Regulation and Differentiation within Field-districts in Imaginal Discs of Drosophila

Development ◽  
1953 ◽  
Vol 1 (3) ◽  
pp. 213-216
Author(s):  
E. Hadorn
Keyword(s):  
Detailed Analysis ◽  
Building Materials ◽  
Imaginal Discs ◽  
Body Cavity ◽  
The Body ◽  
Host Larva ◽  
Genital Disc ◽  
Genital Apparatus ◽  
Different Parts ◽  
Third Instar Larvae

Genital imaginal discs of third instar larvae of Drosophila have been cut into medial, paramedial, or transverse parts of different sizes. The fragments were then implanted into the body cavity of a host larva. This medium provides the implants with ample nutritional material and hormones. The fragments thus differentiate their imaginal structures simultaneously with the metamorphosing host. A detailed analysis of the respective differentiations of the various parts has led to the following results and revealed the following properties of the different blastemata which are embodied in a genital disc (Hadorn et al., 1946, 1949, 1950). 1. The building materials of the different parts (elemental organs) of the genital apparatus can be localized within the larval disc and a schematic map can be designed which indicates the positions of the presumptive areas (districts) which give rise either to sperm pumps, claspers, anal plates, spermathecae, or vaginal plates.

Developmental behaviour of fragments of symmetrical and asymmetrical imaginal discs of Drosophila melanogaster (Diptera)

Development ◽  
1966 ◽  
Vol 16 (2) ◽  
pp. 355-368
Author(s):  
Gerold Schubiger ◽  
Rolf Nöthiger
Keyword(s):  
Drosophila Melanogaster ◽  
Early Stage ◽  
Imaginal Discs ◽  
Genital Disc ◽  
Genital Apparatus ◽  
Larval Host ◽  
Sex Comb ◽  
Very High

Earlier experiments have demonstrated a very high ‘regulative’ ability in the genital disc of Drosophila melanogaster. Medially sectioned discs, even from mature larvae, are able to form a fully differentiated normal genital apparatus if the fragments are cultured in vivo in a larval host for a sufficient length of time before metamorphosis. Even a quarter of a disc has this ‘regulative’ ability. However, it should be emphasized that the fragment as a unit is not capable of ‘regulation’, but only its single anlage elements (Hadorn, Bertani & Gallera, 1949; Hadorn, 1963; Ursprung, 1959). These findings appeared to contradict the prevailing belief that Drosophila exhibits a mosaic development. This view was favoured by Geigy (1931), who showed that an anlage pattern of presumptive imaginal structures was already present at an early stage of embryogenesis. Similarly, mosaic development in the leg disc was postulated by Bodenstein (1941), who found, for example, that when half of a leg disc formed the sex comb the complementary half did not.

Effects of Different Diets of a Host, Agria affinis (Fall.) (Diptera: Sarcophagidae), on the Development of a Parasitoid, Aphaereta pallipes (Say) (Hymenoptera: Braconidae)

1961 ◽  
Vol 93 (11) ◽  
pp. 1041-1044 ◽  
Author(s):  
H. L. House ◽  
J. S. Barlow
Keyword(s):  
Life History ◽  
Body Cavity ◽  
The Body ◽  
Host Larva ◽  
Onion Maggot ◽  
Hylemya Antiqua ◽  
Host Diet

Agria [= Pseudosarcophaga] affinis (Fall.) and Aphaereta pallipes (Say) make an excellent host-parasitoid couple for a determination of effects of host diet on a parasitoid. The anatomy, life history, and behaviour of these insects have been described (Salkeld, 1959; Coppel et al., 1959). Moreover, A. affinis can be reared axenically on chemically defined diets and it is readily attacked in the laboratory by A. pallipes, a parasitoid of the onion maggot, Hylemya antiqua (Meig.). This parasitoid deposits eggs into the body cavity of its host and these increase in size: the duration of the egg stage depends on the age of the host larva when parasitized (Salkeld, 1959).

Updating long-held assumptions about fat stigma: For women, body shape plays a critical role

2020 ◽  
Author(s):  
Jaimie Krems ◽  
Steven L. Neuberg
Keyword(s):  
Body Shape ◽  
Critical Role ◽  
The Body ◽  
Theoretical Assumption ◽  
Obesity Stigma ◽  
Obese Female ◽  
Three Samples ◽  
Female Bodies ◽  
Different Parts ◽  
Fat Stigma

Heavier bodies—particularly female bodies—are stigmatized. Such fat stigma is pervasive, painful to experience, and may even facilitate weight gain, thereby perpetuating the obesity-stigma cycle. Leveraging research on functionally distinct forms of fat (deposited on different parts of the body), we propose that body shape plays an important but largely underappreciated role in fat stigma, above and beyond fat amount. Across three samples varying in participant ethnicity (White and Black Americans) and nation (U.S., India), patterns of fat stigma reveal that, as hypothesized, participants differently stigmatized equally-overweight or -obese female targets as a function of target shape, sometimes even more strongly stigmatizing targets with less rather than more body mass. Such findings suggest value in updating our understanding of fat stigma to include body shape and in querying a predominating, but often implicit, theoretical assumption that people simply view all fat as bad (and more fat as worse).

Study on Pramana Shareera in relation to Prakriti

2016 ◽  
Vol 2 (3) ◽  
Author(s):  
Rajendra Pai N. ◽  
U. Govindaraju
Keyword(s):  
Observational Study ◽  
Upper Limb ◽  
Lower Limb ◽  
Characteristic Property ◽  
The Body ◽  
Artificial Limbs ◽  
Body Parts ◽  
Unit Of Measurement ◽  
The Individual ◽  
Different Parts

Ayurveda in its principle has given importance to individualistic approach rather than generalize. Application of this examination can be clearly seem like even though two patients suffering from same disease, the treatment modality may change depending upon the results of Dashvidha Pariksha. Prakruti and Pramana both used in Dashvidha Pariksha. Both determine the health of the individual and Bala (strength) of Rogi (Patient). Ayurveda followed Swa-angula Pramana as the unit of measurement for measuring the different parts of the body which is prime step assessing patient before treatment. Sushruta and Charaka had stated different Angula Pramana of each Pratyanga (body parts). Specificity is the characteristic property of Swa-angula Pramana. This can be applicable in present era for example artificial limbs. A scientific research includes collection, compilation, analysis and lastly scrutiny of entire findings to arrive at a conclusion. Study of Pramana and its relation with Prakruti was conducted in 1000 volunteers using Prakruti Parkishan proforma with an objective of evaluation of Anguli Pramana in various Prakriti. It was observed co-relating Pramana in each Prakruti and Granthokta Pramana that there is no vast difference in measurement of head, upper limb and lower limb. The observational study shows closer relation of features with classical texts.

Myiasis in Bufo regularis caused by a Tabanid Larva

Parasitology ◽  
1924 ◽  
Vol 16 (1) ◽  
pp. 111-112
Author(s):  
Edward Hindle
Keyword(s):  
Fibrous Tissue ◽  
Dorsal Surface ◽  
Body Cavity ◽  
The Body ◽  
Careful Examination ◽  
Large Female ◽  
Considerable Time ◽  
Ventral Region ◽  
Cylindrical Structure ◽  
The Right

In December, 1922, whilst dissecting a large female example of Bufo regularis, one of my students noticed a cylindrical structure extending along the ventral region of the body-cavity. A careful examination showed that this structure consisted of an elongated sac-like diverticulum of the right lung, containing an almost full-grown specimen of a dipterous larva, which could be seen through the membraneous wall of the diverticulum. The base of the latter, in addition to its point of origin from the lung, was also connected to the dorsal surface of the liver by strands of fibrous tissue, suggesting that the growth had been in existence some considerable time in order to cause such adhesions. Posteriorly, the diverticulum hung freely in the body cavity and extended to the extreme hinder end. Its dimensions were 5·5 cm. in length, by 0·5 cm. in diameter, but tapering towards each extremity.

ENCAPSULATION OF RHABDITOID NEMATODES IN MOSQUITOES

1962 ◽  
Vol 40 (7) ◽  
pp. 1269-1275 ◽  
Author(s):  
Joan F. Bronskill
Keyword(s):  
Aedes Aegypti ◽  
Endemic Species ◽  
Body Cavity ◽  
Fourth Instar ◽  
The Body ◽  
Histological Structure ◽  
Adult Tissue ◽  
Defence Reaction ◽  
Blood Sinus

In third and fourth instar larvae of Aedes aegypti (L.), juveniles of the rhabditoid, DD136, penetrate the blood sinus and cardial epithelium of the proventriculus to enter the body cavity of the host, where they complete their development. By 5 hours, a thick capsule developed about many of the ensheathed immature adults of DD136 within the body cavity of A. aegypti larvae. This rapid defence reaction of the mosquito to DD136, which has both a melanin and a cellular manifestation, occurs both in the exotic mosquito A. aegypti and in the two endemic species tested, Aedes stimulans (Walker) and Aedes trichurus (Dyar). The resistance of A. stimulans to an endemic rhabditoid, possibly of the Diplogasteridae, is also similar. The histological structure of the capsule is not affected during metamorphosis in A. aegypti; however, during histogenesis of adult tissue displacement and (or) distortion of some tissues and organs may be caused by the presence of the capsule within the host's body cavity. The activity of the adult A. aegypti is normal when this distortion or displacement is minor. Though usually encapsulated DD136 are retained within the body cavity of A. aegypti during metamorphosis, sometimes they are partially or completely expelled from the host's body cavity at the time of molting.

Studies on Tapeworm Physiology

1949 ◽  
Vol 26 (1) ◽  
pp. 1-15
Author(s):  
J. D. SMYTH
Keyword(s):  
Bacterial Infections ◽  
Detrimental Effect ◽  
Horse Serum ◽  
Body Cavity ◽  
The Body ◽  
Nutrient Media ◽  
Medium Strength ◽  
By Products ◽  
Histochemical Examination

1. Plerocercoid larvae of the pseudophyllidean cestode Ligula intestinalis from the body cavity of roach, were cultured in vitro at 40°C. in a variety of saline and nutrient media. About 65% of such cultures were aseptic. 2. During cultivation, larvae produced acid by-products (unidentified) and the pH fell rapidly. 3. The presence of these acid by-products slowed down development, or, if present in sufficient quantity, caused death. 4. In order to obtain development in nutrient media in a period (3 days) comparable to that required in a bird (the normal host) it was necessary to renew the medium 24-hourly. 5. 6% of the eggs produced from a worm cultured in horse serum were fertile. Fertile eggs were never obtained from larvae cultured in any other media. 6. Certain bacterial infections had no apparent detrimental effect on development, but others were toxic. 7. Some larvae underwent development in non-nutrient medium (¾ strength Locke's solution). The exact conditions under which this occurred was not determined. 8. Fragments (3 cm. long), of larvae or larvae with either scolex or posterior half removed, underwent development to the stage of oviposition in nutrient media. 9. Histochemical examination revealed that the plerocercoid larvae were almost fat-free. During cultivation, very large quantities of cytoplasmic fat were produced the quantity being proportional to the duration of cultivation. Fat was produced even under starvation conditions (i.e. during cultivation in saline) and can be considered a metabolic by-product. 10. The fresh plerocercoid contained great quantities of glycogen in the parenchyma and muscle regions. After cultivation in nutrient or saline media, considerable quantities were still present.

Respiratory disease in foreign body aspiration in children

1927 ◽  
Vol 23 (11) ◽  
pp. 1145-1150
Author(s):  
G. M. Lopatin
Keyword(s):  
Foreign Body ◽  
Respiratory Tract ◽  
Respiratory Disease ◽  
Foreign Bodies ◽  
Foreign Body Aspiration ◽  
The Body ◽  
Different Parts

Aspiration of foreign bodies into the windpipe usually results in respiratory damage. This lesion may be of varying intensity and may be localized in different parts of the respiratory tract or lungs. Both the intensity and the localization of the lesion may depend on a number of reasons and above all on the location of the foreign body and its type, but also on the constitutional characteristics of the body and on many other causes. Aspirated foreign bodies are found in the trachea or larynx and almost as often in the bronchi.

Transplantations de gonades indifférenciées chez l'hermaphrodite simultané Eisenia foetida (Oligochète, Lumbricidae)

Development ◽  
1973 ◽  
Vol 30 (1) ◽  
pp. 143-161
Author(s):  
Par J. C. Relexans
Keyword(s):  
Nervous System ◽  
Sexual Differentiation ◽  
The Body ◽  
Simultaneous Hermaphrodite ◽  
Eisenia Foetida ◽  
Turn On ◽  
Opposite Sex ◽  
Adjacent Wall ◽  
Physiological Gradients ◽  
Different Parts

Transplantations of undifferentiated gonads in the simultaneous hermaphrodite Eisenia foetida (Oligochaeta, Lumbricidae) leading to evidence of local factors (inductors?) of sexual differentiation The hypothesis of a ♀ sex capable of autodifferentiation and of a ♂ sex depending on an androgen hormone has been verified in several gonochoric or hermaphrodite invertebrates. In order to test the validity of this hypothesis in the hermaphrodite Eisenia foetida we have investigated the influence of the gonads' environment on their differentiation by transplanting undifferentiated gonads, dorsally and ventrally, on different parts of the body. The gonads, taken with the adjacent wall of the body from new-born worms, are grafted on worms of the same age; some grafts do, others do not, retain their nervous system. The control transplantation in which a graft of a given presumptive sex is transplanted in a region of the same sex can lead to inversions. These inversions have a rare and short-lived character in the gonads coming from presumptive testes. They are more frequent and more or less durable in the gonads coming from presumptive ovaries. These results can only be explained by the existence, within the grafts of the two presumptive sexes, of a dominant relationship between one and the other sexual potentiality which can be momentarily inverted by trophic disturbances caused by the transplantation. The heterosexual transplantations, in which a graft of a given presumptive sex is transplanted in the region of the opposite sex, show that the frequency of the inversions is doubled in relation to the frequency obtained in the control transplantations. The inversions which occur in the presumptive testes can be lasting and even permanent. These results lead to the opinion that to the effects of transplantation is added an inductive action from the host, leading to masculinity in the ♂ region and femininity in the ♀ region. The transplantations outside of the sexual ventral regions lead to inversions of which the character and frequency recall those obtained in the control transplantations. They suggest that these regions are devoid of inductive sexualizing power. The very slight variations of frequency of the inversions observed along the antero-posterior and dorso-ventral axes can be explained by the existence of physiological gradients acting on the balance of the graft's own potentialities. The removal of the nervous system in the grafts shows that this system plays a part, probably trophic, in favour of the masculine potentialities of the graft. In conclusion, our experiments lead to the rejection of the hypothesis of the ♀ sex capable of autodifferentiation in Eisenia, in order to adopt that of a sexual balance between the ♂ and ♀ potentialities determining, according to their dominant relationship, the synthesis of ♂ or ♀ ‘inductors’ respectively in the ♂ and ♀ ventral regions. These inductors act in turn on the bipotential sexual cells.

Sign in / Sign up

Export Citation Format

Share Document