Chromosome behaviour and structural hybridity in the tradescantiae. II.

1937 ◽  
Vol 35 (2) ◽  
pp. 259-280 ◽  
Author(s):  
C. D. Darlington

1929 ◽  
Vol 21 (2) ◽  
pp. 207-286 ◽  
Author(s):  
C. D. Darlington


1961 ◽  
Vol 48 (4) ◽  
pp. 109-110 ◽  
Author(s):  
Arun Kumar Sharma ◽  
Tapati Chatterjee
Keyword(s):  




1972 ◽  
Vol 14 (2) ◽  
pp. 397-401 ◽  
Author(s):  
Kathleen Church

Chromosome behaviour occurring from premeiotic DNA synthesis to leptotene of meiosis is described for both males (spermatogenesis) and females (oogenesis) in the grasshopper Melanoplus femur-rubrum. These events include a period of chromosome spiralization and contraction following premeiotic DNA synthesis and prior to leptotene. The diploid complement of chromosomes becomes visible in both sexes. No pairing between homologous chromosomes or chiasmata are observed in either sex. The results suggest that synapsis and crossing over must occur following preleptotene spiralization during spermatogenesis and oogenesis in this grasshopper.



CYTOLOGIA ◽  
1939 ◽  
Vol 10 (1-2) ◽  
pp. 1-14 ◽  
Author(s):  
O. Meurman ◽  
Eeva Therman


2010 ◽  
Vol 11 (2) ◽  
pp. 91-102 ◽  
Author(s):  
Claire E. Walczak ◽  
Shang Cai ◽  
Alexey Khodjakov
Keyword(s):  


Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 63-66 ◽  
Author(s):  
Batia Pazy ◽  
Uzi Plitmann

Idiosyncratic chromosome behaviour during meiosis was found in pollen mother cells of Cuscuta babylonica Choisy, a thread-like holoparasitic herb. Its main features are among the following: (i) telomeric association between homologues through most stages of the process, which leads to persisting chromatid bivalents (= "demibivalents"); (ii) uncommon chromosome segregation in first and second anaphase; and (iii) prolonged intensified heterochromatinization. Although "regular" in its own way, this process leads to the formation of unviable products. Its further investigation might contribute to our understanding of the role of the spindle and chromosome movement in the ordinary process of meiosis. Key words: meiosis (abnormal), persisting demibivalents, Cuscuta babylonica.





2000 ◽  
Vol 113 (7) ◽  
pp. 1231-1239 ◽  
Author(s):  
Y. Bhaud ◽  
D. Guillebault ◽  
J. Lennon ◽  
H. Defacque ◽  
M.O. Soyer-Gobillard ◽  
...  

The morphology and behaviour of the chromosomes of dinoflagellates during the cell cycle appear to be unique among eukaryotes. We used synchronized and aphidicolin-blocked cultures of the dinoflagellate Crypthecodinium cohnii to describe the successive morphological changes that chromosomes undergo during the cell cycle. The chromosomes in early G(1) phase appeared to be loosely condensed with numerous structures protruding toward the nucleoplasm. They condensed in late G(1), before unwinding in S phase. The chromosomes in cells in G(2) phase were tightly condensed and had a double number of arches, as visualised by electron microscopy. During prophase, chromosomes elongated and split longitudinally, into characteristic V or Y shapes. We also used confocal microscopy to show a metaphase-like alignment of the chromosomes, which has never been described in dinoflagellates. The metaphase-like nucleus appeared flattened and enlarged, and continued to do so into anaphase. Chromosome segregation occurred via binding to the nuclear envelope surrounding the cytoplasmic channels and microtubule bundles. Our findings are summarized in a model of chromosome behaviour during the cell cycle.



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