al–O octahedra and acid-arsenate tetrahedra. Sodium cations occur both peripheral to the layers and within cavities in the layers. An SO4 tetrahedron and an H2O group also are in the interlayer region.

Gajardoite, KCa0.5As3+4O6Cl2·5H2O, a new mineral related to lucabindiite and torrecillasite from the Torrecillas mine, Iquique Province, Chile

The new mineral gajardoite (IMA2015-040), KCa0.5As3+4O6Cl2·5H2O, was found at the Torrecillas mine, Iquique Province, Chile, where it occurs as a secondary alteration phase in association with native arsenic, arsenolite,chongite, talmessite and torrecillasite. Gajardoite occurs as hexagonal plates up to ∼100 μm in diameter and 5 μm thick, in rosette-like subparallel intergrowths. Crystals are transparent, with vitreous lustre and white streak. The Mohs hardness is ∼1½, tenacity is brittleand fracture is irregular. Cleavage is perfect on {001}. The measured density is 2.64 g/cm3 and the calculated density is 2.676 g/cm3. Optically, gajardoite is uniaxial (–) with ω = 1.780(3) and ε = 1.570(5) (measured in white light). The mineral is very slowly soluble in H2O and slowly soluble in dilute HCl at room temperature. The empirical formula, determined from electron-microprobe analyses, is (K0.77Ca0.71Na0.05Mg0.05)∑1.58As4O11Cl1.96H9.62.Gajardoite is hexagonal, P6/mmm, a = 5.2558(8), c = 15.9666(18) Å, V = 381.96(13) Å3 and Z = 1. The eight strongest powder X-ray diffraction lines are [dobs Å(I)(hkl)]: 16.00(100)(001), 5.31(48)(003),3.466 (31)(103), 3.013(44)(104), 2.624(51)(006,110,111), 2.353(36)(113), 1.8647(21)(116,205) and 1.4605(17) (119,303,216). The structure, refined to R1 = 3.49% for 169 Fo > 4σF reflections, contains two types of layers. One layer of formulaKAs3+4O6Cl2 consists of two neutral As2O3 sheets, between which are K+ cations and on the outside of which are Cl– anions. This layer is topologically identical to a slice of the lucabindiite structureand similar to a slice of the torrecillasite structure. The second layer consists of an edge-sharing sheet of Ca(H2O)6 trigonal pyramids with isolated H2O groups centred in the hexagonal cavities in the sheet.

Torrecillasite, Na(As,Sb)43+O6Cl, a new mineral from the Torrecillas mine, Iquique Province, Chile: description and crystal structure

The new mineral torrecillasite (IMA2013-112), Na(As,Sb)43+O6Cl, was found at the Torrecillas mine, Iquique Province, Chile, where it occurs as a secondary alteration phase in association with anhydrite, cinnabar, gypsum, halite, lavendulan, magnesiokoritnigite, marcasite, quartz, pyrite, scorodite, wendwilsonite and other potentially new As-bearing minerals. Torrecillasite occurs as thin colourless prisms up to 0.4 mm long in jack-straw aggregates, as very thin fibres in puff balls and as massive intergrowths of needles. Prisms are elongated on [100] with diamond-shaped cross-section and irregular terminations. Crystals are transparent, with adamantine lustre and white streak. The Mohs hardness is 2½, tenacity is brittle and fracture is irregular. Cleavage on (001) is likely. The calculated density is 4.056 g cm−3. Optically, torrecillasite is biaxial (−) with α = 1.800(5), β = 1.96(1), γ = 2.03(calc.) (measured in white light). The measured 2V is 62.1(5)°, no dispersion or pleochroism were observed, the optical orientation isX=c,Y=b,Z=a. The mineral is very slowly soluble in H2O, slowly soluble in dilute HCl and rapidly soluble in concentrated HCl. The empirical formula, determined from electron-microprobe analyses, is (Na1.03Mg0.02)∑1.05(As3.39Sb0.62)∑4.01O6.07Cl0.93. Torrecillasite is orthorhombic,Pmcn, a= 5.2580(9),b= 8.0620(13),c= 18.654(3) Å,V= 790.7(2) Å3andZ= 4. The eight strongest X-ray powder diffraction lines are [dobsÅ(I)(hkl)]: 4.298(33)(111), 4.031(78)(014,020), 3.035(100)(024,122), 2.853(39)(115,123), 2.642(84)(124,200), 2.426(34)(125), 1.8963(32)(225) and 1.8026(29)(0·1·10,233). The structure, refined toR1= 4.06% for 814Fo>4σFreflections, contains a neutral, wavy As2O3layer parallel to (001) consisting of As3+O3pyramids that share O atoms to form six-membered rings. Successive layers are flipped relative to one another and successive interlayer regions contain alternately either Na or Cl atoms. Torrecillasite is isostructural with synthetic orthorhombic NaAs4O6Br.

Aster formation in eggs of Xenopus laevis. Induction by isolated basal bodies.

We have assayed various materials for their ability to induce aster formation by microinjection into unfertilized eggs of Xenopus laevis. We have found that purified basal bodies from Chlamydomonas reinhardtii and Tetrahymena pyriformis induce the formation of asters and irregular cleavage furrows within 1 h after injection. Other microtubule structures such as flagella, flagellar axonemes, cilia, and brain microtubules are completely ineffective at inducing asters or cleavage furrows in unfertilized eggs. When known amounts of sonicated Tetrahymena and Chlamydomonas preparations are injected into unfertilized eggs, 50% of the injected eggs show a furrowing response at approximately 3 cell equvalents for Chlamydomonas and 0.1 cell equivalent for Tetrahymena. These results are close to those expected if basal bodies were the effective astral-inducing agent in these cells. Other materials effective at inducing asters in unfertilized eggs, such as crude brain nuclei, sperm, and a particulate fraction from brain known to induce parthenogenesis in eggs of Rana pipiens, probably contain centrioles as the effective agent. Our experiments provide the first functional assay to indicate that centrioles play an active role in aster initiation. None of the injected materials effective in unfertilized eggs produced any observable response in fully grown oocytes. Oocytes and eggs were found to have equal tubulin pools as judged by colchicine-binding activity. Therefore, the inability of oocytes to form asters cannot be due to a lack of an organizing center or to a lack of tubulin. Experiments in which D2O was found to stimulate aster-like fibrous areas in eggs but not oocytes suggest that the inability of oocytes to form asters may be due to an inability of tubulin in oocytes to assemble.