Chromosome elimination in germ line – soma differentiation of Acricotopus lucidus (Diptera, Chironomidae)

Genome ◽  
2006 ◽  
Vol 49 (3) ◽  
pp. 269-274 ◽  
Author(s):  
Wolfgang Staiber
Keyword(s):  
Dna Sequences ◽  
Germ Line ◽  
Chromosome Elimination ◽  
Fish Analysis ◽  
Sister Chromatids ◽  
Early Embryos ◽  
One Step ◽  
Pole Cells ◽  
Acricotopus Lucidus

During germ line – soma differentiation in early syncytial embryonic development of the chironomid Acricotopus lucidus, a complement of supernumerary chromosomes, the so-called germ line limited chromosomes (Ks), is excluded from the future somatic nuclei in the course of elimination mitoses. The Ks lag behind in the equatorial plane, while the somatic chromosomes (Ss) segregate equally. After elimination mitoses, the Ks are only present in the pole cells, the primary germ cells. In the divisions before their elimination, the Ks frequently showed delayed separation of sister chromatids with high-frequency formation of anaphasic bridges and lagging in pole movement as detected in 4′,6-diamidino-2-phenylindole (DAPI)-stained squash preparations of early embryos. To determine if all of the Ks are eliminated in one step during a single mitosis, a fluorescence in situ hybridization (FISH) analysis of early embryonic divisions was performed using probes of germ line specific repetitive DNA sequences, which specifically label the Ks in their centromeric regions. In most cases, all of the Ks are lost in one mitosis; however, occasionally one or several of the Ks can escape their elimination by segregating and moving poleward together with the Ss. The escaping Ks will then be eliminated in one of the following mitoses. This clearly indicates that the specific conditions to eliminate Ks are not restricted to only one division. Possible mechanisms of elimination of Ks are discussed.Key words: germ line limited chromosomes, elimination mitosis, germ line – soma differentiation, FISH.

scholarly journals Identification of a component of Drosophila polar granules

Development ◽  
1988 ◽  
Vol 103 (4) ◽  
pp. 625-640 ◽  
Author(s):  
B. Hay ◽  
L. Ackerman ◽  
S. Barbel ◽  
L.Y. Jan ◽  
Y.N. Jan
Keyword(s):  
Germ Line ◽  
Posterior Pole ◽  
Nuclear Bodies ◽  
Maternal Origin ◽  
Pole Cell ◽  
Polar Granules ◽  
Early Embryos ◽  
Biochemical Studies ◽  
Males And Females ◽  
Pole Cells

Information necessary for the formation of pole cells, precursors of the germ line, is provided maternally and localized to the posterior pole of the Drosophila egg. The maternal origin and posterior localization of polar granules suggest that they may be associated with pole cell determinants. We have generated an antibody (Mab46F11) against polar granules. In oocytes and early embryos, the Mab46F11 antigen is sharply localized to the posterior embryonic pole. In pole cells, it becomes associated with nuclear bodies within, and nuage around, the nucleus. Immunoreactivity remains associated with cells of the germ line throughout the life cycle of both males and females. This antibody recognizes a 72–74 × 10(3) Mr protein and is useful both as a pole lineage marker and in biochemical studies of polar granules.

scholarly journals Germ line-specific DNA sequences are present on all five micronuclear chromosomes in Tetrahymena thermophila.

1983 ◽  
Vol 3 (11) ◽  
pp. 1909-1919 ◽  
Author(s):  
K M Karrer
Keyword(s):  
In Situ Hybridization ◽  
Dna Sequences ◽  
Tetrahymena Thermophila ◽  
Germ Line ◽  
Plasmid Vector ◽  
Ciliated Protozoan ◽  
Specific Sequence ◽  
Individual Probe ◽  
Vector Pbr322

The development of the macronucleus from the zygotic micronucleus in the ciliated protozoan Tetrahymena spp. involves the elimination of specific DNA sequences (M. C. Yao and M. Gorovsky, Chromosoma 48:1-18 1974). The present study demonstrates that micronucleus-specific DNA is present on all five of the micronuclear chromosomes. Fragments of micronuclear DNA from Tetrahymena thermophila were cloned in the plasmid vector pBR322. A procedure was developed to examine the organization of the cloned sequences in micro- and macronuclear DNA without nick translating each individual probe. Twenty-three percent of randomly selected DNA sequences examined by this method were micronucleus (germ line) specific. They were all members of families of repeated sequences. Hybridization of six micronucleus-specific DNA sequences to micronuclear DNA from nullisomic strains of T. thermophila, which are lacking one or more pairs of chromosomes in the micronucleus, suggested that these sequences are present on several chromosomes. One micronucleus-specific sequence was shown by in situ hybridization to be present on all five of the micronuclear chromosomes.

Chromosomal localization of two novel repetitive sequences isolated from the Chenopodium quinoa Willd. genome

Genome ◽  
2011 ◽  
Vol 54 (9) ◽  
pp. 710-717 ◽  
Author(s):  
B. Kolano ◽  
B.W. Gardunia ◽  
M. Michalska ◽  
A. Bonifacio ◽  
D. Fairbanks ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Repetitive Dna ◽  
Dna Sequences ◽  
Repetitive Sequences ◽  
Chenopodium Quinoa ◽  
5S Rdna ◽  
Rrna Gene ◽  
Fish Analysis ◽  
Rdna Loci

The chromosomal organization of two novel repetitive DNA sequences isolated from the Chenopodium quinoa Willd. genome was analyzed across the genomes of selected Chenopodium species. Fluorescence in situ hybridization (FISH) analysis with the repetitive DNA clone 18–24J in the closely related allotetraploids C. quinoa and Chenopodium berlandieri Moq. (2n = 4x = 36) evidenced hybridization signals that were mainly present on 18 chromosomes; however, in the allohexaploid Chenopodium album L. (2n = 6x = 54), cross-hybridization was observed on all of the chromosomes. In situ hybridization with rRNA gene probes indicated that during the evolution of polyploidy, the chenopods lost some of their rDNA loci. Reprobing with rDNA indicated that in the subgenome labeled with 18–24J, one 35S rRNA locus and at least half of the 5S rDNA loci were present. A second analyzed sequence, 12–13P, localized exclusively in pericentromeric regions of each chromosome of C. quinoa and related species. The intensity of the FISH signals differed considerably among chromosomes. The pattern observed on C. quinoa chromosomes after FISH with 12–13P was very similar to GISH results, suggesting that the 12–13P sequence constitutes a major part of the repetitive DNA of C. quinoa.

scholarly journals Germ line-specific DNA sequences are present on all five micronuclear chromosomes in Tetrahymena thermophila

1983 ◽  
Vol 3 (11) ◽  
pp. 1909-1919
Author(s):  
K M Karrer
Keyword(s):  
In Situ Hybridization ◽  
Dna Sequences ◽  
Tetrahymena Thermophila ◽  
Germ Line ◽  
Plasmid Vector ◽  
Ciliated Protozoan ◽  
Specific Sequence ◽  
Individual Probe ◽  
Vector Pbr322

The development of the macronucleus from the zygotic micronucleus in the ciliated protozoan Tetrahymena spp. involves the elimination of specific DNA sequences (M. C. Yao and M. Gorovsky, Chromosoma 48:1-18 1974). The present study demonstrates that micronucleus-specific DNA is present on all five of the micronuclear chromosomes. Fragments of micronuclear DNA from Tetrahymena thermophila were cloned in the plasmid vector pBR322. A procedure was developed to examine the organization of the cloned sequences in micro- and macronuclear DNA without nick translating each individual probe. Twenty-three percent of randomly selected DNA sequences examined by this method were micronucleus (germ line) specific. They were all members of families of repeated sequences. Hybridization of six micronucleus-specific DNA sequences to micronuclear DNA from nullisomic strains of T. thermophila, which are lacking one or more pairs of chromosomes in the micronucleus, suggested that these sequences are present on several chromosomes. One micronucleus-specific sequence was shown by in situ hybridization to be present on all five of the micronuclear chromosomes.

Differentiation of triticale cultivars through FISH karyotyping of their rye chromosomes

Genome ◽  
2013 ◽  
Vol 56 (5) ◽  
pp. 267-272 ◽  
Author(s):  
Maia Fradkin ◽  
María Rosa Ferrari ◽  
Shirley Mary Espert ◽  
Víctor Ferreira ◽  
Ezequiel Grassi ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
In Situ Hybridization ◽  
Dna Sequences ◽  
Fish Analysis ◽  
Repetitive Dna Sequences ◽  
Agronomic Characters ◽  
Breeding Programs ◽  
Specific Localization ◽  
Highly Repetitive Dna

The aim of this work was to cytogenetically characterize triticale cultivars through fluorescence in situ hybridization (FISH) analysis of their rye chromosomes. In the present work, we studied six cultivars of triticale (‘Cayú-UNRC’, ‘Cumé-UNRC’, ‘Genú-UNRC’, ‘Ñinca-UNRC’, ‘Quiñé-UNRC’, and ‘Tizné-UNRC’), released by the Universidad Nacional de Río Cuarto (UNRC), Córdoba, Argentina. The cultivars were obtained from the International Center for the Improvement of Maize and Wheat (CIMMYT) and improved for fresh forage, haymaking, and feed grain at UNRC. The distribution and organization of highly repetitive DNA sequences of Secale cereale (pSc74, pSc200, pSc250, and pSc119.2) using FISH analyses revealed a specific localization of the signals for several rye chromosomes, which allowed us to distinguish the cultivars. Cluster analysis showed a great cytogenetic similarity among the rye cultivars used to originate these hybrids. The knowledge of the variability among triticale cultivars is necessary to propose future crosses in breeding programs. This study will also be valuable to identify commercial seeds and to analyze the possible association between agronomic characters and the presence of certain rye chromosomes or specific regions in these chromosomes.

Unusual germ line limited chromosomes in Acricotopus lucidus (Diptera, Chironomidae)

Genome ◽  
1987 ◽  
Vol 29 (5) ◽  
pp. 702-705 ◽  
Author(s):  
W. Staiber
Keyword(s):  
Salivary Gland ◽  
Polytene Chromosome ◽  
Germ Line ◽  
Chromosome Elimination ◽  
Male Meiosis ◽  
Laboratory Stock ◽  
Gland Cells ◽  
Salivary Gland Cells ◽  
Chromosome I ◽  
Acricotopus Lucidus

A small supernumerary polytene chromosome was found during the last 8 years in some rare cases in larval salivary gland cells of Acricotopus lucidus (Diptera, Chironomidae). The chromosome may be derived from the germ line restricted parts of the genome. It consists of a short heterochromatic segment and of euchromatic sections with banding patterns homologous to sections of the short arm of soma chromosome I. When examining male meiosis, an exceptional small germ line limited chromosome was found. It is believed that this chromosome was not always recognized during soma elimination as a germ line limited chromosome, probably because of its partial homology to one of the soma chromosomes, and was then polytenized in salivary gland cells. Another germ line limited chromosome with a characteristic morphology and with a special behavior in differential gonial mitosis was found to have existed for more than 12 years in a laboratory stock. In differential gonial mitosis this special germ line limited chromosome partly pairs with the long arm of soma chromosome I. The present results strongly support the idea that the germ line limited chromosomes of A. lucidus are derived from the soma chromosomes, and show that chromosomes of the germ line restricted part of the genome can persist for many generations in a laboratory stock in spite of complex chromosome elimination mechanisms in the primary germ cells. Key words: germ line limited chromosomes, supernumerary polytene chromosome, salivary gland, Acricotopus lucidus.

Repeated DNA sequences isolated by microdissection. I. Karyotyping of barley (Hordeum vulgare L.)

Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1082-1090 ◽  
Author(s):  
Winfried Busch ◽  
Regina Martin ◽  
Reinhold G. Herrmann ◽  
Uwe Hohmann
Keyword(s):  
In Situ Hybridization ◽  
Hordeum Vulgare ◽  
Fluorescence In Situ Hybridization ◽  
Dna Sequences ◽  
Fish Analysis ◽  
Hordeum Vulgare L ◽  
Agropyron Elongatum ◽  
D Genome ◽  
In Situ Experiments

We report on microdissection, cloning and sequence, and Southern and fluorescence in situ hybridization (FISH) analysis of one moderately and one highly amplified repetitive DNA element, pHvMWG2314 and pHvMWG2315, respectively, isolated from barley (Hordeum vulgare L.) chromosome arm 3HL. The pHvMWG2315 sequence hybridizes to all 14 telomeric or subtelomeric regions of the barley chromosomes as determined by FISH. The 50 different hybridization sites that include intercalary signals allow the discrimination of all 14 chromosome arms and the construction of a karyotype of barley. The tandemly repeated subtelomeric element of 331 bp exists in all Triticeae species tested (H. vulgare, Agropyron elongatum, Secale cereale, Triticum tauschii, T. turgidum, and T. aestivum). It is AT rich (66%), exhibits 84% sequence homology to subfragments of the D genome "specific" 1-kb element pAsl of T. tauschii and 75% homology to the interspersed genome-specific DNA sequence pHcKB6 from H. chilense. The repetitive sequence pHvMWG2314 is moderately amplified in barley and highly amplified in hexaploid wheat. The in situ experiments revealed no distinct signals on barley chromosomes, indicating a dispersed character for the sequence. The significance of the results for the identification of chromosomes and chromosome aberrations in FISH experiments are discussed.Key words: karyotype, fluorescence in situ hybridization, FISH, DNA sequencing.

scholarly journals Retrotransposon-Related DNA Sequences in the Centromeres of Grass Chromosomes

Genetics ◽  
1998 ◽  
Vol 150 (4) ◽  
pp. 1615-1623 ◽  
Author(s):  
Joseph T Miller ◽  
Fenggao Dong ◽  
Scott A Jackson ◽  
Junqi Song ◽  
Jiming Jiang
Keyword(s):  
In Situ Hybridization ◽  
Dna Sequences ◽  
Blot Hybridization ◽  
Artificial Chromosome ◽  
Fish Analysis ◽  
Sequence Identity ◽  
Centromere Function ◽  
Eukaryotic Species

Abstract Several distinct DNA fragments were subcloned from a sorghum (Sorghum bicolor) bacterial artificial chromosome clone 13I16 that was derived from a centromere. Three fragments showed significant sequence identity to either Ty3/gypsy- or Ty1/copia-like retrotransposons. Fluorescence in situ hybridization (FISH) analysis revealed that the Ty1/copia-related DNA sequences are not specific to the centromeric regions. However, the Ty3/gypsy-related sequences were present exclusively in the centromeres of all sorghum chromosomes. FISH and gel-blot hybridization showed that these sequences are also conserved in the centromeric regions of all species within Gramineae. Thus, we report a new retrotransposon that is conserved in specific chromosomal regions of distantly related eukaryotic species. We propose that the Ty3/gypsy-like retrotransposons in the grass centromeres may be ancient insertions and are likely to have been amplified during centromere evolution. The possible role of centromeric retrotransposons in plant centromere function is discussed.

Fluorescent in situ hybridization and C-banding analyses of highly repetitive DNA sequences in the heterochromatin of rye (Secale montanum Guss.) and wheat incorporating S. montanum chromosome segments

Genome ◽  
1995 ◽  
Vol 38 (4) ◽  
pp. 795-802 ◽  
Author(s):  
Angeles Cuadrado ◽  
Nicolás Jouve
Keyword(s):  
In Situ Hybridization ◽  
Repetitive Dna ◽  
Dna Sequences ◽  
Secale Cereale ◽  
Fluorescent In Situ Hybridization ◽  
Fish Analysis ◽  
C Banding ◽  
Translocation Breakpoints ◽  
Secale Montanum

The molecular characterization of C-banded regions of Secale montanum Guss. by means of in situ hybridization was performed in order to provide new information about their chromosome structure relative to cultivated rye, Secale cereale L. Accurate identification of individual chromosomes was achieved using simultaneous and (or) successive fluorescent in situ hybridization (FISH) and C-banding. FISH identification was performed using total rye DNA, three highly repetitive rye DNA sequences (pSc119.2, pSc74, and pSc34), and the ribosomal RNA probes pTa71 (18S, 5.8S, and 26S rDNA) and pTa794 (5S rDNA). FISH was also used to identify the chromosome segment involved in two spontaneous translocation lines recovered from a 'Chinese Spring' – S. montanum wheat–rye addition line. FISH analysis revealed the exact translocation breakpoints and allowed the identification of the transferred rye segments. The value of this type of analysis is discussed.Key words: Secale cereale, Secale montanum, rye, repetitive DNA, fluorescence in situ hybridization.

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