Composite eggs and Siamese twins in paedogenetic gall midges

Development ◽  
1972 ◽  
Vol 28 (3) ◽  
pp. 647-657
Author(s):  
Dirk F. Went ◽  
René Camenzind
Keyword(s):  
Gall Midge ◽  
Follicular Epithelium ◽  
Oocyte Nucleus ◽  
Gall Midges ◽  
Cell Complexes ◽  
Siamese Twins ◽  
Egg Chambers ◽  
Oocyte Stage ◽  
Nurse Chamber

Several types of composite eggs were found in two species of paedogenetic gall midges. One composite egg, consisting of two blastoderms, was cultured in vitro, and its development was recorded on film. Two other composite eggs were fixed in the oocyte stage; each contained two nurse chambers, two egg chambers and one oocyte nucleus. Some other ‘eggs’ are described, which consisted merely of a nurse chamber or of one or two oocytes and of the follicular epithelium. It is argued that the formation of composite eggs and incomplete eggs must be due to errors in the formation of the oocyte-nurse cell complexes. The article also describes three Siamese twins in larval stage which were found in two paedogenetic gall-midge species. In two twins the larvae were linked posterior–posterior, while in the third they were connected anterior–anterior. It is assumed that the Siamese twin-larvae evolved from composite eggs.

Two actions of juvenile hormone on the follicle cells of Rhodnius prolixus Stål

1975 ◽  
Vol 53 (8) ◽  
pp. 1187-1188 ◽  
Author(s):  
Randa Abu-Hakima ◽  
K. G. Davey
Keyword(s):  
Juvenile Hormone ◽  
Developmental Stages ◽  
Normal Animal ◽  
Rhodnius Prolixus ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Intercellular Spaces

The follicular epithelium of vitellogenic oocytes from allatectomized females of Rhodnius fails to develop large intercellular spaces when exposed to juvenile hormone (JH) in vitro. This suggests that in the normal animal, the follicle cells require JH at two developmental stages. Differentiation of the cells in the presence of JH represents one requirement, and only those cells which have undergone this initial priming are fully competent to exhibit the second response, the development of intercellular spaces.

scholarly journals MicroRNA regulation of CTP synthase and cytoophidium in Drosophila melanogaster

2018 ◽  
Author(s):  
Najat Dzaki ◽  
Woo Wai Kan ◽  
Ghows Azzam
Keyword(s):  
De Novo ◽  
Mirna Gene ◽  
Target Prediction ◽  
Metabolic Enzyme ◽  
Gene Count ◽  
Micro Rnas ◽  
Egg Chambers ◽  
Regulatory Effects ◽  
Qpcr Quantification

AbstractCTPsyn is a crucial metabolic enzyme which synthesizes CTP molecules through the de novo or salvage pathway. It has the extraordinary ability to compartmentalize into filaments termed cytoophidia. Although this property is retained amongst orthologues, and cytoophidia are therefore found across kingdoms, the mechanisms behind their formation remain unknown. Micro-RNAs (miRNAs) are single-stranded RNA with length of 20 – 22 nucleotides, capable of exerting mRNA silencing and degradation as a form of regulation. D. melanogaster itself has a high total gene count to miRNA gene number ratio, alluding to the possibility that CTPsyn may too come under the regulatory effects of these small RNAs. A thorough miRNA overexpression involving 123 UAS-miRNA lines, followed by staining of ovarian cytoophidia dme-egg chambers, revealed a small group of candidates which confer either a lengthening or truncating effect on the structure. Prime candidates are identified on the basis of consistency. MiR-975 and miR-1014 are both cytoophidia-elongating, whereas miR-190 and miR-932 are cytoophidia-shortening. Though target prediction shows that miR-975 and miR-932 do indeed have binding sites on CTPsyn mRNA, in vitro assays instead revealed that none of the four candidates may actually do so. This suggests that the effects asserted by overexpressed miRNAs indirectly reach CTPsyn and its cytoophidia through the actions of middling elements. In silico target prediction and qPCR quantification indicated that, at least for miR-932 and miR-1014, these undetermined elements may be players in fat metabolism. This is the first study to thoroughly investigate miRNAs in connection to CTPsyn expression and activity in any species. The findings presented could serve as a basis for further queries into not only the fundamental aspects of the enzyme’s regulation, but may uncover new facets of closely related pathways as well.

scholarly journals Cecidomyiidae (Diptera, Insecta): richness of species and distribution in Brazil

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Valéria Cid Maia
Keyword(s):  
Plant Species ◽  
Atlantic Forest ◽  
Gall Midge ◽  
The Other ◽  
Amazon Forest ◽  
Gall Midges ◽  
Species Origin ◽  
Neotropical Species ◽  
Fauna Composition ◽  
Almost All

Abstract: Most Neotropical species of Cecidomyiidae (Diptera) have been described from Brazil, but a list of species with occurrence in the country has never been published. Little is known about their distribution and richness in the Brazilian phytogeographic domains. Additionally, a list of host plant species has never been gathered. The present study aims to fill these knowledge gaps and provides an overview of this family in Brazil. For this, data were obtained mainly from the literature, but also from the Cecidomyiidae collection of Museu Nacional and two herbaria (RB and R). Based on the site "Flora do Brasil 2020", botanical names were updated and plant species origin and distribution were verified. A total of 265 gall midge species have been recorded in Brazil, most from the Atlantic Forest (183), followed by Cerrado (60), and Amazon Forest (29). The other phytogeographic domains shelter from five to ten species. Phytophagous gall midges occur on 128 plant species of 52 families, almost all native, being 43 endemic to Brazil (21 endemic to Atlantic Forest, five to Cerrado, and one to Amazon). Although, the taxonomical knowledge is focused on the Atlantic Forest, each domain has its own fauna composition and these informations can be useful for environmental conservational purposes. About 58% of the Brazilian fauna are known only from the type-locality. In order to fill these gaps, it is necessary and important to collect in uninvestigated areas.

Injected nuclei in frog oocytes: fate, enlargement, and chromatin dispersal

Development ◽  
1976 ◽  
Vol 36 (3) ◽  
pp. 523-540
Author(s):  
J. B. Gurdon
Keyword(s):  
Bovine Serum Albumin ◽  
Xenopus Laevis ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Oocyte Nucleus ◽  
Oocyte Cytoplasm ◽  
Nuclear Injection

A method is described by which nuclei associated with some cytoplasm can be rapidly prepared from a suspension of cells. The method involves the use of lysolecithin and bovine serum albumin. Oocytes of Xenopus laevis were injected with about 200 nuclei prepared from human He La cells by this method. Nuclei were deposited in oocyte cytoplasm, in the oocyte nucleus, or in the dispersed contents of a ruptured oocyte nucleus. Injected He La nuclei enlarge up to several hundred times in volume in the course of a few days. Their enlargement is associated with chromatin dispersion, increased binding of an acidic dye, and with the reduction in size, and eventual disappearance, of nucleoli. The amount of He La nucleus enlargement is much greater when the oocyte nucleus is ruptured. The fate of injected nuclei was followed by the use of HeLa nuclei whose DNA had been previously la belled with [3H] thymidine. La belled DNA does not pass from injected He La nuclei into the oocyte nucleus. Injected nuclei appear not to fuse with each other or with the oocyte nucleus. Nuclei prepared by the above method look morphologically healthy in oocytes cultured in vitro for up to one month after nuclear injection. Nuclei prepared by other methods, such as those involving the use of detergents, undergo deterioration within a few days after injection into oocytes.

scholarly journals A new species of Omphale Haliday 1833 (Hymenoptera: Eulophidae) from Brazil, parasitic on gall-midges on Croton floribundus Spreng (Euphorbiaceae)

2013 ◽  
Vol 13 (3) ◽  
pp. 34-37 ◽  
Author(s):  
Gabriela Cristina Gomes ◽  
Maíce Siqueira Franco ◽  
Christer Hansson
Keyword(s):  
New Species ◽  
Gall Midge ◽  
Parasitic Wasp ◽  
Neotropical Region ◽  
Gall Midges ◽  
The Third ◽  
A New Species

A tritrophic relationship involving the plant Croton floribundusSpreng (Euphorbiaceae), an unidentified gall-midge belonging to eitherClinodiplosis Kieffer 1895 or Alycaulus Rübsaamen 1916 (Diptera: Cecidomyiidae), and a new species of parasitic wasp belonging toOmphale Haliday 1833 (Hymenoptera: Eulophidae) is described. The gall andOmphale japii sp. nov., are described and illustrated. This is the third record ofOmphale from Brazil and the new species is compared to otherOmphale species from the Neotropical region.

scholarly journals Ultrastructure of in vitro oocyte maturation in buffalo (Bubalus bubalis)

Zygote ◽  
2010 ◽  
Vol 18 (4) ◽  
pp. 309-314 ◽  
Author(s):  
Rafael Gianella Mondadori ◽  
Tiago Rollemberg Santin ◽  
Andrei Antonioni Guedes Fidelis ◽  
Khesller Patrícia Olázia Name ◽  
Juliana Souza da Silva ◽  
...  
Keyword(s):  
Polar Body ◽  
Bubalus Bubalis ◽  
Ultrastructural Changes ◽  
Oocyte Nucleus ◽  
Cortical Granules ◽  
Immature Oocytes ◽  
Transmission Electron ◽  
High Lipid ◽  
First Polar Body

SummaryThe objective of the present study was to describe ultrastructural changes in the nucleus and cytoplasmic organelles during in vitro maturation (IVM) of buffalo cumulus–oocyte complexes (COCs). The structures were collected by ovum pick-up (OPU). Some COCs, removed from maturation medium at 0, 6, 12, 18 and 24 h, were processed for transmission electron microscopy. The average number of COCs collected by OPU/animal/session was 6.4, and 44% of them were viable. Immature oocytes had a peripherally located nucleus, Golgi complex and mitochondrial clusters, as well as a large number of coalescent lipid vacuoles. After 6 h of IVM, the oocyte nucleus morphology changed from round to a flatter shape, and the granulosa cells (GC) lost most of their contact with zona pellucida (ZP). At 12 h the first polar body was extruded and the aspect of lipid droplet changed to dark, probably denoting lipid oxidation. Cortical granules were clearly visible at 18 h of maturation, always located along the oocyte periphery. At 24 h of IVM the number of cortical granules increased. Ultrastructure studies revealed that: (1) immature oocytes have a high lipid content; (2) the perivitelline space (PS) increases during IVM; (3) Golgi complexes and mitochondrial clusters migrate to oocyte periphery during IVM; (4) 6 h of IVM are enough to lose contact between GC and ZP; (5) the oocyte lipid droplets’ appearance changes between 6 and 12 h of IVM.

scholarly journals GALL MIDGES, CONTARINIA AGRIMONIAE FELT AND DASINEURA SPP. (DIPTERA: CECIDOMYIIDAE), ASSOCIATED WITH BLACKBERRY FLOWER INJURIES AND NUBBINS

HortScience ◽  
1996 ◽  
Vol 31 (5) ◽  
pp. 750a-750 ◽  
Author(s):  
Herbert D. Stiles ◽  
Paul J. Semtner
Keyword(s):  
North Carolina ◽  
North American ◽  
Fruit Set ◽  
Gall Midge ◽  
Soil Surface ◽  
Flower Bud ◽  
Gall Midges ◽  
History Of

Larvae of Contarinia agrimoniae Felt, a gall midge, were discovered during 1986 in blossoms of blackberry cultivars and wild-growing plants that had a history of poor fruit set and `nubbin' formation (Stiles, Semtner, and Reed, 1996). Other species damage blackberries in Europe, but the only North American recognition of Rubus flower bud infestation was with Dasineura rubiflorae Felt during 1886 (Gagne, 1989). During 1995 we found larvae of a Dasineura spp. in damaged buds at two, widely separated, commercial, North Carolina, blackberry sites. It is not known if the latter insects are different from the species that was collected during 1886. Midge larvae probably overwinter in soil under affected plants so we sprayed diazinon on the soil surface before bloom to kill larvae or interfere with pupation and reduce crop injuries. Infested `Shawnee' and `Cheyenne' buds were ≈100% more numerous among controls than diazinon-treated plots. Numbers of larvae varied among infested buds; 83 were observed in one bud from a nontreated `Cheyenne' plot.

scholarly journals Memoirs: The Development of the Ovary and Ovarian Egg of a Mosquito, Anopheles maculipennis, Meig

1921 ◽  
Vol s2-65 (259) ◽  
pp. 395-448
Author(s):  
A. J. NICHOLSON
Keyword(s):  
Mitotic Division ◽  
Follicular Epithelium ◽  
Oocyte Nucleus ◽  
Nurse Cells ◽  
Anterior Portion ◽  
Tracheal System ◽  
Short Period ◽  
Entrapped Air ◽  
The Individual ◽  
Second Period

1. The period at which the ovaries of A. maeulipennis commence to develop depends on the season and locality. Normally this is from about the middle of March to the beginning of April. 2. A meal of blood appears to be necessary for the production of eggs. 3. One meal of blood is sufficient to cause eggs to be produced. After the lapse of a day the large blood-mass in the stomach shows two zones: a posterior partially-digested portion and an anterior portion of apparently fresh blood. This appearance has sometimes been taken as evidence that more than one meal of blood has been consumed. 4. The eggs are fully developed six days after the insect has fed on blood. 5. In the case of two insects which were observed at the time of oviposition the eggs were laid immediately after dark. 6. The muscle-bands of the ovarian sheaths are striped; not unstriped as is usual in insects. 7. A large number of vacuolated cells are found in the ovary. The nature of these is not clear, but they appear to have some relation to the tracheal system. 8. The chorion of the egg is highly specialized to retain air round the egg, and the buoyancy of the egg is entirely due to the entrapped air. 9. The floats are-produced by a very specialized form of folding of the follicular epithelium. 10. The micropyle apparatus is produced by specialized cells of the epithelium, the ‘rosette-cells’. 11. Immediately below the micropyle is a specialized portion of the inner wall, the ‘stopper’. 12. The inner and outer walls of the egg, though formed of entirely different substances, are both secreted by the follicular epithelium. 13. The inner wall is first gelatinous in nature and transparent; but, after the egg is laid, becomes brittle and dark in colour, causing the egg to appear black. This change in character only takes place when the eggs are laid on water. 14. The mature egg contains two distinct kinds of yolk, one of large granules which are proteid in nature, and the other of small granules the nature of which I have been unable to determine. 15. There are two distinct periods of growth of the eggfollicles, the first culminating in the ‘resting stage’ and the second only commencing after the mosquito has bad a meal of blood. 16. Each egg-follicle consists of a follicular epithelium surrounding seven nurse-cells and an oocyte. These appear to be the product of a single oogoniuni. 17. The cells of the follicular epithelium multiply by mitotic division during the whole of the first period of growth. In the second period, though the follicular epithelium increases greatly in area, this is due purely to the increase in size of the individual cells. 18. From the earliest stages separate vegetative and germinal portions can be distinguished in the oocyte nucleus. 19. During the second period of growth the oocyte nucleus branches throughout the entire oocyte. 20. The branching nucleus, in conjunction with the nursecells, takes an active part in the nutrition of the oocyte. 21. The branching of the nucleus may be regarded as a mechanism for the purpose of increasing the surface. 22. I have observed a similar method of branching of the oocyte nucleus in Theobaldia annulata, and it probably also exists in Necrophorus vespillo and Si1pha sp. 23. The branching nucleus is almost entirely the product of the nucleolus. 24. The branching nucleus is morphologically and physiologically comparable to the Corpuscles of Balbiani of other animals. 25. The germinal portion of the nucleus, the ‘chromatin residue’, is the product of the condensation of the spirerae threads. 26. The ‘chromatin residue’ becomes invisible for a short period and reappears after oviposition as the segmentation nucleus. 27. The chromatin of the active nurse-cells consists of minute bars situated on a much convoluted band of linin. 28. Degeneration of a certain number of egg-follicles is normal during the development of the ovary. 29. Sporozoa are frequently found in the eggs, often completely replacing the whole of the yolk.

Sign in / Sign up

Export Citation Format

Share Document