QUANTITATIVE CHANGES IN GIBBERELLIN AND RNA CORRELATED WITH SENESCENCE OF THE SHOOT APEX IN THE ‘ALASKA’ PEA

Senescence of shoot apices of Pisum sativum L. ‘Alaska’ as measured by cessation of stem elongation was delayed by removal of flowers and by treatment with gibberellin A₃ and was hastened by treatment with AMO-1618 (2 isopropyl-4-dimethylamino-5-methylphenyl-1-piperi-dinecarboxylate methyl chloride). Ontogenetic changes in relative endogenous gibberellin levels and in capability of gibberellin biosynthesis in deflowered and control plants were determined indirectly by studying time-course changes in the sensitivity, as indicated by the growth response, of these plants to applied gibberellin and AMO-1618. The results of these experiments suggest that the endogenous gibberellin level varies directly with the growth rate. Analyses of total RNA and protein in shoot tips of deflowered and control plants revealed that the levels of these substances also vary directly with growth rate throughout ontogeny. It is concluded that decreases in endogenous gibberellin, RNA and protein are factors correlated with senescence of the shoot apex.     

ON NEW MATERIAL OF STEGODON WITH RECOLLECTIONS OF THE CLASSIFICATION OF STEGODON IN CHINA

ReviseddiagnoaisCraniumcompressedanteroposteriorlyandhighvertical1y.Superiortuskslargeandstraight,nolowerincisors'Ridge-platesprogressiveIymulti-plyingfromsixtoelevenintheintermediateteeth,fromninetofifteenandhaIfilltheposteriormolars.Thereisamediancleftoritsvestigesintheanteriorridge-platesoftheprimitivespecies.Conesrapidlysubdividingbybinaryorternary.fissionintomultipleconelets(8-l2).Ridge-plateselevatingfrombrachyodonttosubhypsodont.Cementdevelopingintheval1eys.RemarksSarwar(l977)propose…     

REACTION NORMS OF MORPHOLOGICAL TRAITS IN DROSOPHILA: ADAPTIVE SHAPE CHANGES IN A STENOTHERM CIRCUMTROPICAL SPECIES?

Reaction norms of wing length, thorax length, and ovariole number were studied according to growth temperature in the circumtropical Drosophila ananassae, and compared to similar data from the cosmopolitan D. melanogaster. In the two species convex reaction norms were observed, but they were not parallel and sometimes exhibited intersections either at high (wing) or at low (thorax) temperature. On average, D. ananassae may be considered as a species with a bigger thorax but shorter wings than D. melanogaster. The shapes of reaction norms were analyzed and compared after quadratic polynomial adjustments. Significant differences were observed, in several cases between polynomial parameters, and in all cases between characteristic points that is, Maximum Value (MV) and Temperature of Maximum Value (TMV). The wing/thorax ratio may also be considered as a specific trait related to wing loading. Major differences were observed between the two species for the mean value and the shape of the response curves of this trait. The main observation of this work was however a shift of TMVs for wing and thorax length and ovariole number in D. ananassae toward higher temperatures. These variations in the reaction norms corresponded to a shift in the species thermal range, suggesting that temperature adaptation was accompanied by a modification of the shape of the response curves.     

IS MEASUREMENT OF CIRCULATING TUMOR DNA OF DIAGNOSTIC USE IN PATIENTS WITH THYROID NODULES?

Objective: Circulating tumor DNA (ctDNA), a subset of cell-free DNA (cfDNA), is a potential biomarker for thyroid cancer. We determined the performance of a ctDNA panel for detecting thyroid malignancy in patients with thyroid nodules.Methods: Sixty-six patients with thyroid nodules without a prior history of cancer enrolled in a prospective, 1-year study in which blood was drawn for ctDNA analysis prior to undergoing fine-needle aspiration biopsy (FNAB) of thyroid nodules. The ctDNA panel consisted of 96-mutations in 9 cancer driver genes. The primary outcome measures were the sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of our ctDNA panel for the diagnosis of thyroid malignancy as determined by pathologic and/or molecular tissue examination.Results: Results from 10 subjects could not be determined due to inadequate volume or technical issues. The final classifications of the thyroid nodules were 13 malignant and 43 benign lesions. A KRAS G12V mutation was detected in the plasma of 1 patient with stage IVA papillary carcinoma whose tissue contained the same mutation. Two of the 43 patients with benign lesions also had ctDNA detected, giving a sensitivity of 7.7%, specificity of 95.35%, PPV of 33.33%, and NPV of 77.35%. There were no significant differences between benign or malignant lesions in cfDNA levels.Conclusion: Neither cfDNA measurements nor our panel of ctDNA mutations are sensitive or specific enough to provide valuable information over FNAB. An expanded panel and the inclusion of proteomics may improve sensitivity and specificity for thyroid cancer detection.Abbreviations: cfDNA = cell-free DNA; ctDNA = circulating tumor DNA; FNAB = fine-needle aspiration biopsy; NIFTP = noninvasive follicular thyroid neoplasm with papillary-like nuclear features     

CHANGES OF GLYCEROL CONTENT IN DIAPAUSE LARVAEOF THE ORANGE WHEAT BLOSSOM MIDGE, SITODIPLOSIS MOSELLANA （GEHIN） IN VARIOUS SEASONS

The glycerol contents in diapause larvae of the orange wheat blossom midge, Sitodiplosis mosellana (Gehin), collected from various seasons, were measured. The results showed that there was less glycerol content in larvae during living on the wheat head. Content of glycerol began to increase significantly when the larvae left the wheat head and entered the soil. A change trend of upper- lower- upper- lower in larvae glycerol contents during diapause in soil was observed from June to April of next year. More glycerol could be examined in larvae collected in summer and winter than in spring and autumn. There was not more glycerol in cocooned larvae than that in non-cocooned larvae during various seasons from the point of statistics. Comparing the glycerol content of larvae being diapause in the first year with that of larvae in the second year, there was yet no obvious difference when larvae were collected in the same season belonged to different years. Therefore, it is shown that the content of glycerol in larvae of the wheat midge in diapause is affected mainly by the seasons or diapause intensity.     

PLASMA LEVELS OF INTERFERON-γ CORRELATE WITH AGE-RELATED DISTURBANCES OF CIRCADIAN RHYTHMS AND SURVIVAL IN A NON-HUMAN PRIMATE

Aging can be associated with changes in circadian rhythms and reduction in adaptive immune responses accompanied by expansion of memory T cells and elevated levels of pro-inflammatory cytokines. Recent findings suggest the cytokine interferon-γ (IFN-γ) can affect the function of the hypothalamic suprachiasmatic nucleus (SCN), the master mammalian circadian pacemaker, both in vitro and in vivo. We studied the correlation of plasma levels of IFN-γ and changes in circadian rhythms in a non-human primate species, the nocturnal mouse lemur (Microcebus murinus). Plasma IFN-γ and dehydroepiandrosterone sulfate (DHEA-S), a known biomarker of aging, were determined in middle- to old-age animals by immunoenzymoassay. Daily rhythms of locomotor activity and body temperature as well as survival time of the lemurs were recorded. With aging, mean levels of DHEA-S decreased whereas IFN-γ increased. Aged animals showed biological rhythm alterations characterized by a high percentage of diurnal activity, anticipation of the activity onset relative to lights-off, short free-running period, and delayed occurrence of minimal body temperature. The magnitude of these disturbances was correlated with the plasma level of IFN-γ but not DHEA-S. Most remarkably, in contrast to DHEA-S, increased levels of IFN-γ correlated with duration of the lifetime of the lemurs. These results show the degree of circadian rhythm alterations in an individual is correlated with plasma IFN-γ level during aging, and that plasma IFN-γ level may predict survival, at least in this non-human primate. (Author correspondence: fabienne.aujard@wanadoo.fr)