Cytotaxonomy of the Simulium damnosum complex from central and northeastern Tanzania

Genome ◽  
1993 ◽  
Vol 36 (1) ◽  
pp. 112-130 ◽  
Author(s):  
William S. Procunier ◽  
Abraham I. S. Muro
Keyword(s):  
Sibling Species ◽  
Polytene Chromosomes ◽  
Malpighian Tubule ◽  
Taxonomic Status ◽  
Insect Vector ◽  
Simulium Damnosum ◽  
Species Complexes ◽  
Salivary Gland Polytene Chromosome ◽  
Larval Salivary Gland ◽  
Population Substructuring

A cytotaxonomic study of the medically important insect vector, Simulium damnosum s.l., revealed the presence of seven and possibly eight distinct taxa from central and northeastern Tanzania. Larval salivary gland polytene chromosome maps are presented for the first time for five cytotypes and one sibling species, which include the Nkusi form, the Sanje form, the Kisiwani form, Ketaketa C1 and C2, and the Kibwezi form. Inversion disequilibrium in males of the Kibwezi form indicate population substructuring is occurring and that this population may be in the early stages of speciation. Adults of the sibling species S. damnosum Kibwezi form and cytotype of the S. damnosum Nkusi form were identified using Malpighian tubule polytene chromosomes. The taxonomic status of the populations under study are discussed in relation to previously published papers and unpublished reports. Dimorphisms for centromere band enhancement occur on all three polytene chromosomes of the complement. The same centromere band can be polymorphic, sex linked, fixed, or lost in various cytotypes. In constructing a partial phylogeny, a hypothetical intermediate is proposed to account for the diverse fate of these centromere band dimorphisms and other inversion polymorphisms in different members of this nearly pan African complex. This pattern of chromosome restructuring is consistent with that seen for other species complexes within the Simuliidae.Key words: Simulium damnosum complex, Tanzania, cytotaxonomy, phylogenetics, and vector biology.

A cytotaxonomic investigation of seven species in the Eusimulium vernum group (Diptera: Simuliidae)

1986 ◽  
Vol 64 (2) ◽  
pp. 296-311 ◽  
Author(s):  
Fiona F. Hunter ◽  
Victoria Connolly
Keyword(s):  
Sibling Species ◽  
North American ◽  
Banding Pattern ◽  
Polytene Chromosomes ◽  
The Other ◽  
Undescribed Species ◽  
Species Complexes

Using the banding pattern of Eusimulium vernum (Macquart) as a standard, the polytene chromosomes of seven North American members of the vernum group are described. These are Eusimulium aestivum (Davies, Peterson, and Wood), E. impar (Davies, Peterson, and Wood), E. gouldingi (Stone), E. croxtoni (Nickolson and Mickel), E. pugetense Dyar and Shannon, E. quebecense (Twinn), and an undescribed species provisionally designated Simulium sp. near furculatum/croxtoni. Two of these species, pugetense and quebecense, apparently are sibling species complexes. An inversion cladogram separates the seven species into two distinct lineages; aestivum, impar, pugetense, and quebecense belong to one and gouldingi, croxtoni, and Simulium sp. to the other.

Genetic Analysis of the Drosophila 63F Early Puff: Characterization of Mutations in E63-1 and maggie, a Putative Tom22

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 229-244
Author(s):  
Martina Vaskova ◽  
A M Bentley ◽  
Samantha Marshall ◽  
Pamela Reid ◽  
Carl S Thummel ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Genetic Analysis ◽  
Polytene Chromosomes ◽  
Reading Frame ◽  
Protein Levels ◽  
Ef Hand ◽  
Larval Salivary Gland ◽  
Complementation Groups ◽  
Inducible Genes ◽  
Early Puff

Abstract The 63F early puff in the larval salivary gland polytene chromosomes contains the divergently transcribed E63-1 and E63-2 ecdysone-inducible genes. E63-1 encodes a member of the EF-hand family of Ca2+-binding proteins, while E63-2 has no apparent open reading frame. To understand the functions of the E63 genes, we have determined the temporal and spatial patterns of E63-1 protein expression, as well as undertaken a genetic analysis of the 63F puff. We show that E63-1 is expressed in many embryonic and larval tissues, but the third-instar larval salivary gland is the only tissue where increases in protein levels correlate with increases in ecdysone titer. Furthermore, the subcellular distribution of E63-1 protein changes dynamically in the salivary glands at the onset of metamorphosis. E63-1 and E63-2 null mutations, however, have no effect on development or fertility. We have characterized 40 kb of the 63F region, defined as the interval between Ubi-p and E63-2, and have identified three lethal complementation groups that correspond to the dSc-2, ida, and mge genes. We show that mge mutations lead to first-instar larval lethality and that Mge protein is similar to the Tom22 mitochondrial import proteins of fungi, suggesting that it has a role in mitochondrial function.

A modification of Heidenhain's iron-haematoxylin technique, as used to stain smears of Drosophila larval polytene chromosomes and neuroblast cells

1971 ◽  
Vol 49 (1) ◽  
pp. 132-133 ◽  
Author(s):  
Albert E. Moorman
Keyword(s):  
Acetic Acid ◽  
Salivary Gland ◽  
Methyl Alcohol ◽  
Polytene Chromosomes ◽  
Larval Salivary Gland

Acetic-acid-fixed smears of Drosophila larval salivary gland chromosomes and of neuroblast cells from the larval ganglion undergoing mitosis are prepared by a modification of Heidenhain's iron-haematoxylin technique, in which absolute methyl alcohol is the solvent of all reagents used in the staining process.

p75, a polypeptide component of karyoskeletal protein-enriched fractions associated with transcriptionally active loci of Drosophila melanogaster polytene chromosomes

1988 ◽  
Vol 8 (5) ◽  
pp. 1877-1886
Author(s):  
B M Benton ◽  
S Berrios ◽  
P A Fisher
Keyword(s):  
Tissue Culture ◽  
Drosophila Melanogaster ◽  
Transcriptional Regulation ◽  
Salivary Gland ◽  
Indirect Immunofluorescence ◽  
Polytene Chromosomes ◽  
Nuclear Interior ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Larval Salivary Gland

A 75-kilodalton polypeptide has been identified which copurifies with karyoskeletal protein-enriched fractions prepared from Drosophila melanogaster embryos. Results of indirect immunofluorescence experiments suggest that this protein, here designated p75, is primarily associated with puffed regions of larval salivary gland polytene chromosomes. In nonpolytenized Schneider 2 tissue culture cells, p75 appeared to be localized throughout the nuclear interior during interphase. In mitotic cells, p75 was redistributed diffusely. A possible role for karyoskeletal elements in transcriptional regulation is discussed.

scholarly journals Molecular forms of Anopheles subpictus and Anopheles sundaicus in the Indian subcontinent

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Ankita Sindhania ◽  
Manoj K. Das ◽  
Gunjan Sharma ◽  
Sinnathamby N. Surendran ◽  
B. R. Kaushal ◽  
...  
Keyword(s):  
Sibling Species ◽  
Molecular Form ◽  
Indian Subcontinent ◽  
Phylogenetic Analyses ◽  
Coastal Areas ◽  
Molecular Forms ◽  
Nominal Species ◽  
Anopheles Subpictus ◽  
Species Complexes ◽  
Molecular Phylogenetic

Abstract Background Anopheles subpictus and Anopheles sundaicus are closely related species, each comprising several sibling species. Ambiguities exist in the classification of these two nominal species and the specific status of members of these species complexes. Identifying fixed molecular forms and mapping their spatial distribution will help in resolving the taxonomic ambiguities and understanding their relative epidemiological significance. Methods DNA sequencing of Internal Transcribed Spacer-2 (ITS2), 28S-rDNA (D1-to-D3 domains) and cytochrome oxidase-II (COII) of morphologically identified specimens of two nominal species, An. subpictus sensu lato (s.l.) and An. sundaicus s.l., collected from the Indian subcontinent, was performed and subjected to genetic distance and molecular phylogenetic analyses. Results Molecular characterization of mosquitoes for rDNA revealed the presence of two molecular forms of An. sundaicus s.l. and three molecular forms of An. subpictus s.l. (provisionally designated as Form A, B and C) in the Indian subcontinent. Phylogenetic analyses revealed two distinct clades: (i) subpictus clade, with a single molecular form of An. subpictus (Form A) prevalent in mainland India and Sri Lanka, and (ii) sundaicus clade, comprising of members of Sundaicus Complex, two molecular forms of An. subpictus s.l. (Form B and C), prevalent in coastal areas or islands in Indian subcontinent, and molecular forms of An. subpictus s.l. reported from Thailand and Indonesia. Based on the number of float-ridges on eggs, all An. subpictus molecular Form B were classified as Species B whereas majority (80%) of the molecular Form A were classified as sibling species C. Fixed intragenomic sequence variation in ITS2 with the presence of two haplotypes was found in molecular Form A throughout its distribution. Conclusion A total of three molecular forms of An. subpictus s.l. and two molecular forms of An. sundaicus s.l. were recorded in the Indian subcontinent. Phylogenetically, two forms of An. subpictus s.l. (Form B and C) prevalent in coastal areas or islands in the Indian subcontinent and molecular forms reported from Southeast Asia are members of Sundaicus Complex. Molecular Form A of An. subpictus is distantly related to all other forms and deserve a distinct specific status.

Cytogenetic analysis of Malpighian tubule polytene chromosomes of Culex pipiens (Diptera: Culicidae)

Genome ◽  
1998 ◽  
Vol 41 (6) ◽  
pp. 751-755 ◽  
Author(s):  
Anna Zambetaki ◽  
Nicole Pasteur ◽  
Penelope Mavragani-Tsipidou
Keyword(s):  
Culex Pipiens ◽  
Polytene Chromosomes ◽  
Malpighian Tubule ◽  
Malpighian Tubules ◽  
Molecular Cytogenetic ◽  
Routine Basis ◽  
Weak Points ◽  
Chromosome Maps ◽  
Global Vector ◽  
Polytene Nuclei

A simple technique is described for obtaining well-spread and readable Malpighian tubule polytene nuclei of Culex pipiens on a routine basis. Detailed polytene chromosome maps are presented with a description of the most prominent landmarks of each chromosome, the regions with asynapsis and the most frequent weak points identified in the polytene arms. Usable Malpighian tubule polytene chromosomes should facilitate molecular cytogenetic, genetic, and potentially biosystematic studies on this medically important global vector of viral inducing encephalitis.Key words: Culex pipiens, polytene chromosomes, Malpighian tubules, banding pattern, photomap.

Biological Evidence of Sibling Species in Aphytis maculicornis (Masi). (Hymenoptera, Aphelinidae)

1954 ◽  
Vol 86 (2) ◽  
pp. 90-96 ◽  
Author(s):  
Mostafa Hafez ◽  
Richard L. Doutt
Keyword(s):  
Biological Control ◽  
Sibling Species ◽  
Applied Field ◽  
Recent Literature ◽  
Taxonomic Status ◽  
Biological Characteristics ◽  
Actual Practice ◽  
Taxonomic Identification ◽  
Biological Aspects ◽  
Control Work

In biological control work an early taxonomic identification of imported entomophagous species is helpful but not essential, for in this applied field of entomology the behaviour and biological characteristics of species are held paramount to their taxonomic status. In actual practice it frequently happens that a species is imported, tested, colonized, and established before its specific taxonomic identity is conclusively determined. Examples exist in recent literature where one may find references to such insects designated as “Aphytis X”, “Waikane Opius”, etc. While this situation is not altogether comfortable to the worker in biolngical control it arises as a natural conseqnence of the initial and necessary concentration on the ecological and biological aspects of insect groups. It is particularly intensified by the fact that many parasitic groups are still poorly understood taxonomically.

Deforestation: effects on vector-borne disease

Parasitology ◽  
1993 ◽  
Vol 106 (S1) ◽  
pp. S55-S75 ◽  
Author(s):  
J. F. Walsh ◽  
D. H. Molyneux ◽  
M. H. Birley
Keyword(s):  
South America ◽  
West Africa ◽  
Anopheles Gambiae ◽  
South East Asia ◽  
Vector Ecology ◽  
Disease Patterns ◽  
Simulium Damnosum ◽  
Species Complexes ◽  
Vector Borne ◽  
Reservoir Hosts

SUMMARYThis review addresses' changes in the ecology of vectors and epidemiology of vector-borne diseases which result from deforestation. Selected examples are considered from viral and parasitic infections (arboviruses, malaria, the leishmaniases, nlariases, Chagas Disease and schistosomiasis) where disease patterns have been directly or indirectly influenced by loss of natural tropical forests. A wide range of activities have resulted in deforestation. These include colonisation and settlement, transmigrant programmes, logging, agricultural activities to provide for cash crops, mining, hydropower development and fuelwood collection. Each activity influences the prevalence, incidence and distribution of vector-borne disease. Three main regions are considered – South America, West & Central Africa and South-East Asia. In each, documented changes in vector ecology and behaviour and disease pattern have occurred. Such changes result from human activity at the forest interface and within the forest. They include both deforestation and reafforestation programmes. Deforestation, or activities associated with it, have produced new habitats for Anopheles darlingi mosquitoes and have caused malaria epidemics in South America. The different species complexes in South-East Asia (A. dirus, A. minimus, A. balabacensis) have been affected in different ways by forest clearance with different impacts on malaria incidence. The ability of zoophilic vectors to adapt to human blood as an alternative source of food and to become associated with human dwellings (peridomestic behaviour) have influenced the distribution of the leishmaniases in South America. Certain species of sandflies (Lutzomyia intermedia, Lu. longipalpis, Lu. whitmani), which were originally zoophilic and sylvatic, have adapted to feeding on humans in peridomestic and even periurban situations. The changes in behaviour of reservoir hosts and the ability of pathogens to adapt to new reservoir hosts in the newly-created habitats also influence the patterns of disease. In anthroponotic infections, such as Plasmodium, Onchocerca and Wuchereria, changes in disease patterns and vector ecology may be more difficult to detect. Detailed knowledge of vector species and species complexes is needed in relation to changing climate associated with deforestation. The distributions of the Anopheles gambiae and Simulium damnosum species complexes in West Africa are examples. There have been detailed longitudinal studies of Anopheles gambiae populations in different ecological zones of West Africa. Studies on Simulium damnosum cytoforms (using chromosome identification methods) in the Onchocerciasis Control Programme were necessary to detect changes in distribution of species in relation to changed habitats. These examples underline the need for studies on the taxonomy of medically-important insects in parallel with long-term observations on changing habitats. In some circumstances, destruction of the forest has reduced or even removed disease transmission (e.g. S. neavei-transmitted Onchocerca in Kenya). Whilst the process of deforestation can be expected to continue, hopefully at a decreased rate, it is expected that unpredictable and sometimes rapid changes in disease patterns will pose problems for the public health services.

Population cytogenetic studies on Simulium feuerborni Edwards (Diptera: Simuliidae) from northern Thailand

Genome ◽  
1999 ◽  
Vol 42 (1) ◽  
pp. 80-86 ◽  
Author(s):  
Chaliow Kuvangkadilok ◽  
Suwannee Phayuhasena ◽  
Visut Baimai
Keyword(s):  
Polytene Chromosomes ◽  
Natural Populations ◽  
Gene Pools ◽  
Northern Thailand ◽  
Y Chromosomes ◽  
Larval Salivary Gland ◽  
Hardy Weinberg Equilibrium ◽  
Chiang Mai Province ◽  
Chromosome I ◽  
Paracentric Inversions

A standard photographic map of Simulium feuerborni (Diptera: Simuliidae) was constructed from larval salivary gland polytene chromosomes and is described herein. Analysis of polytene chromosomes was made from wild larvae collected from the four populations at Doi Inthanon National Park, Chiang Mai Province, northern Thailand. Simulium feuerborni has three pairs of chromosomes (2n = 6) which are arranged from the longest to the shortest. Chromosome I is metacentric while chromosomes II and III are submetacentric. A total of six simple paracentric inversions have been detected in these natural populations of S. feuerborni. These inversions (IS-1, IL-1, IIL-1, IIL-2, IIIS-1, IIIL-1) occurred in all chromosome arms except for the arm IIS. Significant deviation from Hardy-Weinberg equilibrium has been observed in inversion IIIL-1 at Hui Sai Luaeng suggesting the existence of two gene pools in this population. There is no indication of sex linkage associated with an inversion sequence in these populations. Thus, the X and Y chromosomes of S. feuerborni could not be recognized in this study.Key words: Simulium, polytene chromosome map, inversion polymorphisms

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