Inheritance of a chromosomal polymorphism in odd-year pink salmon from southeastern Alaska

Genome ◽  
1999 ◽  
Vol 42 (5) ◽  
pp. 816-820 ◽  
Author(s):  
R B Phillips ◽  
M P Matsuoka ◽  
W W Smoker ◽  
A J Gharrett

In previous work we found a high frequency of heterozygotes for a fission translocation involving the seventh chromosome pair in odd-year populations of pink salmon (Oncorhynchus gorbuscha) sampled from Washington State to south central Alaska. The populations from southeastern Alaska and northern British Columbia had high frequencies of heterozygotes for a second rearrangement of this same chromosome pair. In these fish one fission product, the larger acrocentric chromosome bearing the nucleolar organizer region (NOR), has undergone an inversion to produce a submetacentric chromosome. In this paper, we present inheritance data on pink salmon from the Gastineau hatchery stock in Juneau, Alaska, where individuals with the two rearrangements are found. Although most of the fish were either homozygous for the normal cytotype or heterozygous for the inversion cytotype, a few individuals heterozygous for the fission cytotype were found. Ten males and ten females were karyotyped, and crosses were set up in all combinations. Individuals with both rearrangements were found in crosses between the two types of heterozygotes, and the ratios of cytotypes in the progeny did not deviate significantly from the expected values. No significant difference in viability of offspring from crosses between individuals with different cytotypes was found up to the age of hatching.Key words: salmon, chromosomal polymorphism, translocation, inversion, cytotype.

1996 ◽  
Vol 33 (5) ◽  
pp. 527-532 ◽  
Author(s):  
M. BratuliĆ ◽  
Ž GrabareviĆ ◽  
B. ArtukoviĆ ◽  
D. Capak

Twenty-eight canine mammary tumors were evaluated for histopathologic classification as recommended by the World Health Organization and silver-binding nucleolar organizer region (AgNOR) and nucleolus counts. Samples of surgically excised tumors and tumors taken at necropsy were fixed in neutral formalin, embedded in paraffin, and cut into 1-3-μm-thick sections. Two sections were taken from each tumor: one was stained with hematoxylin and eosin and the other was treated with the silver staining technique for the demonstration of AgNORs. After histopathologic classification, the number of nucleoli and the number of AgNORs/nucleus and AgNORs/nucleolus were determined. Statistical analysis (Student's t-test) showed a significant difference in the mean number of nucleoli ( P < 0.005), mean number of AgNORs/nucleolus ( P < 0.001), and mean number of AgNORs/nucleus ( P < 0.005) between benign and malignant canine mammary tumors. There was no significant differences between metastatic and nonmetastatic malignant tumors.


2000 ◽  
Vol 23 (3) ◽  
pp. 563-567 ◽  
Author(s):  
Patricia Pasquali Parise-Maltempi ◽  
Rita Maria Pereira Avancini

Pattonella intermutans has 2n = 12 chromosomes including three metacentric and two submetacentric pairs of autosomes and an XX/XY sex chromosome pair. The autosomes are characterized by the presence of a C band in the pericentromeric region while sex chromosomes are totally heterochromatic. The FISH technique showed a nucleolar organizer region (NOR) in autosome IV.


Biologia ◽  
2010 ◽  
Vol 65 (5) ◽  
Author(s):  
Kátia Ferreira ◽  
Giovana Torres ◽  
Saulo Sousa ◽  
Aparecida Santos

AbstractMeiotic behavior, pollen morphology, interphasic nucleus pattern and karyotype description for Senna occidentalis (Caesalpinioideae — Fabaceae) are presented. The species had non-reticulate interphasic nucleus and homogeneous chromosome condensing with minute distal late-condensing portions in prometaphase. In mitotic metaphase, chromosome number was 2n = 28 (9 m + 5 sm), with secondary constriction in one chromosome pair. Detection of four nucleoli indicated existence of two chromosome pairs bearing Nucleolar Organizer Region (NOR). Meiotic behavior was regular, with high meiotic index (95%). Pollen grains, classified as polar/spheroidal, presented 90% viability.


2020 ◽  
Vol 2 (4) ◽  
pp. 285-292
Author(s):  
Hassan ALgarsh ◽  
◽  
Hana Abusaida ◽  
Fairouz Torjman ◽  
◽  
...  

Introduction: This experimental study gauged the value of argyrophilic nucleolar organizer region (AgNOR) staining as a possible technique for the estimation of cell kinetics in conventional histology sections, in benign and malignant breast lesions. Methods: With a silver staining technique and immunohistochemistry, we associated the numbers of AgNORs and Ki67 scores in 30 breast carcinomas and 10 benign breast lesions. Results: The mean values of Ag NORs silver stain dots count for normal, benign, grade II and III were 1.28±0.17, 2.83±0.68, 5.23±0.87 and 7.32±0.92, respectively. There was a statistically significant difference (p≤0.001) was noticed between the all individual groups, among the normal and breast lesion as well as among the GII and GIII. Immunohistochemical Results of Ki-67 protein exhibited homogenous golden-brown color in control case and a positive brown granules or diffuse dark brown color in the nuclei of both benign and malignant cases under the 400X magnify examined under the light microscope. Discussion: AgNOR counts performed on routine formalin-fixed paraffin sections could provide substantial kinetic evidence. Additionally, the difference in AgNOR counts between benign and malignant tumors is such that they may be of diagnostic worth.


1994 ◽  
Vol 72 (11) ◽  
pp. 1951-1956 ◽  
Author(s):  
P. Ráb ◽  
E. J. Crossman

A comparison was made of the localization of nucleolar organizer region (NOR) sites in the karyotypes of the North American pikes and pickerels Esox lucius, E. masquinongy, E. niger, and the two subspecies of E. americanus (Esocidae). NORs were located by silver staining or chromomycin A3 fluorescence. The study revealed that the position of chromosomal NORs in all Esox taxa examined was the same: the pericentromeric region of one middle-sized chromosome pair. The same NOR phenotype was found previously in a related European species, Umbra krameri (Umbridae), and in U. pygmaea, one of the two North American representatives of the genus. The NOR phenotype of the remaining North American species (U. limi) is different. It is hypothesized that this kind of NOR phenotype, shared by two phyletic lineages in the Esocae, represents an ancestral character for the members of that group.


2007 ◽  
Vol 67 (4 suppl) ◽  
pp. 897-903 ◽  
Author(s):  
S. Morelli ◽  
MR. Vicari ◽  
LAC. Bertollo

The taxonomy/systematics of the Erythrinidae fish is still imprecise, with several doubts on their relationships. Karyotypes and chromosomal characteristics of some species of the Hoplias lacerdae group (Erythrinidae), from different Brazilian hydrographic basins and pisciculture stations, were analyzed in the present study, using conventional Giemsa staining, C-banding, silver staining, Mithramycin and Distamycin/DAPI fluorochromes, and fluorescent in situ hybridization (FISH). A diploid chromosome number of 2n = 50 and karyotypes composed of meta- and submetacentric chromosomes without sex-related differences were found. Only one active NOR (Nucleolar Organizer Region) site was found, which was identified by silver staining (Ag-NOR) and FISH, located on the chromosome pair 11, although additional 45S rDNA sites were also mapped on other chromosome pairs only by FISH. The Ag-NOR of the chromosome pair 11 was found to be GC-rich, appearing positive after Mithramycin staining. Mithramycin-positive/DAPI-negative sites were also observed in the centromeric/pericentomeric regions of the chromosome pairs 4, 6, 15, and 19, which have also affinity to silver nitrate. However, these four sites were not detected by FISH with the rDNA probe, indicating to be only argentophilic GC-rich heterochromatic regions. Chromosome data show that the karyotype evolution in Hoplias lacerdae group is relatively conserved and follows a particular pathway concerning the other Erythrinidae fishes, such as Hoplias malabaricus, Hoplerythrinus unitaeniatus, and Erythrinus erythrinus, in which polytypic karyotypes are found. Thus, the H. lacerdae group shows chromosome features that are not closely related to those of the congeneric H. malabaricus group. These finds, together with genetic and morphologic data, are important tools to be considered in a major revision of the Erythrinidae family, as well as for conservation programs.


1991 ◽  
Vol 69 (11) ◽  
pp. 2826-2830 ◽  
Author(s):  
Yucheng Li ◽  
John R. Gold

Chromosomal nucleolar organizer region (NOR) phenotypes are documented for all four extant species in the North American cyprinid fish genus Pimephales. All four species (P. notatus, P. promelas, P. tenellus, and P. vigilax) possess 2n = 50 chromosomes and a pair of NOR-bearing chromosomes with the NOR situated terminally on the short arm of a medium-sized to large submetacentric chromosome (NOR phenotype C). Trypsin G-banding demonstrated that the C NOR chromosome in all four species is homologous. Two of the species (P. tenellus and P. promelas) also possess a C′ NOR chromosome, which is defined as an NOR situated terminally on the short arm of a large submetacentric chromosome that is also the largest chromosome in the complement. The C′ NOR chromosome occurs infrequently in P. promelas, being found in only 8% or so of all metaphases examined. Trypsin G-banding demonstrated that the C′ NOR chromosomes in the two Pimephales species are homologous to one another and to the C′ NOR chromosomes found in the cyprinid genus Cyprinella. A presumed derivative of the C′ NOR chromosome occurs in the monotypic cyprinid genus Opsopoeodus. The NOR chromosomal data support monophyly of the four extant species of Pimephales, and further suggest that the genus Pimephales belongs in a monophyletic assemblage with, among others, the cyprinid genera Cyprinella and Opsopoeodus. The data do not support the previous hypothesis that Pimephales is a basal clade outside of a larger assemblage of "Notropis"-like, shiners.


1988 ◽  
Vol 66 (6) ◽  
pp. 1460-1473 ◽  
Author(s):  
Catherine Thiriot-Quiévreux

Chromosome number and morphology were studied in nine species of pelagic opisthobranchs ("pteropods"). Among Thecosomata, seven species were investigated. Limacina inflata has a diploid chromosome number of 2n = 20 with metacentric and submetacentric chromosome pairs. Creseis acicula has 2n = 20 (five metacentric and five submetacentric pairs). Creseis virgula has 2n = 20 (seven metacentric, one submetacentric, one subtelocentric – submetacentric, and one submetacentric – subtelocentric pair). Clio pyramidata has 2n = 22 (five metacentric, one submetacentric, two submetacentric – subtelocentric, two subtelocentric, and one telocentric pair). Cavolinia inflexa has 2n = 24 (six metacentric, one submetacentric, two subtelocentric – submetacentric, one subtelocentric – telocentric, and two subtelocentric pairs). Peraclis reticulata has 2n = 24 (six metacentric and six submetacentric or subtelocentric pairs). Cymbulia peroni has 2n = 34 (six metacentric, three submetacentric, seven subtelocentric, and one telocentric pair). Among Gymnosomata, two species were investigated. Pneumodermopsis canephora has 2n = 32 (two metacentric, three submetacentric, four submetacentric – subtelocentric, one subtelocentric – submetacentric, five subtelocentric, and one telocentric – subtelocentric pair). Pneumoderma atlanticum has 2n = 32 (three metacentric, five submetacentric, four submetacentric – subtelocentric or subtelocentric – submetacentric, and four subtelocentric pairs). For three of the nine pteropod species, material was abundant enough to permit staining for the nucleolar organizer region. This region occurred on pair 9 in Creseis acicula, on pair 6 in Cavolinia inflexa and on pair 2 in Pneumodermopsis canephora. Results on number, morphology, and size of the chromosomes of each of the studied species are discussed. The present chromosomal evidence confirms the separation, sometimes seen as controversial, of the pelagic opisthobranchs into the orders Thecosomata and Gymnosomata. The Thecosomata constitute an isolated order among opisthobranchs by their striking chromosomal diversity. In contrast, the Gymnosomata show cytogenetic features that suggest an evolutionary trend with plesiomorphic characters, as in the Anaspidea and Sacoglossa.


2021 ◽  
Vol 43 (3) ◽  
pp. 237-249 ◽  
Author(s):  
Thanh Dat Ta ◽  
Nomar Espinosa Waminal ◽  
Thi Hong Nguyen ◽  
Remnyl Joyce Pellerin ◽  
Hyun Hee Kim

Abstract Background DNA tandem repeats (TRs) are often abundant and occupy discrete regions in eukaryotic genomes. These TRs often cause or generate chromosomal rearrangements, which, in turn, drive chromosome evolution and speciation. Tracing the chromosomal distribution of TRs could therefore provide insights into the chromosome dynamics and speciation among closely related taxa. The basic chromosome number in the genus Senna is 2n = 28, but dysploid species like Senna tora have also been observed. Objective To understand the dynamics of these TRs and their impact on S. tora dysploidization. Methods We performed a comparative fluorescence in situ hybridization (FISH) analysis among nine closely related Senna species and compared the chromosomal distribution of these repeats from a cytotaxonomic perspective by using the ITS1-5.8S-ITS2 sequence to infer phylogenetic relationships. Results Of the nine S. tora TRs, two did not show any FISH signal whereas seven TRs showed similar and contrasting patterns to other Senna species. StoTR01_86, which was localized in the pericentromeric regions in all S. tora, but not at the nucleolar organizer region (NOR) site, was colocalized at the NOR site in all species except in S. siamea. StoTR02_7_tel was mostly localized at chromosome termini, but some species had an interstitial telomeric repeat in a few chromosomes. StoTR05_180 was distributed in the subtelomeric region in most species and was highly amplified in the pericentromeric region in some species. StoTR06_159 was either absent or colocalized in the NOR site in some species, and StoIGS_463, which was localized at the NOR site in S. tora, was either absent or localized at the subtelomeric or pericentromeric regions in other species. Conclusions These data suggest that TRs play important roles in S. tora dysploidy and suggest the involvement of 45S rDNA intergenic spacers in “carrying” repeats during genome reshuffling.


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