Chiasmate meiosis in male black fly (Diptera: Simuliidae) larvae associated with mermithid infections (Nematoda: Mermithidae)

2008 ◽  
Vol 86 (10) ◽  
pp. 1198-1202 ◽  
Author(s):  
A. L. Sharp ◽  
F. F. Hunter
Keyword(s):  
Developmental Stage ◽  
Meiotic Chromosome ◽  
Gonad Development ◽  
Black Flies ◽  
Black Fly ◽  
Meiotic Chromosomes ◽  
Gonad Morphology ◽  
Late Instar ◽  
Early Instar

Mermithid nematodes (Nematoda: Mermithidae) parasitize larval, pupal, and adult black flies (Diptera: Simuliidae) and may result in the development of intersex adults, generally considered to be feminized males. Simuliid gonad morphology and meiotic chromosome condition were examined in both early-instar larvae and late-instar larvae (≈ pharate pupae) to determine the developmental stage at which mermithid-associated feminization was initiated. We found that feminization occurred in early-instar larvae prior to gill histoblast formation. Infected larvae were morphologically male (rounded testes present) or female (elongated ovaries present), with morphological males exhibiting either male (achiasmate) or female (chiasmate) meiotic chromosomes; morphological females only had chiasmate chromosomes. Mermithid infection can also inhibit simuliid gonad development completely.

ECOLOGY OF BLACK FLIES (DIPTERA: SIMULIIDAE) OF THE SOURIS RIVER, MANITOBA AS A BASIS FOR CONTROL STRATEGY

1981 ◽  
Vol 113 (3) ◽  
pp. 223-234 ◽  
Author(s):  
A. R. Westwood ◽  
R. A. Brust
Keyword(s):  
Control Program ◽  
Abundant Species ◽  
Pest Species ◽  
Black Flies ◽  
Black Fly ◽  
Simulium Vittatum ◽  
Late Instar ◽  
Simulium Decorum ◽  
Fly Control ◽  
Wire Cage

AbstractTen species of black flies were collected from the Souris River, Manitoba between April 1977 and October 1978. Adults of Simulium luggeri Nicholson and Mickel, Simulium meridionale Riley, Simulium venustum Say, Simulium verecundum Stone and Jamnback, and Simulium johannseni johannseni (Hart) were collected feeding on livestock and humans, and are well known pest species. Simulium vittatum Zetterstedt was the most abundant species, but was not a pest on man or domestic animals. Simulium tuberosum (Lundström) and Simulium johannseni duplex Shewell and Fredeen were the least abundant species. Simulium j. johannseni, S. j. duplex, S. venustum, S. verecundum, S. tuberosum, and Cnephia dacotensis (Dyar and Shannon) appeared to be univoltine species while S. luggeri, S. meridionale, Simulium decorum Walker, and S. vittatum were multivoltine in the Souris River.An evaluation of cone, plate, rope, and wire cage sampling devices for black fly larvae and pupae indicated that cone samplers provided a more representative sample for population assessment.In a black fly control program, of the Souris River, Manitoba two separate larvicide treatments in spring may be necessary. In the case of two treatments, the first should be aimed at late instar larvae of S. j. johannseni, S. venustum, and S. verecundum. Since the majority of S. luggeri and S. meridionale would be in the egg stage at this time, a second treatment, 10–14 days later, would be necessary to control late instar larvae of these species.

EFFECTS OF ALTOSID AND DIMILIN ON BLACK FLIES (DIPTERA: SIMULIIDAE): LABORATORY AND FIELD TESTS

1978 ◽  
Vol 110 (10) ◽  
pp. 1103-1110 ◽  
Author(s):  
A. B. McKague ◽  
R. B. Pridmore ◽  
P. M. Wood
Keyword(s):  
Maximum Concentration ◽  
Field Tests ◽  
Adult Emergence ◽  
Artificial Substrates ◽  
Submerged Vegetation ◽  
Black Flies ◽  
Small Stream ◽  
Black Fly ◽  
Late Instar ◽  
High Reduction

AbstractAdult emergence of Simulium verecundum S. and J. and S. decorum Walk. was reduced 58–94% by exposure of late instar larvae to 0.1 ppm Altosid or Altosid SR-10 for 1 h. Pupae were not affected by the presence of 0.1 ppm Altosid SR-10 in the rearing water. Adult emergence of S. verecundum was reduced 95% when mixed larval instars were reared in the presence of 0.001 ppm Dimilin. Last instar larvae died as a result of abnormal metamorphosis. Black fly mortality was 86–100% with 1-h exposures to 0 1–0.2 ppm Dimilin, and 100% with a 15-min exposure to 1 ppm at 22 ± 2 °C, lower temperatures giving similar results.Release of Altosid over a 48-h period from formulated blocks gave a concentration of 0.002–0.006 ppm in a small stream. Emergence of adults was completely suppressed for 23 days 18 m downstream and 17 days 43 m downstream. Applications of 1 ppm Dimilin for 15 min to two streams resulted in the gradual elimination of black fly larvae from artificial substrates, a high reduction in adult emergence, and the formation of abnormal larvae following the tests. The maximum concentration of Dimilin detected in the water was 0.31 ppm during application; however, submerged vegetation residues as high as 18.9 ppm were found 1 h following the second application, decreasing to less than 0.05 ppm 14 days later.

scholarly journals Molecular organization of mammalian meiotic chromosome axis revealed by expansion STORM microscopy

2019 ◽  
Vol 116 (37) ◽  
pp. 18423-18428 ◽  
Author(s):  
Huizhong Xu ◽  
Zhisong Tong ◽  
Qing Ye ◽  
Tengqian Sun ◽  
Zhenmin Hong ◽  
...  
Keyword(s):  
Meiotic Chromosome ◽  
Molecular Organization ◽  
Homologous Chromosomes ◽  
Meiotic Chromosomes ◽  
C Terminus ◽  
Stochastic Optical Reconstruction Microscopy ◽  
Optical Reconstruction ◽  
20 Nm ◽  
Chromosome Axis

During prophase I of meiosis, chromosomes become organized as loop arrays around the proteinaceous chromosome axis. As homologous chromosomes physically pair and recombine, the chromosome axis is integrated into the tripartite synaptonemal complex (SC) as this structure’s lateral elements (LEs). While the components of the mammalian chromosome axis/LE—including meiosis-specific cohesin complexes, the axial element proteins SYCP3 and SYCP2, and the HORMA domain proteins HORMAD1 and HORMAD2—are known, the molecular organization of these components within the axis is poorly understood. Here, using expansion microscopy coupled with 2-color stochastic optical reconstruction microscopy (STORM) imaging (ExSTORM), we address these issues in mouse spermatocytes at a resolution of 10 to 20 nm. Our data show that SYCP3 and the SYCP2 C terminus, which are known to form filaments in vitro, form a compact core around which cohesin complexes, HORMADs, and the N terminus of SYCP2 are arrayed. Overall, our study provides a detailed structural view of the meiotic chromosome axis, a key organizational and regulatory component of meiotic chromosomes.

Gonad morphology and gametogenesis in the deep-sea jellyfish Atolla wyvillei and Periphylla periphylla (Scyphozoa: Coronatae) collected from Cape Hatteras and the Gulf of Mexico

2009 ◽  
Vol 90 (6) ◽  
pp. 1095-1104 ◽  
Author(s):  
Cathy H. Lucas ◽  
Adam J. Reed
Keyword(s):  
Gulf Of Mexico ◽  
Gonad Development ◽  
Bell Diameter ◽  
Western Atlantic ◽  
Gonad Morphology ◽  
Time Period ◽  
Cape Hatteras ◽  
Literature Evidence ◽  
Long Time ◽  
North Western

Observations on gonad morphology and the structure of ovaries and testes of the coronate scyphozoans Atolla wyvillei and Periphylla periphylla are described based on samples collected from the Gulf of Mexico and Cape Hatteras (north-western Atlantic). In A. wyvillei, gonads of distinguishable sex were observed in medusae as small as 17 mm bell diameter (BD). Spermatogenesis occurred within follicles (average 366 × 254 μm) that were evenly distributed throughout the gonad. Oocytes in different stages of development were observed in all the females with gonads. Oocytes arise from the gastrodermis and migrate into the mesoglea to develop from early-mid to late vitellogenic oocytes characterized by a large nucleus and granular (organic-rich) cytoplasm. The largest oocytes measured were 543 μm and 263 μm from the Gulf of Mexico and Cape Hatteras respectively. Possible reasons for this difference are discussed. In P. periphylla gonads were also initially observed in medusae 17 mm BD, although not all larger medusae had obvious gonads. Unlike A. wyvillei sperm follicles were arranged in long convoluted rows normally only one follicle thick. The organization of ooytes in female P. periphylla was very similar to A. wyvillei, although the gonads were small and the number of oocytes present in each gonad very low (<22). The largest oocyte measured was 777 μm in a 53 mm BD medusa. Although medusae were collected from one time period only (September) in this study, our findings appear to be in agreement with literature evidence indicating that coronate jellyfish produce few eggs continuously over a long time period. Aspects of gonad development and gametogenesis are discussed with respect to potential differences in site productivity and species identification.

scholarly journals Evaluation of Partially Submerged Sticky Traps On Lake Spillways For Adult Black Fly (Diptera: Simuliidae) Surveillance and Arbovirus Detection

2018 ◽  
Vol 34 (4) ◽  
pp. 306-310
Author(s):  
Michael C. Cavallaro ◽  
Eric Risley ◽  
Paige Lockburner
Keyword(s):  
Adult Female ◽  
Rural Areas ◽  
Surveillance Systems ◽  
Black Flies ◽  
Culex Mosquito ◽  
Sticky Traps ◽  
Black Fly ◽  
Equine Encephalitis Virus ◽  
Simulium Decorum ◽  
Average Standard Error

ABSTRACT Sentinel surveillance systems demonstrate an improved ability to supplement monitoring data and anticipate arbovirus outbreaks (i.e., sentinel avian species). Management complications can arise during unpredictable or unseasonal disease detections, especially in rural areas where resident distribution is patchy. Using spillways near residential lake communities as static surveillance locations, we tested a novel partially submerged sticky trapping technique and screened wild populations of adult female black flies (Diptera: Simuliidae) for West Nile virus (WNV) and eastern equine encephalitis virus (EEEV). Trap site selection criteria considered the density of immature black fly colonization on spillway surfaces and the number of positive detections of arboviral targets in nearby Culex mosquito populations. On average (±standard error), sticky traps captured 134 (±33) adult black flies over a 24-h period, with 1 trap capturing as many as 735 individuals. Although we detected positive cases of WNV from 20 Culex mosquito trapping sites within 16 km (approx. flight radius) of the selected lake spillways, mixed pools of adult female Simulium vittatum complex and Simulium decorum were all negative for both arboviruses. This study yielded an application for partially submerged sticky traps to collect adult female black flies. Its potential uses for monitoring the infection rates of more well-documented Simulium parasites are discussed.

scholarly journals Surveillance along the Rio Grande during the 2020 Vesicular Stomatitis Outbreak Reveals Spatio-Temporal Dynamics of and Viral RNA Detection in Black Flies

Pathogens ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1264
Author(s):  
Katherine I. Young ◽  
Federico Valdez ◽  
Christina Vaquera ◽  
Carlos Campos ◽  
Lawrence Zhou ◽  
...  
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Temporal Dynamics ◽  
Rio Grande ◽  
Maximum Temperature ◽  
Black Flies ◽  
Southern Mexico ◽  
Black Fly ◽  
The Usa ◽  
Vesicular Stomatitis

Vesicular stomatitis virus (VSV) emerges periodically from its focus of endemic transmission in southern Mexico to cause epizootics in livestock in the US. The ecology of VSV involves a diverse, but largely undefined, repertoire of potential reservoir hosts and invertebrate vectors. As part of a larger program to decipher VSV transmission, we conducted a study of the spatiotemporal dynamics of Simulium black flies, a known vector of VSV, along the Rio Grande in southern New Mexico, USA from March to December 2020. Serendipitously, the index case of VSV-Indiana (VSIV) in the USA in 2020 occurred at a central point of our study. Black flies appeared soon after the release of the Rio Grande’s water from an upstream dam in March 2020. Two-month and one-year lagged precipitation, maximum temperature, and vegetation greenness, measured as Normalized Difference Vegetation Index (NDVI), were associated with increased black fly abundance. We detected VSIV RNA in 11 pools comprising five black fly species using rRT-PCR; five pools yielded a VSIV sequence. To our knowledge, this is the first detection of VSV in the western US from vectors that were not collected on premises with infected domestic animals.

Host–Parasite Behavioral Interactions in a Recently Introduced, Whooping Crane Population

2015 ◽  
Vol 6 (1) ◽  
pp. 220-226 ◽  
Author(s):  
Richard S. King ◽  
Patrick C. McKann ◽  
Brian R. Gray ◽  
Michael S. Putnam
Keyword(s):  
Reproductive Performance ◽  
Black Flies ◽  
Behavioral Differences ◽  
Whooping Crane ◽  
Black Fly ◽  
Grus Canadensis ◽  
Sandhill Crane ◽  
Conservation History ◽  
Whooping Cranes ◽  
Sandhill Cranes

Abstract The whooping crane Grus americana has a long conservation history, but despite multiple attempts across North America, introduction success is lacking. Recently introduced, captively reared whooping cranes have had periods of poor reproductive performance in central Wisconsin that sometimes coincided with black fly (Diptera: Simuliidae) emergences. Sandhill crane Grus canadensis reproductive performance in central Wisconsin is approximately double that of whooping cranes. We used comfort behaviors as a measure of black fly harassment to infer whether behavioral differences existed between nesting sandhill cranes and nesting whooping cranes and between successful and unsuccessful whooping crane pairs. To further explore the interaction between black flies and incubating whooping cranes, we examined differences in behaviors between incubating birds and their off-nest mates. Compared to their off-nest mates, incubating whooping cranes exhibited elevated comfort behaviors, suggesting a bird at a nest may experience greater harassment from black flies. Sandhill cranes had elevated head-flicks over whooping cranes. Whooping cranes exhibited more head-rubs than sandhill cranes, and successful whooping crane pairs had elevated head-rubs over pairs that deserted their nests. Behavioral differences between sandhill cranes and whooping cranes as well as differences in reproductive performance, could be explained by exposure to local breeding conditions. Whereas sandhill cranes have nested in the area for hundreds, if not thousands, of years, whooping cranes were only recently introduced to the area. Behavioral differences between the species as well as those between successful and unsuccessful whooping crane pairs could also be explained by the effect of captive exposure, which could affect all whooping crane introductions.

scholarly journals A molecular model for the role of SYCP3 in meiotic chromosome organisation

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Johanna Liinamaria Syrjänen ◽  
Luca Pellegrini ◽  
Owen Richard Davies
Keyword(s):  
Molecular Model ◽  
Meiotic Chromosome ◽  
Lateral Element ◽  
Homologous Chromosomes ◽  
Meiotic Chromosomes ◽  
Double Stranded Dna ◽  
Evolutionarily Conserved ◽  
20 Nm ◽  
Chromosome Organisation

The synaptonemal complex (SC) is an evolutionarily-conserved protein assembly that holds together homologous chromosomes during prophase of the first meiotic division. Whilst essential for meiosis and fertility, the molecular structure of the SC has proved resistant to elucidation. The SC protein SYCP3 has a crucial but poorly understood role in establishing the architecture of the meiotic chromosome. Here we show that human SYCP3 forms a highly-elongated helical tetramer of 20 nm length. N-terminal sequences extending from each end of the rod-like structure bind double-stranded DNA, enabling SYCP3 to link distant sites along the sister chromatid. We further find that SYCP3 self-assembles into regular filamentous structures that resemble the known morphology of the SC lateral element. Together, our data form the basis for a model in which SYCP3 binding and assembly on meiotic chromosomes leads to their organisation into compact structures compatible with recombination and crossover formation.

scholarly journals Localization of RAP1 and topoisomerase II in nuclei and meiotic chromosomes of yeast

1992 ◽  
Vol 117 (5) ◽  
pp. 935-948 ◽  
Author(s):  
F Klein ◽  
T Laroche ◽  
ME Cardenas ◽  
JF Hofmann ◽  
D Schweizer ◽  
...  
Keyword(s):  
Topoisomerase Ii ◽  
Meiotic Chromosome ◽  
Nuclear Periphery ◽  
Yeast Cells ◽  
Activator Protein 1 ◽  
Interphase Nuclei ◽  
Telomeric Sequences ◽  
Meiotic Chromosomes ◽  
Punctate Staining

Topoisomerase II (topoII) and RAP1 (Repressor Activator Protein 1) are two abundant nuclear proteins with proposed structural roles in the higher-order organization of chromosomes. Both proteins co-fractionate as components of nuclear scaffolds from vegetatively growing yeast cells, and both proteins are present as components of pachytene chromosome, co-fractionating with an insoluble subfraction of meiotic nuclei. Immunolocalization using antibodies specific for topoII shows staining of an axial core of the yeast meiotic chromosome, extending the length of the synaptonemal complex. RAP1, on the other hand, is located at the ends of the paired bivalent chromosomes, consistent with its ability to bind telomeric sequences in vitro. In interphase nuclei, again in contrast to anti-topoII, anti-RAP1 gives a distinctly punctate staining that is located primarily at the nuclear periphery. Approximately 16 brightly staining foci can be identified in a diploid nucleus stained with anti-RAP1 antibodies, suggesting that telomeres are grouped together, perhaps through interaction with the nuclear envelope.

scholarly journals Society Islands beach bum black flies (Diptera: Simuliidae) 

Zootaxa ◽  
2017 ◽  
Vol 4311 (3) ◽  
pp. 373
Author(s):  
DOUGLAS A. CRAIG ◽  
NEAL L. EVENHUIS
Keyword(s):  
The Body ◽  
Western Pacific ◽  
Immature Stages ◽  
Black Flies ◽  
Black Fly ◽  
Society Islands

Aspects of the body of work on the Central and Western Pacific black fly Simulium (Inseliellum) are briefly reviewed. Female adults collected from beaches in Tahiti and Raiatea are described as Simulium (Inseliellum) littopyga n. sp., Simulium (Inseliellum) littosocius n. sp. and Simulium (Inseliellum) littosodalis n. sp.. Immature stages of the three species are not associated. 

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