Previous studies conducted in these laboratories showed the pigment in the eye of Forbesichthys papilliferus, when exposed to light, migrated from the stratum pigmenti into the layer of rods and cones. It was thought advisable to investigate this matter further. The following lines of investigation were conducted, viz: to determine the rate at which the pigment migrates from the stratum pimenti into the layer of rods and cones when exposed to sunlight; to determine the rate at which the pigment migrates from the stratum pigmenti into the layer of rods and cones when exposed to artificial light; and to determine the rate of the reverse process or the rate of migration of pigment from the layer of rods and cones back into the stratum pigmenti after light is excluded.

The suprapopulation dynamics of Acanthocephalus dirus were studied in the definitive host, Etheostoma squamiceps, and two intermediate hosts, Lirceus fontinalis and Gammarus minus, from Lick Creek, Warren County, Kentucky. The study was conducted from December 1981 through January 1983. A total of 448 isopods, L. fontinalis, was examined for larval A. dirus and 9 (2.01%) were infected. Infected isopods were observed from September through December 1982. There was no correlation between the presence of larvae and lack of pigmentation. A total of 441 amphipods, G. minus, was examined. Of these, 21 (4.76%) were infected. Infected amphipods were observed in all months except May, June, July, and September 1982. In both intermediate hosts, ovarian balls were present in the pseudocoelom of female cystacanths. This suprapopulation was unique in that it utilized two intermediate hosts, of different orders, within a single ecosystem. This is the first time that an amphipod has been reported to play a substantial role in propagating the life cycle of an acanthocephalan of the genus Acanthocephalus. A total of 180 E. squamiceps was examined, and 118 (65.5%) were infected with A. dirus. No significant difference in prevalence of infection or in the mean intensity of infection was observed between male and female hosts. No seasonal periodicity of the parasites in E. squamiceps was observed. There was, however, d significant difference in the attachment sites of the parasites in the gut of the fish during different months and seasons. This was associated with recruitment periods of the parasite by the definitive host. All parasites were sexually mature, and the overall ratio of males to females was 1:1. Acanthocephalus dirus were overdispersed in E. squamiceps, and there was a positive correlation between host total length and density of parasites.

Laboratory germinated seedlings of Liquidambar styraciflua L., sweet gum, from Barren County, Kentucky, subjected to a flooding or inundation test were shown to respond in significantly different ways than did the controls. Plants with root systems standing in water showed a much shorter period of non-dormancy than plants that were not subjected to submergence when both were grown under long day, warm temperature conditions in growth chambers. There was no evidence of transfer of a growth retardant or dormin-like compound in water transferred from plants grown under short day (long night) conditions to plants with roots submerged under long day (short night) periods. The root weights and shoot weights of plants grown under long day dry conditions were significantly higher (.001 level) than the root and shoot weights of seedlings subjected to root submergence although there was no significant difference between the root-shoot ratios. Plants receiving the submerged treatment showed significantly higher (.001 level) values of wood specific gravity than control seedlings grown under dry or normal test conditions. Root stocks of the submerged plants showed anatomical differences when compared with plants not submerged during the test. Submerged root stocks possessed structures with superficially resembled enlarged lenticels. Laboratory germinated seedlings of Liguidambar formosana Hance obtained from Taiwan showed no response to photoperoid under the warm temperature cycle (32-24 C). Once these seedlings were placed under a cooler temperature cycle (24-10 C) they exhibited cessation of growth and formation of dormant buds. Seedlings of Liquidambar formosana differed from L. styraciflua seedlings in having significantly fewer (.001 level) stomata per leaf area, a significantly lower (.001 level) leaf area, and a significantly lower (.001 level) seed weight.

Interrupted-night photoperiod experiments were carried out in green anoles (Anolis carolinensis) in July and August 1981 in order to explore the possibility that seasonal timing of testicular regression regulated by day length involves circadian rhythms. The influence that temperature has on testicular responsiveness to light was also assessed. Testicular weight responses to different interrupted-night photoperiod treatments were similar in anoles kept at constant warm temperatures but varied in anoles kept at constant cold temperatures. Rates of decline of spermatogenesis in response to different interrupted-night photoperiod treatments were, on the other hand, similar in anoles kept at constant cold temperatures but varied in anoles kept at constant warm temperatures. Testicular regression occurred at a faster rate in anoles held in environmental chambers set at constant warm temperatures or at a thermocycle of warmcold temperatures compared with the rate in anoles kept at constant cold temperatures or at a thermocycle of cold-warm temperatures regardless of photoperiodic conditions. Results of this study support the concept that the mechanism whereby day length influences the timing of testicular regression does involve circadian rhythms. The results further indicate that the temperature experienced, particularly during day light hours, can modify the influence of day length on the timing of testicular regression.

1. Comparisons of the mean weight per hundred fruits of fourteen populations demonstrate a definite cline, seed originating from the northern habitats being heavier. 2. The fruit length, wing length and total length of the fruit material from thirteen populations increases with increase in latitude. 3. The average caloric value for all populations tested was 5,092 +/- 165 calories per gram. Due to the heavier weight of the fruit from the northern provinces, an higher energy content per fruit is indicated with increase in latitude. 4. Stratification and germination tests separate the populations into two large geographical groups with the northern populations germinating at the colder (4-5 C) temperatures and the southern populations requiring longer stratification periods and warmer germination temperatures. 5. Removal of the pericarp induces germination. Stratification of the depericarped material increases the germination capacity. 6. There is an highly water soluble inhibitor (probably abscisic acid) in both the pericarp and embryo tissues.

Caloric values of insects and arachnids from two woods and two meadow ecosystems were compared. No significant difference was found between the orders Diptera, Homoptera, Orthoptera, Hemiptera, Hymenoptera, or Coleoptera. Caloric values of the class Arachnida were significantly higher in the woods ecosystem at the .05 level of significance. The order Lepidoptera differed at the .01 level of significance and was also higher in the woods samples. For all orders combined the caloric values of the woods samples were higher than the meadow samples at the .001 level of significance. No consistent pattern was found in seasonal variation in caloric values but fluctuations occurred differently in each order. No significant difference was found in caloric values between animals collected in the spring and those collected in the fall. Members of the orders Neuroptera and Odonata were lowest in energy content in both woods and meadow ecosystems. Hemopterans were among the highest in caloric value in both systems. All other orders were intermediate. The greatest differences in caloric values existed between the woods and meadow lepidopterans. All caloric values in this study were found to be lower than those reported by other workers. Seasonal distribution of insects within an ecosystem were considered. The numbers within each order varied independently according to season, stage of life cycle, and feeding habits of the various genera within the order. Although the area from which the samples were taken was not the same for woods and meadow, habitat preference is still obvious in certain orders. Dipterans were more dense in the woods as compared to other orders, while orthopterans accounted for the majority of specimens from the meadows. Arachnids exhibited preference for a wooded habitat. vii

A plasmid (pGEM-SD) was constructed in which the Shine-Dalgarno sequence had been deleted from pGEM-7zf(+) plasmid to generate a vector for regulated expression of antisense RNA. The binding of antisense RNA to mRNA provides a potent mechanism by which specific transcripts can be translationally inactivated. Although part of the lac operator sequence was deleted in pGEM-SD plasmid, it was proven that mRNA still can be induced under the control of lac promoter. Recombinant plasmids were generated by ligating bacterial genornic DNA into pGEM-SD plasmid, but the orientation of the inserted gene with respect to the lac promoter has not been determined. These preliminary results show that gene expression can be turned on and off via the pGEM-SD vector. Future experiments will screen antisense recombinant clones for those which would inhibit specific gene products by plating on different selective indicator media both with and without the inducer IPTG. This will allow investigation of the biological functions associated with genomic DNA sequences by means of gene mapping with antisense RNA.

A deoxyribonuclease (DNase) has been isolated from a purified preparation of soybean nuclei. The procedure, involving solubilization of proteins using ammonium sulfate, Sephadex G-75, DEAE-Cellulose and CMSephadex chromatography and non-denaturing polyacrylamide gel electrophoresis, resulted in a 554-fold purification with a yield of 6% of the enzyme. The purified enzyme had a molecular weight of 60 KDa as monitored by non-denaturing polyacrylamide gel electrophoresis. In addition, high-molecular-weight (HMW) soybean DNA, essentially free from protein, RNA and other contaminates, has been isolated from soybean to be used as a substrate for the enzyme. Enzyme activity was directly proportional to the concentration of enzyme and substrate as determined by a spectrophotometric assay. In the presence of divalent cations (Mn2+), the enzyme hydrolyzed soybean DNA, calf thymus DNA and pBR322 DNA but was inactive with yeast RNA. The enzyme was partially inhibited by KC1. Endonuclease activity was indicated on agarose gels using covalently closed circular pBR322 DNA and spectrophotometric analysis of assay products following Sephadex G-10 chromatography. The enzyme had a Km for soybean DNA of 4.5 μg/ml and a Vmax of 0.02 ΔA260/min.

Clock-driven endogenous circadian rhythms in ommatidial morphology have been reported in Leucophaea maderae. The parameters used to measure changes in ommatidial morphology over time were palisade layer and rhabdom areas and the organization of lightscreening pigment granules about the rhabdom. The fact that the palisade layer area only partially returned to the light-adapted state in vivo during subjective midday was indicative of a passive mechanism, not involving the clock output. Complete return of the palisade layer area to the light-adapted state during the daytime in animals held under LD 12:12 indicated light might play an active role. Temporal changes in rhabdom area were not previously reported. Light-screening pigment granules changed in concentration about the rhabdom on a daily basis; however, this rhythm did not persist on a circadian basis. Therefore, it seemed that control of pigment granule movement resided, at least in part, within the photoreceptor itself. The focus of this investigation was to determine if control of photomechanical movement in response to light did, in fact, reside within the photoreceptor itself. The research was divided into two phases: 1) a preliminary component, Phase One, where the effect of different lengths of light exposure on dark-adapted ommatidial structure was monitored in vivo in order to determine an effective length of light exposure; 2) Phase Two, the effect of light exposure for a length of 10 minutes, a duration found to be effective in Phase One, on ommatidial morphology in dark-adapted eyes was monitored in vitro. All eye samples were surgically removed from cockroaches entrained to a LD 12:12 photoperiodic cycle during the dark phase. The in vitro samples were maintained in physiological cockroach saline for ten minutes whether treated with light or not. All photoreceptive tissue was fixed, stained, dehydrated, embedded and sectioned in preparation for examination using a Zeiss transmission electron microscope. Palisade layer and rhabdom areas were determined from photomicrographs using a Jandel PC3-D computer program. Light-screening pigment granule organization was determined by counting the number of granules within a 13.5 µ diameter circle centered about the rhabdom. The palisade layer area changes in vivo from dark-adapted to light-adapted were consistent with previous reports; however, the in vitro response was the opposite of that expected. The rhabdom response was significantly different between in vivo and in vitro conditions, however, the trends in response to light for both palisade layer and rhabdom areas were similar. The results with respect to rhabdom area are not similar to those previously reported. The aggregation of light-screening pigment granules in response to light in vivo was similar to the in vitro response, but at a depressed level -- suggesting some level of control at the photoreceptor level and the possibility that some control resided in a central nervous system locus other than or inclusive of the optic lobe pacemaker. Support for separate pathways of control of palisade layer area changes and light-screening pigment granule movement was noted.

All eukaryotic organisms display rhythms which persist under constant environmental conditions with periods of approximately, but very seldom exactly, 24 hours. Such rhythms are "circadian" and are driven by an internal "biological clock." Circadian rhythms of locomotor activity, retinal sensitivity to light and ommatidial morphology have been characterized in the cockroach, Leucophaea maderae (L.). It is not known whether the same clock(s) controls both circadian rhythms of electroretinogram (ERG) amplitude and morphological changes of the compound eye. In order to determine whether the location of the clock that controls morphological changes is in the same location as the one that controls ERG, brain lesions were made proximal or distal to the region of the putative clock regulating the expression of a circadian rhythm in eye sensitivity to light in anesthetized cockroaches. These and sham operated control animals were held for approximately two weeks under LD 12:12 at 25±2°C conditions in environmental chambers. After this time period, conditions of continuous darkness were established in order to allow rhythms to free run. Eye tissue was removed on subjective midday two and subjective midnight two, fixed, embedded, sectioned and the sections were examined and photographed using a Zeiss transmission electron microscope. Observations were made to establish the presence or absence of a circadian rhythm of submicrovillar cysternae area (SMC), as well as rhabdom area and screening pigment granules organization (SPG). The results indicate that the clock, located in the lobular neuropil region of the optic lobe that controls the rhythm of morphological changes in the eye, is in the same proximity as that which controls the changes in ERG amplitude.