The ruby eye-color mutant in the house fly, Musca domestica L. A case of duplicate genes.
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3-Hydroxykynurenine is virtually absent from st larvae but accumulates during adult development in the puparium. Over the period of adult emergence, the accumulated 3-hydroxykynurenine is excreted so that st adults contain none. Larvae of st fed on tryptophan-C-14 medium produce labeled 3-hydroxykynurenine, at a reduced rate, perhaps, compared to wild type. Xanthurenic acid levels in st pupae are similar to those in wild type. Thus the failure of st larvae to accumulate 8-hydroxykynurenine does not seem to be due either to an inability to synthesize this compound or to an excessive rate of its conversion to xanthurenic acid. Rather, it appears that the mechanism of 3-hydroxykynureneine storage during larval life is defective, so that this compound is excreted at an abnormally high rate. The inability of the pigment cells of the eyes of st to synthesize xanthommatin may result form a similar defect in their ability to take up or store 3-hydroxykynurenine.
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Four phenotypes of a sex-linked, maternally influenced semi-lethal eye color mutant of Glossina morsitans morsitans Westwood were fed on Trypanosoma congolense Broden infected guinea pigs. Infection rates were evaluated 25 days later by means of dissection. Procyclic as well as mature infections were significantly more common among females with salmon-colored eyes (sal/sal) than among heterozygous (+/sal, phenotypically wild-type) females. A tendency was found for more mature infections among sal/Y males than among wild-type males. Similarly, females tended to be more infected than males with both procyclic and mature infections. These results indicate that the genotype of the fly, exemplified by the allele salmon, might influence the development of T. congolense in G.m. morsitans. A possible explanation for this phenomenon is discussed.
The cases of 76 patients with chronic radiation dermatitis resulting from low-dose ionizing radiation for benign disease were reviewed retrospectively for risk factors leading to the development of neoplasia. The patients were studied with respect to original hair color, eye color, sun reactive skin type, benign disease treated, area treated, age at treatment, and age at development of first skin cancer. Analysis of data showed 37% of patients had sun-reactive skin type I, 27% had type II, and 36% had type III. Types IV through VI were not represented. There appeared to be an overrepresentation of types I and II. Increased melanin pigmentation may therefore be either directly or indirectly protective against the development of skin cancers in patients who have received low-dose superficial ionizing radiation for benign disease. The sun-reactive skin type of patients with chronic radiation dermatitis may be used as a predictor of skin cancer risk when the total dose of ionizing radiation is not known.
Atypical nevi and other potential risk factors for uveal melanoma were studied in 109 uveal melanoma patients and 149 controls. Information concerning employment, medical history, drug use, family history of cancer, excess sun exposure, and blistering sunburn before and after the age of 15 was obtained. A total skin examination was performed and skin type, hair color, eye color, freckles, actinic damage, the total number of common acquired nevi, and the number of clinically atypical nevi were noted. More atypical nevi were found in uveal melanoma patients than in controls (age- and sex-adjusted odds ratio of 2.9 [95% confidence interval 1.2-6.3] for one or two atypical nevi versus none; odds ratio of 5.1 [95% CI 1.3-20.0] for three or more atypical nevi versus none). Light skin types and freckling also prevailed in uveal melanoma cases. In our study, atypical nevi are more common in uveal melanoma patients than in controls. Further studies will have to indicate whether risk factors comparable to those for cutaneous melanoma really exist for uveal melanoma.
The relationship between cutaneous malignant melanoma (MM) and possible risk factors was assessed in a case-controlled study. Two hundred patients and 200 non-melanoma controls of German origin matched for age and sex were interviewed and examined for pigmented moles and pigmentation characteristics. In patients with MM significantly more melanocytic nevi greater than or equal to 2 mm (MCN) were found (mean, 53 MCN) compared to control cases (mean, 18 MCN). For persons with greater than 60 MCN the relative risk (RR) for developing MM increased 15 times compared to less than or equal to 10 MCN. Additional independent markers for an increased risk were presence of atypical MCN (RR = 7 vs. none) found in 45% of patients and in 5% of the control group, moderate to large numbers of actinic lentigines (RR = 6.2 vs. none), and lack of tanning as well as a tendency to sunburn (skin type I; RR = 2.2 vs skin type IV) No significant correlation was found between the relative risk for MM and hair color, eye color, duration of free time sun exposure and number of sunburns. Individuals with permanent outdoor profession and sun exposure, however, showed a clearly increased relative risk for developing MM.
Temperature-sensitive mutations, at the prune locus (pnts) of Drosophilia melanogaster, were induced with EMS. The majority of the new class of mutations, designated pnts-e, do not interact with the mutation Killer of prune (Kpn) at all of the experimental temperatures, i.e., pnts-e, Kpn flies do not die. One mutation, designated pnts-ek, is temperature-senstive with respect to both the eye coloration and the interaction with Kpn. pntr (temperature-non-sensitive), pnts-e, and pnts-ek alleles were found to differ with respect to both quantity of drosopterines and the color of the eyes. The temperature-sensitive period (TSP) for pn eye color occurs at a late pupal stage. The TSP for the pn--Kpn interaction lasts from the beginning of the first laraval instar to eclosion [22]. It is concluded that all pn mutations known to date occupy the same functional unit. The various pn mutations affect the same metabolic step to various degrees: the eye color phenotype results from a reduction in the end product, while the interaction with Kpn depends on the amount of the accumulated precursor. No recombination between pn alleles was found among more than 106 zygotes that were scored. The reasons for this failure are discussed.
Student participants in group therapy were hypothesized to improve on three dimensions of behavior as a result of therapy. It was further hypothesized that improvement would be related to participant eye color, with dark-eyed persons demonstrating greatest improvement and lighter-eyed individuals demonstrating lesser improvement. Differences were also expected from Ss by program. Ss were 35 male and female master's level students in clinical, counseling, and educational psychology programs, ranging in age from 23 to 39 years. Dependent measures were collected before and after therapy with the Vriend and Dyer Scale, an instrument yielding three factors: Self Defeating Behaviors, Fully Functioning Behaviors, and Personal Mastery Index. The design utilized a 3 (eye color) X 2 (program) two-way ANOVA, fixed effects model. Significant main effects were found for Fully Functioning Behaviors: by eye color (p less than .002) and by program (p less than .03). No interactions or other main effects were found.
An account is provided of two genetic schemes in the Drosophila melanogaster female designed as rapid detectors of chemically induced aneuploidy, including both chromosome gain and chromosome loss. One scheme is referred to as FIX, in which the female carried free (heterozygously) inverted X (chromosomes) and the other, ZESTE, where females do not carry inversions and the X-linked sexually dimorphic zeste mutation plays the key role in the detection of aneuploid offspring. The principle attribute of the FIX system is that all euploid offspring are wild-type for body and eye color whereas aneuploid females have a yellow body and aneuploid males white eyes; int he ZESTE system all euploid individuals are wild-type for eye color, aneuploid females possess zeste-colored eyes and aneuploid males white eyes. In addition induced polyploidies (2X:2A gametes) appear as yellow and zeste male intersexes in the FIX and ZESTE systems, respectively. In this way all aneuploids are recognized immediately. Consequently, detection of compounds with weak effects requiring large sample sizes may be made in a fraction of the time associated with more traditional schemes for aneuploidy detection in Drosophila.
Seventy-two subjects were randomly drawn across grades K-12 and administered an instrument designed to measure developmental skills within seven skill area categories. A three-way ANOVA, fixed effects model, was used for data analysis. Subjects were blocked by eye color, sex, and grade level for the purpose of investigating the relationship between eye color and sex to self-paced and reactive behaviors. Significant differences were obtained on the main effect of eye color in five of the seven categories examined. There were three significant first order interactions (sex X eye color) and one three-way interaction. The findings support the hypothesis of Worthy that eye color is a dependable predictor of subjects' general behavioral competency area (self-paced or reactive) and adds considerable support for his thesis that self-paced and reactive behaviors are to some degree inherited.
Stromal pigments from the irises of 28 species of birds having brightly colored eyes were extracted and analyzed. Carotenoids were present in six species and they were the sole bright pigment in only two of these. The iris pigments of the majority of the birds examined were soluble in 0.1 M NaOH and chromatographic analysis indicated they were primarily pteridines and purines. The pteridines often occurred in a crystalline state, either alone or, more commonly, in conjunction with purines.
Using recent data from cancer incidence surveys and measures of UVB exposure levels at seven geographic locations within the United States, we estimate the dose-response relation between UVB and skin melanoma incidence. Mathematical models used information from general population interview studies conducted in these locations to adjust for potentially confounding factors such as age, skin color, ancestry, eye color, hair color, sunburn sensitivity, prevalence of moles, freckles, and hours spent outdoors, use of sunscreen/lotion, and other variables. The effect of geographic UVB exposure on incidence was found to be statistically significant (p less than 0.01) after adjusting for each variable and certain combinations of these variables. We found that incidence rates for those skin melanomas arising in the face, head, neck, or upper extremities (i.e, the most exposed sites) were more sensitive to UVB increases than the incidence rates for those lesions occurring in the ordinarily less exposed sites of the trunk and lower extremities.
The roles of constitutional factors and benign nevi in causation of malignant melanoma were examined in a case-control study of 511 patients and 511 matched controls in Western Australia. The strongest risk factor was the number of palpable benign nevi on a subject's arms. Compared to the risk of melanomas for persons having no palpable nevi on the arms, the relative risk of melanoma was 2.0 for persons with 1-4 nevi, 4.0 for persons with 5-9 nevi, and 11.3 for persons with 10 or more nevi (P less than .0001). Of the several pigmentary traits known to have associations with melanoma, inability to tan was the most important. Susceptibility to sunburn and hair color also had significant effects that were independent of tanning ability; however, after these traits were controlled, measured skin color and eye color had no additional effects. A reduced risk of melanoma was observed in persons having two or more Southern European grandparents [odds ratio (OR) = 0.39; P = .025]. Persons of Celtic origin did not have a significantly increased risk (OR = 1.18). Possession of one or more affected blood relatives was related to an increased risk of melanoma (OR = 2.69; P less than .0001). The effects of pigmentary traits, benign nevi, ethnic origin, and family history as risk factors were largely independent of one another.
This national multicenter study by the French Task Force on Osteoporosis Research and Information (Groupe de Recherche et d'Information sur l'Ostéoporose GRIO) was carried out to define clinical features in women presenting with a first osteoporosis-related vertebral crush fracture. Seventy-four patients with a less than three-month history of back pain due to a first vertebral fracture documented on the basis of stringent roentgenographic criteria, were compared to 74 normal age-matched female controls. Mean age at first vertebral fracture was 67 +/- 7 years. Cases and controls filled out a 78-item questionnaire on morphology, reproductive function, environmental factors, and previous fractures. The circumstances of onset and site of the vertebral fracture were recorded. Both groups were comparable in terms of age, body weight, hair color and eye color, whereas mean height was smaller by 2 cm in cases (p < 0.02). Among data on reproductive function, the only difference was a younger age at last menses among cases (47.7 +/- 5.7 versus 49.8 +/- 4.8 years); number of pregnancies and duration of breast-feeding were comparable in cases and controls. Environmental factors (smoking, alcohol use, physical activity, dietary calcium) were similar in the two groups. Cases were more likely than controls to report a history of appendicular fractures and/or a positive family history for vertebral osteoporosis. This study in French women suggests that the first osteoporotic vertebral fracture occurs approximately 20 years after cessation of menses and that risk factors include earlier age at last menses, a history of fracture, and a family history of vertebral osteoporosis.
The claret (ca) locus of Drosophila melanogaster comprises two separately mutable domains, one responsible for eye color and one responsible for proper disjunction of chromosomes in meiosis and early cleavage divisions. Previously isolated alleles are of three types: (1) alleles of the claret (ca) type that affect eye color only, (2) alleles of the claret-nondisjunctional (cand) type that affect eye color and chromosome behavior, and (3) a meiotic mutation, non-claret disjunctional (ncd), that affects chromosome behavior only. In order to investigate the genetic structure of the claret locus, we have isolated 19 radiation-induced alleles of claret on the basis of the eye color phenotype. Two of these 19 new alleles are of the cand type, while 17 are of the ca type, demonstrating that the two domains do not often act as a single target for mutagenesis. This suggests that the two separately mutable functions are likely to be encoded by separate or overlapping genes rather than by a single gene. One of the new alleles of the cand type is a chromosome rearrangement with a breakpoint at the position of the claret locus. If this breakpoint is the cause of the mutant phenotype and there are no other mutations associated with the rearrangement, the two functions must be encoded by overlapping genes.