The salivary gland chromosomes of seven taxa in the subgenus Stegopterna (Diptera, Simuliidae, Cnephia)

1969 ◽  
Vol 47 (1) ◽  
pp. 115-119 ◽  
Author(s):  
D. P. Madahar
Keyword(s):  
Salivary Gland ◽  
North American ◽  
Nucleolar Organizer ◽  
Close Relation ◽  
Standard Sequence ◽  
Y Chromosomes ◽  
Chromosome Ii ◽  
Chromosome I

The salivary gland chromosomes are described for seven taxa in the subgenus Stegopterna Enderlein of Cnephia Enderlein. All taxa have the typical blackfly complement with n = 3. The widely distributed North American Cnephia mutata Malloch has the nucleolar organizer in IL and the standard sequence in IS. All other taxa display a shift of the nucleolus to IS and homozygosity for the inversion IS-1. The Scandinavian C. richteri Enderlein apparently exhibits no further changes, the northern North American C. emergens Stone is characterized by the additional inversions, IS-2, IIIS-1, IIIL-1. The remaining four taxa, designated here as C. "Y", C. "X", C. "O", C. "W" are western North American, presumably undescribed and close to C. mutata. Their close relation to one another is indicated by the sharing of some inversion polymorphisms. They differ in certain floating autosomal inversions, and C. "O" and C. "W" in having distinctive and complex Y-chromosomes, based on chromosome I (C. "O") or chromosome II (C. "W"). A diagram illustrating the cytophylogenetic relations of the seven taxa is presented.

THE SALIVARY GLAND CHROMOSOMES OF THREE NORTH AMERICAN SPECIES OF TWINNIA (DIPTERA: SIMULIIDAE)

1966 ◽  
Vol 44 (5) ◽  
pp. 937-943 ◽  
Author(s):  
K. Rothfels ◽  
Margaret Freeman
Keyword(s):  
Salivary Gland ◽  
North American ◽  
North American Species ◽  
Centromere Region ◽  
Standard Sequence ◽  
Chromosome Iii

The salivary gland chromosomes of the three known North American species of Twinnia Stone and Jamnback are described, and compared with those of Prosimulium Roubaud. Twinnia tibblesi S. and J. has the standard arm association and the standard sequence in IS, II, IIIL. It differs from standard in inversions IL-1, IIIS-2,3, and a repatterning of the centromere region of chromosome III. Twinnia nova (Dyar and Shannon) and T. biclavata Shewell share these T. tibblesi traits and, in addition, have, in common, inversion IIIL-1 and a whole arm interchange giving the combinations IIL, IIIL and IIS, IIIS. Twinnia biclavata differs from T. nova by inversion IS-1 and a nucleolar shift. Both are good species. Evidence is presented that Twinnia is phylogenetically intermediate between Gymnopais Stone and the subgenus Helodon Enderlein of Prosimulium.

Pattern of X-Y chromosome pairing in the Taiwan vole, Microtus kikuchii

Genome ◽  
2001 ◽  
Vol 44 (1) ◽  
pp. 27-31 ◽  
Author(s):  
K Mekada ◽  
M Harada ◽  
L K Lin ◽  
K Koyasu ◽  
P M Borodin ◽  
...  
Keyword(s):  
Synaptonemal Complex ◽  
Chromosome Pairing ◽  
Sex Chromosomes ◽  
Meiotic Prophase ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
The Other ◽  
Banding Patterns ◽  
Y Chromosomes

Pairing of X and Y chromosomes at meiotic prophase and the G- and C-banding patterns and nucleolar organizer region (NOR) distribution were analyzed in Microtus kikuchii. M. kikuchii is closely related to M. oeconomus and M. montebelli, karyologically and systematically. The formation of a synaptonemal complex between the X and Y chromosomes at pachytene and end-to-end association at diakinesis – metaphase I are only observed in three species in the genus Microtus; M. kikuchii, M. oeconomus, and M. montebelli. All the other species that have been studied so far have had asynaptic X–Y chromosomes. These data confirm that M. kikuchii, M. oeconomus, and M. montebelli are very closely related, and support the separation of asynaptic and synaptic groups on the phylogenetic tree.Key words: Microtus kikuchii, Microtus phylogeny, karyotype, synaptic sex chromosomes, synaptonemal complex.

scholarly journals MULTIPLE GENE SITES FOR 5S AND 18 + 28S RNA ON CHROMOSOMES OF GLYPTOTENDIPES BARBIPES (STAEGER)

1974 ◽  
Vol 62 (1) ◽  
pp. 132-144 ◽  
Author(s):  
Wu-Nan Wen ◽  
Pedro E. León ◽  
Donald R. Hague
Keyword(s):  
Drosophila Melanogaster ◽  
Salivary Gland ◽  
Nucleolar Organizer ◽  
Balbiani Ring ◽  
5S Rna ◽  
Multiple Gene ◽  
Main Site ◽  
Chromosome Iii ◽  
The Right

Ribosomal RNAs (28 + 18S and 5S) and 4S RNA extracted from the chironomid Glyptotendipes barbipes were iodinated in vitro with 125I and hybridized to the salivary gland chromosomes of G. barbipes and Drosophila melanogaster. Iodinated 18 + 28 S RNA labeled three puffed sites with associated nucleoli on chromosomes IR, IIL, and IIIL of G. barbipes and the nucleolar organizer of Drosophila. Labeled 5S RNA hybridized to three sites on chromosome IIIR, two sites on chromosome IIR and one site in a Balbiani ring on chromosome IV of Glyptotendipes. Most of the label produced by this RNA was localized seven bands away from the centromere on the right arm of chromosome III, and we consider this to be the main site complementary to 5S RNA in the chironomid. This same RNA preparation specifically labeled the 56 EF region of chromosome IIR of Drosophila which has been shown previously to be the only site labeled when hybridized with homologous 5S RNA. Hybridization of G. barbipes chromosomes with iodinated 4S RNA produced no clearly localized labeled sites over the exposure periods studied.

Polytene chromosomes of Simulium (Psaroniocompsa) daltanhani (Diptera: Simuliidae) from Central Amazonia, Brazil

Zootaxa ◽  
2008 ◽  
Vol 1676 (1) ◽  
pp. 57 ◽  
Author(s):  
NEUSA HAMADA ◽  
ELENY DA SILVA PEREIRA ◽  
PETER H. ADLER
Keyword(s):  
Banding Pattern ◽  
Polytene Chromosomes ◽  
Nucleolar Organizer ◽  
Species Group ◽  
Chromosomal Complement ◽  
Central Amazonia ◽  
Similar Banding Pattern ◽  
Chromosome I

Last-instar larvae of Simulium (Psaroniocompsa) daltanhani Hamada and Adler from a stream in Central Amazonia were analyzed cytologically by mapping their polytene chromosomes. Simulium daltanhani has the nucleolar organizer in the short arm of chromosome I, heterogametic females, and an absence of autosomal polymorphisms. The chromosomes carry multiple rearrangements relative to other analyzed members of the S. quadrifidum species group in the subgenus Psaroniocompsa. One-third of the chromosomal complement is rearranged relative to the sequence of S. ulyssesi, the species with the most similar banding pattern among studied members of the S. quadrifidum group.

Localization of the nucleolar organizer and heterochromatin evolution in three European brown frogs: Rana dalmatina, Rana graeca, Rana iberica

1989 ◽  
Vol 10 (4) ◽  
pp. 387-396 ◽  
Author(s):  
Gaetano Odierna
Keyword(s):  
Genome Size ◽  
North American ◽  
Constitutive Heterochromatin ◽  
Nucleolar Organizer ◽  
Frog Species ◽  
Brown Frog ◽  
Rana Dalmatina

AbstractThis study investigates the karyotypes, genome sizc, constitutive heterochromatin, and NOR localization in three European brown frog species: Rana iberica, R. dalmatina and R. graeca. The three species all possess a karyotype of 26 chromosomes. The genome size is respectively 6.9, 9.7 and 11.3 pg/N in R. iberica, R. dalmatina and R. graeca. Constitutive heterochromatin is 1.7% in R. iberica, 3.1 % in R. dalmatina and 7.0% in R. graeca. The NOR is located on the long arm of the 10th chromosome in R. iberica and R. graeca, whereas it is pericentromerically localized on the short arm of the 3rd chromosome in R. dalmatina. A single NOR extrasite is found in R. graeca. Results suggest that European brown frogs have evolved independently from North American and Asian groups. Moreover, the variation observed in constitutive heterochromatin is informative of different amplification levels of satellite-like DNA. Data also suggest that in R. dalmatina NOR localization on the 3rd chromosome may be derivcd by amplification of a pre-existing NOR site.

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.

scholarly journals Sequence and expression divergence of an ancient duplication of the chaperonin groESEL operon in Vibrio species

Microbiology ◽  
2014 ◽  
Vol 160 (9) ◽  
pp. 1953-1963
Author(s):  
Nityananda Chowdhury ◽  
Joseph J. Kingston ◽  
W. Brian Whitaker ◽  
Megan R. Carpenter ◽  
Analuisa Cohen ◽  
...  
Keyword(s):  
Vibrio Vulnificus ◽  
Genomic Analysis ◽  
Duplication Event ◽  
Comparative Genomic ◽  
Human Pathogens ◽  
Additional Species ◽  
Evolutionary Advantage ◽  
Shock Proteins ◽  
Chromosome Ii ◽  
Chromosome I

Heat-shock proteins are molecular chaperones essential for protein folding, degradation and trafficking. The human pathogen Vibrio vulnificus encodes a copy of the groESEL operon in both chromosomes and these genes share <80 % similarity with each other. Comparative genomic analysis was used to determine whether this duplication is prevalent among Vibrionaceae specifically or Gammaproteobacteria in general. Among the Vibrionaceae complete genome sequences in the database (31 species), seven Vibrio species contained a copy of groESEL in each chromosome, including the human pathogens Vibrio cholerae, Vibrio parahaemolyticus and V. vulnificus. Phylogenetic analysis of GroEL among the Gammaproteobacteria indicated that GroESEL-1 encoded in chromosome I was the ancestral copy and GroESEL-2 in chromosome II arose by an ancient gene duplication event. Interestingly, outside of the Vibrionaceae within the Gammaproteobacteria, groESEL chromosomal duplications were rare among the 296 genomes examined; only five additional species contained two or more copies. Examination of the expression pattern of groEL from V. vulnificus cells grown under different conditions revealed differential expression between the copies. The data demonstrate that groEL-1 was more highly expressed during growth in exponential phase than groEL-2 and a similar pattern was also found in both V. cholerae and V. parahaemolyticus. Overall these data suggest that retention of both copies of groESEL in Vibrio species may confer an evolutionary advantage.

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