Karyotype, C-banding, chromosomal location of active nucleolar organizing regions, and B-chromosomes in Lasius niger (Hymenoptera, Formicidae)

Genome ◽  
1990 ◽  
Vol 33 (2) ◽  
pp. 267-272 ◽  
Author(s):  
T. Palomeque ◽  
E. Chica ◽  
R. Díaz de la Guardia
Keyword(s):  
Germ Cells ◽  
Chromosomal Location ◽  
Ganglion Cells ◽  
Cerebral Ganglion ◽  
B Chromosomes ◽  
Lasius Niger ◽  
Nucleolar Organizing Regions ◽  
Nucleolar Organizing Region ◽  
C Banding ◽  
Numerical Variation

The karyotype of Lasius niger (n = 15) was analysed using C-banding and observation of nucleolar organizing region (NOR) sites. C-banding showed the existence of heterochromatin in the paracentromeric regions of all chromosomes. Two sites with primary NORs were found in chromosomes 6 and 8. Chromosome 13 showed a secondary NOR. In both cases, the NORs were located in the paracentromeric region. B-chromosomes were found in male and female germ cells. They exhibited intra- and inter-individual numerical variation. No B-chromosomes were observed in somatic cells (cerebral ganglion cells) of all castes. The Bs are telocentric, small, and clearly distinguishable from the regular members of the complement. They show positive heteropycnosis in meiotic prophase and they are highly C-band positive. The activity of NORs does not change when Bs are present. Several aspects of the behaviour of these Bs are examined.Key words: C-bands, nucleolar organizing region (primary), nucleolar oganizing region (secondary), B-chromosomes, Formicidae.

Cytogenetic studies in gomphocerine grasshoppers. II. Chromosomal location of active nucleolar organizing regions

1986 ◽  
Vol 28 (4) ◽  
pp. 540-544 ◽  
Author(s):  
Josefa Cabrero ◽  
Juan Pedro M. Camacho
Keyword(s):  
Chromosomal Location ◽  
Nucleolar Organizer ◽  
X Chromosomes ◽  
Nucleolar Organizing Regions ◽  
Nucleolar Organizing Region ◽  
Primary Activity ◽  
Cytogenetic Studies ◽  
Almost All ◽  
Active Nors

Nucleolar organizing region (NOR) location has been studied in 20 species of gomphocerine grasshoppers. In the 17 species with 2n (♀) = 17, the largest number carry an active NOR on the L2, L3, and X chromosomes. The M4, M5, M6, and S8 show NOR activity in some species, but the L1 and M7 do not carry a NOR in any. While almost all NORs on L2, L3, and X show primary activity, a majority of these on the M4, M5, M6, and S8 are secondary and express a nucleolus only in a minority of male meiocytes. The NORs are located preferentially at particular chromosomal sites; primary active NORs prevail in interstitial locations, while secondary active NORs predominate in paracentromeric locations. In the majority of the species analyzed in this report, primary and secondary active NORs coincide with C-bands. Euchorthippus pulvinatus is an exception; here NORs do not seem to be related to C-bands. However, the nucleolar-associated heterochromatin in this species can be demonstrated by a N-banding technique.Key words: nucleolar organizer, NOR (primary), C-bands, heterochromatin, NOR (secondary).

Karyotypes, C-banding, and chromosomal location of active nucleolar organizing regions in Tapinoma (Hymenoptera, Formicidae)

Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 277-280 ◽  
Author(s):  
T. Palomeque ◽  
E. Chica ◽  
M. A. Cano ◽  
R. Díaz de la Guardia
Keyword(s):  
Chromosomal Location ◽  
Nucleolar Organizer ◽  
The Other ◽  
Chromosome Differentiation ◽  
Nucleolar Organizing Regions ◽  
C Banding ◽  
Secondary Activity ◽  
Primary Activity ◽  
Tapinoma Erraticum ◽  
Tapinoma Nigerrimum

The haploid and diploid karyotypes of Tapinoma erraticum (n = 8) and Tapinoma nigerrimum (n = 9) were analyzed using C-banding and observation of NOR sites. C-banding showed the existence of heterochromatin in the paracentromeric regions of all chromosomes. The analysis of NOR sites in these species proved the existence of primary activity NOR in one or two chromosomes, respectively, whereas the other chromosomes showed secondary activity NOR, expressed only in a minority of cells. In both species the NOR were located in paracentromeric regions. These results are discussed in relation to a hypothesis of chromosome differentiation of these species.Key words: C-bands, nucleolar organizer, NOR (primary), NOR (secondary), Formicidae.

Identification of histaminergic neurons in Aplysia

1990 ◽  
Vol 64 (3) ◽  
pp. 736-744 ◽  
Author(s):  
A. Elste ◽  
J. Koester ◽  
E. Shapiro ◽  
P. Panula ◽  
J. H. Schwartz
Keyword(s):  
Presynaptic Inhibition ◽  
Ganglion Cells ◽  
Lucifer Yellow ◽  
Cerebral Ganglion ◽  
Abdominal Ganglion ◽  
Serotonergic Neuron ◽  
Histaminergic Neurons ◽  
The Central Nervous System ◽  
Bag Cells ◽  
The Right

1. We have identified putative histaminergic neurons in the central nervous system of Aplysia californica by light-microscopic autoradiography after uptake of [3H]histamine and by immunohistochemistry with the use of an antibody specific for histamine. 2. In the cerebral ganglion cells previously shown to contain histamine (C2 and 2 large neighboring cells in the E cluster and a group of smaller cells in the L cluster) were identified both by uptake of [3H]histamine and by histamine immunoreactivity. The identification of C2 was confirmed by experiments in which individual C2s were characterized electrophysiologically and injected with Lucifer yellow before processing for immunohistochemistry. The giant serotonergic neuron did not take up [3H]histamine and was not immunoreactive. 3. In the abdominal ganglion two clusters of cells--one in the left hemiganglion and the other in the right--took up [3H]histamine and were histamine immunoreactive. These clusters are located in the regions occupied by the 30 identified respiratory interneurons, R25 and L25. Individual cells in the R25 and L25 clusters were identified electrophysiologically, marked by injection of Lucifer yellow, and processed for immunocytochemistry. Eleven of the 30 L25 cells examined (from 7 ganglia) and 2 of the 25 R25 cells (from 6 ganglia) that had been marked with Lucifer yellow were also histamine immunoreactive. 4. Also in the abdominal ganglion, identified cells in the L32 cluster were not histamine immunoreactive and did not take up [3H]histamine. These interneurons, which mediate presynaptic inhibition, had previously been considered histaminergic. Neurons in the ganglion known to use transmitters other than histamine (L10, R2, RB cells, and bag cells) were not histamine immunoreactive.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Chromosomal polymorphism in 12 populations of Mikania micrantha (Compositae)

1999 ◽  
Vol 22 (3) ◽  
pp. 433-444 ◽  
Author(s):  
Eliane M.D. Maffei ◽  
M.A. Marin-Morales ◽  
P.M. Ruas ◽  
C.F. Ruas ◽  
N.I. Matzenbacher
Keyword(s):  
Chromosomal Polymorphism ◽  
The United States ◽  
B Chromosomes ◽  
Mitotic Chromosomes ◽  
Mikania Micrantha ◽  
Perennial Weed ◽  
C Banding ◽  
Size Number ◽  
Chromosomal Differentiation ◽  
First Time

Mikania micrantha is a climbing perennial weed of the family Asteraceae, with a vast distribution from South America to south of the United States. This species is widely distributed throughout Brazil, where it shows little morphological variation. Mitotic chromosomes of 12 populations of M. micrantha derived from several Brazilian sites were studied using Feulgen staining and C-banding. The populations included eight diploid (2n = 36 and 42) and four tetraploid (2n = 72) cytotypes. Chromosome numbers of 2n = 36 and 2n = 42 are reported for the first time for M. micrantha. These populations had a secondary constriction in the middle of the larger arm of chromosome pair 1, following the same pattern described for all Mikania species analyzed so far. Numerical and structural variation of the chromosomes was quite common among the karyotypes and nearly all cytotypes differed from each other in some aspect. Most of the chromosomal differentiation may be attributed to inversions and addition or deletion of DNA fragments. C-banding, applied to three of the 12 populations, also revealed polymorphism in the distribution of heterochromatin. Additionally, one to 14 supernumerary or B-chromosomes were observed. The Bs were detected in six of the 12 populations and varied in size, number, and structure among karyotypes and also among cells of the same root meristem. The B chromosomes were also heterochromatic, showing a C-banding pattern similar to the A chromosomes, and suggesting that they may be derived from the chromosomes of the A complement.

The Distribution of Esterase in the Nervous System and other Tissues of the Insect Rhodnius prolixus

1958 ◽  
Vol s3-99 (48) ◽  
pp. 441-450
Author(s):  
V. B. WIGGLESWORTH
Keyword(s):  
Nervous System ◽  
Germ Cells ◽  
Alimentary Canal ◽  
Fat Body ◽  
Ganglion Cells ◽  
Cytoplasmic Localization ◽  
Nerve Roots ◽  
Dermal Glands ◽  
Pericardial Cells ◽  
Single Well

Cholinesterase in Rhodnius is limited to the neuropile, the nerve-roots, and the larger nerves. None is present in the axons; it seems to be confined to the interneuronal cytoplasm, the product of the glial cells. The intensity of the reaction is greatest in the synaptic regions and appears to be proportional to the amount of interneuronal material. The ganglion cells contain traces of a non-specific esterase; and larger amounts of non-specific esterase occur in the glial layer between the cells. A similar enzyme is plentiful within the perineurium cells. Non-specific esterases occur in many other tissues: salivary glands and alimentary canal, pericardial cells, haemocytes, oenocytes, dermal glands and epidermal cells, germ-cells and fat-body. Esterase is absent from the muscle endplates. The cytoplasmic localization and the reaction of these enzymes to inhibitors are described. In the fat-body, each droplet of fat has a single well-defined ‘cap’ of esterase, presumably lipase. It is suggested that this controls the transfer of triglycerides to and from the storage vacuoles. Esterase is not associated with the mitochondria; but there is evidence that the enzyme may be disposed as fine filaments, particularly over the surface of the nucleus. Some of these widely distributed ‘esterases’ may be cathepsins.

Effects of restriction endonucleases on nucleolar organizing regions in the ant Tapinoma nigerrimum

Genome ◽  
1998 ◽  
Vol 41 (6) ◽  
pp. 872-875
Author(s):  
P Lorite ◽  
T Palomeque
Keyword(s):  
Ribosomal Rna ◽  
Chromosome Region ◽  
Restriction Endonucleases ◽  
Limiting Factor ◽  
Naked Dna ◽  
Nucleolar Organizing Regions ◽  
Nucleolar Organizing Region ◽  
Partial Digestion ◽  
Tapinoma Nigerrimum

The effects of some restriction endonucleases (REs) on the nucleolar organizing regions and on the genes for ribosomal RNA (rDNA) were analyzed using the nucleolar organizing region of the chromosome 6 of Tapinoma nigerrimum as an experimental model, since, in accordance with previous studies, the genes for ribosomal RNA seem to be present only in this chromosome. In situ non-digestion of the nucleolar organizing region was observed when EcoRI and HindIII were used. However, very evident digestion and partial digestion respectively were observed when HaeIII and Tru9I were used. Southern blot analysis realized on naked DNA digested with the same REs and using rDNA of Drosophila melanogaster as probe showed that there are target sequences for these enzymes in the rDNA. In accordance with the results obtained, the rDNA is poor in EcoRI and HindIII sequences, contains moderate amounts of Tru9I sequences, and is rich in HaeIII sequences. All the data obtained suggest that in the nucleolar organizing region of Tapinoma nigerrimum, the major, if not the only, limiting factor affecting in situ digestion by the REs used is the presence and frequency of their specific restriction targets. Consequently, extraction of DNA from this chromosome region depends on the size of the fragments originated.Key words: chromosome banding, Formicidae, NORs, rDNA, restriction endonucleases.

Variation in the heterochromatin and nucleolar organizing regions of Allium subvillosum L. (Liliaceae)

Genome ◽  
1990 ◽  
Vol 33 (6) ◽  
pp. 779-784 ◽  
Author(s):  
M. Jamilena ◽  
C. Ruiz Rejón ◽  
M. Ruiz Rejón
Keyword(s):  
Chromosome Pair ◽  
Wild Population ◽  
Supernumerary Chromosome ◽  
Fluorescence Pattern ◽  
Nucleolar Organizing Regions ◽  
Nucleolar Organizing Region ◽  
The Third ◽  
Chromosome Segments

Two kinds of polymorphisms have been found in a wild population of Allium subvillosum L. (Liliaceae): (i) extra C-bands and supernumerary chromosome segments on three chromosome pairs and (ii) the absence of the nucleolar organizing region (NOR) in one member of the third chromosome pair (there are two other NOR-bearing chromosome pairs in the karyotype of this species). The fluorescence pattern (chromomycin A3 (CMA3) positive and 4,6-diamidino-2-phenylindole (DAPI) negative) of the extra heterochromatin is similar to that of the standard. The absence of the NOR on the third chromosome pair is related to a variation in the NOR-associated heterochromatin (the chromosomes with no NOR do not have the distal C-band from the satellite, but the proximal C-band may be present). The characteristics of the karyotype of this species, its heterochromatin distribution, and the possible mechanisms by which the polymorphisms may originate are discussed.Key words: Allium, supernumerary segments, heterochromatin, polymorphisms, nucleolar organizing regions.

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