The effect of a single amino acid substitution on the antigenic specificity of the loop region of lysozyme.
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Bobwhite quail embryos were exposed to ethanol (5 mg every other day) from E5 to E21. Control embryos received comparable saline injections or were untreated. At 24 h posthatch, the neonates were tested in a single call approach test, using a Bobwhite maternal exodus call which had previously been shown to be a potent attractant to these animals. Almost all animals in all three groups approached the call, and latency of approach did not differ among the groups. The ethanol-treated animals, however, spent significantly less time within the approach area and exited the area significantly more often than did either the saline or untreated controls. Overall hyperactivity or loss of auditory acuity did not appear to account for the response deficits. These results suggest that species-specific behaviors might be a useful paradigm for the study of fetal alcohol effects.
The acute toxicity of hexazinone, a herbicide intended for general noncropland areas and selected crop uses (alfalfa and sugarcane), has been evaluated to establish proper handling guidelines and to measure its potential impact on the environment. The material is slightly to moderately toxic when given as a single oral dose; its LD50 in male rats is 1690 mg/kg, in male guinea pigs 860 mg/kg, and in male dogs greater than 3400 mg/kg although in the dog emesis prevented accurate quantitation. When the material is administered intraperitoneally, the LD50 in rats is 530 mg/kg. Repeated doses (five oral doses per week for 2 weeks) of 300 mg/kg to rats produced slight weight loss in one of two replicate experiments. In both studies, no gross or histologic alterations were apparent. Hexazinone is a moderate to severe eye irritant in the rabbit and produced only mild erythema in rabbit skin at 5278 mg/kg, a dose which did not produce lethality or other clinical signs. Subchronic dermal exposures (10 consecutive doses) to rabbits produced increases in serum alkaline phosphatase and glutamic-pyruvic transaminase at the highest levels tested (680 and 770 mg/kg in two separate experiments) with no effects seen at 150 mg/kg. There were no alterations in livers from treated rabbits examined by light microscopy. No dermal sensitization was produced when concentrations of up to 50% were tested in guinea pigs. One-hour inhalation exposure of up to 7.48 mg/liter did not produce mortality in rats.(ABSTRACT TRUNCATED AT 250 WORDS)
Compared with control birds receiving ad libitum free-water, the total water intake of male and female northern bobwhite declined when only mealworms were available as a source of water. Male northern bobwhite sustained tissue mass and reproductive function with mealworms as their only source of water. Female northern bobwhite could not sustain body, ovary, and oviduct mass, and rate of egg production with mealworms as their only source of water. We suggest that, without free-water, breeding females require a diet with a water:dry matter ratio of greater than 1:1.29 (> 44% water).
1. Mature, male chickens, Bobwhite quail, and rats differed with respect to glutathione S-transferase (GST) activity in the kidney, duodenum and testis, but species differences were not observed in the liver. 2. GST activity was present in the heart, spleen, liver, duodenum, kidney, testis, cerebral cortex, cerebellum, optic tecta, and medulla oblongata of chickens with differences in tissues and breeds. 3. Renal GST activity was higher in female chickens, whereas enzyme activity in the brain was higher in males. 4. Hepatic GST activity fluctuated about a mean of 784 nmol min-1 mg protein-1 with a 12 hr periodicity which was not a feeding phenomenon. 5. The results demonstrate that GST activity occurs in diverse tissues of the chicken and Bobwhite quail with kidney greater than liver greater than duodenum greater than testis, compared to testis greater than liver greater than duodenum greater than kidney in the rat. Hepatic GST activity exhibits an ultradian periodicity.
Intestinal absorption of a polychlorinated biphenyl, dieldrin, and mercury (from HgCl2) was measured in adult Northern bobwhites, Eastern screech owls, American kestrels, black-crowned night-herons and mallards in vivo by an in situ luminal perfusion technique. bobwhites, screech owls and kestrels absorbed much more of each xenobiotic than black-crowned night-herons and mallards. Mallards absorbed less dieldrin and mercury than black-crowned night-herons. Mercury absorption by kestrels was more than twice that in screech owls and eight times that observed in mallards. Pronounced differences in xenobiotic absorption rates between bobwhites, screech owls and kestrels on the one hand, and black-crowned night-herons and mallards on the other, raise the possibility that absorptive ability may be associated with the phylogenetic classification of birds.
Perchlorate originates as a contaminant in the environment from the use of salts in the manufacture of solid rocket fuels and munitions. Monitoring potential perchlorate contamination in the environment is of interest, however, very few analytical methods have been developed for perchlorate determination in biological samples. Analysis of complex samples by ion chromatography is complicated by matrix components that can interfere with perchlorate determination. However, a recently developed preconcentration/preelution (PC/PE) ion chromatography method has demonstrated the capability to analyze certain complex samples such as high salinity water, milk, and hydroponic fertilizers. The ability of this method to reduce sample background and lower detection limits in ion chromatography for various biological samples was evaluated in this study. The PC/PE method was applicable to the analysis of kidneys, livers, zebrafish, quail eggs, lettuce, and urine. Optimal operating conditions were determined for each matrix. Ranges of optimal wash volumes were shorter when 15 mM NaOH prewash solutions were used compared with 10mM and good recovery was achieved for most matrices with an injection period > or =60s. Prewash solution concentration did not appear to significantly affect matrix background. The PC/PE method was capable of reducing sample background when compared to EPA Method 314.0, which resulted in detection limits, with the exception of zebrafish and urine, that were two-fold lower than those achieved with EPA Method 314.0.
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Cochlosoma anatis [Kotlán, A., 1923. Zentralbl. Bakteriol. Parasitenkd. Infektienskr. Hyg. 90, pp. 24-28] is a flagellated protozoan parasite of birds. We have encountered C. anatis in turkeys with enteritis. Experimental oral inoculations of turkeys with 1 x 10(6) to 10 x 10(6) trophozoites consistently reproduced infections in recipients. Trophozoites were most numerous in the jejunum and ileum but could be observed in the duodenum, ceca, colon, and feces. When 12 naive turkeys were placed on contaminated litter vacated by excreting turkeys only one of 12 became infected. When eight naive turkeys were placed in boxes with birds currently excreting trophozoites, seven of eight became infected. Trophozoites could not survive exposure to water or to freezing. Attempts to culture trophozoites in modified Diamond's medium, Kiester's medium, RPMI 1640 medium with 10% fetal bovine serum, or on cultured bovine turbinate cells were not successful. Four of six bobwhite quail and one of eight chickens orally inoculated with 10 x 10(6) to 20 x 10(6) trophozoites had detectable infections. Trophozoites were observed only in the ilea of bobwhite quail and the ceca of the positive chicken. Trophozoites collected from chickens and bobwhite quail remained infectious for turkeys.
Unlike the other sensory modalities of precocial infants, the visual modality does not normally become functional until after birth or hatching. Despite this unique developmental status, the role of emerging visual experience on postnatal perceptual organization remains unclear. In this study, bobwhite quail hatchlings were reared in conditions that manipulated postnatal experience with maternal visual cues, either alone or in conjunction with maternal auditory cues. Results revealed that bobwhite chicks require postnatal exposure to both maternal auditory and visual cues following hatching to demonstrate species-specific perceptual preferences. Chicks that received temporally disparate maternal auditory and visual cues or experience with only maternal visual or maternal auditory cues failed to show species-typical perceptual responsiveness. These results suggest that developmental mechanisms involving both visual and auditory sensory experience underlie the emergence of early intersensory integration.
The binding of murine monoclonal antibody HyHEL-5 to lysozyme has been the subject of extensive crystallographic, computational, and experimental investigations. The complex of HyHEL-5 with hen egg lysozyme (HEL) features salt bridges between Fab heavy chain residue Glu(50), and Arg(45) and Arg(68) of HEL. This interaction has been predicted to play a dominant role in the association on the basis of molecular electrostatics calculations. The association of aspartic acid and glutamine mutants at position 50(H) of the cloned HyHEL-5 Fab with HEL and bobwhite quail lysozyme (BQL), an avian variant bearing an Arg(68) --> Lys substitution in the epitope, was characterized by isothermal titration calorimetry and sedimentation equilibrium. Affinities for HEL were reduced by 400-fold (E50(H)D) and 40,000-fold (E50(H)Q) (DeltaDeltaG degrees estimated at 4.0 and 6.4 kcal mol(-1), respectively). The same mutations reduce affinity for BQL by only 7- and 55-fold, respectively, indicating a reduced specificity for HEL. The loss of affinity upon mutation is in each case primarily due to an unfavorable change in the enthalpy of the interaction; the entropic contribution is virtually unchanged. An enthalpy-entropy compensation exists for each interaction; DeltaH degrees decreases, while DeltaS degrees increases with temperature. The DeltaCp for each mutant interaction is less negative than the wild-type. Mutant-cycle analysis suggests the mutations present in the HyHEL-5 Fab mutants are linked to those present in the BQL with coupling energies between 3 and 4 kcal mol(-1).
The relationship between growth rate and development of function in leg and pectoral muscles was studied in four species of galliform birds ranging from 125 g to 18 kg and, for comparison, in an altricial species, the European starling (80 g). An index to neonatal maturity (muscle dry content proportion as a fraction of adult value) was higher in leg than in pectoral muscles and lower in larger than in smaller galliforms. The maturity index was substantially lower in starling neonates. After the first week posthatch, however, the maturity index was highest in larger species. Exponential growth rates decreased linearly with increasing maturity in both pectoral and leg muscles, following similar regressions in all species including the starling. At a particular value of the maturity index, the exponential growth rate was higher in pectoral than in leg muscles. The exponential growth rates of muscles of neonatal large galliforms were lower than expected from their low maturity. This may represent the down-regulation shortly after hatching of the high exponential growth rate needed to reach a large hatching mass in a short incubation period. A slower growth rate immediately posthatch may be necessary if the relatively immature neonatal digestive system cannot deliver nutrients or metabolized energy required for more rapid growth. Smaller species may not be faced with the constraint of rapid growth toward the end of the embryonic period.
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The effects of a wide range of ammonium perchlorate (AP) concentrations in drinking water on thyroid function in bobwhite quail chicks was investigated at 2, 4, and 8 weeks of exposure. We measured plasma thyroid hormones (THs) to evaluate organismal thyroid status, thyroid weights to evaluate hypothalamic-pituitary-thyroid (HPT) axis activation, and thyroidal TH content to assess TH stores. At the highest AP exposures plasma THs were decreased, thyroid glands were hypertrophied, and thyroidal TH content was decreased. As in our previous studies, thyroidal thyroxine (T(4)) content was the most sensitive indicator of decreased thyroid function; plasma T(4) and thyroid weight were much less sensitive. The lack of sensitivity of these variables appears to result from cyclic patterns of thyroid responses involving the HPT axis and intermittent release of stored THs from the thyroid gland. With sustained AP exposure (8 weeks), at the lowest range of AP concentrations used, chicks showed adaptation in thyroid function that fully compensated for the initial (2 week) effects of AP. At the intermediate AP concentrations there was partial compensation for the initial AP effects. At the highest AP exposures used, thyroid function was very low throughout the study, with no indication of compensatory responses. The capability of chicks to increase some aspects of their thyroid function adaptively in response to some levels of sustained AP exposure is contrary to the common generalization that developing animals are most vulnerable to environmental contaminants.
We assessed whether exposure to amodal properties in bimodal stimulation (e.g. rhythm, rate, duration) could educate attention to amodal properties in subsequent unimodal stimulation during prenatal development. Bobwhite quail embryos were exposed to an individual bobwhite maternal call under several experimental and control conditions during the day prior to hatching. Experimental groups received redundant auditory and visual exposure to the temporal features of an individual maternal call followed by unimodal auditory exposure to the same call immediately or after a 2-hr or 4-hr delay. Control groups received (1) the same exposure but in the reverse sequence (unimodal --> redundant bimodal), (2) asynchronous bimodal --> unimodal, (3) only unimodal exposure, or (4) only bimodal exposure. All experimental groups showed a significant preference for the familiar maternal call over a novel maternal call when tested 2 days after hatching, whereas none of the control groups showed a significant preference for the familiar call. These results indicate that intersensory redundancy can direct attention to amodal properties in bimodal stimulation and educate attention to the same amodal properties in subsequent unimodal stimulation where no intersensory redundancy is available.
The life cycle and morphology of a previously undescribed species of Cryptosporidium isolated from commercial broiler chickens is described. The prepatent period for Cryptosporidium baileyi n. sp. was three days post oral inoculation (PI) of oocysts, and the patent period was days 4-24 PI for chickens inoculated at two days of age and days 4-14 for chickens inoculated at one and six months of age. During the first three days PI, most developmental stages of C. baileyi were found in the microvillous region of enterocytes of the ileum and large intestine. By day 4 PI, most parasites occurred in enterocytes of the cloaca and bursa of Fabricius (BF). Mature Type I meronts with eight merozoites first appeared 12 h PI and measured 5.0 x 4.9 micrometers. Mature Type II meronts with four merozoites and a large granular residuum first appeared 48 h PI and measured 5.1 x 5.1 micrometers. Type III meronts with eight short merozoites and a large homogeneous residuum first appeared 72 h PI and measured 5.2 x 5.1 micrometers. Microgamonts (4.0 x 4.0 micrometers) produced approximately 16 microgametes that penetrated into macrogametes (4.7 x 4.7 micrometers). Macrogametes gave rise to two types of oocysts that sporulated within the host cells. Most were thick-walled oocysts (6.3 x 5.2 micrometers), the resistant forms that passed unaltered in the feces. Some were thin-walled oocysts whose wall (membrane) readily ruptured upon release from the host cell. Sporozoites from thin-walled oocysts were observed penetrating enterocytes in mucosal smears. The presence of thin-walled, autoinfective oocysts and the recycling of Type I meronts may explain why chickens develop heavy intestinal infections lasting up to 21 days. Oocysts of C. baileyi were inoculated orally into several animals to determine its host specificity. Cryptosporidium baileyi did not produce infections in suckling mice and goats or in two-day-old or two-week-old quail. One of six 10-day-old turkeys had small numbers of asexual stages only in the BF. Four of six one-day-old turkeys developed mild infections only in the BF, and sexual stages of the parasite were observed in only one of the four. All seven one-day-old ducks and seven two-day-old geese developed heavy infections only in the BF with all known developmental stages present.
Many animals produce alarm signals when they detect a potential predator, but we still know little about the information contained in these signals. Using presentations of 15 species of live predators, we show that acoustic features of the mobbing calls of black-capped chickadees (Poecile atricapilla) vary with the size of the predator. Companion playback experiments revealed that chickadees detect this information and that the intensity of mobbing behavior is related to the size and threat of the potential predator. This study demonstrates an unsuspected level of complexity and sophistication in avian alarm calls.