Three New Ontario Black Flies of the Genus Prosimulium (Diptera: Simuliidae): Part I. Descriptions, Morphological Comparisons with Related Species, and Distribution

1958 ◽  
Vol 90 (12) ◽  
pp. 697-719 ◽  
Author(s):  
P. D. Syme ◽  
D. M. Davies
Keyword(s):  
Salivary Gland ◽  
Banding Pattern ◽  
Related Species ◽  
External Environment ◽  
Black Flies ◽  
Eastern Canada ◽  
Phylogenetic Relations ◽  
Morphological Detail

Chromosonial studies have elucidated phylogenetic relations in Drosophila (White, 1954), culicids (Jucci, 1952) and chironomids (Bauer, 1936, 1945). Since it appeared promising to apply this approach to the Simuliidae, Rothfels and Dunbar (1953) began a cytological survey of the black flies of eastern Canada during the summer of 1951. They found that in this group the giant salivary gland chromosomes provided “a wealth of descriptive morphological detail in their number and gross morphology, in the characteristics of expanded centromere regions, in the location of specific nucleolar sites, in the degree of pairing of constituents, and in the ultimate discernible banding pattern…. Since these features are not functionally related to the external environment, the confusing effects of convergence are minimized, resemblances may be taken to indicate relation, and grouping is possible according to natural affinities” (Rothfels and Dunbar, 1953).

TRIPLOIDY IN NATURAL POPULATIONS OF THE BLACK FLY CNEPHIA MUTATA (MALLOCH)

1959 ◽  
Vol 37 (4) ◽  
pp. 571-589 ◽  
Author(s):  
V. R. Basrur ◽  
K. H. Rothfels
Keyword(s):  
Salivary Gland ◽  
Banding Pattern ◽  
Natural Populations ◽  
Chromosomal Polymorphism ◽  
Genetic Exchange ◽  
Black Flies ◽  
Female Progeny ◽  
Southern Ontario ◽  
Black Fly ◽  
Standard Sequence

Populations of Cnephia mutata in southern Ontario contain both diploid and triploid individuals. The diploid form is bisexual and lacks chromosomal polymorphism except for a rearrangement involved in its cytological sex determining mechanism. The triploids are parthenogenetic; they produce female progeny only and are highly heterozygous for inversions. The banding pattern of the salivary gland chromosomes of diploids and triploids is very similar; the identical standard sequence occurs in both. The complete lack of autosomal inversions in diploids contrasted with their abundance in triploids indicates that effective genetic exchange does not occur between the two forms; they are reproductively completely isolated, although opportunity for cross-mating would seem to exist. The origin of polyploid parthenogenetic forms in black flies is discussed and the view is favored that they are autopolyploid and automictic.

THE SALIVARY GLAND CHROMOSOMES OF SIX CLOSELY RELATED BLACK FLIES NEAR EUSIMULIUM CONGAREENARUM (DIPTERA: SIMULIIDAE)

1967 ◽  
Vol 45 (4) ◽  
pp. 377-396 ◽  
Author(s):  
Robert W. Dunbar
Keyword(s):  
Salivary Gland ◽  
Related Species ◽  
Chromosome Banding ◽  
Black Flies ◽  
Distinct Form ◽  
Closely Related Species ◽  
Banding Patterns ◽  
Natural Group ◽  
Y Chromosomes ◽  
Giant Chromosome

The salivary gland chromosomes of nearctic black flies which form a natural group in Eusimulium close to E. congareenarum were analyzed in detail. Comparisons of their giant chromosome banding patterns disclosed six cytological segregates in two subgroups; subgroup A, with E. innocens, E. anatinum, E. congareenarum, and a cytologically distinct form near the latter designated E. congareenarum 'b'; subgroup B, with E. excisum and E. rivuli. Within each subgroup closely related species differ at least by (1) two or three interspecific inversions, (2) the intraspecific specific inversions present, and (3) the details of the X and Y chromosomes. The differences between the subgroups include (1) the position of the nucleolus, (2) the identity of the sex chromosomes as either the first or third pair, and (3) about 15 interspecific inversions between E. congareenarum and E. excisum, the most closely related species from either subgroup. The phylogenetic interrelationships have been traced by means of the interspecific inversions.

Use of tall fescue EST-SSR markers in phylogenetic analysis of cool-season forage grasses

Genome ◽  
2005 ◽  
Vol 48 (4) ◽  
pp. 637-647 ◽  
Author(s):  
M A. Rouf Mian ◽  
Malay C Saha ◽  
Andrew A Hopkins ◽  
Zeng-Yu Wang
Keyword(s):  
Phylogenetic Analysis ◽  
Ssr Markers ◽  
Tall Fescue ◽  
Related Species ◽  
Grass Species ◽  
Forage Grass ◽  
Forage Grasses ◽  
Cool Season ◽  
Phylogenetic Relations ◽  
Wide Range

Microsatellites or simple sequence repeats (SSRs) are highly useful molecular markers for plant improvement. Expressed sequence tag (EST)-SSR markers have a higher rate of transferability across species than genomic SSR markers and are thus well suited for application in cross-species phylogenetic studies. Our objectives were to examine the amplification of tall fescue EST-SSR markers in 12 grass species representing 8 genera of 4 tribes from 2 subfamilies of Poaceae and the applicability of these markers for phylogenetic analysis of grass species. About 43% of the 145 EST-SSR primer pairs produced PCR bands in all 12 grass species and had high levels of polymorphism in all forage grasses studied. Thus, these markers will be useful in a variety of forage grass species, including the ones tested in this study. SSR marker data were useful in grouping genotypes within each species. Lolium temulentum, a potential model species for cool-season forage grasses, showed a close relation with the major Festuca–Lolium species in the study. Tall wheatgrass was found to be closely related to hexaploid wheat, thereby confirming the known taxonomic relations between these species. While clustering of closely related species was found, the effectiveness of such data in evaluating distantly related species needs further investigations. The phylogenetic trees based on DNA sequences of selected SSR bands were in agreement with the phylogenetic relations based on length polymorphism of SSRs markers. Tall fescue EST-SSR markers depicted phylogenetic relations among a wide range of cool-season forage grass species and thus are an important resource for researchers working with such grass species.Key words: phylogeny, EST-SSR, forage grasses, tall fescue.

scholarly journals UNDER-REPLICATION OF RIBOSOMAL CISTRONS IN POLYTENE CHROMOSOMES OF RHYNCHOSCIARA

1974 ◽  
Vol 62 (1) ◽  
pp. 215-222 ◽  
Author(s):  
A. G. Gambarini ◽  
F. J. S. Lara
Keyword(s):  
Salivary Gland ◽  
In Situ Hybridization ◽  
Xenopus Laevis ◽  
Related Species ◽  
Polytene Chromosomes ◽  
Chromosome X ◽  
Heterologous Hybridization ◽  
Ribosomal Cistrons ◽  
Rhynchosciara Americana

DNA preparations obtained from several tissues of Rhynchosciara americana and two related species, R. milleri and R. papaveroi, were hybridized to R. americana rRNA. The percentage of hybridization was found to be higher in tissues with low polyteny than in tissues with high polyteny, suggesting a relationship between the amount of rDNA and the tissue polyteny. This could be explained by under-replication of ribosomal cistrons in polytene cells, such as those from the salivary gland. Only slight tissue-dependent changes in the percentages of hybridization can be observed in heterologous hybridization using Xenopus laevis rRNA. The possibility that these experiments could not detect differences in the amount of ribosomal cistrons among tissues is discussed. The female:male ratio for the percentages of hybridization in the salivary gland of R. americana agrees with the results obtained by in situ hybridization experiments (16, 17) which have shown that the rRNA cistrons are distributed among chromosomes other than chromosome X.

A comparison of polytene chromosomes in salivary glands and orbital bristle trichogen cells in Ceratitis capitata

Genome ◽  
1991 ◽  
Vol 34 (2) ◽  
pp. 215-219 ◽  
Author(s):  
A. Zacharopoulou ◽  
K. Bourtzis ◽  
Ph. Kerremans
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Banding Pattern ◽  
Ceratitis Capitata ◽  
Polytene Chromosomes ◽  
Biological Significance ◽  
Fruit Fly ◽  
Banding Patterns ◽  
Homologous Chromosomes ◽  
Different Tissues

The banding patterns of polytene chromosomes in different tissues of the Mediterranean fruit fly, Ceratitis capitata, vary to such an extent that homologous chromosomes cannot be recognised. However, analyses of autosomal breakpoints in several translocation strains allowed chromosomes from the two tissues to be aligned despite their difference in banding pattern. These results were discussed, considering the different hypotheses of the origin and biological significance of polytene chromosome bands.Key words: polytene chromosomes, salivary gland chromosomes, orbital bristle trichogen cell chromosomes, Ceratitis capitata.

The Balbiani ring and the polytene chromosomes of Drosophila bicornuta

Genome ◽  
1992 ◽  
Vol 35 (1) ◽  
pp. 64-67 ◽  
Author(s):  
P. Mavragani-Tsipidou ◽  
Z. G. Scouras ◽  
A. Natsiou-Voziki
Keyword(s):  
Salivary Gland ◽  
Larval Development ◽  
Banding Pattern ◽  
Polytene Chromosomes ◽  
Balbiani Ring

A study of the BR1 and of the most prominent puffs during larval development and after in vitro ecdysterone treatment, as well as of the banding pattern and inverted tandem chromosomal duplications of the salivary gland chromosomes of Drosophila bicornuta, is presented in this report. These data are compared and discussed with those of D. auraria and D. serrata, two other montium species.Key words: Drosophila, Balbiani ring, duplications, ecdysterone.

Morphology and description of Helicotylenchus crassatus n. sp. (Nematoda: Hoplolaimidae) from eastern Canada

1973 ◽  
Vol 51 (11) ◽  
pp. 1195-1200 ◽  
Author(s):  
R. V. Anderson
Keyword(s):  
Related Species ◽  
Diagnostic Value ◽  
Eastern Canada ◽  
Closely Related Species ◽  
Parasitic Species ◽  
Head Skeleton ◽  
Vaginal Sphincter ◽  
Plant Parasitic

A new plant parasitic species of the genus Helicotylenchus Steiner, 1945, common to eastern Canada, is described and illustrated. Helicotylenchus crassatus can be distinguished from closely related species by the sclerotization of the head skeleton, size and position of the anterior cephalid, and thickness of the vagina. The morphology and diagnostic value of the head skeleton, hypodermal commissures, vulva, vagina, vaginal sphincter, and oviduct are discussed.

Control of Black Fly Larvae (Diptera: Simuliidae) in the Forests of Eastern Canada by Aircraft Spraying

1960 ◽  
Vol 92 (10) ◽  
pp. 745-754 ◽  
Author(s):  
A. S. West ◽  
A. W. A. Brown ◽  
D. G. Peterson
Keyword(s):  
Black Flies ◽  
Eastern Canada ◽  
Black Fly ◽  
North Shore ◽  
The North ◽  
Fly Larvae ◽  
And Control ◽  
St Lawrence River ◽  
Made In

The results reported in this paper are part of a study of the biology and control of black flies in the forests of Eastern Canada conducted on the north shore of the St. Lawrence River, near Baie Comeau, Quebec, during 1954, 1955, and 1956. Reference to this study is made in a review by Peterson and Wolfe (1958). The identification and biology of the black flies of this region has been reported on by Wolfe and Peterson (1959) who also describe the topography of the region. The important feature of this rugged area is an abundance of fast-flowing streams which provide highly suitable environments for the development of black-fly populations.

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