The parental origin of the distal pronucleus in dispermic human zygotes

Zygote ◽  
1994 ◽  
Vol 2 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Ya-xu Tang ◽  
Santiago Munné ◽  
Adrienne Reing ◽  
Glenn Schattman ◽  
Jamie Grifo ◽  
...  
Keyword(s):  
Polar Body ◽  
In Situ Hybridisation ◽  
Parental Origin ◽  
Fluorescence In Situ Hybridisation ◽  
Y Chromosomes ◽  
Female Pronucleus ◽  
Second Polar Body ◽  
Androgenetic Embryos ◽  
High Yields ◽  
Human Zygotes

SummaryThe purpose of this investigation was to determine the parental origin og the pronucleus furthest from the second polar body (the distal pronucleus) in dispermic human zygotes. Infact dispermic embryos (n = 53) and those from which the distal pronucles (n =50) was removed at the zygote stage were biopsied after cleavage. Blastomeres were sexed using either coamplification of X and Y probes using a duplex polymerase chain reaction (PCR), or simultaneous fluorescence in situ hybridisation (FISH) with directly fluorochrome-labelled probes for chromosomes X, Y and 18. The ratio X/Y was determined in both groups of embryos by assessing a minimum of two blastomeres. If the pronuclei in dispermic zygotes are topographcially in a fixed position, the X/Y ratio should change from 1:3 in dispermic embryos to 1:1 in enucleated ones. The ratio of embryos containing only an X chromosome and those with X as well as Y chromosomes in the intact dispermic zygotes was 1.0:2.3 which is similar to the theoretical ratio of 1:3. This ratio was 1.0:1.3 in dispermic zygotes from which the distal pronuclei were removed. This ratio is not significantly different from the 1:1 ratio based on a statistical analysis with a sample size of 50. These sex ratios would have been considered different if more than 200 enucleations had been performed. Although the ratio X/Y was altered following removal of distal pronuclei, suggesting frequent targeting of male pronuclei, accidental removal of the female pronucleus could not be excluded. This indicates that enucleation of dispermic zygotes could produce high yields of gynogenetic and androgenetic embryos for research purposes. Clinical application aimed at producing biparental zygotes may be hazardous, since mosaicism was common among enucleated embryos.

Fertilization and ooplasmic movements in the ascidian egg

Development ◽  
1989 ◽  
Vol 105 (2) ◽  
pp. 237-249 ◽  
Author(s):  
C. Sardet ◽  
J. Speksnijder ◽  
S. Inoue ◽  
L. Jaffe
Keyword(s):  
Polar Body ◽  
Surface Velocity ◽  
Second Phase ◽  
Animal Pole ◽  
Male Pronucleus ◽  
Vegetal Pole ◽  
Female Pronucleus ◽  
Ooplasmic Segregation ◽  
Second Polar Body ◽  
Sperm Aster

Using light microscopy techniques, we have studied the movements that follow fertilization in the denuded egg of the ascidian Phallusia mammillata. In particular, our observations show that, as a result of a series of movements described below, the mitochondria-rich subcortical myoplasm is split in two parts during the second phase of ooplasmic segregation. This offers a potential explanation for the origin of larval muscle cells from both posterior and anterior blastomeres. The first visible event at fertilization is a bulging at the animal pole of the egg, which is immediately followed by a wave of contraction, travelling towards the vegetal pole with a surface velocity of 1.4 microns s-1. This wave accompanies the first phase of ooplasmic segregation of the mitochondria-rich subcortical myoplasm. After this contraction wave has reached the vegetal pole after about 2 min, a transient cytoplasmic lobe remains there until 6 min after fertilization. Several new features of the morphogenetic movements were then observed: between the extrusion of the first and second polar body (at 5 and 24–29 min, respectively), a series of transient animal protrusions form at regular intervals. Each animal protrusion involves a flow of the centrally located cytoplasm in the animal direction. Shortly before the second polar body is extruded, a second transient vegetal lobe (‘the vegetal button’) forms, which, like the first, resembles a protostome polar lobe. Immediately after the second polar body is extruded, three events occur almost simultaneously: first, the sperm aster moves from the vegetal hemisphere to the equator. Second, the bulk of the vegetally located myoplasm moves with the sperm aster towards the future posterior pole, but interestingly about 20% remains behind at the anterior side of the embryo. This second phase of myoplasmic movement shows two distinct subphases: a first, oscillatory subphase with an average velocity of about 6 microns min-1, and a second steady subphase with a velocity of about 26 microns min-1. The myoplasm reaches its final position as the male pronucleus with its surrounding aster moves towards the centre of the egg. Third, the female pronucleus moves towards the centre of the egg to meet with the male pronucleus. Like the myoplasm, the migrations of both the sperm aster and the female pronucleus shows two subphases with distinctly different velocities. Finally, the pronuclear membranes dissolve, a small mitotic spindle is formed with very large asters, and at about 60–65 min after fertilization, the egg cleaves.

Microtubules and parental genome organisation during abnormal fertilisation in humans

Zygote ◽  
2002 ◽  
Vol 10 (3) ◽  
pp. 223-228 ◽  
Author(s):  
Vanesa Yanina Rawe ◽  
Santiago Brugo Olmedo ◽  
Florencia Noemí Nodar ◽  
Alfredo Daniel Vitullo
Keyword(s):  
Phase Contrast ◽  
Polar Body ◽  
Phase Contrast Microscopy ◽  
Genome Organisation ◽  
Contrast Microscopy ◽  
Chromatin Configuration ◽  
Second Polar Body ◽  
Main Pattern ◽  
Human Zygotes

We analysed the distribution of β-tubulins, acetylated α-tubulins and chromatin configuration in 113 human zygotes showing abnormal fertilisation, 16-18 h after conventional in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI). After a first characterisation using phase contrast microscopy, immunofluorescence staining was performed in 67 IVF and 46 ICSI zygotes that developed one, three or more pronuclei and/or subnuclei, with or without extrusion of the second polar body. Independently of the number of pronuclei found, β-tubulins were uniformly distributed throughout the cytoplasm of the abnormal zygotes. We did not observe any kind of microtubule alteration with respect of the ploidy level and/or its origin. The most frequent abnormal fertilisation pattern found after IVF was the presence of three or four pronuclei (74.6%). On the other hand, the presence of one pronucleus (63.0%) was the main pattern found after ICSI. No differences between the two groups were seen in terms of development of subnuclei. Anamolies detected after IVF and ICSI showed different aetiologies such as parthenogenetic activation, gynogenetic or androgenetic development, as well as digynic or diandric fertilisation.

scholarly journals Morphology of gametes, post-fertilization events and the effect of temperature on the embryonic development of Astyanax altiparanae (Teleostei, Characidae)

Zygote ◽  
2016 ◽  
Vol 24 (6) ◽  
pp. 795-807 ◽  
Author(s):  
Matheus Pereira dos Santos ◽  
George Shigueki Yasui ◽  
Pedro Luiz Porfírio Xavier ◽  
Nadya Soares de Macedo Adamov ◽  
Nivaldo Ferreira do Nascimento ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Polar Body ◽  
Effect Of Temperature ◽  
Male And Female ◽  
Fundamental Information ◽  
Spherical Head ◽  
Typical Morphology ◽  
Female Pronucleus ◽  
Second Polar Body ◽  
First Time

SummaryThe aim of this study was to describe the morphology of gametes, post-fertilization events and subsequent temperature effects on the early developmental stages of the neotropical species Astyanax altiparanae. The sperm of this species presents a typical morphology of teleost sperm with a spherical head (diameter = 1.88 µm), midpiece (diameter = 0.75 µm) and a single flagellum (length = 18.67 µm). The extrusion of the second polar body and fusion of male and female pronucleus were reported for the first time in this species. Additionally, we observed the formation of the fertilization cone, which prevents polyspermic fertilization. Developmental stages at 22°C, 26°C and 30°C gave rise to fertilization rates at 91.12, 91.42 and 93.04% respectively. Hatching occurred at 25 hpf at 22°C, 16 hpf at 26°C and 11 hpf at 30°C and the hatching rates were 61.78%, 62.90% and 59.45%, respectively. At 22°C, the second polar body was extruded at ≈6 mpf and the male and female pronucleus fused at ≈10 mpf. This fundamental information is important for the field and opens up new possibilities in fish biotechnology, including micromanipulation and chromosome-set manipulation.

Head area measurements of dead, live, X- and Y-bearing bovine spermatozoa

2004 ◽  
Vol 16 (7) ◽  
pp. 681 ◽  
Author(s):  
T. Révay ◽  
S. Nagy ◽  
A. Kovács ◽  
M. E. Edvi ◽  
A. Hidas ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Imaging System ◽  
In Situ Hybridisation ◽  
Membrane Integrity ◽  
Fluorescence In Situ Hybridisation ◽  
Y Chromosomes ◽  
Significant Difference ◽  
Bovine Spermatozoa ◽  
Head Area

The head area of bull spermatozoa was measured after viability and acrosome staining using trypan blue and Giemsa stains, followed by X- and Y-chromosome-specific fluorescence in situ hybridisation (FISH). The former staining made possible the categorisation of cells according to morphology and membrane integrity, whereas the latter allowed distinction of spermatozoa bearing X- and Y-chromosomes. Individual spermatozoa could be followed during the consecutive steps of staining, measurement and FISH. Using a high-resolution digital imaging system and measurement software, the head area of more than 3000 cells of five bulls was determined precisely. In all bulls, morphologically normal, viable cells with intact acrosomes were significantly smaller than dead cells with damaged acrosomes. No significant difference in the head area between X- and Y-chromosome-bearing viable, acrosome-intact spermatozoa was found in individual bulls. However, significant between-bull differences were detected in all cell categories.

scholarly journals Subnuclear localisation is associated with gene activation not repression or parental origin at the imprinted Dlk1-Dio3 locus

2021 ◽  
Author(s):  
Rahia Mashoodh ◽  
Lisa C Hulsmann ◽  
Frances L Dearden ◽  
Nozomi Takahashi ◽  
Anne C Ferguson-Smith
Keyword(s):  
Gene Expression ◽  
Transcriptional Repression ◽  
Es Cells ◽  
In Situ Hybridisation ◽  
Nuclear Periphery ◽  
Gene Activation ◽  
Three Dimensional ◽  
Embryonic Stem ◽  
Parental Origin ◽  
Fluorescence In Situ Hybridisation

At interphase, de-condensed chromosomes have a non-random three-dimensional architecture within the nucleus, however, little is known about the extent to which nuclear organisation might influence expression or vice versa. Here, using imprinting as a model, we use 3D RNA- and DNA-fluorescence-in-situ-hybridisation in normal and mutant mouse embryonic stem cells to assess the relationship between imprinting control, gene expression and allelic distance from the nuclear periphery. We compared the two parentally inherited imprinted domains at the Dlk1-Dio3 domain and find a small but reproducible trend for the maternally inherited domain to be further away from the periphery if the maternally expressed gene Gtl2/Meg3 is active compared to when it is silenced. Using Zfp57KO ES cells, which harbour a paternal to maternal epigenotype switch, we observe active alleles significantly further away from the nuclear periphery with the distance from the periphery being proportional to the number of alleles active within the cell. This distribution of alleles suggests an activating effect of the nuclear interior rather than a repressive association with the nuclear periphery. Although we see a trend for the paternally inherited copy of the locus to be closer to the nuclear periphery, this appears to be linked to stochastic gene expression differences rather than parental origin. Our results suggest that transcriptional activity, rather than transcriptional repression or parental origin, defines sub-nuclear localisation at an endogenous imprinted domain.

scholarly journals Rapid Multi-Hybridisation FISH Screening for Balanced Porcine Reciprocal Translocations Suggests a Much Higher Abnormality Rate Than Previously Appreciated

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 250
Author(s):  
Rebecca E O’Connor ◽  
Lucas G Kiazim ◽  
Claudia C Rathje ◽  
Rebecca L Jennings ◽  
Darren K Griffin
Keyword(s):  
Semen Analysis ◽  
In Situ Hybridisation ◽  
Economic Loss ◽  
Environmental Damage ◽  
Fluorescence In Situ Hybridisation ◽  
Reciprocal Translocations ◽  
Chromosome Translocations ◽  
Farrowing Rate ◽  
Significant Economic Loss

With demand rising, pigs are the world’s leading source of meat protein; however significant economic loss and environmental damage can be incurred if boars used for artificial insemination (AI) are hypoprolific (sub-fertile). Growing evidence suggests that semen analysis is an unreliable tool for diagnosing hypoprolificacy, with litter size and farrowing rate being more applicable. Once such data are available, however, any affected boar will have been in service for some time, with significant financial and environmental losses incurred. Reciprocal translocations (RTs) are the leading cause of porcine hypoprolificacy, reportedly present in 0.47% of AI boars. Traditional standard karyotyping, however, relies on animal specific expertise and does not detect more subtle (cryptic) translocations. Previously, we reported development of a multiple hybridisation fluorescence in situ hybridisation (FISH) strategy; here, we report on its use in 1641 AI boars. A total of 15 different RTs were identified in 69 boars, with four further animals XX/XY chimeric. Therefore, 4.5% had a chromosome abnormality (4.2% with an RT), a 0.88% incidence. Revisiting cases with both karyotype and FISH information, we reanalysed captured images, asking whether the translocation was detectable by karyotyping alone. The results suggest that chromosome translocations in boars may be significantly under-reported, thereby highlighting the need for pre-emptive screening by this method before a boar enters a breeding programme.

scholarly journals Connecting structure to function with the recovery of over 1000 high-quality metagenome-assembled genomes from activated sludge using long-read sequencing

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Caitlin M. Singleton ◽  
Francesca Petriglieri ◽  
Jannie M. Kristensen ◽  
Rasmus H. Kirkegaard ◽  
Thomas Y. Michaelsen ◽  
...  
Keyword(s):  
16S Rrna ◽  
Wastewater Treatment Plants ◽  
In Situ Hybridisation ◽  
Amplicon Sequencing ◽  
Rrna Genes ◽  
Fluorescence In Situ Hybridisation ◽  
Sequencing Data ◽  
High Quality ◽  
16S Rrna Amplicon Sequencing ◽  
Long Read

AbstractMicroorganisms play crucial roles in water recycling, pollution removal and resource recovery in the wastewater industry. The structure of these microbial communities is increasingly understood based on 16S rRNA amplicon sequencing data. However, such data cannot be linked to functional potential in the absence of high-quality metagenome-assembled genomes (MAGs) for nearly all species. Here, we use long-read and short-read sequencing to recover 1083 high-quality MAGs, including 57 closed circular genomes, from 23 Danish full-scale wastewater treatment plants. The MAGs account for ~30% of the community based on relative abundance, and meet the stringent MIMAG high-quality draft requirements including full-length rRNA genes. We use the information provided by these MAGs in combination with >13 years of 16S rRNA amplicon sequencing data, as well as Raman microspectroscopy and fluorescence in situ hybridisation, to uncover abundant undescribed lineages belonging to important functional groups.

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