scholarly journals LOCALIZATION OF RIBOSOMAL DNA WITHIN OOCYTES OF THE HOUSE CRICKET, ACHETA DOMESTICUS (ORTHOPTERA: GRYLLIDAE)

1972 ◽  
Vol 55 (2) ◽  
pp. 310-321 ◽  
Author(s):  
Mac Donald Cave

A large DNA-containing body is present in addition to the chromosomes in oocytes of the house cricket Acheta domesticus. Large masses of nucleolar material accumulate at the periphery of the DNA body during the diplotene stage of meiotic prophase I. RNA-DNA hybridization analysis demonstrates that the genes which code for 18S and 28S ribosomal RNA are amplified in the ovary. In situ hybridization indicates that the amplified genes are localized within the DNA body of early prophase cells. As the cells proceed through diplotene the DNA which hybridizes with ribosomal RNA is gradually incorporated into the developing nucleolar mass.

Genetics ◽  
2003 ◽  
Vol 163 (2) ◽  
pp. 539-544 ◽  
Author(s):  
Hasanuzzaman Bhuiyan ◽  
Gunilla Dahlfors ◽  
Karin Schmekel

Abstract The synaptonemal complex (SC) keeps the synapsed homologous chromosomes together during pachytene in meiotic prophase I. Structures that resemble stacks of SCs, polycomplexes, are sometimes found before or after pachytene. We have investigated ndt80 mutants of yeast, which arrest in pachytene. SCs appear normal in spread chromosome preparations, but are only occasionally found in intact nuclei examined in the electron microscope. Instead, large polycomplexes occur in almost every ndt80 mutant nucleus. Immunoelectron microscopy using DNA antibodies show strong preferential labeling to the lateral element parts of the polycomplexes. In situ hybridization using chromosome-specific probes confirms that the chromosomes in ndt80 mutants are paired and attached to the SCs. Our results suggest that polycomplexes can be involved in binding of chromosomes and possibly also in synapsis.


1994 ◽  
Vol 42 (9) ◽  
pp. 1271-1276 ◽  
Author(s):  
M Numata ◽  
T Ono ◽  
S Iseki

DNA (cytosine-5)-methyltransferase (DNA MTase) is the only enzyme known to be involved in the methylation of mammalian DNA. Although the expression of DNA MTase gene is abundant in the testis, little is known about the role of this enzyme during spermatogenesis. We examined the distribution of DNA MTase mRNA in mouse testis by in situ hybridization histochemistry with an oligonucleotide probe. The mRNA signal was observed in the seminiferous tubules and was localized predominantly in spermatogonia and spermatocytes, particularly during the earlier steps of meiotic prophase I, with maximal intensity in the early pachytene cells. These results suggest some significant role for DNA MTase in spermatogenesis.


1990 ◽  
Vol 10 (9) ◽  
pp. 5021-5025
Author(s):  
E Keshet ◽  
A Itin ◽  
K Fischman ◽  
U Nir

ferT is a testis-specific transcript of FER encoding a truncated version of the potential tyrosine kinase. Using in situ hybridization analysis, we found that ferT was transiently expressed during spermatogenesis and that expression was restricted to spermatocytes at the pachytene stage of meiotic prophase. This pattern of expression is unprecedented by other tyrosine kinases and suggests a role for ferT in a particular stage of spermatogenesis.


Genome ◽  
1994 ◽  
Vol 37 (6) ◽  
pp. 1018-1021 ◽  
Author(s):  
M. Nenno ◽  
K. Schumann ◽  
W. Nagl

This is the first report of fluorescence in situ hybridization (FISH) on plant polytene chromosomes. Different protease pretreatments have been tested to improve fluorescence in situ hybridization FISH on polytene chromosomes of a plant, Phaseolus coccineus, with the aim to enable the detection of low-copy genes. The structural preservation of the chromosomes and the distinctness of the FISH signals were comparatively analysed with a probe for the ribosomal RNA genes after digestion with pepsin and trypsin. The pepsin pretreatment resulted in a general loosening of chromatin with good conservation of chromosome morphology and an increased number and density of signal points. The six nucleolus organizers exhibited significant differences in condensation. The pretreatment with pepsin enabled the detection of the low-copy genes encoding the seed storage protein phaseolin.Key words: plant, Leguminosae, ribosomal RNA genes, seed storage protein genes, protease.


2010 ◽  
Vol 79 (4) ◽  
pp. 335-339 ◽  
Author(s):  
Masashi Yamamoto ◽  
Shingo Terakami ◽  
Toshiya Yamamoto ◽  
Norio Takada ◽  
Tatsuya Kubo ◽  
...  

Mycorrhiza ◽  
1999 ◽  
Vol 8 (4) ◽  
pp. 203-206 ◽  
Author(s):  
Sophie Trouvelot ◽  
Diederik van Tuinen ◽  
Mohamed Hijri ◽  
V. Gianinazzi-Pearson

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