The nucleolar cycle in karyomeres ofTetranychus urticae Koch (Acari, Tetranichidae) in relation to replication of fragments of holokinetic chromosomes

PROTOPLASMA ◽  
1984 ◽  
Vol 123 (1) ◽  
pp. 78-82 ◽  
Author(s):  
M. J. Tempelaar ◽  
L. J. Drenth-Diephuis
Keyword(s):  
Holokinetic Chromosomes ◽  
Nucleolar Cycle

Karyotype, reproductive organs, and pattern of gametogenesis in Zorotypus hubbardi Caudell (Insecta: Zoraptera, Zorotypidae), with discussion on relationships of the order

2002 ◽  
Vol 80 (6) ◽  
pp. 1047-1054 ◽  
Author(s):  
Valentina G Kuznetsova ◽  
Seppo Nokkala ◽  
Dmitri E Shcherbakov
Keyword(s):  
Reproductive Organs ◽  
Holokinetic Chromosomes ◽  
First Time ◽  
Zorotypus Hubbardi

For the first time, the karyotype is described in a representative of the order Zoraptera. Zorotypus hubbardi Caudell (Zorotypidae) have holokinetic chromosomes and male karotype of 2n = 38 (36 + neo-XY). Males possess two follicles in each testis and females have six panoistic ovarioles in each ovary. Oogenesis and, more closely, spermato genesis, including meiosis and sperm formation, have been studied. Based on the presence of panoistic ovaries and holokinetic chromosomes, Crampton's hypothesis that Zoraptera represent a group of Polyneoptera nearest to the origin of Paraneoptera is considered the most plausible.

The nucleolar cycle in man

1977 ◽  
Vol 25 (1) ◽  
pp. 103-110
Author(s):  
M. Anastassova-Kristeva
Keyword(s):  
Gene Expression ◽  
Mitotic Division ◽  
Tissue Cultures ◽  
Nucleolar Number ◽  
Satellite Chromosomes ◽  
Nucleolar Cycle ◽  
Group D ◽  
Secondary Constrictions ◽  
Nucleolus Organizers

Tissue cultures of human embryonal kidney and ovary were examined. In the nuclei of both tissues, one to ten nucleoli have been found. The maximum number of nucleoli is connected with the gene expression of rDNA of the 10 nucleolus organizers of chromosome pairs Nos. 13, 14, 15, 21 and 22, which have secondary constrictions and are the satellite chromosomes in man. The small percentage of cells with 10, 9 and 8 nucleoli is attributed to the rapid association of 3 of the homologous acrocentrics (perhaps of group D). Two of the satellite (SAT) pairs probably associate later after mitosis. The process of fusion is dynamic, resulting in one interphase nucleous—a manifestation of the association of all SAT chromosomes. Dissociation of the nucleolus occurs upon entering prophase, due to the condensation of the chromosomes and retreat of rDNA to the respective secondary constrictions. As a result, the nucleolar number increases again. The pattern of the nucleolar kinetics within the course of one mitotic division is described.

scholarly journals Insights into the karyotype and genome evolution of haplogyne spiders indicate a polyploid origin of lineage with holokinetic chromosomes

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jiří Král ◽  
Martin Forman ◽  
Tereza Kořínková ◽  
Azucena C. Reyes Lerma ◽  
Charles R. Haddad ◽  
...  
Keyword(s):  
Genome Evolution ◽  
Holokinetic Chromosomes

Nucleolar cycle and chromatoid body formation: Is there a relationship between these two processes during spermatogenesis of Dendropsophus minutus (Amphibia, Anura)?

Micron ◽  
2011 ◽  
Vol 42 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Rita Luiza Peruquetti ◽  
Sebastião Roberto Taboga ◽  
Lia Raquel de Souza Santos ◽  
Classius de Oliveira ◽  
Maria Tercília Vilela de Azeredo-Oliveira
Keyword(s):  
Chromatoid Body ◽  
Body Formation ◽  
Nucleolar Cycle
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