scholarly journals CYTOGENETIC STUDIES IN NORTH AMERICAN MINNOWS (CYPRINIDAE). IV. SOMATIC POLYPLOIDY IN GILA BICOLOR

1977 ◽  
Vol 19 (4) ◽  
pp. 657-662 ◽  
Author(s):  
John C. Avise ◽  
John R. Gold
Keyword(s):  
North American ◽  
Kidney Tissue ◽  
Single Individual ◽  
Somatic Polyploidy ◽  
Polyploid Cells ◽  
Cytogenetic Studies ◽  
Cytological Mechanism ◽  
In Cells

The kidney tissue of a single individual of the California minnow Gila bicolor (Girard) contained polyploid cells in about 1.7% frequency. Chromosome spreads of triploid, tetraploid, hexaploid, octaploid, and dodecaploid cells were observed and may have arisen through endoreduplication of ancestral diploid and triploid cells. The cytological mechanism producing the triploid cells is unknown. Diplochromosomes were not present. The distribution of ploidy in cells of this individual is not random. In particular, cells having undergone one round of chromosomal increase appear increasingly susceptible to additional rounds of chromosomal gain.

scholarly journals Cytogenetic studies in North American minnows(Cyprinidae). VII. Karyotypes of 13 species from the southern united states.

CYTOLOGIA ◽  
1981 ◽  
Vol 46 (1/2) ◽  
pp. 105-115 ◽  
Author(s):  
J. R. Gold ◽  
W. D. Womac ◽  
F. H. Deal ◽  
J. A. Barlow, Jr.
Keyword(s):  
United States ◽  
North American ◽  
Southern United States ◽  
Cytogenetic Studies

Description and first occurrence of Myxidium zealandicum (Protozoa: Myxosporidia) in the North American eel Anguilla rostrata LeSueur

1977 ◽  
Vol 55 (1) ◽  
pp. 52-59 ◽  
Author(s):  
M. P. Komourdjian ◽  
W. C. Hulbert ◽  
J. C. Fenwick ◽  
T. W. Moon
Keyword(s):  
North American ◽  
Kidney Tissue ◽  
Quebec City ◽  
Anguilla Rostrata ◽  
Fast Green ◽  
American Eel ◽  
The North ◽  
First Occurrence ◽  
Scanning Electron ◽  
St Lawrence River

Myxidium zealandicum Hine, 1975 is described from gills and kidney of the North American eel Anguilla rostrata collected from the St. Lawrence River near Quebec City and Cornwall. Cysts of M. zealandicum on gills measured up to 1 by 2 mm and in kidneys up to 15 by 20 mm. In addition to single spherical cysts, several polymorphous forms were also observed on the gills. Polymorphous cysts were not found in the kidney. Different stages of spore development were evident in gill cysts and were differentiated by means of a lead hematoxylin – fast green stain. Number and pattern of spore striations were examined by scanning electron microscopy and were highly variable. The invasion of the parasite into kidney tissue appeared to result in less physiological damage to the host than did gill invasion. The existence of this parasite, previously found in eel species in New Zealand, in a North American eel species is discussed.

scholarly journals Cytogenetic studies in North American minnows(Cyprinidae). XVIII. Chromosomal NOR variation among eight species.

CYTOLOGIA ◽  
1990 ◽  
Vol 55 (3) ◽  
pp. 483-492 ◽  
Author(s):  
J. R. Gold ◽  
J. D. Jenkin ◽  
P. K. Powers
Keyword(s):  
North American ◽  
Cytogenetic Studies

scholarly journals Evaluation of mitotic activity in tapetal cells of grapevine (Vitis L.)

2021 ◽  
Vol 49 (2) ◽  
pp. 11975
Author(s):  
Neiva Izabel PIEROZZI ◽  
Mara FERNANDES MOURA
Keyword(s):  
Mitotic Activity ◽  
Meiotic Stage ◽  
Polyploid Cells ◽  
Cytogenetic Studies ◽  
Tapetal Cells ◽  
Diploid Cells ◽  
Chromosome Spreading ◽  
Interesting Alternative ◽  
Large Nucleolus

The knowledge with reference to the grapevine tapetum has been centered on its anatomy/morphology and hardly anything at all is known about its mitotic activity throughout the microsporogenesis. The aim of this study was to ascertain the mitotic activity in tapetal cells of some grapevines (Vitis L.) broadening knowledge about this tissue and simultaneously corroborating the viability of its use as an alternative tissue for further cytogenetic studies. Young buds of 12 grapevine varieties at different meiotic stages were squashed and tapetal cells a prometaphase/metaphase scored in each meiotic stage. Mitotic activity was observed since the beginning of microsporogenesis, where it was more intense, decreasing toward tetrad. Polyploid tapetal cells arose through endomitosis while the microsporogenesis advanced. Two types of polyploid cells were evidenced, those with two or more individualized diploid chromosome groups and those with only one polyploid group. The percentage of diploid cells and of polyploid cells with two or more individualized diploid groups was higher during the first stage of microsporogenesis, though decreasing and giving way to cells with one large polyploid group as microsporogenesis moved toward tetrad. The nucleolus number was scored at interphase at different stages. Two and four nucleoli prevailed in tapetal cells at all stages except at tetrad where one large nucleolus was seen. The results showed that despite of the squashing technique applied, grapevine tapetum has a substantial amount of cells with mitotic activity with a satisfactory chromosome spreading therefore establishing an interesting alternative and promising tissue for later cytomolecular studies.

scholarly journals Architecture of Ambrosia psilostachya DC. Individuals in different habitats

2012 ◽  
Vol 64 (4) ◽  
pp. 115-122
Author(s):  
Maciej Korczyński ◽  
Ewa Krasicka-Korczyńska
Keyword(s):  
North American ◽  
The State ◽  
Single Individual ◽  
Green Areas ◽  
Mechanical Factors ◽  
Number Of Shoots

<i>Ambrosia psilostachya</i> is a plant of North American origin, well-domesticated in Poland. It covers ruderal habitats and is found in crops and in city green areas. The density of ragweed shoots in the researched areas ranged from 55 to 111 per m<sup>2</sup>. The production of biomass of this species relates to the production of synanthropic communities and city lawns. The factor limiting the population is cutting which affects mostly the number of shoots per patch, less considerably the state of a single individual. Habitats affected by mechanical factors are the biggest source of pollen causing allergies .

Development of Novel Microsatellite Markers for the Northern Goshawk (Accipiter Gentilis) and their Utility in Cross-Species Amplification

2016 ◽  
Vol 9 (3) ◽  
pp. 195-199 ◽  
Author(s):  
Christy L. Haughey ◽  
George K. Sage ◽  
Gabriel R. DeGange ◽  
Sarah A. Sonsthagen ◽  
Sandra L. Talbot
Keyword(s):  
Microsatellite Markers ◽  
North American ◽  
Individual Identification ◽  
Accipiter Gentilis ◽  
North American Population ◽  
Single Individual ◽  
Northern Goshawk ◽  
Species Of Conservation Concern ◽  
Conservation Concern ◽  
Northern Goshawks

The Northern Goshawk ( Accipiter gentilis) is a large forest raptor with a Holarctic distribution and, in some portions of its range, a species of conservation concern. To augment previously reported genetic markers, 13 novel polymorphic microsatellite markers were developed to establish individual identification and familial relationships, to assess levels of genetic diversity, and to identify diagnostic markers. Of the 22 loci tested, 13 were polymorphic, seven were monomorphic, and two failed to amplify. This suite of microsatellite loci yielded a combined probability of parental exclusion of 98%; a single individual sampled from a North American population can be reliably identified using a combination of seven of the 13 polymorphic loci. Cross-species screening in Cooper's Hawks (A. cooperii) and Sharp-shinned Hawks (A. striatus) of the 20 loci that successfully amplified in Northern Goshawks identified 13 loci as polymorphic in each species. Six of these loci (Age1303, Age1308, Age1309, Age1312, and Age1314) appeared to be useful in distinguishing between Accipiter species. These markers will be useful to researchers investigating populations of North American accipiters.

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