Mutants of Arabidopsis thaliana with a glucosinolate content different from wild type were isolated by screening a mutagenized population of plants. Six mutants were detected out of a population of 1200 screened. One of these mutants, TUI, was analyzed in detail. Leaf and seed tissues of line TUl lack or have reduced amounts of many of the aliphatic glucosinolates found in the wild type due to a recessive allele, gsml, of a single nuclear gene, GSM1. The seed phenotype is inherited as a maternal effect suggesting that the embryo is dependent on the maternal tissue for its glucosinolates. Experiments involving feeding of "4C-labeled intermediates suggested that the gsml allele results in a metabolic block which decreases the availability of several amino acid substrates required for glucosinolate biosynthesis: 2-amino-6-methylthiohexanoic acid, 2-amino-7-methylthioheptanoic acid, and 2-amino-8-methylthiooctanoic acid. The mutation does not result in any obvious changes in morphology or growth rate. A pathway for the biosynthesis of glucosinolates in A. thaliana is proposed.Glucosinolates are anionic thioglucosides (Fig. 1) synthesized by many species of the order Capparales including all the Brassicaceae (for reviews see refs. 6 and 26). The primary biological function of glucosinolates is unknown, although a role in plant defense against bacterial and fungal pathogens and insect predators has been suggested (reviewed by Fenwick et al. [6]).The presence of glucosinolates in crop species has several important consequences. First, dietary problems in livestock can result when fodder with high levels of glucosinolates are consumed. Thus, glucosinolates severely restrict the amount of glucosinolate-containing meal that can be used in animal feed supplements (24). Second, the distinctive flavor associated with Brassicaceae species which serve as vegetable and

Previous studies examining sun exposure and ocular melanoma have produced inconsistent results. We investigated this association in a population-based case-control study in Australia. Cases (n ‫؍‬ 290) aged 18 -79 years were diagnosed between January 1996 and July 1998. Controls (n ‫؍‬ 893) were randomly selected from the electoral rolls and frequencymatched to cases by age, sex and state. A self-administered questionnaire and a telephone interview measured sun exposure on weekdays and weekends at 10, 20, 30 and 40 years of age and over the whole of life for specific jobs and recreations. Multivariate logistic regression models of ocular melanoma and sun exposure contained age, sex, region of birth, eye color and measures of ocular and cutaneous sun sensitivity as covariates. Choroid and ciliary body melanoma (n ‫؍‬ 246) was positively associated with time outdoors on weekdays and, less persuasively, total time outdoors but not ambient solar irradiance. Odds ratios increased with increasing exposure to OR 1.8 (95% confidence interval 1.1-2.8) for the highest quarter of sun exposure on weekdays up to 40 years of age for men and women together. The strongest positive associations were for total exposure up to 40 years of age, lifetime occupational exposure and total exposure at about 20 years of age in men; all had odds ratios between 2 and 3 in the highest exposure categories. There was inconclusive evidence for an association between sun exposure and iris (n ‫؍‬ 25) or conjunctival (n ‫؍‬ 19) melanomas. Sun exposure is an independent risk factor for choroidal and ciliary body melanoma in Australia. © 2002 Wiley-Liss, Inc. Key words: ocular melanoma; aetiology; sun exposure; UV radiation; AustraliaThe estimated risks of ocular melanoma associated with personal sun exposure, ambient solar irradiance and use of protective wear have been inconsistent both within and between case-control studies. [1][2][3][4][5][6][7][8][9] However, positive associations with factors less prone to measurement error, such as indicators of sun sensitivity 10 and exposure to artificial sources of UV radiation (e.g., welding arcs and sunlamps), 4,9 suggest a positive association with solar radiation.Possible explanations for past inconclusive results include nonpopulation-based ascertainment of cases and controls, use of qualitative or crude quantitative sun-exposure measures and inadequate control of potential confounding factors, particularly sun sensitivity. Moreover, previous studies collected little or no sun-exposure data for the early years of life. If sun exposure is a risk factor for melanoma of the choroid and ciliary body, the commonest subsites of ocular melanoma, the aetiologically relevant exposure period is probably from birth to the early 20s, when there is some transmission of UV radiation by the crystalline lens to these posterior ocular sites. 11,12 Finally, the unique exposure characteristics of the eye necessitate accounting for personal protective behaviors and environmental factors in estimating ocular sun exposure...

Routinely collected incidence data have often lacked specific identification of ocular melanoma in the past and with increasing diagnosis and management of this disease by noninvasive techniques may now underestimate the true incidence. We attempted to accurately measure the incidence of ocular melanoma in Australia from 1990 to 1998 using 2 population-based sources, cancer registries and ophthalmologists. We examined the distribution across the continent, by latitude and in subpopulations, and evaluated the extent of nonnotification to cancer registries. One-half (51%) of the incident cases from 1996 to 1998 were diagnosed clinically and had no tissue diagnosis. An estimated 20% of melanomas, mainly those lacking a tissue diagnosis, were not notified to Australian cancer registries, but only 1.3% were not notified by ophthalmologists. Expert reviewers agreed that a high proportion (95%) of clinically diagnosed lesions were probable or possible melanomas. Incidence was significantly higher in men than in women, especially at older ages, relatively uniform across the Australian states with only weak evidence of a latitude gradient, and higher in rural than in urban areas. The incidence of ocular melanoma in people born in Southern Europe was half and in those born in Asia only 20% of the rate in people born in Australia and New Zealand. We concluded that it was possible to identify a high proportion of cases by surveying relevant sources additional to cancer registries and to be reasonably confident of the accuracy of the clinical diagnoses. The higher incidence in older men, who probably have higher sun exposure, than in older women and in residents of rural areas, where outdoor work is more prevalent, than in urban areas; the low incidence in dark-eyed populations, who may have a lower sensitivity to or less transmission of solar radiation to the choroid; and the preferential location of ocular melanomas in ocular sites known to receive the highest exposure to solar radiation all support a role for solar radiation in the aetiology of ocular melanoma. The absence of a strong latitude gradient in incidence does not argue against such a role because exposure of the eye to solar UV is probably determined most by the horizon sky, where ambient solar UV is less affected by latitude.

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