Homologies between the amino acid sequences of some vertebrate peptide hormones and peptides isolated from invertebrate sources.

1. The 4K-prothoracicotropic hormone (PTTH) or bombyxin and the melanization-reddish coloration hormone of the silkworm Bombyx mori resemble insulin and insulin-like growth factors. 2.

Comparative developmental physiology and molecular cytology of the polytrophic ovarian follicles of the blowfly Sarcophaga bullata and the fruitfly Drosophila melanogaster.

1. The ovarian follicles of Sarcophaga and Drosophila consist of one oocyte and 15 nurse cells, the whole being surrounded by follicle cells. Although oocyte and nurse cells are genetically identical sibling cells, and although they are interconnected by cytoplasmic bridges, their physiology is very different.

Immunocytochemical localization of human growth hormone- and prolactin-like antigenic determinants in the insects, Locusta migratoria and Sarcophaga bullata.

1. By use of the peroxidase-antiperoxidase immunocytochemical method, substances immunoreactive to antisera directed against human growth hormone (hGH) and prolactin (hPrl) were localized in the nervous system of larval and adult Locusta migratoria and of adult Sarcophaga bullata belonging to different age groups. 2.

Seasonal changes of testis volume and sperm quality in adult fallow deer (Dama dama) and their relationship to the antler cycle.

Four adult male fallow deer were investigated for 1-4 consecutive years to study the relationships between annual changes in testis volume, sperm quality and antler status. Testicular volume started to increase in July/August, peaked just before the rut, declined until December to 50% of maximum, persisted at this level up to February/March and reached minimal volume after antler casting in late April. There was no apparent age effect on the seasonality of testis size fluctuations.

NPY-like peptides occur in the nervous system and midgut of the migratory locust, Locusta migratoria and in the brain of the grey fleshfly, Sarcophaga bullata.

The distribution of the NPY-like substances in the nervous system and the midgut of the migratory locust, Locusta migratoria and in the brain of the grey fleshfly, Sarcophaga bullata was determined by immunocytochemistry using an antiserum directed against synthetic porcine NPY. The peroxidase-antiperoxidase procedure revealed that NPY immunoreactive cell bodies and nerve fibers were observed in the brain, optic lobes, corpora cardiaca, suboesophageal ganglion and ventral nerve cord of the locust and in the brain, optic lobes and suboesophageal ganglion of the fleshfly. In the locust midgut, numerous endocrine cells and nerve fibers penetrating the outer musculature contained NPY-like immunoreactivity.

Biological, chromatographical, and radioimmunological evidence for a melanotropin-like peptide in the central nervous system of Locusta migratoria.

Our recent immunocytochemical study has demonstrated the existence of alpha-melanocyte stimulating hormone (alpha-MSH)-like material in the locust central nervous system. The aim of the present study was to further characterize alpha-MSH in the locust brain by its biological effect on frog skin and by high-pressure liquid chromatography in combination with radioimmunological and biological detection methods. Parallel radioimmunoassay (RIA) curves of crude nervous tissue extracts coupled with bioactivity in a very specific bioassay suggest similarity between the locust alpha-MSH-like substance and synthetic alpha-MSH.

Coexistence of melanin-concentrating hormone and alpha-melanocyte-stimulating hormone immunoreactivities in the central nervous system of the locust, Locusta migratoria.

The distribution of melanin concentrating hormone (MCH) in the central nervous system of the locust Locusta migratoria was studied by the indirect immunofluorescence technique, using antibodies against salmon MCH. Most MCH-immunoreactive perikarya were found in the optic lobes at both sides of the brain, dorsally with respect to the lamina ganglionaris. The same neurons also contain alpha-melanocyte-stimulating hormone (alpha-MSH)-like material.

Methionine-enkephalin immunoreactivity in the gonads and nervous system of two insect species: Locusta migratoria and Sarcophaga bullata.

Methionine(met)-enkephalin immunoreactivity as visualized by the peroxidase-antiperoxidase procedure, is present in spermatogonia, spermatocytes, spermatids, and young ovarian follicles of Locusta (panoistic type) and Sarcophaga (polytrophic type). Follicle cells and mature spermatozoa are always immunonegative as are locust vitellogenic follicles. In oocytes and in trophocytes, the met-enkephalin-like material first appears around the nucleus and is then dispersed throughout the cytoplasm.

Model of jaw depression during feeding in Astatotilapia elegans (Teleostei: Cichlidae): Mechanisms for energy storage and triggering.

Suction feeding in Astatotilapia elegans occurs by a series of rapid, coupled movements of various head parts. The lower jaw rotates with respect to the neurocranium through an angle of 62° in less than 15 ms. The power requirements for jaw depression are calculated from a mathematical model and may reach a peak of ±4 watt in a 12-cm-long specimen.

The ecology of Lake Nakuru (Kenya) : V. Production and consumption of consumer organisms.

Consumer production and consumption were studied in the equatorial alkaline-saline Lake Nakuru from 1972 to 1976. Together with earlier reports (including a study of the dominant consumer, the Lesser Flamingo Phoeniconaias minor), the data provide the basis for estimating the major pathways of energy flow. Detritus food chains were not included in this project.

The ecology of Lake Nakuru (Kenya) : IV. Biomass and distribution of consumer organisms.

Consumer biomass and spatial distribution in the equatorial alkaline-saline Lake Nakuru were studied from 1972-1976. These data will provide the basis for estimating feeding and production rates and for quantifying energy flow at the consumer level. Two of the main consumers, the Lesser Flamingo (Phoeniconaias minor) and the Soda Tilapia (Sarotherodon alcalicus grahami), were covered by earlier papers.

The ecology of Lake Nakuru (Kenya) : III. Abiotic factors and primary production.

Abiotic factors, standing crop and photosynthetic production were studied in the equatorial alkaline-saline closed-basin Lake Nakuru (cond. 10,000-160,000 μS). Meteorological conditions and abiotic factors offer suppositions for a high primary productivity: mean solar radiation is 450-550 kerg·cm·s, with little seasonal variation, regular winds circulate the lake every day and nutrient concentrations are usually high (>100 μg P-PO·l).

Ganglioside changes in the chicken optic lobes and cerebrum during embryonic development : Transient occurrence of "novel" multisialo-gangliosides.

The developmental profiles of 15 different gangliosides of the optic lobes and cerebrum of the chicken were followed from the 6 th day of incubation to hatching and correlated to morphological development. Five of these gangliosides appearing in both structures between the sixth and tenth day, have not been reported previously in higher vertebrates. Three chromatographed on TLC-plates similarly to G, G, and G gangliosides, which have been demonstrated in fish brain.

Gangliosides, sialoglycoproteins and acetylcholinesterase of the developing mouse brain.

The developmental accretion of up to nine individual gangliosides in foetal brains, peri- and postnatal cortices, postnatal cerebelli and olfactory lobes and in the liver and the spleen were investigated in mice and compared with that of glycoprotein-bound sialic acid and the activity of the acetylcholinesterase.In foetal brain and in postnatal liver and spleen more sialic acid was found bound to glycoproteins than to gangliosides. In postnatal brain structures, however, ganglioside-NeuAc predominated and increased between the 7th and 21st d about 2-fold in the olfactory lobes and cerebellum and more than 3-fold in the cortex.

Factors effecting manubrium-regeneration in hydromedusae (Coelenterata).

1. Umbrellar fragments of the leptomedusaCampanularia johnstoni with or without parts of the radial canal demonstrate a gradient in the potential for manubrium regeneration and in regeneration time. 2.

Morphogenetic action of the subcommissural organ on tail regeneration inXenopus larvae.

In an earlier paper (Hauser, 1969) it was suggested that the subcommissural organ (SCO) in the roof of the diencephalon might control normal straight regeneration after amputation of the tail tip inXenopus larvae, by means of Reissner's fibre (RF) its secretory product in the central canal of the spinal cord. This hypothesis has been experimentally tested, with results that appear to confirm it, as follows: 1. Elective destruction of the SCO caused characteristically disturbed tail regeneration, while other brain lesions did not affect normal tail regeneration.