Demonstration of generators of the locomotor and respiration rhythms in the cervico-thoracic spinal cord of rabbits

In curarized Rabbits whose cervico-thoracic cord has been isolated through C2 and Th12 transections, a pharmacological activation (nialamide-DOPA) disclosed distinct rhythmic efferent activities, locomotor-like bursts in forelimb muscle nerves and "respiratory" discharges in the phrenic nerves: they originate respectively from a cervico-thoracic locomotion generator and from a "respiration" generator; these spinal generators appear to be interconnected with each other.     

Conversion of mammalian cyclic GMP-dependent protein kinase into modulator-dependent protein kinase (type II) in vitro

The spontaneous conversion of mammalian cyclic GMP-dependent protein kinase (G-PK) into modulator-dependent protein kinase (type II) (M-PKII) in the absence of cGMP or histone was observed in vitro. The findings, together with similarity in substrate protein specificity, suggest that M-PKII is the catalytic subunit of mammalian G-PK.     

Nucleolus organizer region location and ‘ring’ chromosomes in the bharal

Summary Silver-staining has been used to identify the nucleolus organizer regions (NORs) in the bharal. These show homology with sheep, goat, cattle and aoudad. The association of the NORs on both telomeres of chromosome 3 results in a ring chromosome.     

H-Y Evolution

Summary The female: male sex ratio in litters born to C57 black mice immunized with male spleen preparations is 21 and males were stillborn. In additionDrosophila busckii males are H-Y antigen positive. It is argued that H-Y is the primary testicular determinant and that this role is evolutionarily ancient.     

Presence of natural killer cells in Peyer's patches of the mouse

Summary Natural cell-mediated cytotoxicity of normal murine Peyer's patch cells against Ehrlich ascites carcinoma was found in a short-term⁵¹Cr release assay. Peyer's patch and lymph node cells showed natural cytotoxicity at approximately the same level.Acknowledgments. This work was supported by grant No. 10.5 from the Polish Academy of Sciences.     

Giant collagen fibres in the gonopodium of the mosquitofishHeteradria formosa,Agassiz, 1853 (Pisces,Poeciliidae)

Summary The gonopodium of the mosquitofishHeteradria formosa was studied by transmission electron microscopy. In cross-section the gonopodium shows the following structure from the outside inwards: mutilayered epidermis, basal lamina and central supporting tissue, in which vessels and nerves are embedded. At the top of the gonopodium giant collagen fibres are found, which measure up to 150 m in length and 6 m in diameter. These fibres reinforce the gonopodium.This research was supported by the Deutsche Forschungsgemeinschaft. Address for reprints: Forschungsgruppe Dermatologie der Universität Heidelberg, Im Neuenheimer Feld 324, D-6900 Heidelberg.     

Epithelial-mesenchymal interaction in differentiation of duodenal epithelium of fetal rats in organ culture

Summary Epithelial-mesenchymal interaction in the differentiation of duodenal epithelium of fetal rats was investigated by recombination experiments in vitro. The proportion of goblet cells in duodenal epithelium was significantly greater on recombination of developing duodenal epithelium with mesenchyme of the glandular stomach than on recombination with that of the duodenum. Mesenchyme of the glandular stomach or forestomach was better than duodenal mesenchyme in supporting morphogenesis of duodenal epithelium. Treatment of tissues with N-methyl-N-nitro-N-nitrosoguanidine (MNNG) did not affect these tissue interactions.This work was supported by grants-in-aid for cancer research from the Ministry of Education, Science and Culture, Japan.Acknowledgment. The authors wish to express their gratitude to Prof. T. Mizuno of the University of Tokyo for valuable suggestions.     

Inheritance and expression ofEsterase-1 allozymes inPeromyscus leucopus

Summary We analyzed inheritance of 5Es-1 alleles inP. leucopus and found them to be co-dominant and segregating from a single autosomal locus, thereby verifying assumptions of Mendelian inheritance imfield data. We also described an allele that is silent in hemolysate, but is active in liver extract.Acknowledgment. Laboratory analysis was partially supported by a grant-in-aid (No. 0171-02-240-76) to Kaufman from the Research Foundation of State University of New York.     

Digestive enzymes in the gut and salivary gland of the larvae ofChilo auricilius Ddgn.

Summary Amylase, - and -glucosidase, - and -galactosidase, -fructosidase, trypsin, aminotripeptidase, leucine-aminopeptidase, prolinase, prolidase glycyl-L-leucine dipeptidase and glycylglycine dipeptidase are present in the 3rd instar larvae ofChilo auricilius.Dr Kishan Singh, Indian Institute of Sugarcane Research, Lucknow, is gratefully acknowledged for providing necessary facilities.     

Hemolymph volume determination in the tomato fruitworm,Heliothis zea

Summary The hemolymph volume ofHeliothis zea larvae was determined by the amaranth dye method and found to vary from 28 to 288 l. It averaged 30.6% of b.wt, a value comparable to that obtained with C¹⁴ inulin. Amaranth became evenly distributed in the hemocoele in 3–5 min.