Synaptonemal complexes and chromosome chains in the rodent Ellobius talpinus heterozygous for ten Robertsonian translocations

Chromosoma ◽  
1986 ◽  
Vol 94 (2) ◽  
pp. 94-102 ◽  
Author(s):  
Yu. F. Bogdanov ◽  
O. L. Kolomiets ◽  
E. A. Lyapunova ◽  
I. Yu. Yanina ◽  
T. F. Mazurova
Keyword(s):  
Robertsonian Translocations ◽  
Synaptonemal Complexes

Synaptonemal complexes of chains and rings in mice heterozygous for multiple Robertsonian translocations

1994 ◽  
Vol 2 (2) ◽  
pp. 137-145 ◽  
Author(s):  
Reiner Johannisson ◽  
Heinz Winking
Keyword(s):  
Robertsonian Translocations ◽  
Synaptonemal Complexes

The influence of Robertsonian translocations on semen parameters

2020 ◽  
pp. 87-88
Author(s):  
М.В. Андреева ◽  
М.И. Штаут ◽  
Т.М. Сорокина ◽  
Л.Ф. Курило ◽  
В.Б. Черных
Keyword(s):  
Male Infertility ◽  
Semen Parameters ◽  
Meiotic Arrest ◽  
Robertsonian Translocations ◽  
Prophase I ◽  
Infertile Men ◽  
Fertility Problems ◽  
Spermatogenesis Impairment

Обследованы 19 мужчин с нарушением фертильности, носителей транслокаций rob(13;14) и rob(13;15). Показано, что нарушение репродуктивной функции обусловлено блоком сперматогенеза в профазе I мейоза, приводящего к азооспермии или олигоастенотератозооспермии и мужскому бесплодию. We examined 19 infertile men, carriers of translocations rob (13;14) and rob (13;15). We assume that fertility problems are resulted from spermatogenesis impairment because of meiotic arrest at prophase I stages, that leads to azoospermia or oligoastenoteratozoospermia and male infertility.

scholarly journals Robertsonian Translocations: An Overview of 872 Robertsonian Translocations Identified in a Diagnostic Laboratory in China

PLoS ONE ◽  
2015 ◽  
Vol 10 (5) ◽  
pp. e0122647 ◽  
Author(s):  
Wei-Wei Zhao ◽  
Menghua Wu ◽  
Fan Chen ◽  
Shuai Jiang ◽  
Hui Su ◽  
...  
Keyword(s):  
Diagnostic Laboratory ◽  
Robertsonian Translocations

Molecular Cytogenetic Classification of Down Syndrome and Screening of Somatic Aneuploidy in Mothers

2021 ◽  
pp. 1-9
Author(s):  
Sushil Kumar Jaiswal ◽  
Ashok Kumar ◽  
Amit Kumar Rai
Keyword(s):  
Down Syndrome ◽  
Peripheral Blood ◽  
Trisomy 21 ◽  
Health Management ◽  
Chromosome 21 ◽  
Robertsonian Translocations ◽  
Significant Difference ◽  
And Control

Down Syndrome (DS) caused by trisomy 21 results in various congenital and developmental complications in children. It is crucial to cytogenetically diagnose the DS cases early for their proper health management and to reduce the risk of further DS childbirths in mothers. In this study, we performed a cytogenetic analysis of 436 suspected DS cases using karyotyping and fluorescent in situ hybridization. We detected free trisomies (95.3%), robertsonian translocations (2.4%), isochromosomes (0.6%), and mosaics (1.2%). We observed a slightly higher incidence of DS childbirth in younger mothers compared to mothers with advanced age. We compared the somatic aneuploidy in peripheral blood of mothers having DS children (MDS) and control mothers (CM) to identify biomarkers for predicting the risk for DS childbirths. No significant difference was observed. After induced demethylation in peripheral blood cells, we did not observe a significant difference in the frequency of aneuploidy between MDS and CM. In conclusion, free trisomy 21 is the most common type of chromosomal abnormality in DS. A small number of DS cases have translocations and mosaicism of chromosome 21. Additionally, somatic aneuploidy in the peripheral blood from the mother is not an effective marker to predict DS childbirths.

An Ultrastructural and Radioautographic Study of Early Oogenesis in the Toad Xenopus Laevis

1973 ◽  
Vol 12 (1) ◽  
pp. 71-93
Author(s):  
LESLEY WATSON COGGINS
Keyword(s):  
Electron Microscope ◽  
Xenopus Laevis ◽  
Thymidine Incorporation ◽  
Ultrastructural Level ◽  
Extrachromosomal Dna ◽  
Late Pachytene ◽  
Synaptonemal Complexes ◽  
Round Nucleus ◽  
A Cell ◽  
Major Period

Early oogenesis in the toad Xenopus laevis has been investigated at the ultrastructural level, with particular reference to the formation of extrachromosomal DNA. Thymidine incorporation was localized by electron microscope radioautography. In oogonia, the nucleus is irregular in outline and may contain several nucleoli. Oocytes, from premeiotic interphase to late pachytene, are found in cell nests which are estimated to consist of about 16 cells each. Adjacent oocytes within a nest are connected by intercellular bridges and develop synchronously. Each premeiotic interphase-leptotene oocyte has a round nucleus which contains one or two centrally located, spherical nucleoli. Electron-microscope radioautography showed that all nuclei in a cell nest incorporate thymidine synchronously during premeiotic S-phase. In zygotene oocytes, axial cores and synaptonemal complexes are observed in the nucleus and abut against the inner nuclear membrane in the region nearest the centre of the cell nest. The nucleolus is still more-or-less round in outline, but is asymmetrically positioned in the nucleus. It lies near the nuclear envelope on the side of the nucleus furthest away from the attachment of the chromosome ends, that is, nearest the outside of the cell nest. Each nucleolus is surrounded by a fibrillar ‘halo’ of nucleolus-associated chromatin into which a low level of thymidine incorporation occurs during zygotene. This is thought to represent the start of the major period of amplification of the ribosomal DNA. Pachytene is characterized by the presence of synaptonemal complexes in the nucleus. The nucleolus becomes very irregular in outline. The fibrillar area around it, which represents the extrachromosomal DNA, increases in size and thymidine is incorporated over the whole of this region. In late pachytene, many small fibrogranular bodies, the multiple nucleoli, are formed in it. The members of a cell nest become separated from one another at this time and begin to develop asynchronously. In diplotene, synaptonemal complexes are no longer observed in the nucleus. The most prominent structures in the nucleus are now the multiple nucleoli, which increase greatly in number in early diplotene. A large increase in cytoplasmic volume occurs and the oocyte grows in size.

Trivalent behavior during prophase I in male mice heterozygous for three Robertsonian translocations: an electron-microscopic study

1989 ◽  
Vol 52 (3-4) ◽  
pp. 105-110 ◽  
Author(s):  
P. Grao ◽  
M.D. Coll ◽  
M. Ponsà ◽  
J. Egozcue
Keyword(s):  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Male Mice ◽  
Electron Microscopic ◽  
Robertsonian Translocations ◽  
Prophase I
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