scholarly journals Production of mouse androgenetic embryos using spindle perturbation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Takaya Totsuka ◽  
Miho Ohsugi
Keyword(s):  
Androgenetic Embryos

In vitro development of haploid mouse embryos produced by bisection of one-cell fertilized eggs

Development ◽  
1977 ◽  
Vol 38 (1) ◽  
pp. 187-202
Author(s):  
Andrzej K. Tarkowski
Keyword(s):  
X Chromosome ◽  
Culture Conditions ◽  
Extrinsic Factors ◽  
Cell Stage ◽  
Glass Needle ◽  
Androgenetic Embryos ◽  
Haploid Embryos ◽  
Vitro Development ◽  
Further Development

F1(CBA × C57BL'10) mouse eggs originating from spontaneous or induced ovulation and fertilized by CBA-T6T6 or PO spermatozoa were bisected with a glass needle into halves each containing a pronucleus. This technique offers a unique opportunity of producing both androgenetic and gynogenetic haploid embryos from one egg. Out of 600 operated eggs, in 406 (67·7%) both halves survived. During 96 h of culture in vitro the fragments were inspected once daily and finally examined in air-dried preparations. Eighty-seven per cent of halves underwent first cleavage but their further development was to a large extent affected by extrinsic factors connected with experimental procedure (mainly by suboptimal and variable culture conditions) and by the origin of eggs (those from spontaneous ovulation being superior). For this reason developmental capabilities of egg halves were assessed in a selected group of pairs in which at least one partner reached the stage of four or more blastomeres. The observed ratio between pairs with both or only one sister embryo developing successfully suggests that androgenetic embryos carrying Y rather than X chromosome can cleave twice but do not survive beyond 4-cell stage. None of the metaphase plates from older embryos contained a Y chromosome. These observations imply that the X chromosome is genetically active during early cleavage and that a full haploid set is required for preimplantation development to be completed. Formation of blastocysts varied from batch to batch, with an average of 12·8% and maximal incidence of 29·5% . In 34 pairs both fragments developed beyond the 4-cell stage but in only one case did both form blastocysts. Haploid blastocysts were composed of 27 cells on average which was about a half of the number of cells in control diploid zona-free whole eggs. Ten out of 51 embryos with metaphase plates proved to be haploid/diploid mosaics.

Variations in endogenous polyamine content of maize calli obtained from zygotic and androgenetic embryos

1995 ◽  
Vol 40 (2) ◽  
pp. 139-144 ◽  
Author(s):  
N. Boget ◽  
J. M. Torn� ◽  
L. Willadino ◽  
M. Santos
Keyword(s):  
Polyamine Content ◽  
Androgenetic Embryos

Evolution in vitro du contenu en ADN nucléaire et de la ploïdie des embryons polliniques du Datura innoxia

1981 ◽  
Vol 59 (4) ◽  
pp. 508-517 ◽  
Author(s):  
Brigitte S. Sangwan-Norreel
Keyword(s):  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Datura Innoxia ◽  
Cell Numbers ◽  
Irregular Structures ◽  
Three Stages ◽  
Androgenetic Embryos ◽  
Haploid Embryos ◽  
Vitro Development

Nuclear DNA content was estimated by densitometry in three stages of in vitro development of Datura innoxia Mill. embryos (3–25 cells) obtained from pollen. At the same time, the sizes, structure and arrangements of nuclei in young embryos were examined and chromosome numbers of adult embryos were determined. Results showed that: (i) Embryos originating from pollen were haploid, diploid, aneuploid, or myxoploid. Proportions of each ploidy level varied with cell numbers in embryos, and with ages of cultures, (ii) Young diploid embryos were very regular and had dense nuclei of one type only. Haploid embryos were less regular; they had one or two types of nuclei whose texture was often looser than that of diploid embryo nuclei. Aneuploid and myxoploid embryos had very irregular structures, (iii) Initiation of androgenetic embryos was spread out in time from the 2nd to the 12th day of culture. Embryos showed different nuclear features if they were initiated at the beginning, in the middle, or at the end of the culture period. Embryos initiated early were mostly haploid and the proportion of abnormal ploidy embryos was low during the 1st week of culture. In Datura innoxia, therefore, embryos must be taken after 1 week of culture to obtain the population which is most favourable to further genetic breeding. [Journal translation]

scholarly journals Derivation of androgenetic embryonic stem cells from m-carboxycinnamic acid bishydroxamide (CBHA) treated androgenetic embryos

2013 ◽  
Vol 58 (23) ◽  
pp. 2862-2868 ◽  
Author(s):  
Ling Shuai ◽  
ChunJing Feng ◽  
HaiJiang Zhang ◽  
Qi Gu ◽  
YunDan Jia ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Embryonic Stem ◽  
Androgenetic Embryos

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.

Efficient production of androgenetic embryos by round spermatid injection

genesis ◽  
2009 ◽  
Vol 47 (3) ◽  
pp. 155-160 ◽  
Author(s):  
Hiromi Miki ◽  
Michiko Hirose ◽  
Narumi Ogonuki ◽  
Kimiko Inoue ◽  
Fuyuko Kezuka ◽  
...  
Keyword(s):  
Round Spermatid ◽  
Efficient Production ◽  
Androgenetic Embryos ◽  
Round Spermatid Injection

scholarly journals Dysregulated Gene Expression of Imprinted and X-Linked Genes: A Link to Poor Development of Bovine Haploid Androgenetic Embryos

2021 ◽  
Vol 9 ◽  
Author(s):  
Luis Aguila ◽  
Joao Suzuki ◽  
Amanda B. T. Hill ◽  
Mónica García ◽  
Karine de Mattos ◽  
...  
Keyword(s):  
Gene Expression ◽  
Genomic Imprinting ◽  
X Chromosome ◽  
De Novo ◽  
Chromosomal Abnormalities ◽  
Methylation Status ◽  
Blastocyst Stage ◽  
Developmental Potential ◽  
Stage Of Development ◽  
Androgenetic Embryos

Mammalian uniparental embryos are efficient models for genome imprinting research and allow studies on the contribution of the paternal and maternal genomes to early embryonic development. In this study, we analyzed different methods for production of bovine haploid androgenetic embryos (hAE) to elucidate the causes behind their poor developmental potential. Results indicate that hAE can be efficiently generated by using intracytoplasmic sperm injection and oocyte enucleation at telophase II. Although androgenetic haploidy does not disturb early development up to around the 8-cell stage, androgenetic development is disturbed after the time of zygote genome activation and hAE that reach the morula stage are less capable to reach the blastocyst stage of development. Karyotypic comparisons to parthenogenetic- and ICSI-derived embryos excluded chromosomal segregation errors as causes of the developmental constraints of hAE. However, analysis of gene expression indicated abnormal levels of transcripts for key long non-coding RNAs involved in X chromosome inactivation and genomic imprinting of the KCNQ1 locus, suggesting an association with X chromosome and some imprinted loci. Moreover, transcript levels of methyltransferase 3B were significantly downregulated, suggesting potential anomalies in hAE establishing de novo methylation. Finally, the methylation status of imprinted control regions for XIST and KCNQ1OT1 genes remained hypomethylated in hAE at the morula and blastocyst stages, confirming their origin from spermatozoa. Thus, our results exclude micromanipulation and chromosomal abnormalities as major factors disturbing the normal development of bovine haploid androgenotes. In addition, although the cause of the arrest remains unclear, we have shown that the inefficient development of haploid androgenetic bovine embryos to develop to the blastocyst stage is associated with abnormal expression of key factors involved in X chromosome activity and genomic imprinting.

scholarly journals Effect of increased copper ion content in the medium on the regeneration of androgenetic embryos of carrot (Daucus carota L.)

2012 ◽  
Vol 65 (2) ◽  
pp. 73-82 ◽  
Author(s):  
Urszula Kowalska ◽  
Katarzyna Szafrańska ◽  
Dorota Krzyżanowska ◽  
Waldemar Kiszczak ◽  
Ryszard Górecki ◽  
...  
Keyword(s):  
Prolonged Exposure ◽  
Copper Ion ◽  
Copper Stress ◽  
Negative Effects ◽  
Daucus Carota L ◽  
Regeneration Time ◽  
Freeze Dried ◽  
Soluble Phenols ◽  
Androgenetic Embryos

The study was conducted to determine the effect of elevated concentrations of copper in the medium on the regeneration of androgenetic embryos of the carrot cultivar ‘Kazan F<sub>1</sub>’ obtained in anther cultures and to determine the level of soluble phenols produced in the regenerates under copper stress. Green embryos were laid out on 4 regeneration media based on B5 medium (G a m b o r g et al. 1968) without hormones, containing 0.1 – control, 1, 10, and 100 μM CuSO<sub>4</sub>×5H<sub>2</sub>O. The plant material was passaged 3 times, after 4, 9 and 15 weeks. During these passages the emerging structures were examined; they were classified in terms of growth and development <i>in vitro</i>, weighed and counted. The levels of soluble phenols in the freeze-dried regenerates were determined. The elevated concentrations of copper in the regeneration media affected positively the formation of complete plants (rooted rosettes) and secondary embryos during the first 4 weeks of culture. After a longer regeneration time (9, 15 weeks), the elevated concentrations of copper caused negative effects: deformation of rosettes. After 15 weeks, the number of rooted rosettes decreased. The 9-week culture subjected to copper stress brought about an increase in the amounts of soluble phenols. The highest values were recorded in the rosettes treated with 10 μM CuSO<sub>4</sub>. Prolonged exposure to media containing elevated concentrations of CuSO<sub>4</sub> caused a reduction in the accumulation of phenolic compounds in the rosettes.

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