Continuous light abolishes the maternal entrainment of the circadian activity rhythm of the pups in the field mouse

Summary 1212-h cycles of presence and absence of mother mouse act as a zeitgeber and entrain the circadian rhythm of locomotor activity in the pups ofMus booduga under continuous darkness or continuous dim light. Continuous higher illumination of 15–25 lx abolishes this impressive maternal entrainment.Acknowledgment. We are grateful to the DST, Government of India, for financial support under their IRHPA scheme. N.V. is the recipient of a Senior Research Fellowship of CSIR, New Delhi. We thank Dr. R. Subbaraj for discussions.     

Chromosomal location of α-amylase structural genes in rye (Secale cereale L.)

Summary Rye (Secale cereale L.) -amylase isozymes are controlled by at least four loci located on the 5R (three) and 7R (one) chromosomes. In the case of Imperial and King II cultivars, two of the three 5R chromosome loci could be specifically located on the 5Rl chromosome arm; the other one was located on the 5RS. The locus of 7R chromosome was located on the 7RL chromosome arm of Imperial rye.     

The toxicity of twoBacillus thuringiensis δ-endotoxins to gypsy moth larvae is inversely related to the affinity of binding sites on midgut brush border membranes for the toxins

Summary The-endotoxin fromBacillus thuringiensis subspecieskurstaki strain HD1-9 is almost 400 times more potent than the-endotoxin from strain HD-73 as a gypsy moth larvicide. The two-endotoxins compete for a high-affinity binding site on the brush border membrane of larval gypsy moth midguts. The affinity for the-endotoxin from strain HD-73 is much greater than the affinity for the-endotoxin from strain HD1-9.     

Can we predict the mating pattern ofDrosophila females from the sperm length distribution in males?

Summary In order to test the validity of the prediction of the mating pattern of females from the sperm length distribution in males, three species ofDrosophila were analysed. Males in the three species are equally polygynous but females differ in the level of polyandry. A low recurrence polyandry is observed in the sperm dimorphic speciesD. affinis while a high recurrence polyandry is observed in the sperm monomorphic speciesD. latifasciaeformis andD. littoralis. These results are consistent with the hypothesis proposed previously that sperm dimorphism in males can only be maintained by a selective alternative in females (i.e. facultative female polygamy), whereas a stricter mating system (e.g., obligatory polyandry) should only result in sperm monomorphism irrespective of the absolute value of sperm length.     

Single amino acid substitutions insn-glycerol-3-phosphate dehydrogenase allozymes fromDrosophila virilis

Summary The amino acid sequence was compared among the three allelic variants (allozymes) ofsn-glycerol-3-phosphate dehydrogenase inD. virilis, which are detected by one-dimensional electrophoresis. The GPDH^f variant was different from the GPDH^m by only one substitution of 68-lysine for asparagine; GPDH^s differed from GPDH^m by substitution of 127-glycine for arginine. No electrophoretically silent substitutions were found in a total of 352 amino acid residues.     

Effect of urochordamines on larval metamorphosis of ascidians

Two pteridine-containing bromophysostigmine alkaloids, urochordamine A and B, which were isolated from ascidians as larval metamorphosis promoters, were converted to more polar compounds, urochordamine A and B, respectively, when left standing in protic solvents. These four compounds promoted larval metamorphosis of the ascidianHalocynthia roretzi in the order A>A>B>B, and induced metamorphosis of the pediveliger larvae of the musselMytilus edulis galloprovincialis.     

Total synthesis of orellinine,a minor toxic component of the fungusCortinarius orellanus fries

Summary The 3,3,4,4-tetrahydroxy-2,2-bipyridyl-N-oxide has been synthesized by dealkylation of the corresponding tetramethyl derivative. The chemical properties of this compound are identical to those reported for the minor fungal toxin ofCortinarius orellanus, orellinine.This work is part of the Tesi di Laurea of Miss Cinzia Pierucci.     

Chromosomes and giemsa-bands of the Idaho spotted ground squirrel,Spermophilus brunneus (Howell)

-Spermophilus brunneus . , 13 18 ,S. brunneus S. townsendii mollis (2n=38) , , ; ;S. brunneus . S. brunneus , Spermophilus.

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Supported by National Science Foundation Grants No. GB32114X and No. GB 29131X, and the Sprague Foundation. We thankD. Pozin for technical assistance.     

Effect of photoperiod and all-female grouping on the estrous cycle of the bandicoot rat,Bandicota bengalensis

Summary Female bandicoot rats showing irregular cycles in 12L12D, were exposed to light-darkness cycles of 1L23D, 4L20D and 8L16D. Significant regularization of the estrous cycle was observed in 8L16D with most of the rats exhibiting a regular 3-day cycle and the regularity was further enhanced by all-female grouping (4/cage).     

The role of the pentose-phosphate pathway in adjustment of the heart to a high load and the development of myocardial hypertrophy

, , - - - . .     

Contribution to the X-ray diffraction methods for precision determinations of polycrystal lattice parameters

. . : , . u-, .     

Chromosomes and some issues of the evolution of the ground squirrel genusCitellus (Rodentia: Sciuridae)

Citellus (s. str.) relictus, C. dauricus C. pygmaeus (2=36, NF=72). . (Colobotis) erythrogenys . fulvus -. . (Urocitellus) undulatus (2n=32, NF=64) . columbianus. Citellus, , Citellus, . , .     

G-band patterns as chromosomal markers,and the interpretation of chromosomal evolution in wild sheep (Ovis)

- . Ovis musimon (2n=54) O. orientalis (2n=54) - - -O. canadensis mexicana (2n=54) O. musimon x O. canadensis ₁₂ - . ₂ 27 . - .

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Supported by National Science Foundation Grant no. GB 32114X and the Sprague Foundation. We thank Dr. T. C. Hsu for assistance in making the chromosome preparations and for advice and encouragement. The Trustees of the Rachelwood Wildlife Research Preserve generously allowed the biopsy of specimens of their custody. Mr.Arthur Popham kindly provided the specimens from Iran while Dr.R. M. Robinson obtained biopsies from the desert sheep.     

Studies on rII region of T2L phage

rII T2L , rII T4B. rII T2L rII T4B. T2L rII T4B.     

ω10-Lipoxygenase products of α-linolenic acid are esterified to phospholipids inHydra vulgaris

We have recently reported the occurrence of 9(R)-hydroxy-, 9(R)-hydroperoxy- and 9-keto-octadeca-10E,12Z,15Z-trienoic acids (9-HOTrE, 9-HPOTrE and 9-KOTrE) inHydra vulgaris, and their biosynthesis from -linolenic acid (-LA) through the action of an enantioselective 10(R)-lipoxygenase (10-LO). Here we describe the finding of these -LA metabolites as esters to the 2-position of phosphatidylcholine, phosphatidylethanolamine and, in trace amounts, phosphatidylinositol. Small amounts of a compound co-eluting with an authentic standard of 9(R)-hydroxy-octadeca-10E,12Z-dienoic acid, a metabolite potentially derived from the action of 10-LO on linoleic acid, were also found esterified with phospholipids. Since direct peroxidation of membrane lipids has been described, experiments were aimed at establishing whether -LA metabolite-containing phospholipids could originate, inH. vulgaris, from either spontaneous or 10-LO-catalyzed oxidation of phospholipid-bound -LA. Incubation of either unlabelled or radiolabelled PUFA-containing phosphoglycerides withH. vulgaris 10-LO did not result in their peroxidation. This suggests that -LA and LA metabolites are incorporated into glycerophospholipids after their formation by 10-LO, and that, as in mamals, membrane phospholipids may serve as a reservoir for these bioactive compounds. This is the first example in an invertebrate species of lipoxygenase products esterified to phosphoglycerides.     

Hotspots of homologous recombination

Homologous recombination occurs at higher than average frequency at and near hotspots. Hotspots are special nucleotide sequences recognized by proteins that promote, directly or indirectly, a rate limiting step of recombination. This review focuses on two well-studied examples, the Chi sites of the bacteriumEscherichia coli and the M26 site of the fission yeastSchizosaccharomyces pombe. Chi, 5 G-C-T-G-G-T-G-G 3, is recognized by the RecBCD enzyme, which nicks the DNA near Chi and produces a 3-ended single-stranded DNA tail; this tail is a potent substrate for homologous pairing by RecA and single-stranded DNA binding proteins. M26, 5 A-T-G-A-C-G-T 3, is recognized by a heterodimeric protein and stimulates, by an as-yet-unknown mechanism, meiotic recombination at and near theade6 gene. Additional hotspots in bacteria, fungi, and mammals enhance recombination directly or indirectly via a variety of mechanisms. Although hotspots are widespread among organisms, the biological role of their localized enhancement of recombination remains a matter of speculation.     

Mass spectrometric determination of the amino acid sequence in peptides: Desulfurization of sulfur-containing peptides

, N- 20 - .     

Volatiles from clover headHypera meles (Fab.) and alfalfaH. postica (Gyllenhal) weevils: search for pheromones

Summary Volatile fractions of the clover head,Hypera meles (Fab.), and alfalfa,Hypera postica (Gyllenhal), weevils contained three of four boll weevil,Anthonomus grandis (Boh.), pheromone components, (Z)-3,3-dimethylcyclohexane ^1,-ethanol and (Z)- and (E)-3,3-dimethylcyclohexane-^1,-acetaldehyde. Also found were eight oxygenated monoterpenes, previously identified as precursors and intermediates of the boll weevil pheromones.     

Morphological and histochemical demonstration of a glycocalyx on the cell surface ofChattonella antiqua,a ‘naked flagellate’

Summary Electron microscopy demonstrated the presence of glycocalyx on the cell surface ofChattonella antiqua, which was previously believed to be naked. Histochemical analysis of this structure indicates that the glycocalyx consists of at least two different types of acidic complex carbohydrates, sulfated and nonsulfated, together with a neural carbohydrate-protein complex with 1,2-glycol groups and -D-mannosyl and -D-glucosyl residues.     

Separation of rat liver mitochondrial amine oxidases

.