Centromeric heterochromatin in the karyotype of the male Greater Kudu (Tragelaphus strepsiceros)

Summary The chromosomes of a male Kudu (Tragelaphus strepsiceros) have been studied by C-banding and H³ thymidine labelling. It is suggested that heterochromatin may have accumulated on the 14th pair of autosomes before its translocation to the Y-chromosome.     

The karyotype of the black rat (Rattus rattus L.). Another population with a 38-chromosomes complement

Riassunto In una popolazione italiana diRattus rattus L. è stato messo in evidenza un cariotipo a 38 cromosomi; la differenza nel numero diploide rispetto a quanto noto per altre popolazioni della stessa specie è dovuta a due fusioni centriche in condizione omozigote. Il confronto con i cariotipi forniti da altri autori per la specieRattus rattus ci fa proporre anche per questa specie di Roditori la presenza di un fenomeno di polimorfismo cromosomico.     

The influence of the sex-hormone testosterone on body temperature and metabolism of the male Japanese quail (Coturnix coturnix japonica).

Testosterone causes a significant body temperature decrease in male quails. Oxygen consumption/g b. wt remains the same, however.     

Chemical basis of pupal cannibalism in a caterpillar (Utetheisa ornatrix).

The moth Utetheisa ornatrix derives protection against predation from systemic pyrrolizidine alkaloids (PAs) that it sequesters as a larva from its foodplants (Leguminosae, Crotalaria spp.). We here show, in laboratory tests, that Utetheisa deficient in body PA can make up for the chemical shortfall by cannibalizing pupae. We present evidence indicating that cannibalism in larvae is elicited not by hunger, but possibly by PA deficiency itself, and that in making cannibalistic choices larvae prefer PA-containing over PA-free pupae. PAs themselves, either in crystalline form or as additives to food items, proved phagostimulatory to larvae. In nature Utetheisa tend to pupate away from their foodplant, essentially out of reach of larval attack. The threat of cannibalism may have contributed to the evolution of this pupation behavior.     

The karyotype,C-bands and AgNO3-bands of a lungless salamander from Korea:Onychodactylus fischeri (Boulenger) (Amphibia,Urodela)

The karyotype of a lungless salamander,Onychodactylus fischeri, from Korea was analyzed and compared with that of the Japanese congeneric species,O. japonicus. In both species the diploid karyotype consists of78 chromosomes, including 6 pairs of large chromosomes, 6 pairs of medium-sized ones, and the remaining 27 pairs of microchromosomes. The chromosome number ofO. fischeri, 2n=78, is, like that ofO. japonicus, the largest so far reported in the order Urodela. C-banding showed that constitutive heterochromatin inO. fischeri was mainly in the centromeric regions and near the secondary constrictions of the large chromosomes. AgNO₃-bands were located in the secondary constrictions associated with C-band heterochromatin.     

Sexual receptivity of the female and insemination power of the male Culex pipiens autogenicus (Diptera, Culicidae). The cases of strict monogamy and occasional polygamy]

Females of Culex pipiens autogenicus generally have two refractory periods: post-emergence refractory period (during the first 48 hrs. after emergence) and post-insemination refractory period. Males of Culex pipiens autogenicus can inseminate 2 to 3 females. After the 4th insemination he can no longer completely fulfill his reproductory role. Therefore the female can inseminated by another male.     

Antischistosomal and some toxicological properties of a nitrodiphenylaminoisothiocyanate (C 9333-Go/CGP 4540).

A procedure to enhance the schistosomicidal effectiveness in vivo of an isothiocyanate derivative and some of its antischistosomal properties are reported. Determinations of the effects of this compound on tissue thiol levels and on highly sensitivity bacterial tester strains have indicated that its mutagenic potential is of a low order and that the latter is decreased further after reduction of the host's intestinal bacterial flora.     

New evidence of a 38-chromosomes karyotype in South American populations of the roof rat,Rattus Rattus L. (rodentia,muridae)

Resumen En dos poblaciones deRattus rattus, una de Mehuin (Valdivia, Chile) y otra de Capripe (Monagas, Venezuela), se encontró un cariotipo de 2n=38 cromosomas en todos los individuos estudiados. Este cariotipo corresponde al que presentan en forma monomórfica otras poblaciones de la rata negra de América del Sur y de Italia, y diffiere del cariotipo normal de la especie, que es de 42 cromosomas. Se postula que las distintas poblaciones sudamericans deRattus rattus deben haber invadido el Continente, acompañando al hombre, en distintas irrupciones, a partir de una forma de 38 cromosomas de origen mediterráneo.     

Lipid thesaurismosis rheumatism. Joint manifestation during glucocerebrosidase deficiency (Gaucher's disease). Ultrastructural study of the synovial membrane]

Articular inflammatory involvement may be the first sign of gluocecerebrosidase deficiency (Gaucher's disease). Electron microscope study shows specific synovial storage lesions which explain arthritic manifestations. Furthermore presence of mitochondrial microcrystals, (apatite?), suggest microcrystal pathogenesis of Gaucher's arthritis.     

Production of urea during mixed leukocyte culture (MLC). Effect of presensitization by a skin allograft]

An increased production of urea has been demonstrated during mixed cultures between allograft donor and recipient leukocytes. This phenomenon may also be observed during primary MLC (i.e, without previous allograft) but to a lesser degree. This increased production of urea during MLC results from an increase of arginase activity in spleen cell population(s) resulting in an increased arginine transformation into urea and ornithine, as demonstrated by the release of an amount of ornithine equivalent to that of urea in the culture supernatant.     

Cytogenetic studies of Hynobiidae (Urodela). XIV. Analysis of the chromosome of a Chinese salamander, Batrachuperus pinchonii (David)

The chromosome number of a Chinese salamander, Batrachuperus pinchonii, was re-examined. Adults and embryonic specimens had a diploid number of 66, with 33 bivalents during meiosis, in contrast to previous reported results. Furthermore, when C-banding analysis was performed with embryos, chromosomes with banding patterns homoeologous to those of Salamandrella keyserlingii and Hynobius species were found. It appears, therefore, that Batrachuperus, Salamandrella and Hynobius might be derived from a common ancestral species in eastern Asia. Received 22 August 1997; received after revision 14 October 1997; accepted 20 November 1997     

Sperm predence in a hermaphroditic nematode (Caenorhabditis elegans) is due to competitive superiority of male sperm

When male and hermaphroditeCaenorhabditis elegans mate, the male's sperm outcompete the hermaphrodite's own sperm and fertilize a majority of the offspring. Here, we investigate the mechanism of male sperm precedence. We rule out the possibility that male sperm are stronger and more competitive because they are activated later than hermaphrodite sperm. We also find that a previously known gender difference in sperm activation does not influence sperm competition. Male sperm, rinsed free of seminal fluid, retained the capacity to take precedence after artificial insemination. Therefore, we conclude that male sperm themselves are competitively superior to hermaphrodite sperm. This trait maximizes outcrossing after mating and may increase both genetic diversity and heterozygosity of offspring whose parents, due to self-fertilization, may be highly homozygous.     

The effects of a juvenile hormone analogue on the male reproductive organs of the red cotton bug,Dysdercus cingulatus (Heteroptera)

Summary The maleDysdercus cingulatus F., when treated with the JHa, methyl-3, 7, 11-trimethyl-7, 11-dichloro-2-dodecenoate, showed striking morphological deformities in the gonads, such as formation of additional apical growth on the testes, highly deformed, reduced vasa deferentia and accessory glands.Acknowledgments. We wish to thank Prof. P. Ramchender Rao, Head, Department of Zoology, Osmania University for facilities and encouragement. The financial assistance to P. Judson and B. Julius Divakar by the Council of Scientific and Industrial Research, New Delhi is gratefully acknowledged.     

Lipid thesaurismosis rheumatism. Arthropathies in alpha galactosidase A deficiency (Fabry's disease). Ultrastructural study of the synovial membrane demonstrating microcrystals in the mitochondria of synoviocytes]

Articular manifestations may be the onset of genetic alpha galactosidase deficiency (Fabry's disease). Ultrastructural study shows typical osmiophilic lamellar inclusions of trihexosylceramides in synoviocytes, capillaries and adipocytes. Furthermore microcrystals identical to those seen in Gaucher's disease and type II hyperlipoproteinemia were observed in mitochondria and free in cytoplasm. These data suggest a microcrystalline pathogenesis of these arthropathies, as in gout and chondrocalcinosis, and what we have generally called crystallopathic arthropathies.     

A cytogenetic study of a barbary sheep (Ammotragus lervia) x domestic goat (Capra hircus) hybrid

Summary An account is given of stillborn male twins born to a female Saanen goat (Capra hircus) and a Barbary ram (Ammotragus lervia). The cytogenetics of the cultured hybrid cells are described and attention is drawn to the high proportion of cells which lacked one chromosome.Acknowledgment. I. gratefully acknowledge the help of Mr G.E. Embleton who took the skin biopsy of the Barbary ram.