Shell abnormalities in scaphitid ammonites

The kinds incidence of shell abnormalities were investigated in over 2000 adult Late Cretaceous scaphitid ammonites. Most are species of Hoploscaphites Discoscaphites from the Maastrichtian Fox Hills Formation; for comparison, four older species of Scaphites were also studied. Four kinds of abnormalities vary in their incidence among the Fox Hills taxa but display no general trends. (1) Morton's syndrome, shell asymmetry unrelated to external injury, occurs in 3 to 6% of the Fox Hills scaphites. (2) Suture wander. veering-off of the ventral lobe of the suture from the midline of the venter, occurs in most Fox Hills taxa with an incidence ranging from 1 to 11%. (3) Stretch pathology, an attenuation of the shell on the posterior part of the adult body chamber, is confined to Hoploscaphifes nicolleti. (4) Externally inflicted injury, indicated by repaired damage on mature shells, has an average incidence of 10% in Fox Hills scaphites except in the stratigraphically youngest H. nebrascensis H. cheyennewis which approach 25 40% respectively. Good correlation between percent injuries adult size ornamentation is obtained only in Discoscaphifes; all morphs of the co-occurring Hoploscaphites display nearly the same incidence of injuries regardless of their morphologic variation. The stratigraphically youngest H. nebrascensis becomes larger more nodose simultaneously sustains more injuries. However, its dimorph H. cheyennensis remains morphologically unchanged although its incidence of injuries quadruples. These injury data, in themselves, do not support the hypothesis that predators were contributing more heavily to the mortality of Maastrichtian ammonites precipitated their extinction.     

An elongated segment of DNA observed between two human α globin genes

Summary Detailed restriction enzyme analysis of the DNA from a Chinese female showed that one of her chromosomes had a >17.5 kb deletion of DNA, including the , 2, and 1 globin genes, which is present in many Southeast Asians with an -thalassemia-1 chromosome. Her normal chromosome had the expected cluster of -like globin genes (5----2-1-3), but the segment of DNA between the two globin genes was elongated by some 0.5–0.7 kb. Analyses of various restriction sites suggested that this normal variant of the human globin gene complex is due to a crossover between a normal chromosome with () and a chromosome with an -thalassemia-2 (–^3.7) and an -21-hybrid gene.     

Control of the Synthesis of Macromolecules During Amino Acid and Thymine Starvation in Bacillus subtilis

Studies of Maal?e, Lark, and others with amino acid- and thymine-starved cultures revealed successive steps in the biosynthesis of Escherichia coli chromosomes. In this study, the corresponding mechanisms in Bacillus subtilis 168 were examined. Using a strain requiring both thymine and tryptophan, we found that, 3 hr after the start of amino acid starvation, when the deoxyribonucleic acid (DNA) content of the culture had increased 40 to 50%, DNA synthesis ceased. After 4 to 5 hr, 100% of the cells were immune to thymineless death; their chromosomes had presumably been completed. Immune cultures slowly incorporated (3)H-thymine. Thymine incorporation increased 20-fold 30 min after readdition of amino acids, indicating reinitiation of chromosome synthesis. Simultaneous presence of amino acids and thymine was required for reinitiation. If 5-bromouracil (5-BU) was added instead of thymine, newly replicated DNA segments could be separated by centrifugation in CsCl. Analysis of the CsCl fractions by a transformation assay showed that the order in which the markers were synthesized was ade-16, thr-5, leu-8, metB5. Less than half the chromosomes started resynthesis synchronously in 5-BU. Nevertheless, chromosome alignment in the amino acid-starved culture is probably very good: marker frequency analysis of its DNA gives the same normalized frequencies as DNA from "perfectly" aligned spores. Full viability is maintained in the chromosome-arrested culture for 10 hr in thymine-free medium in the absence or presence of amino acids. In the latter condition, protein synthesis proceeds, and the cells filament and become more lysozyme-sensitive. Such cells must be incubated and plated on hypertonic or on slow-growth media; otherwise, they undergo "quasiosmotic" thymineless death. This death is thus apparently not directly attributable to any damage of chromosomal DNA. Further, weakening of the teichoic acid portion of the cell wall is not involved, since (32)P incorporation into teichoic acid is normal. Chloramphenicol prevents quasiosmotic thymineless death and also inhibits (32)P incorporation into teichoic acid. Chromosome-synthesizing cultures suffer thymineless death of two types: quasiosmotic death, and death insusceptible to osmotic rescue.     

Genetic Signature of Histiocytic Sarcoma Revealed by a Sleeping Beauty Transposon Genetic Screen in Mice

Histiocytic sarcoma is a rare, aggressive neoplasm that responds poorly to therapy. Histiocytic sarcoma is thought to arise from macrophage precursor cells via genetic changes that are largely undefined. To improve our understanding of the etiology of histiocytic sarcoma we conducted a forward genetic screen in mice using the Sleeping Beauty transposon as a mutagen to identify genetic drivers of histiocytic sarcoma. Sleeping Beauty mutagenesis was targeted to myeloid lineage cells using the Lysozyme2 promoter. Mice with activated Sleeping Beauty mutagenesis had significantly shortened lifespan and the majority of these mice developed tumors resembling human histiocytic sarcoma. Analysis of transposon insertions identified 27 common insertion sites containing 28 candidate cancer genes. Several of these genes are known drivers of hematological neoplasms, like Raf1, Fli1, and Mitf, while others are well-known cancer genes, including Nf1, Myc, Jak2, and Pten. Importantly, several new potential drivers of histiocytic sarcoma were identified and could serve as targets for therapy for histiocytic sarcoma patients.     

Characterization of the human visceral adipose tissue secretome

Adipose tissue is an endocrine organ involved in storage and release of energy but also in regulation of energy metabolism in other organs via secretion of peptide and protein hormones (adipokines). Especially visceral adipose tissue has been implicated in the development of metabolic syndrome and type 2 diabetes. Factors secreted by the stromal-vascular fraction contribute to the secretome and modulate adipokine secretion by adipocytes. Therefore, we aimed at the characterization of the adipose tissue secretome rather than the adipocyte cell secretome. The presence of serum proteins and intracellular proteins from damaged cells, released during culture, may dramatically influence the dynamic range of the sample and thereby identification of secreted proteins. Part of the study was therefore dedicated to the influence of the culture setup on the quality of the final sample. Visceral adipose tissue was cultured in five experimental setups, and the quality of resulting samples was evaluated in terms of protein concentration and protein composition. The best setup involved one wash after the 1st h in culture followed by two or three additional washes within an 8-h period, starting after overnight culture. Thereafter tissue was maintained in culture for an additional 48-114 h to obtain the final sample. For the secretome experiment, explants were cultured in media containing L-[(13)C(6),(15)N(2)]lysine to validate the origin of the identified proteins (adipose tissue- or serum-derived). In total, 259 proteins were identified with > or =99% confidence. 108 proteins contained a secretion signal peptide of which 70 incorporated the label and were considered secreted by adipose tissue. These proteins were classified into five categories according to function. This is the first study on the (human) adipose tissue secretome. The results of this study contribute to a better understanding of the role of adipose tissue in whole body energy metabolism and related diseases.     

Adsorption of bacteriophages phi 29 and 22a to protoplasts of Bacillus subtilis 168.

Adsorption of bacteriophages phi 29 and 22a to protoplasts of Bacillus subtilis 168 is described. The number of binding sites on bacilli and protoplasts is determined for each phage. Bacilli and protoplasts possess roughly the same number of sites per unit area for phi 29, i.e., approximately 700 sites per bacillus. There are also approximately 700 sites per bacillus for 22a, but only about one-third as many sites per unit area on the protoplast surface. A model for phi 29 adsorption is proposed.     

Effect of three low-dose fish oil supplements, administered during pregnancy, on neonatal long-chain polyunsaturated fatty acid status at birth

Adequate long-chain polyunsaturated fatty acid (LCP) status during pregnancy is important. We studied the effect of three low-dose fish oil supplements, administered during uncomplicated pregnancy, on neonatal LCP status at term delivery. Supplements were administered from the second trimester to delivery, either as fish oil capsules ("fish-1": 336 mg LCPomega3, n=15; and "fish-3": 1,008 mg LCPomega3, n=20) or milk-based supplement ("Mum": 528 mg LCPomega3, n=24). Fifty-seven untreated women served as controls. Fatty acids of umbilical veins (UV) and arteries (UA) were measured. The fish-1 group showed no differences, compared to controls. The Mum group had higher 20:5omega3, 22:5omega3, 22:6omega3, LCPomega3 and 22:6omega3/22:5omega6 in UV and UA. The fish-3 group had higher 22:5omega3 and 22:6omega3 (UA), LCPomega3 and 22:6omega3/22:5omega6 (UV and UA) and 20:3omega6 (UV). A 500-1000 mg daily LCPomega3 supplement, taken either as a milk-based supplement or fish oil capsules, effectively increases fetal LCPomega3 status, without affecting LCPomega6 status.     

How should a clever baboon choose and move rocks?

Chacma baboons (Papio ursinus) intentionally overturn rocks to feed on the invertebrates beneath. However, baboons do not move all the rocks they encounter, with this presumably reflecting cost–benefit (or effort–reward) trade‐offs in their foraging behavior. We ask, how do “clever baboons” choose rock sizes and shapes and move these rocks? Using optimal foraging theory, we predicted that baboons would prefer to move medium‐sized rocks, a trade‐off between moving larger rocks that might require more effort to move, and smaller rocks that likely do not provide enough prey (the reward) to make the effort worthwhile. We also expected baboons to prefer rounded rocks as these will require less energy to move by rolling (rather than being flipped as for flat rocks) and that the effort of rock movement might be offset by moving rocks along the shortest axis. We show that baboons have clear preferences for specific rock sizes (medium‐sized) and shapes (angular and flat when these were medium‐sized), and the way in which rocks are moved (along the shortest axis). Prey occurred infrequently under rocks. The low predictability of prey beneath rocks suggests that such prey, when encountered, is of considerable value to baboons for them to expend the search effort, and also explains the extensive nature of rock movement by baboons in the landscape. Our study provides a novel application of the optimal foraging theory concept and has important implications for understanding and predicting how animals choose to move rocks.