Preparation and karyotype analysis of mitotic chromosomes of the freshwater spongeSpongilla lacustris

Chromosoma ◽  
1993 ◽  
Vol 102 (10) ◽  
pp. 724-727 ◽  
Author(s):  
Georg Imsiecke ◽  
Ulrich Pascheberg ◽  
Werner E. G. M�ller
Keyword(s):  
Karyotype Analysis ◽  
Mitotic Chromosomes

Genome analysis of Thinopyrum bessarabicum and T. elongatum

1985 ◽  
Vol 27 (6) ◽  
pp. 722-728 ◽  
Author(s):  
Richard R. -C. Wang
Keyword(s):  
Reciprocal Cross ◽  
Parental Species ◽  
Karyotype Analysis ◽  
Pollen Grains ◽  
Structural Rearrangements ◽  
Mitotic Chromosomes ◽  
Hybrid Plants ◽  
Glume Length ◽  
Thinopyrum Bessarabicum ◽  
I Cells

Thinopyrum bessarabicum (2n = 14; JJ) was successfully crossed with T. elongatum (2n = 14; EE) but the reciprocal cross failed. Five of the 19 F1 plants headed in a greenhouse without being vernalized. Spikes of F1 hybrids were intermediate to those of the parents for number of florets per spike, glume length, and the first rachis internode length, but similar to those of T. bessarabicum and T. elongatum for spike length and number of spikelets per spike, respectively. Karyotypes of mitotic chromosomes in the parental species revealed that three of the seven chromosomes in the J and E genomes were similar in length and arm ratio. Meiosis in the F1 hybrids substantiated the conclusion from karyotype analysis that the other four chromosomes had undergone some structural rearrangements such as reciprocal translocation. Metaphase-I cells in hybrid plants averaged 2.68 I, 4.68 II, 0.27 III, 0.27 IV, and 0.01 V. Although 10% of the pollen grains were stainable with I2–KI, F1 plants of T. bessarabicum × T. elongatum did not set seed upon selfing. It is concluded that the J and E genomes are so closely related that the E genome designation should be changed to Je. The evidence reported here supports the transfer of Lophopyrum elongatum to the genus Thinopyrum. Wheat breeders should be able to utilize the genes in T. bessarabicum as readily as those in T. elongatum.Key words: Genome, mitosis, meiosis, karyotype, idiogram, hybrid.

Sulfhydryl bond formation is a prerequisite for proper cycling of centrosomes and chromosomes in mammalian tissue culture cells

1993 ◽  
Vol 51 ◽  
pp. 342-343
Author(s):  
Heide Schatten ◽  
Neidhard Paweletz ◽  
Ron Balczon
Keyword(s):  
Tissue Culture ◽  
Cell Cycle Progression ◽  
Group Formation ◽  
Sulfhydryl Group ◽  
Mammalian Tissue ◽  
Mitotic Chromosomes ◽  
Microtubule Network ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Transmission Electron

To study the role of sulfhydryl group formation during cell cycle progression, mammalian tissue culture cells (PTK2) were exposed to 100¼M 2-mercaptoethanol for 2 to 6 h during their exponential phase of growth. The effects of 2-mercaptoethanol on centrosomes, chromosomes, microtubules, membranes and intermediate filaments were analyzed by transmission electron microscopy (TEM) and by immunofluorescence microscopy (IFM) methods using a human autoimmune antibody directed against centrosomes (SPJ), and a mouse monoclonal antibody directed against tubulin (E7). Chromosomes were affected most by this treatment: premature chromosome condensation was detected in interphase nuclei, and the structure in mitotic chromosomes was altered compared to control cells. This would support previous findings in dividing sea urchin cells in which chromosomes are arrested at metaphase while the centrosome splitting cycle continues. It might also support findings that certairt-sulfhydryl-blocking agents block cyclin destruction. The organization of the microtubule network was scattered probably due to a looser organization of centrosomal material at the interphase centers and at the mitotic poles.

Detection Y Chromosome Microdeletions Among Iraq Population in Infertile Patients with Azoospermia and Severe Oligospermia

2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Samah A Hammood ◽  
Alaauldeen S M AL-Sallami ◽  
Saleh M Al-Khafaji
Keyword(s):  
Y Chromosome ◽  
Karyotype Analysis ◽  
Semen Analysis ◽  
Obstructive Azoospermia ◽  
Severe Oligozoospermia ◽  
Infertile Men ◽  
Y Chromosome Microdeletions ◽  
Detailed Evaluation ◽  
Health Organization ◽  
Infertile Patients

Objective: To detection of microdeletions of Y chromosome and study the frequency of microdeletions in infertile men with non-obstructive azoospermia or severe oligozoospermia(Middle Euphrates center)in Iraq population. Material and methods: 153 males were included in the study, the casesweredivided into groups according to the infertility etiology and semen analysis according to Word health organization, the frequencies and the characteristicsof Y chromosome microdeletions were investigated in groups. Multiplex PCR was applied to detect the microdeletions. Results:Y chromosome microdeletion was detected in 42 (40.7%) of 153 cases ,Microdeletions in azoospermia showed more frequently detected 28 (52.8%), followed by severe oligospermia 14 (28 %),Microdeletions in the AZFc region were the most common 12 (22.64%), followed by AZFb 11(20.75%) and AZFa 5(9.43%) in azoospermia compared to severe oligospermisAZFc 6 (12%) AZFb 4 (8 %) and AZFa 4 (8%). Conclusion: Y chromosome microdeletions were detected quite frequently in certain infertility subgroups. Therefore, detailed evaluation of an infertile man by physical examination, semen analysis, hormonal evaluationsand when required, karyotype analysis may predict the patients for whom Y chromosome microdeletionanalysis is necessary and also prevent cost increases. Recommendation: This study emphasizes that analysis of microdeletions should be carried out for all patients with idiopathic azoospermia and severe oligospermia who are candidates for intracytoplasmic sperm injection

scholarly journals Diversification of the Balloon bushcrickets (Orthoptera, Hexacentrinae, Aerotegmina) in the East African mountains

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Beata Grzywacz ◽  
Elżbieta Warchałowska-Śliwa ◽  
Maciej Kociński ◽  
Klaus-Gerhard Heller ◽  
Claudia Hemp
Keyword(s):  
Molecular Phylogeny ◽  
Large Scale ◽  
Diploid Number ◽  
Karyotype Analysis ◽  
Spatial Separation ◽  
Eastern Arc Mountains ◽  
East African ◽  
Habitat Islands ◽  
Extinction Event ◽  
Underlying Processes

AbstractEast African mountains constitute a network of isolated habitat islands among dry savannah and are thus ideal for studying species diversification processes. This study elucidated the phylogenetic and phylogeographic relationships of all bushcricket species comprising the genus Aerotegmina. Our analysis indicated that large-scale climatic and topographic processes in Africa are likely to have driven speciation in this group, and revealed the cytogenetic traits of the species. Molecular phylogeny supported the monophyly of Aerotegmina and showed that the genus probably originated in the old Eastern Arc Mountains of Tanzania and Kenya. Two lineages were distinguished: small- and large-sized species with geographically distinct habitats. The underlying processes are thought to be eight dispersals, ten vicariance events, and one extinction event linked to repeated fragmentation of the African rainforest. Those processes, in conjunction with habitat change, probably also led to the spatial separation of the species into a northern clade with a diploid number of chromosomes 2n = 32 + X0 or 2n = 30 + neo-XY and a southern clade with a reduced number of chromosomes (2n = 28 + X0 or 24 + neo-X1X2Y). Karyotype analysis suggests that Aerotegmina is currently in the process of speciation.

Structure and variability of nucleolar organizer regions in Parodontidae fish

1984 ◽  
Vol 26 (5) ◽  
pp. 564-568 ◽  
Author(s):  
Orlando Moreira-Filho ◽  
Luiz Antonio Carlos Bertollo ◽  
Pedro Manoel Galetti Jr.
Keyword(s):  
Chromosome Pair ◽  
Constitutive Heterochromatin ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Mitotic Chromosomes ◽  
Homozygous Condition ◽  
Nucleolar Organizing Regions ◽  
Nucleolar Chromosome

Nucleolar organizer regions (NORs) were studied in mitotic chromosomes of four species of fish of family Parodontidae: Parodon tortuosus, Apareiodon affinis, Apareiodon ibitiensis, and Apareiodon piracicabae. All four species exhibited only a single nucleolar chromosome pair in their karyotypes. Intraspecific differences were observed in the size of these chromosomes; however, these were not very clear for A. affinis and A. piracicabae, Apareiodon piracicabae exhibited two clearly visible NORs in each of the nucleolar chromosomes, which was the only configuration practically found in this species. This trait therefore predominates in a homozygous condition in the population investigated. Regions of constitutive heterochromatin adjacent to the two NORs were detected. Possible mechanisms that may have originated the two NORs are discussed.Key words: nucleolar organizing regions, fish.

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