Circadian rhythms in Neurospora crassa: Lipid deficiencies restore robust rhythmicity to null frequency and white-collar mutants

The conidiation rhythm in the fungus Neurospora crassa is a model system for investigating the genetics of circadian clocks. Null mutants at the frq (frequency) locus (frq9 and frq10) make no functional frq gene products and are arrhythmic under standard conditions. The white-collar strains (wc-1 and wc-2) are insensitive to most effects of light, and are also arrhythmic. All three genes are proposed to be central components of the circadian oscillator. We have been investigating two mutants, cel (chain-elongation) and chol-1 (choline-requirer), which are defective in lipid synthesis and affect the period and temperature compensation of the rhythm. We have constructed the double mutant strains chol-1 frq9, chol-1 frq10, chol-1 wc-1, chol-1 wc-2, cel frq9, cel frq10, and cel wc-2. We find that these double mutant strains are robustly rhythmic when assayed under lipid-deficient conditions, indicating that free-running rhythmicity does not require the frq, wc-1, or wc-2 gene products. The rhythms in the double mutant strains are similar to the cel and chol-1 parents, except that they are less sensitive to light. This suggests that the frq, wc-1, and wc-2 gene products may be components of a pathway that normally supplies input to a core oscillator to transduce light signals and sustain rhythmicity. This pathway can be bypassed when lipid metabolism is altered.

Management deficiencies in environmental enforcement : "forceless enforcement" : hearing before the Committee on Governmental Affairs, United States Senate, One Hundred Second Congress, first session, June 19, 1991.

Shipping list no.: 93-0101-P.

Nutritional deficiencies; diagnosis and treatment,

"References" at end of each chapter. Bibliography: p. 370-371.

Bibliography on the influence of mineral deficiencies on growth and reproduction of farm animals,

Mimeographed.

The pathology of the vitamin B complex deficiencies in the chicken.

This essay won the Poultry Disease Essay contest for 1949.

Deficiencies in basic hydrologic data. Report of the Special Advisory Committee on Standards and Specifications for Hydrologic Data.

Thorndike Saville, chairman.

Inventory of public groundwater supply : system deficiencies of urban areas /

Bibliography: p. 4.

Inventory of public surface [water] supply : system deficiencies.

Bibliography: leaf 5.

An authentic biography of General La Fayette. In which many errors and deficiencies existing in the memoirs heretofore published, are corrected and supplied.

Mode of access: Internet.

Past is prologue : educational deficiencies and the youth labor market problem /

Includes bibliographical references (leaves 17-21).

An examination of Commodore Porter's Exposition in which some of the errors and inaccuracies of that publication are rectified, and some of its deficiencies supplied.

Mode of access: Internet.

Digest of appropriations for the support of the government of the United States for the service of the fiscal year ending ..., and on account of deficiencies for prior years, made by the ... session of the ... Congress /

Description based on: 1901/1902.

Nutritional deficiencies in livestock,

Mode of access: Internet.

Nutrient deficiencies in greater yam and their effects on leaf nutrient concentrations

This paper describes the first systematic study of nutritional deficiencies of greater yam (Dioscorea alata). Yam plants (cv. 'Mahoa'a') were propagated from tuber discs and grown in nutrient solution, with nutrients supplied following a modified programmed nutrient-addition method. After an establishment period of four weeks, deficiencies of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), iron (Fe), boron (B), manganese (Mn), copper (Cu), zinc (Zn), and molybdenum (Mo) were induced by omitting the relevant nutrient from the solution. Foliar symptoms were recorded photographically. Notably, deficiencies of the mobile macronutrients failed to induce senescence of oldest leaves, while vine growth and younger leaves were affected. Leaf blades of the main stem were sampled in sequence and analyzed chemically, providing the distribution of each nutrient from youngest to oldest leaves in both adequately supplied and deficient plants. The nutrient-concentration profiles, together with the visible symptoms, indicated that little remobilization of mobile macronutrients had occurred. For both macro- and micronutrients, young leaves gave the best separation of nutrient concentrations between well-nourished and deficient plants.