Multiple variants in subtelomeric regions of normal karyotypes

We describe a human genomic cosmid clone, 56.1.1, that contains subtelomeric sequences present on multiple human chromosomes. In particular, using fluorescence in situ hybridization, we have identified 16 sites of hybridization on 12 chromosomes. In a sample of 8 unrelated individuals, 10 of these sites showed interindividual variation. Co-hybridization with other polymorphic probes allowed us to demonstrate cytologically heterozygosity at three sites in six individuals. The chromosomal distribution of hybridization sites in a family strongly suggests that these variants are inherited in a Mendelian fashion. These data show that subtelomeric repeats are a rich source of genetic variability. Possible mechanisms of generation of such variants are discussed.     

Effects of experience on palatability hierarchies of novel plants in the polyphagous grasshopperSchistocerca americana

Summary We studied the influence of diet composition and breadth on the subsequent acceptability of three novel plants to sixth instarSchistocerca americana. Rearing diets of equal breadth differing in composition, and diets differing in breadth, significantly altered first meal length on some but not all of the test plants. These effects on palatability altered and at times reversed the palatability hierarchy of insects reared on different diets. The effects of rearing insects on broad diets were not produced by exposure to the plant odors alone, but apparently required contact with a diversity of plants while feeding. Switching diets for 24 h prior to testing did not alter preferences induced by rearing diets. The relationship of these patterns to induced preferences in other insects, and some possible mechanisms for generating induced preferences, are discussed.     

Surface heterogeneity of bovine sperm revealed by aqueous two-phase partition

Ejaculated, bovine sperm have been subjected to multiple partition in aqueous two-phase systems. This partition, carried out in a countercurrent fashion, reveals heterogeneity of the sperm population with respect to surface properties. The sperm, when partitioned in phase systems that detect non-change associated surface properties (change-insensitive) are largely distributed as two distinct populations. In charge-sensitive phase systems (which principally detect cell surface molecules carrying charge) the sperm do not show any obvious surface heterogeneity. Considerable heterogeneity is revealed in affinity-ligand phase systems containing palmitic acid coupled to one of the phase components-poly(ethylene glycol). There is a difference in surface heterogeneity between sperm which have been washed in buffer or left unwashed, direct from the ejaculate. This is indicative of weak adsorption of proteins to the sperm surface in seminal fluid. These results show that bovine ejaculated sperm is a heterogeneous cell population having unequal distributions of a number of different surface molecules.     

四川省西部鱼类寄生粘孢子虫——1.粘体虫属六新种(粘孢子纲:双壳目)

本文报导四川省西部鱼类寄生粘孢子虫粘体虫属六新种,即异型粘体虫,新种Myxosoma disparis sp.nov.,四川粘体虫,新种Myxosoma sichuanensis sp.nov.,光唇粘体虫,新种Myxosoma acrossochilusi sp.nov.鳅粘体虫,新种Myxosoma nemachilusi sp.nov.斜囊粘体虫,新种Myxosoma obliqua sp.nov.,雅安粘体虫,新种Myxosoma yaanensis sp.nov.。     

Temporal events of gypsy moth vitellogenesis and ovarian development

Abstract The vitellogenic period of gypsy moth ovarian development starts on day 3 of the pupal stage and continues through adulthood. During this period, rapid increases occur in follicle size, protein content, and wet weight of the ovary. Patency is observed on day 3 of the pupal stage.
Pre-vitellogenic follicles are formed in the last larval stadium. Newly formed follicles detach from the germarium on day 4, and increase rapidly to 140 per ovariole at the end of the last larval stadium. The pre-vitellogenic follicles are uniformly around 50 um in diameter. No vitellogenin is incorporated into the oocytes until the pupal stage.
Polyacrylamide gel electrophosesis (PAGE) in the presence of sodium dodecylsulphate (SDS) analysis of male and female haemolymph samples and vitellogenic ovaries demonstrates the presence of two female-specific subunits of vitellogenin of 180 kD and 160 kD. These proteins are detected only in haemolymph and ovarian extracts of vitellogenic females. The molecular weight of the native protein determined by size exclusion chromatography is approximately 400–420 kD.
A highly sensitive double antibody sandwich enzyme-linked immunosorbent assay (ELISA) was developed to monitor the temporal changes in vitellogenin titre in haemolymph. Vitellogenin production starts on day 2 of the last larval stadium, reaching a maximum level by day 6 of the last larval stadium, and decreasing in the late pupal stage as vitellogenin was internalized into the oocytes. This is the first report of vitellogenin production occurring in the larval stage of a holometabolous insect. The fact that vitellogenin production and uptake occur during different stages of development in the gypsy moth, opens up some interesting questions concerning the underlying regulatory mechanisms controlling each process.     

The diagnostic accuracy of sputum and urine cytology

The diagnostic accuracies of sputum and urinary cytology were examined in series spanning more than 20 years. The sensitivity and respiratory tract cytology in 1,289 patients with subsequently proven lung cancer was 69% while that or urine cytology in 860 patients with urinary tract cancer was 77%. The specificities were 96% for lung cancer and 97% for urinary tract cancer. Neither procedure was widely used for routine screening, but diagnostic cytology played an important part in providing a definite morphologic diagnosis in many of these cases. Urinary cytology was also very effective in the follow-up of patients with treated bladder cancer because of its high sensitivity for detecting carcinoma in situ.     

Factors influencing species diversity in saline waters of Death Valley,USA

Salinity is a major factor influencing the distributions and abundances of aquatic macroinvertebrates of saline waters in Death Valley, California, USA. A general pattern of declining numbers of species with increasing salinity is seen in Death Valley waters. Some species are restricted to low salinities, others are found only in highly saline pools, and still others are widely distributed over a broad range of salinities.Salinity alone cannot explain distributions seen in the field. Distributions and abundances of species such as the caddisfly Limnephilus assimilis Banks are broader than would be predicted on the basis of laboratory studies of salinity and temperature. I present evidence that for such species, biotic factors such as reduced predation at high salinities may compensate for increased physiological stress.