Autumnal moth – why autumnal?

1. As for some other spring‐feeding moths, adult flight of Epirrita autumnata (Lepidoptera: Geometridae) occurs in late autumn. Late‐season flight is a result of a prolonged pupal period. Potential evolutionary explanations for this phenological pattern are evaluated. 2. In a laboratory rearing, there was a weak correlation between pupation date and the time of adult emergence. A substantial genetic difference in pupal period was found between two geographic populations. Adaptive evolution of eclosion time can thus be expected. 3. Metabolic costs of a prolonged pupal period were found to be moderate but still of some ecological significance. Pupal mortality is likely to form the main cost of the prolonged pupal period. 4. Mortality rates of adults, exposed in the field, showed a declining temporal trend from late summer to normal eclosion time in autumn. Lower predation pressure on adults may constitute the decisive selective advantage of late‐season flight. It is suggested that ants, not birds, were the main predators responsible for the temporal trend. 5. Egg mortality was estimated to be low; it is thus unlikely that the late adult period is selected for to reduce the time during which eggs are exposed to predators. 6. In a laboratory experiment, oviposition success was maximal at the time of actual flight peak of E. autumnata, however penalties resulting from sub‐optimal timing of oviposition remained limited.     

Cloning of cDNAs for human phosphoribosylpyrophosphate synthetases 1 and 2 and X chromosome localization of PRPS1 and PRPS2 genes

Cloned cDNAs representing the entire, homologous (80%) translated sequences of human phosphoribosylpyrophosphate synthetase (PRS) 1 and PRS 2 cDNAs were utilized as probes to localize the corresponding human PRPS1 and PRPS2 genes, previously reported to be X chromosome linked. PRPS1 and PRPS2 loci mapped to the intervals Xq22-q24 and Xp22.2-p22.3, respectively, using a combination of in situ chromosomal hybridization and human x rodent somatic cell panel genomic DNA hybridization analyses. A PRPS1-related gene or pseudogene (PRPS1L2) was also identified using in situ chromosomal hybridization at 9q33-q34. Human HPRT and PRPS1 loci are not closely linked. Despite marked cDNA and deduced amino acid sequence homology, human PRS 1 and PRS 2 isoforms are encoded by genes widely separated on the X chromosome.     

Genetic control of the mitochondrial form of superoxide dismutase in hexaploid wheat

Extracts of mature grains of a large number of aneuploid derivatives of Triticum aestivum cv. Chinese Spring and of the members of five wheat-alien chromosome addition series were subjected to isoelectric focusing in polyacrylamide gels in order to study the genetic control of superoxide dismutase (SOD). Evidence was obtained that homologous structural genes for the mitochondrial form of SOD are located in the long arms of the homoeologous group 2 chromosomes of Chinese Spring and in chromosome 2R of Secale cereale cv. Imperial. The SOD gene loci located in chromosomes 2A, 2B, 2D, and 2R were designated Sod-A1, Sod-B1, Sod-D1, and Sod-R1, respectively. Chromosome-arm pairing data indicate that 2DL is not homoeologous to either 2AS or 2BL. The results of this study suggest, however, that 2BL is partially homoeologous to both 2AL and 2DL.Technical article No. 21074 of the Texas Agricultural Experiment Station. This work was supported by USDA Grant 83-CRCR-1-1322 to GEH.     

Chromosomal location of genes controlling flavonoid production in hexaploid wheat

Two-dimensional paper chromatography was performed on methanol extracts of leaves of hexaploid bread wheat, Triticum aestivum L. em. Thell. cultivar Chinese Spring, and of the available nullisomic-tetrasomic compensating lines, the tetrasomic lines and the ditelocentric lines. The chromatograms had 27 spots identified as flavonoids and six representing phenolic acids. Some of the areas were complex and contained more than one compound. Four flavonoids were identified as under the control of gene(s) on chromosome arms 1DS, 4DL, 5AS and 6BS. A phenolic glycoside was concluded to be controlled by a gene(s) on chromosome arm 7BL. Gene(s) on chromosome arm 4DL affected the amount of compounds in two other spots, and gene(s) on chromosome arm 4BS reduced the level of all flavonoid compounds. The individual compounds in some of the complex spots may be under the control of gene(s) on homoeologous chromosomes.     

Granulocyte-macrophage colony-stimulating factor increases synthesis and expression of CR1 and CR3 by human peripheral blood neutrophils

Polymorphonuclear leukocytes (PMN) constitutively synthesize various plasma membrane proteins including CR1(3) (CD35), CR3 (or Mac-1) alpha-chain (CD11b) and MHC class I. PMN are also able to up-regulate rapidly the expression of CR1 and CR3 to the plasma membrane in response to agonists such as FMLP. To determine whether constitutive PMN translation was static or up-regulatable, PMN were cultured in the presence or absence of the cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) for 8 h. CR1, CR3 and class I proteins immunoprecipitated from lysates of 35S-methionine pulse-labeled PMN were resolved by SDS-PAGE, fluorographed and quantified by densitometry. GM-CSF-treated PMN synthesized 4.5-fold more class I protein, 3.7-fold more CR1, 2.4-fold more CD11b and 3.4-fold more CR3 beta-chain (CD18), compared with untreated control cells. Actinomycin D treatment of replicate samples of PMN decreased the amount of these proteins synthesized by each group of PMN from 30 to 90%, implying that continued translation was required for the increases in protein synthesis. Nascent CR and class I proteins were inserted into the plasma membrane of PMN, thereby supplementing the molecules already expressed on the cell surface. In addition to these longer term effects of GM-CSF, we observed its acute up-regulatory effects on PMN. GM-CSF induced a five- to 12-fold increase in the expression of CR1 and CR3 on the PMN cell surface within 30 min. These increases were both dose- and time-dependent with maximum up-regulation occurring at 25 pM and at 30 min. In contrast to the long term biosynthetic events, this rapid up-regulation was not dependent on protein synthesis but was due instead to mobilization of CR from intracellular compartments similar to those up-regulated by FMLP. These results demonstrate that PMN can respond to microenvironmental stimuli such as GM-CSF both by rapidly up-regulating and increasing translation and expression of functionally important plasma membrane proteins.     

A novel product of the Duchenne muscular dystrophy gene which greatly differs from the known isoforms in its structure and tissue distribution.

In Swiss 3T3 cells, depletion of protein kinase C (PKC) by prolonged incubation with phorbol esters potentiates the formation of total inositol phosphates in response to bombesin or vasopressin [Blakeley, Corps & Brown (1989) Biochem. J. 258, 177-185]. The characteristics of the accumulation of inositol phosphates in control and PKC-depleted cells stimulated by bombesin, vasopressin or prostaglandin F2 alpha (PGF2 alpha) have now been compared. The potentiation of the PGF2 alpha response was greater than that of the vasopressin response which was, in turn, greater than that of the bombesin response. The time courses of the responses to all three agonists were biphasic, and both phases of the response were amplified in the PKC-depleted cells. These results provide further evidence for the involvement of a PKC-mediated negative-feedback loop regulating phosphoinositide hydrolysis in response to several 3T3 cell mitogens. The differential potentiation of the response to these agonists suggests that PKC might act at multiple sites within the signal transduction pathway.     

Reliability and stability of mothers' reports about their pregnancies with twins.

The objective of this study was to determine if mothers' retrospective reports about events in their pregnancies with twins are reliable and stable. Six hundred and twenty-four mothers completed psychiatric interviews about their twins. These interviews also contained questions about the mothers' pregnancies, the perinatal period, and the child's early development. The mothers reported first on one twin and then on the other with interviews spaced from 3 days to 2 weeks apart. Thus mothers reported on the same pregnancy twice. Of these mothers, 47 were re-interviewed 6 to 18 months later by raters blind to the results of the initial interview. The twin design allowed us to compare the short-term reliability of the 624 mothers' reports of the same pregnancy. The re-interview of the 47 mothers enabled us to compare the stability of reports over a longer time period. Agreement between the reports was measured with the kappa statistic. Kappas were good to excellent for the short-term reports of pregnancy for each twin for the 624 mothers. Kappas were equally high for the 47 mothers that were re-interviewed 6 to 18 months later. Mothers show good reliability and stability of reporting about events during pregnancy.     

The growth and nutrient utilization of the insect cell line Spodoptera frugiperda Sf9 in batch and continuous culture

The growth of the Spodoptera frugiperda cell line Sf9 was studied in batch and continuous culture. The results of batch cultivations showed that glucose was the preferred energy and carbon source limiting the cell density in both TNM-FH and IPL-41 media. Continuous culture using IPL-41-based feeding medium with different glucose (2.5, 5 and 10 g l⁻¹) and yeast extract concentrations (4, 8 and 16 g l⁻¹) showed that in serum-supplemented medium the maximum cell density was limited by glucose and yeast extract concentration. The transition to glucose limitation caused a decrease in growth rate and viability. A high cell density culture (18 × 10⁶ ml⁻¹) was obtained using a glucose concentration of 10 g l⁻¹ and a yeast extract concentration of 8 g l⁻¹ in the feeding medium. A yeast extract concentration of 16 g l⁻¹ inhibited growth. Unlike mammalian cell cultures, lactate, alanine and ammonia were not involved in growth inhibition. Lactate did not accumulate under aerobic conditions. Ammonia accumulation, if observed, was insignificant. The level of alanine synthesized and excreted into the culture medium never reached an inhibitory level. During glucose limitation alanine did not accumulate and ammonia was released. However, even in the presence of glucose significant amounts of Asp, Glu, Gln, Asn, Ser, Arg and Met were utilized for energy production. The amino groups of these amino acids were transferred to pyruvate or used for nucleic acid synthesis and excreted in the form of alanine into the culture medium. The consumption of His, Lys, Thr, Gly, Val, Leu, Phe, Tyr, Trp and Ile by growing Sf-9 cells was almost equal to their concentration in the biomass.     

The effects of diphosphonates on the growth and glycolysis of connective-tissue cells in culture.

1. The effects of two diphosphonates (compounds containing a P-C-P bond), disodium dichloromethanediphosphonate and disodium 1-hydroxyethane-1,1-diphosphonate, on the metabolism of cultured rat calvaria cells, rabbit ear cartilage cells and rat skin fibroblasts were investigated. 2. The diphosphonates had no effect on the growth of cartilage cells and on the exponential growth of the calvaria cells and the fibroblasts. However, dichloromethanediphosphonate stopped the growth of the calvaria cells and the fibroblasts after the beginning of confluence, whereas the untreated cells were still growing to a certain extent. This inhibition was dose-dependent. After the drug was withdrawn, the cells recovered slowly. 1-Hydroxyethane-1,1-diphosphonate had no detectable effect on the growth of any of the cell types studied. Both diphosphonates decreased the cloning efficiency of calvaria cells and fibroblasts. 3. The K+ content of cartilage, calvaria and skin cells was diminished only by the highest (0.25 mM) concentration of dichloromethanediphosphonate. 4. Radioactive dichloromethanediphosphonate and 1-hydroxyethane-1,1-diphosphonate were taken up linearly with time for at least 48 h by calvaria cells and fibroblasts. The diphosphonate concentration in the cells depended on its concentration in the medium. 5. Both diphosphonates, in a dose-dependent fashion, markedly inhibited glycolysis, dichloromethanediphosphonate being more effective than 1-hydroxyethane-1,1-diphosphonate, at drug doses that had no effect on cell growth or cellular K+ content. Calvaria cells were much more sensitive than cartilage cells. When cartilage cells were cultured in an N2 atmosphere, these effects on glucose and lactate metabolism disappeared. 6. As increased acid production appears to be associated with resorption of bone, this decrease in lactate may explain why diphosphonates are effective inhibitors of bone resorption in vivo.