Interspecific play between free ranging guerezas (Colobus guereza) and vervet monkeys (Cercopithecus aethiops)

Interspecific play, like other interspecific interactions, seems to be rare among free-living primates, despite the fact that polyspecific associations occur quite frequently, especially among forest-living species. A number of instances of play between young guerezas and vervet monkeys are described. This play may be dyadic, individual-group, or group-group and usually involves non-contact types of play. It is suggested that interspecific play is most likely to occur if the ranging patterns of groups of sympatric species remains the same over considerable periods of time, if animals of similar ages are of similar sizes, if social signals associated with play are similar, if play activities are performed in a similar way, and if the temporal organization of play bouts is the same.     

Cloned MPC 11 myeloma cells express two kappa genes: a gene for a complete light chain and a gene for a constant region polypeptide.

Cloned MPC 11 mouse plasmacytoma cells synthesize a complete kappa light chain and also a kappa light chain constant region fragment. Partial amino terminal sequences of the in vitro forms of these two proteins have been determined. Both in vitro products contain typical light chain leaders; leaders are defined as the amino terminal sequences present on in vitro products but absent from the in vivo products found in living cells. The in vitro form of the MPC 11 complete light chain contains a leader sequence plus variable and constant region sequences. The in vitro form of the MPC 11 light chain constant region fragment contains a different leader sequence attached directly to a complete constant ragion sequence and has no variable region sequences. Thus the MPC 11 light chain fragment is not a degradation product of the MPC 11 complete light chain (or of any other complete light chain) and must be coded by a separate gene. The results reveal two unusual features of MPC 11 cells: first, expression of a unique variant light chain gene coding the light chain constant region fragment, and second, expression of two different kappa light chain genes (coding the complete light chain and the variant constant region fragment) in a single cell. In addition, evidence is provided that the in vitro forms of kappa light chains, three of which are presented here for the first time, include a minimum of three partially homologous but quite different leader sequences.     

Fetal mouse lung in circumfusion system cultures

Summary Fetal mouse lungs were cultivated, using the dual-rotary circumfusion system for tissue culture, and their histotypic development was surveyed for 75 days by phase-contrast and electron microscopy. Alveoli, terminal bronchioles and alveolar macrophages were photographed periodically with still and time-lapse phase-contrast microscopy. Their histotypic appearance was confirmed by electron micrographs of the 1- and 2 1/2-month-old specimens. These revealed typical alveoli surrounded by a basal lamina and composed of types I and II pneumocytes containing various lamellar-body forms within the type II cells, the alveolar lumen, and the alveolar macrophages. There was a shift from almost all type II cells in the 1-month-old alveoli to the presence of frequent type I cells as constituents of the alveoli in the 2 1/2-month-old cultures. The terminal bronchioles were tubules consisting of ciliated cells with Clara cells interspersed between them. The ciliated cells contained as many as 30 cilia or basal bodies per section and numerous microvilli. They were attached to each other and to the Clara cells by junctional complexes and accessory desmosomes which were generally in the apical ends of the cells. The Clara cells typically had glycogen granules interspersed between lamellae of the endoplasmic reticulum, contained numerous well dispersed mitochondria, occasional lysosome-like granules and crystalloid bodies which appeared to be tubular. Some Clara cells presented a moderately dense secretory granule in the center of the whorl of the endoplasmic reticulum. This work supported by Grant HL19684 from the National Heart and Lung Institute, National Institutes of Health. Pregnant Strong A mice were kindly supplied by Dr. Henry Browning of the Department of Anatomy.     

Mortality from coronary heart disease and stroke in relation to degree of glycaemia: the Whitehall study.

In the Whitehall study of 18 403 male civil servants aged 40-64 years the 10 year mortality rates from coronary heart disease and stroke showed a non-linear relation to two hour blood glucose values, with a significantly increased risk for glucose intolerant subjects with concentrations above the 95th centile point (5.4-11.0 mmol/l; 96-199 mg/100 ml) and for diabetics (blood glucose greater than or equal to 11.1 mmol/l; greater than or equal to 200 mg/100 ml). Multiple logistic analysis showed that between one half and three quarters of the relative risks for deaths from coronary heart disease and stroke were "unexplained" by between group differences in risk factors such as age, blood pressure, obesity, smoking, cholesterol concentration, and electrocardiographic abnormalities. Within the glucose intolerant and diabetic groups the risk factors most strongly related to subsequent death from coronary heart disease were age and blood pressure, with less consistent relations for smoking, cholesterol concentration, and obesity. This study confirms the importance of hypertension as a cardiovascular risk factor in groups with glucose intolerance and diabetes, and this may have important preventive implications.     

Evolutionary conservation of intron position in a subfamily of genes encoding carbohydrate-recognition domains

The structure of the gene encoding a chicken liver receptor, the chicken hepatic lectin, which mediates endocytosis of glycoproteins has been established. The coding sequence is divided into six exons separated by five introns. The first three exons correspond to separate functional domains of the receptor polypeptide (cytoplasmic tail, transmembrane sequence, and extracellular neck region), while the final three exons encode the Ca(2+)-dependent carbohydrate-recognition domain. These results, as well as computer-assisted multiple sequence comparisons, establish this receptor as the evolutionary homolog of the mammalian asialoglycoprotein receptors. It is interesting that the chicken receptor falls into a subfamily of proteins along with the mammalian asialoglycoprotein receptors, since the saccharide-binding specificity of the chicken receptor resembles more closely that of a different set of calcium-dependent animal lectins, which includes the mannose-binding proteins. The portions of the genes encoding the carbohydrate-recognition domains of these proteins lack introns. The results suggest that divergence of intron-containing and intron-lacking carbohydrate-recognition domains preceded shuffling events in which other functional domains were associated with the carbohydrate-recognition domains. This was followed by further divergence, generating a variety of saccharide-binding specificities.     

Lateral diffusion of membrane-spanning and glycosylphosphatidylinositol-linked proteins: toward establishing rules governing the lateral mobility of membrane proteins.

In the plasma membrane of animal cells, many membrane-spanning proteins exhibit lower lateral mobilities than glycosylphosphatidylinositol (GPI)-linked proteins. To determine if the GPI linkage was a major determinant of the high lateral mobility of these proteins, we measured the lateral diffusion of chimeric membrane proteins composed of normally transmembrane proteins that were converted to GPI-linked proteins, or GPI-linked proteins that were converted to membrane-spanning proteins. These studies indicate that GPI linkage contributes only marginally (approximately twofold) to the higher mobility of several GPI-linked proteins. The major determinant of the high mobility of these proteins resides instead in the extracellular domain. We propose that lack of interaction of the extracellular domain of this protein class with other cell surface components allows diffusion that is constrained only by the diffusion of the membrane anchor. In contrast, cell surface interactions of the ectodomain of membrane-spanning proteins exemplified by the vesicular stomatitis virus G glycoprotein reduces their lateral diffusion coefficients by nearly 10-fold with respect to many GPI-linked proteins.     

Quantitative Genetics of Postponed Aging in Drosophila Melanogaster. I. Analysis of Outbred Populations

Selection has been used to create replicated outbred stocks of Drosophila melanogaster with increased longevity, increased later fecundity, and increased levels of physiological performance at later ages. The present study analyzed the quantitative transmission patterns of such stocks, employing extensive replication in numbers of stocks, individuals, and assayed characters. The populations used derived from five lines with postponed aging and five control lines, all created in 1980 from the same founding base population. The following characters were studied: early 24-hr fecundity, early ovary weight, early female starvation resistance, early male starvation resistance, female longevity and male longevity. Numerous crosses were performed to test for non-Mendelian inheritance, average dominance, maternal effects, sex-linkage and between-line heterogeneity. There was only slight evidence for any of these phenomena arising reproducibly in the characters studied. These findings suggest the value of this set of stocks for studies of the physiological basis of postponed aging.     

Incorporation of the gene for a cell-cell channel protein into transformed cells leads to normalization of growth

Summary Incorporation of the gene for connexin 43, a cell-cell channel protein of gap junction, into the genome of communication-deficient transformed mouse 10T1/2 cells restored junctional communication and inhibited growth. Growth was slowed, saturation density reduced and focus formation suppressed, and these effects were contingent on overexpression of the exogenous gene and the consequent enhancement of communication. In coculture with normal cells the growth of the connexin overexpressors was completely arrested, as these cells established strong communication with the normal ones. Thus, in culture by themselves or in coculture, the connexin overexpressor cells grew like normal cells. These results demonstrate that the cell-cell channel is instrumental in growth control; they are the expected behavior if the channel transmits cytoplasmic growth-regulatory signals.     

Crystallographic analysis of the neurophysin-oxytocin complex. A preliminary report

Single crystals of a bovine neurophysin II-oxytocin complex have been obtained using (NH4)2SO4 as the precipitating agent. The crystals diffract to at least 2.7 A resolution, belong to Laue group 4/mmm and exhibit systematic absences consistent with either space group P4(1)2(1)2 or P4(3)2(1)2. The cell dimensions are a = b = 69.07 A and c = 113.26 A. The crystals contain one neurophysin-oxytocin dimer per asymmetric unit. Based on a Vm of 2.9 A3/Da, the solvent content is calculated to be 58%. Chromatographic analysis of the dissolved crystals suggests the presence of three oxytocin molecules per neurophysin dimer.     

Fatty Acid Oxidation and Ketogenesis by Astrocytes in Primary Culture

The oxidation of the fatty acids octanoate and palmitate to CO2 and the ketone bodies acetoacetate and D-(-)-3-hydroxybutyrate was examined in astrocytes that were prepared from cortex of 2-day-old rat brain and grown in primary culture to confluence. Accumulation of acetoacetate (by mass) in the culture medium of astrocytes incubated with octanoate (0.3-0.5 mM) was 50-90 nmol C2 units h-1 mg of protein-1. A similar rate was obtained using radiolabeled tracer methodology with [1-14C]octanoate as labeled substrate. The results from the radiolabeled tracer studies using [1-14C]- and [7-14C]octanoate and [1-14C]-, [13-14C]-, and [15-14C]palmitate indicated that a substantial proportion of the omega-terminal four-carbon unit of these fatty acids bypassed the beta-ketothiolase step of the beta-oxidation pathway and the 3-hydroxy-3-methylglutaryl (HMG)-CoA cycle of the classic ketogenic pathway. The [14C]acetoacetate formed from the 1-14C-labeled fatty acids, obligated to pass through the acetyl-CoA pool, contained 50% of the label at carbon 3 and 50% at carbon 1. By contrast, the [14C]acetoacetate formed from (omega-1)-labeled fatty acids contained 90% of the label at carbon 3 and 10% at carbon 1, whereas that formed from the (omega-3)-labeled fatty acid contained 20% of the label at carbon 3 and 80% at carbon 1. These results indicate that acetoacetate is primarily formed either by the action of 3-oxo-acid-CoA transferase (EC 2.8.3.5) or acetoacetyl-CoA deacylase (EC 3.1.2.11) or both on acetoacetyl-CoA and not by the action of the mitochondrial HMG-CoA cycle involving HMG-CoA lyase (EC 4.1.3.4), which was readily detected, and HMG-CoA synthase (EC 4.1.3.5), which was barely measurable.