Mitosis in the haemocytes ofSarcophaga ruficornis (diptera)

Summary Among the haemocytes ofSarcophaga ruficornis, only the prohaemocytes divide. Injection of phytohaemagglutinin-P induces 100% prohaemocytes to undergo mitosis but does not induce mitosis in other cells. Mitotic stages other than the prophase are apparently very short lived.Acknowledgment. We express our gratitude to the State Council of Scientific and Industrial Research, U.P. for the grant of financial assistance to U.S.S.     

Trypsin activity in the midgut ofSarcophaga ruficornis andMusca domestica (Diptera: Insecta)

Summary The pH and temperature for the optimum activity of trypsin from the midgut ofSarcophaga ruficornis andMusca domestica was 7.5 and 8.0 respectively and 50°C. The enzymic activity increased with the increase in incubation period and enzyme concentration.Thanks are due to Prof.R. Rakshpal for guidance.     

Invertase activity in the midgut ofSarcophaga ruficornis andMusca domestica (diptera: Insecta)

Summary The pH for the optimum activity of the midgut invertase was 5.5 in the adults ofS. ruficornis, 6.0 in its larvae and adults ofM. domestica and 6.5 in the larvae of the latter fly. The optimum temperature was 50°C. Enzyme activity was retarded by the addition of glucose and fructose.     

The effect of diet on the hemolymph amino acid constituents of the larvae and pupae ofSarcophaga ruficornis (Fabricius): (Diptera)

Zusammenfassung Es werden zwei Zuchtgruppen vonSarcophaga ruficornis-Larven hinsichtlich ihres Aminosäuregchaltes des Blutes untersucht. Den auf Fleisch gezüchteten Tieren fehlt Lysin, Glutamin und Taurin, während diese Aminosäuren bei den auf Hundebisquit aufgezogen Larven vorhanden sind, ihnen dagegen Threonin fehlt. Der Aminosäuregehalt im Blut der Puppen beider Zuchtgruppen ist gleich.     

Ontogenetic fate of the neurosecretory cells in the larval brain ofSarcophaga ruficornis (fabricius, 1794) (diptera: Cyclorrhapha)

Résumé Il y a quatre groupes, 1, 2, 3 et 4, de cellules neurosécrétrices dans chaque demi-sphère du cerveau larvaire duSarcophaga ruficornis. Pendant la métamorphose, les groupes 1 et 2 deviennent antérieurs dorsaux et forment des cellules neurosécrétrices médiales de la mouche adulte; le groupe 3 devient ventral mais s'évanouit après l'éclosion de la mouche; le groupe 4 s'évanouit aussi, mais plus tôt.     

The presence of β-phenylethylamine,p-tyramine,m-tyramine and tryptamine in ganglia and foot muscle of the garden snail (Helix aspersa)

Summary The concentrations of -phenylethylamine,p-tyramine,m-tyramine,m-octopamine and tryptamine in the ganglia or foot muscle ofHelix aspersa range from <0.6 to 11 ng/g.p-Octopamine levels are higher in ganglia (327 ng/g) than in foot muscle (4.1 ng/g). Dopamine and 5-hydroxytryptamine range from 840 to 2710 ng/g while their acid metabolites, 3,4-dihydroxyphenylacetic acid, 3-methoxy-4-hydroxyphenylacetic acid and 5-hydroxyindoleacetic acid range from <20 to 130 ng/g.Acknowledgments. We thank Dr A.A. Boulton for helpful discus sion, Dr D.A. Durden for supervising the mass spectrometric analyses, Dr B.A. Davis for the synthesis of the deuterated standards, G.H. Wheatley, E.P. Zarycki and M. Mizuno for expert technical assistance, and Saskatchewan Health and the MRC of Canada for providing financial support.     

A new puffing pattern induced by temperature shock and DNP in drosophila

Riassunto Si è notato che shocks di temperatura possono indurre una variazione di «puffing pattern» in ghiandole salivari di Drosophila. Tali «puffing» sono perfettamente reversibili e rappresentano zone di intensa sintesi di RNA. Si è notato che DNP e Na salicilato portano a simili variazioni di «puffing pattern».     

Changes in glutamine levels during starvation and aestivation in the Indian apple snailPila globosa (Swainson)

Summary The glutamine levels in digestive gland, foot and body fluids of normal, starved and aestivatedPila globosa were estimated. Glutamine content was decreased during starvation and aestivation. The percent decrease was more during aestivation than starvation. The decrease may be due to low glutamine-synthetase activity or increased utilization for uric acid synthesis. This may have an adaptive value during aestivation and starvation.Acknowledgments. C. Sree Ramulu Chetty and P. Aruna are thankful to CSIR for the award of Junior fellowships, during the tenure of which the work has been done.     

Common Molecular Mechanisms of Mammary Gland Development and Breast Cancer

During its lifetime, the mammary gland undergoes many phases of development and differentiation. Much of this occurs during puberty, when the ductal epithelium expands by branching morphogenesis, invading the surrounding fat pad to form an organised mammary tree. Throughout its existence, the epithelium will go through several cycles of proliferation and cell death during pregnancy, lactation and involution. Many of the signalling mechanisms which control the initial invasion of the fat pad by the epithelium, and regulate its continuing plasticity, can be harnessed or corrupted by tumour cells in order to support their aberrant growth and progression towards invasion. This is true not just for the epithelial cells themselves but also for cells in the surrounding microenvironment, including fibroblasts, macrophages and adipocytes. This review examines the complex web of signalling and adhesion interactions controlling branching morphogenesis, and how their alteration can promote malignancy. Current in vivo and in vitro mammary gland models are also discussed. (Part of a Multi-author Review)     

The effect of cyproterone acetate on spermatogenesis and thumb pads of the skipper frog,Rana cyanophlyctis (Schn.)

Summary The administration of cyproterone acetate (CPA) to adult male frogs of the speciesR. cyanophlyctis caused a significant reduction in the number of cell nests with primary spermatogonia (stage 0) per seminiferous tubule cross section, and a marked reduction in the height of the thumb pad epidermis and mucous glands. It is concluded that the development and/or proliferation of primary spermatogonia inR. cyanophlyctis are androgen dependent.The gift of cyproterone acetate from Schering AG is gratefully acknowledged. The authors are thankful to Prof. V.B. Nadkarni, Head Zoology Department, Karnatak University, Dharwad for facilities and encouragement.     

Neuroendocrine control of carbohydrate metabolism in the freshwater bivalve molluscLamellidens marginalis

Summary Blood sugars and foot muscle glycogen were measured in the mussel,L. marginalis after ablation of the cerebral ganglia, and in mussels injected with cerebral ganglionic extract 3 h after ablation. There is a rise in the blood sugar and decrease in foot muscle glycogen 3 h after operation, but no change in sham-operated controls. The effect of ablation is reversed by injecting brain extract into ablated mussels. No such effect could be seen in the controls. The results are suggestive of the presence, in the cerebral ganglia, of a hypoglycaemic factor similar to insulin.     

Regulation of carbohydrate metabolism by the optic tentacles of the garden snailCryptozona ligulata (Gastropoda-Stylommatophora)

Summary The presence of a hyperglycemic factor in the optic tentacles of the snailC. ligulata is reported here. A preliminary characterization based on crude extracts indicates the factor to be water-soluble, heat labile and to be an albumin. The ablation of optic tentacles and injection of optic tentacle extract into operated and normal snails caused a rise in blood sugar, total carbohydrate and glycogen in the foot muscle and mantle and a decrease in hepatopancreatic glycogen. The ablation also caused a fall in blood free amino acids and a rise in the tissues, which was reversed in the blood and foot muscle by injection of the extract. Possible conversion of amino acids to total carbohydrates and glycogen by gluconeogenesis is suggested.     

The effect of Valium® anaesthesia on the radiosensitivity of the skin of the mouse foot

Summary Valium^® anaesthesia significantly reduces the effect of large single doses of X-rays on the mouse foot skin as compared with Nembutal^® anaesthesia. The radioprotective action of Valium may be attributed to a direct effect on the cells of the skin.Supported by the Swiss National Science Foundation (Grant no. 3.682-0.75).Acknowledgments. The authors wish to thank Miss F.T. Josuran, Miss U. Schärer and Mr P.P. Binz for their excellent technical assistance with the experiments.     

Caryotypes de quelques hybrides interspécifiques dePitymys (Mammalia,Rodentia)

Summary The Robertsonian polymorphism ofPitymys subterraneus involves only 1 pair of metacentric autosomes. The crosses of forms with 52, 53 and 54 chromosomes do not show any differences in their reproductive rate. So a single autosome trivalent does not affect the fecondity. Many hybrids have been obtained betweenP. subterraneus (2N=52 or 54) andP. multiplex (2N=48) with 50 or 51 chromosomes, respectively. Even with a heterogenous karyotype they are not entirely sterile. 2 progeny were produced from back-crosses. The 2 parental species seem to result from recent speciation. Only fecondation or embryogenesis occurs in crossingP. duodecimcostatus withP. subterraneus orP. multiplex. The chromosome complement of 1 hybrid embryo ofP. duodecimcostatus (2N=62)×P. multiplex (2N=48) has been studied showing 55 chromosomes.P. duodecimcostatus appears to belong to a more distant evolutionary group.     

Selection of biting sites on man by two malaria mosquito species

While searching for blood, female mosquitoes pass through a behavioural process involving responses to visual, physical and chemical properties of the host. Temperature and humidity are thought to dominate mosquito orientation near the host. We observed that biting of two malaria mosquito species, i.e.Anopheles atroparvus (van Thiel) andAnopheles gambiae s.s. (Giles) preferentially occurs on different body regions of a naked motionless human host. Their preference for the head and foot regions respectively correlated with particular combinations of skin temperature and eccrine sweat gland density. Subsequent modification of the host's odour profile by removing exhaled breath and washing feet results in significant changes of these preferences.     

Diurnal variations in cholinesterase activities in the slug,Laevicaulis alte

Summary Cyclical variations in acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) levels in foot muscle (FM) and AChE activity in central nervous system (CNS) ofLaevicaulis, during 24-h-day, were maximal at 04.00 h and minimal at 12.00 h. But BuChE activity was 180°C out of phase with AChE in CNS. The rhythmic trend of AChE in CNS might be due to true cholinesterase activity.Acknowledgements. The Senior Fellowship (CSIR) awarded to TPK is thankfully acknowledged.     

Splenic B-cell activation in lipopolysaccharide-non-responsive C3H/HeJ mice by lipopolysaccharide ofPorphyromonas gingivalis

Porphyromonas gingivalis 381 lipopolysaccharide (LPS) definitely exhibited mitogenic activity in purified B-cells, separated from spleens of LPS-responsive C3H/HeN mice and LPS-non-responsive C3H/HeJ mice by using a magnetic cell sorting system. The mitogenic activity induced byP. gingivalis LPS was incompletely inhibited by polymyxin B.P. gingivalis LPS also induced a higher production of interleukin-6 (IL-6) in splenic B-cells of C3H/HeN mice as compared withEscherichia coli LPS. Furthermore,P. gingivalis LPS, but notE. coli LPS, induced definite IL-6 production in C3H/HeJ mice.P. gingivalis LPS increased tyrosine, serine/threonine phosphorylation of proteins with various major induced bands in splenic B-cells of both C3H/HeN and C3H/HeJ mice. Additionally, radioiodinatedP. gingivalis LPS, similarly toE. coli LPS, bound to a 73-kDa protein on C3H/HeJ as well as C3H/HeN B-cells. ThusP. gingivalis LPS may activate B-cells of C3H/HeJ as well as C3H/HeN mice via the LPS-specific binding protein on the cells.     

Allele-specific PCR reveals thatCYP6D1 is on chromosome 1 in the house fly,Musca domestica

A cytochrome P450, termed P450lpr, is the major P450 responsible for pyrethroid resistance in the Learn-PyR (LPR) strain of house fly. Recently, the putative gene (CYP6D1) coding for P450_lpr has been sequenced from the LPR and aabys strains of house fly. Allele-specific polymerase chain reaction (ASPCR) was used for linkage group analysis with backcross progeny from the wild type LPR strain and a multiple marker strain (aabys). We found thatCYP6D1 is linked to chromosome 1. The possible role of regulatory or modifying genes responsible for elevated P450_lpr expression is discussed in relation to the chromosomal linkage ofCYP6D1.     

Changes in activity levels of AMP deaminase and adenosine deaminase in the Indian apple snail,Pila globosa (Swainson) during starvation and aestivation stress

Summary Activity levels of AMP deaminase and adenosine deaminase have been studied in hepatopancreas, foot and mantle tissues ofPila globosa with reference to starvation and aestivation. The activity levels of both enzymes were decreased in all the tissues of aestivating snails while in starved animals AMP deaminase activity was increased, in contrast to the decreased adenosine deaminase activity.Acknowledgments. K. Srinivasa Moorthy and B. Kasi Reddy are thankful to the Department of Science and Technology, New Delhi for the financial assistance. Reprint requests should be addressed to C.S.C.