scholarly journals Oocyte Positional Recognition for Automatic Manipulation in ICSI

Micromachines ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 429 ◽  
Author(s):  
Mozafar Saadat ◽  
Amir Hajiyavand ◽  
Ajai-pal Singh Bedi
Keyword(s):  
Body Position ◽  
Polar Body ◽  
Recognition System ◽  
Size Measurement ◽  
Transform Method ◽  
Position Detection ◽  
Polar Bodies ◽  
Fitting Method ◽  
Injection Mechanism ◽  
Intracellular Structure

Polar body position detection is a necessary process in the automation of micromanipulation systems specifically used in intracytoplasmic sperm injection (ICSI) applications. The polar body is an intracellular structure, which accommodates the chromosomes, and the injection must not only avoid this structure but be at the furthest point away from it. This paper aims to develop a vision recognition system for the recognition of the oocyte and its polar body in order to be used to inform the automated injection mechanism to avoid the polar body. The novelty of the paper is its capability to determine the position and orientation of the oocyte and its polar body. The gradient-weighted Hough transform method was employed for the detection of the location of the oocyte and its polar body. Moreover, a new elliptical fitting method was employed for size measurement of the polar bodies and oocytes for the allowance of morphological variance of the oocytes and their polar bodies. The proposed algorithm has been designed to be adaptable with typical commercial inverted microscopes with different criteria. The successful experimental results for this algorithm produce maximum errors of 5% for detection and 10% for reporting respectively.

Memoirs: The Germ-Cell Cycle in Phytophaga destructor Say

1935 ◽  
Vol s2-77 (308) ◽  
pp. 585-604
Author(s):  
MARGOT E. METEALFE
Keyword(s):  
Germ Cells ◽  
Growth Stage ◽  
Germ Line ◽  
Polar Body ◽  
Metaphase Plate ◽  
Body Formation ◽  
Polar Bodies ◽  
Complicated Process ◽  
Female Pronucleus ◽  
Polar Body Formation

1. The somatic cells in both sexes of Phytophaga destructor Say contain four pairs of V-shaped chromosomes, the sex-group being indistinguishable in size or form. 2. The germ-cells in both sexes contain eight pairs of chromosomes. 3. The maturation of the egg follows the normal course of development, eight bivalents being formed. After polar body formation the female pronucleus has eight chromosomes. The polar bodies are never extruded from the egg. 4. Spermatogenesis is a complicated process, the details of which have not been satisfactorily determined. The growth stage appears to take place before the last spermatogonial division. No pairing of chromosome has been observed, and apparently no metaphase plate is formed at meiosis. Eeduction is effected by the expulsion of two buds each containing four chromosomes. Thus only one sperm is produced from each spermatocyte. 5. One or more sperms may enter the egg at fertilization. 6. The germ-line is differentiated from the soma at the eightcell stage. 7. At the fifth cleavage the somatic nuclei eliminate half their number of chromosomes, and are left with eight chromosomes. 8. Migration of the germ nuclei takes place at the sixteencell stage. 9. The relation of the chromosome numbers in the somatic and germ lines is discussed.

Cytological characterisation of the mutant phenotypes produced during early embryogenesis by null and loss-of-function alleles of the gammaTub37C gene in Drosophila

1999 ◽  
Vol 112 (5) ◽  
pp. 659-667 ◽  
Author(s):  
S. Llamazares ◽  
G. Tavosanis ◽  
C. Gonzalez
Keyword(s):  
Polar Body ◽  
Nuclear Proliferation ◽  
Early Embryogenesis ◽  
Drosophila Embryo ◽  
Loss Of Function ◽  
Female Meiosis ◽  
Polar Bodies ◽  
Early Drosophila Embryo ◽  
Gamma Tubulin ◽  
Mutant Phenotypes

We have studied the mutant phenotypes brought about during early embryogenesis by mutation in the gammaTub37C gene, one of the two isoforms of gamma-tubulin that have been identified in Drosophila. We have focused our attention on fs(2)TW1(1) and fs(2)TW1(RU34), a null and a hypomorph allele of this gene, whose sequences we report in this work. We have found that the abnormal meiotic figures observed in mutant stage 14 oocytes are not observed in laid oocytes or fertilised embryos, suggesting that these abnormal meiotic figures are not terminally arrested. We have also concluded that both null and hypomorph alleles lead to a total arrest of nuclear proliferation during early embryogenesis. This is in contrast to their effect on female meiosis-I where hypomorph alleles display a much weaker phenotype. Finally, we have observed that null and hypomorph alleles lead to some distinct phenotypes. Unfertilised laid oocytes and fertilised embryos deficient for gammaTub37C do not contain polar bodies and have a few bipolar microtubule arrays. In contrast, oocytes and embryos from weaker alleles do not have these microtubule arrays, but do contain polar bodies, or polar-body-like structures. These results indicate that gammaTub37C is essential for nuclear proliferation in the early Drosophila embryo.

scholarly journals Iris Segmentation

2018 ◽  
Vol 7 (2.5) ◽  
pp. 77
Author(s):  
Anis Farihan Mat Raffei ◽  
Rohayanti Hassan ◽  
Shahreen Kasim ◽  
Hishamudin Asmuni ◽  
Asraful Syifaa’ Ahmad ◽  
...  
Keyword(s):  
Iris Recognition ◽  
Image Data ◽  
Recognition System ◽  
Environmental Condition ◽  
Segmentation Method ◽  
Iris Segmentation ◽  
Transform Method ◽  
Circular Hough Transform ◽  
Segmentation Methods

The quality of eye image data become degraded particularly when the image is taken in the non-cooperative acquisition environment such as under visible wavelength illumination. Consequently, this environmental condition may lead to noisy eye images, incorrect localization of limbic and pupillary boundaries and eventually degrade the performance of iris recognition system. Hence, this study has compared several segmentation methods to address the abovementioned issues. The results show that Circular Hough transform method is the best segmentation method with the best overall accuracy, error rate and decidability index that more tolerant to ‘noise’ such as reflection.  

The localization of LAP2β during pronuclear formation in bovine oocytes after fertilization or activation

Zygote ◽  
2006 ◽  
Vol 14 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Mamiko Isaji ◽  
Hisataka Iwata ◽  
Hiroshi Harayama ◽  
Masashi Miyake
Keyword(s):  
Chromatin Condensation ◽  
Polar Body ◽  
Somatic Cells ◽  
Histone H3 ◽  
Cumulus Cells ◽  
Polar Bodies ◽  
Second Polar Body ◽  
Pronuclear Formation ◽  
Bovine Oocytes

SummaryWe have shown that the assembly of lamin-associated polypeptide (LAP) 2β was detected surrounding the chromatin mass around the time of extrusion of the second polar body (PB) in some fertilized oocytes, but not in most activated oocytes, by using A23187 and cycloheximide (CaA + CH). Here, we immunohistologically analysed the correlation between LAP2β assembly and chromatin condensation in fertilized and activated oocytes during the second meiosis. In bovine cumulus cells, the onset of LAP2β assembly was observed around anaphase chromosomes with strongly phosphorylated histone H3. No LAP2β assembled around the chromosomes in the first and second polar bodies and the alternative oocyte chromatin (oCh) if histone H3 was phosphorylated. Only histone H3 of oCh was completely dephosphorylated during the telophase II/G1 transition (Tel II/G1), and then LAP2β assembled around only the oCh without phosphorylated histone H3. In the oocytes activated by CaA + CH, LAP2β did not assemble around the condensed oCh during the Tel II/G1 transition, although their histone H3 dephosphorylation occurred rather rapidly compared with that of the fertilized oocytes. The patterns of histone H3 dephosphorylation and LAP2β assembly in oocytes activated by CaA alone showed greater similarity to those in fertilized oocytes than to those in oocytes activated by CaA + CH. These results show that LAP2β assembles around only oCh after complete dephosphorylation of histone H3 after fertilization and activation using CaA alone, and that the timing of histone H3 dephosphorylation and LAP2β assembly in these oocytes is different from that of somatic cells. The results also indicate that CH treatment inhibits LAP2β assembly around oCh but not histone H3 dephosphorylation.

56 THE EFFECT OF VITRIFICATION FOR SHEEP OOCYTES VIABILITY

2015 ◽  
Vol 27 (1) ◽  
pp. 121 ◽  
Author(s):  
Y. M. Toishibekov ◽  
R. K. Tursunova ◽  
M. Sh. Yermekova
Keyword(s):  
Polar Body ◽  
Control Group ◽  
Polar Bodies ◽  
Maturation Medium ◽  
Chi Squared ◽  
Fetal Bovine ◽  
Second Polar Body ◽  
Cryopreservation Techniques ◽  
Humidified Air

Advances in reproduction technologies, such as in vitro maturation, IVF, and in vitro culture, stimulated research for efficient cryopreservation techniques for mammalian oocytes. It is well known that the oocyte is the largest cell of an animal's body and as such, is full of water and, in many species, fat, making it difficult to cryopreserve. The objective of this work was to study the effect of vitrification for cryopreservation of the metaphase II plate (MPII) of sheep oocytes. Ovaries from 20 ewes of Kazakh Arkharo-Merino breed were acquired after slaughter and maintained at 37°C in TCM-199. The maturation medium was TCM-199, containing 1 mM of glutamine, 10% FBS, 5 μg mL–1 FSH, 5 μg mL–1 LH, 1 μg mL–1 oestradiol, 0.3 mM sodium pyruvate, and 100 mM cysteamine. The oocytes were incubated in 400 μL of medium in 4-well dishes covered with mineral oil. The IVM conditions were 5% CO2 in humidified air at 39°C for 24 h. Then they were placed for 10 min in a media with Hoechst 33342 (3 μg mL–1) and cytochalasin B (7 μg mL–1) to facilitate the enucleation of the MPII with a minimum volume of ooplasm. The MPII plates were divided into 2 groups: the vitrification group was exposed to vitrification media containing 1.12 M ethylene glycol (ET) + 0.87 M ME2SO for 5 min and was exposed in vitrification media containing 2.24 M ET + 1.75 M ME2SO for 5 min, and then in vitrification solution containing 4.48 M ET + 40% ME2SO + 0.25 M sucrose for 30 s. Oocytes were loaded into cryoloop and plunged into liquid nitrogen (LN2). Oocytes were thawed in a 25°C water bath and then placed in TCM-199 at 20% fetal bovine serum. After 15 min of incubation the oocytes were activated for extrusion of the second polar body in 1 mg mL–1 Ca ionophore for 5 min and washed for 5 min followed by 4 h in 6-DMAP (0.12 mM) + cycloheximide (0.6 μg mL–1). After activation the MPII were washed and cultured for 20 h. The control group received the same treatment, but they were not vitrified. Differences between the experimental groups were tested using Chi-squared test. Our research showed the expulsion of the second polar body after activation was observed in more than 62.2% of the MPII that were not vitrified (control group), whereas 40.5% of vitrified plates had expulsion of polar bodies (P < 0.05). These preliminary studies showed that it is possible to vitrify MPII plates. On the other hand, the drastic reduction of the volume of the sheep oocytes might make cryopreservation possible with greater efficiency.

Centrosome inheritance in starfish zygotes: behaviour and duplicating capacity of the meiotic centrosomes in maturation division

Zygote ◽  
1999 ◽  
Vol 8 (S1) ◽  
pp. S12-S13
Author(s):  
Miwa Tamura ◽  
Shin-ichi Nemoto
Keyword(s):  
Polar Body ◽  
Ionophore A23187 ◽  
Differential Interference Contrast Microscopy ◽  
Centriole Duplication ◽  
Polar Bodies ◽  
Transmission Electron ◽  
Interference Contrast Microscopy ◽  
Almost All ◽  
Artificial Activation ◽  
Asterina Pectinifera

In zygotes of almost all animals, it has been believed that only the sperm centrosome acts as the mitotic spindle poles. As first proposed a century ago by Boveri (1887), this uniparental (paternal) inheritance of the centrosome must depend on the selective loss of the maternal centrosomes. To trace the fate and duplicating capacity of all the maternal centrosomes/centrioles, including those cast off into polar bodies, we used two kinds of procedures: (1) suppression of polar body (PB) extrusion and (2) transplantation of PB centro-somes into artificially activated eggs.Gametes used in this study were from the starfish, Asterina pectinifera. Oocyte maturation was induced with 1-methyladenine (Kanatani, 1969). Suppression of PB extrusion and artificial activation were done according to Washitani-Nemoto et al. (1994). Micromanipulation was performed by the method of Saiki & Hamaguchi (1993). Behaviour of the centrosomes was examined by staining with an antibody against α-tubulin, polarisation and differential interference-contrast microscopy and transmission electron microscopy.In starfish oocytes, no centriole duplication occurs in meiosis II, hence each pole of a meiosis II spindle is formed by the splitting of paired centrioles in the inner centrosome of a meiosis I spindle into singles. Eventually, each of a second PB (PB2) and a mature egg inherits only one centriole from a meiosis II spindle (a PB1 inherits a pair of centrioles). So, either PB2 and the mature egg inherit a single centriole (Fig. 1; cf. Sluder et al., 1989; Kato et al., 1990). When mature eggs were artificially activated with the Ca2+-ionophore A23187, a single monaster was formed.

scholarly journals In vitro aging of porcine oocytes

2011 ◽  
Vol 49 (No. 3) ◽  
pp. 93-98 ◽  
Author(s):  
I. Petrová ◽  
M. Sedmíková ◽  
E. Chmelíková ◽  
D. Švestková ◽  
R. Rajmon
Keyword(s):  
In Vitro Culture ◽  
Polar Body ◽  
Cell Stage ◽  
Subsequent Aging ◽  
Parthenogenetic Activation ◽  
In Vitro Aging ◽  
Polar Bodies ◽  
Porcine Oocyte ◽  
Parthenogenetic Embryos

Porcine oocytes matured in vitro develop in various ways if they are further cultivated. In our studies these oocytes were cultivated for 1 to 5 days (in vitro aging). During the 1st day of aging, most of them remained at the stage of metaphase II (98%). Then many oocytes underwent the spontaneous parthenogenetic activation. The portion of activated oocytes reached its peak after 2 or 3 days of aging in vitro (39 or 45%). The portion of fragmented oocytes peaked at the same time (28%). During subsequent aging in vitro (i.e. day 4 or 5 of aging), the portion of lysed oocytes significantly increased (30 or 37%). The highest portion of spontaneously activated parthenogenetic embryos at a pronuclear stage (35%) was observed during the 2nd day of aging in vitro. These pronuclear embryos had mainly one polar body with two pronuclei (47% of all pronuclear embryos) or two polar bodies with one pronucleus (38% of all pronuclear embryos). During the 3rd and 5th day of in vitro aging, there was a significant increase in the portion of parthenogenetic embryos cleaved to the 2-cell or 3-cell stage. When considering the prolonged in vitro culture of porcine oocyte, only the first day of aging should be taken into account, since beyond this time significant changes, i.e. parthenogenesis, fragmentation or lysis, occurred in oocytes under in vitro conditions. &nbsp;

Intracytoplasmic sperm injection in dysmorphic human oocytes

Zygote ◽  
1995 ◽  
Vol 3 (4) ◽  
pp. 283-288 ◽  
Author(s):  
Mina Alikani ◽  
Gianpiero Palermo ◽  
Alexis Adler ◽  
Massimo Bertoil ◽  
Marlena Blake ◽  
...  
Keyword(s):  
Intracytoplasmic Sperm Injection ◽  
Smooth Endoplasmic Reticulum ◽  
Polar Body ◽  
Light Microscopic Level ◽  
Human Oocytes ◽  
Fertilisation Rate ◽  
Polar Bodies ◽  
First Polar Body ◽  
Multiple Abnormalities ◽  
Further Development

SummaryFertilisation and development of dysmorphic human oocytes recovered from hyperstimulated ovaries have been evaluated following intracytoplasmic sperm injection (ICSI) for treatment of male infertility. A total of 2968 oocytes at metaphase II of meiosis were injected, of which 806 (27.2%) were dysmorphic at the light microscopic level. Cytoplasmic abnormalities included granularity, areas of necrosis, organelle clustering, vacuoles, and accumulating saccules of smooth endoplasmic reticulum. Anomalies of the first polar body and zona pellucida, as well as non-spherical shapes of oocytes, were also noted. Contrary to previous findings linking some dysmorphisms to non-assisted fertilisation failure, in this study no single abnormality led to a reduction in the fertilisation rate, nor was fertilisation compromised in oocytes with multiple abnormalities. The incidence of normal fertilisation (two pronuclei and two polar bodies) was 69% in both the dysmorphic and non-dysmorphic oocytes. While overall pregnancy and implantation results were not altered in the group of patients (n = 242) in whom at least one dysmorphic oocyte was injected, exclusive replacement of embryos which originated from dysmorphic oocytes led to a higher incidence of early pregnancy loss. It is concluded that aberrations in the morphology of human oocytes – most probably a product of controlled ovarian stimulation – are of little or no consequence to fertilisation or early cleavage after ICSI. It is possible, however, that these embryos have a reduced potential for implantation and further development.

scholarly journals A casein kinase 1 prevents expulsion of the oocyte meiotic spindle into a polar body by regulating cortical contractility

2017 ◽  
Vol 28 (18) ◽  
pp. 2410-2419 ◽  
Author(s):  
Jonathan R. Flynn ◽  
Francis J. McNally
Keyword(s):  
Polar Body ◽  
Spindle Pole ◽  
Casein Kinase ◽  
Meiotic Spindle ◽  
Contractile Ring ◽  
Direct Inhibition ◽  
Casein Kinase 1 ◽  
Asymmetric Cell Divisions ◽  
Polar Bodies ◽  
Cortical Contractility

During female meiosis, haploid eggs are generated from diploid oocytes. This reduction in chromosome number occurs through two highly asymmetric cell divisions, resulting in one large egg and two small polar bodies. Unlike mitosis, where an actomyosin contractile ring forms between the sets of segregating chromosomes, the meiotic contractile ring forms on the cortex adjacent to one spindle pole, then ingresses down the length of the spindle to position itself at the exact midpoint between the two sets of segregating chromosomes. Depletion of casein kinase 1 gamma (CSNK-1) in Caenorhabditis elegans led to the formation of large polar bodies that contain all maternal DNA, because the contractile ring ingressed past the spindle midpoint. Depletion of CSNK-1 also resulted in the formation of deep membrane invaginations during meiosis, suggesting an effect on cortical myosin. Both myosin and anillin assemble into dynamic rho-dependent cortical patches that rapidly disassemble in wild-type embryos. CSNK-1 was required for disassembly of both myosin patches and anillin patches. Disassembly of anillin patches was myosin independent, suggesting that CSNK-1 prevents expulsion of the entire meiotic spindle into a polar body by negatively regulating the rho pathway rather than through direct inhibition of myosin.

Review of the longevity of the second polar body in the mouse

Zygote ◽  
2003 ◽  
Vol 11 (1) ◽  
pp. 23-34 ◽  
Author(s):  
Roland Bartholomeusz
Keyword(s):  
Single Gene ◽  
Polar Body ◽  
Research Model ◽  
Polar Bodies ◽  
Single Gene Disorders ◽  
First Polar Body ◽  
Excellent Research ◽  
Second Polar Body ◽  
Normal Offspring ◽  
Potential Use

The polar bodies are derived from meiotic divisions during oogenesis and are contained together with the oocyte within the zona pellucida. Fertilisation triggers the second meiotic division, at which time the second polar body (PB2) is formed (Hogan et al., 1986; Schatten et al., 1988; Johnson & Everitt, 1995) There is no clear evidence on the fate of the polar bodies in any mammal including the mouse, which is the commonly used research model. However, the polar bodies are generally considered as waste material, and therefore not essential to embryo development. In recent years the polar bodies have gained prominence as they have been used in humans for pre-implantation genetic diagnostic purposes (PGD), of single gene disorders, such as determining whether an embryo may have inherited the cystic fibrosis allele from its mother (Munne et al., 1995; Strom et al., 1998; Rechitsky et al., 2000). PB2 also has a potential use in cloning, for the harvesting of stem cells. Wakayama et al. (1997) have shown that PB2 has the same genetic potential as the female pronuclei and can be used for the production of normal offspring in mice. The successful use of PB2 for these purposes is dependent on its age, for its longevity, rate and nature of degeneration has yet to be determined. While there is little doubt that the first polar body (PB1) experiences a necrotic fate, the same cannot be said for PB2, which may experience an apoptotic fate. Furthermore if PB2 experiences an apoptotic fate rather than a necrotic one, it would not only be the earliest evidence of apoptosis in a mammal but also provide an excellent research model for the study of apoptosis.

Sign in / Sign up

Export Citation Format

Share Document