4 research outputs found
A frame-shift mutation in COMTD1 is associated with impaired pheomelanin pigmentation in chicken
No full textAuthor summaryVertebrates possess two types of melanin, red/yellow pheomelanin and black/brown eumelanin. In this study, we report that the recessive Inhibitor of gold phenotype in chicken, which causes a severe defect in pheomelanin pigmentation, is associated with a mutation that most likely inactivates the COMTD1 gene. This gene encodes an O-methyltransferase enzyme and is present throughout vertebrate evolution, but is one of the many genes in vertebrate genomes for which the biological function is still poorly understood. This is the first report of a COMTD1 mutation associated with a phenotypic effect. We show that the COMTD1 protein is present in mitochondria in pigment cells. Furthermore, inactivation of the gene in a mouse pigment cell line results in a significant reduction in metabolites that are important for the synthesis of pheomelanin. We hypothesize that COMTD1 activity protects pigment cells from oxidative stress and that inactivation of this function impairs the production of pheomelanin. It is likely that COMTD1 has a similar function in other cell types. This study establishes this chicken mutation as a model for further studies of COMTD1 function.The biochemical pathway regulating the synthesis of yellow/red pheomelanin is less well characterized than the synthesis of black/brown eumelanin. Inhibitor of gold (IG phenotype) is a plumage colour variant in chicken that provides an opportunity to further explore this pathway since the recessive allele (IG) at this locus is associated with a defect in the production of pheomelanin. IG/IG homozygotes display a marked dilution of red pheomelanin pigmentation, whilst black pigmentation (eumelanin) is only slightly affected. Here we show that a 2-base pair insertion (frame-shift mutation) in the 5(th) exon of the Catechol-O-methyltransferase containing domain 1 gene (COMTD1), expected to cause a complete or partial loss-of-function of the COMTD1 enzyme, shows complete concordance with the IG phenotype within and across breeds. We show that the COMTD1 protein is localized to mitochondria in pigment cells. Knockout of Comtd1 in a mouse melanocytic cell line results in a reduction in pheomelanin metabolites and significant alterations in metabolites of glutamate/glutathione, riboflavin, and the tricarboxylic acid cycle. Furthermore, COMTD1 overexpression enhanced cellular proliferation following chemical-induced transfection, a potential inducer of oxidative stress. These observations suggest that COMTD1 plays a protective role for melanocytes against oxidative stress and that this supports their ability to produce pheomelanin
New Semi- and Extremely Dwarfing Apple Rootstocks, ' JM 2' and ' JM 5'
No full textJM 2' is a semidwarfing and 'JM 5' is an extremely dwarfing apple rootstock released in 1997 by the National Institute of Fruit Tree Science (NIFTS), Ministry of Agriculture, Forestry and Fisheries. 'JM 2'and 'JM 5' originated from a controlled cross of Malus prunifolia 'Seishi' x 'M.9' made during 1972 - 1975 to obtain new dwarfing rootstock clones that are easy to propagate by hardwood cutting. Over the next 11 years, seedling screening continued at Morioka, and these two clones together with other eight clones were selected in 1984 with the desirable characteristics for putative vigor estimated by the bark/ wood ratio of roots and their propagative ability. Beginning in 1985, these rootstock selections were entered into the regional trial conducted at 12 research sites in apple growing districts in Japan, as selection number Apple Rootstock Morioka No.2 and 5. Based on orchard performance and observations of disease and pest resistance, rootstock varieties were ultimately selected and released as 'JM 2' and 'JM 5' in 1997 and registered as No.8223 and 8224 under the Plant Variety Protection and Seed Act of Japan on July 31, 2000. The rooting abilities of these two JM rootstocks were much better than two other varieties, 'M.9EMLA' and 'M.26EMLA'. Over 90% of 'JM 2' cuttings and over 80% of 'JM 5' cuttings were rooted by using hardwood cutting in the nursery, whereas for 'M.9EMLA' and 'M.26EMLA' fewer than 7% of the cuttings were rooted in this manner. Average shoot lengths of 'JM 2' and 'JM 5' were 82 and 73 cm with shoot diameters of 6.4 and 6.1 mm respectively. 'JM 2' and 'JM 5' were resistant to crown rot (Phytophthora cactorum, P. cambivora). 'JM 2' was susceptible to wooly apple aphid (Eriosoma lanigerum) but 'JM 5' was resistant. On the other hand, 'JM 2' was resistant against Apple chlorotic leaf spot virus (ACLSV), but 'JM 5' was susceptible. 'JM 2' was less susceptible to fire blight (Erwinia amylovora) than 'M.26'. Observations of 'Fuji' trees on 'JM 2' and 'JM 5' over 14 seasons in the orchard at Morioka proved that 'JM 2' was a semidwarfing rootstock, whereas 'JM 5' was an extremely dwarfing rootstock. 'Fuji' trees on 'JM 2' and 'JM 5' tended toward overgrowth of the rootstock. The number of suckers in 'JM 2' was similar to 'M.9EMLA' and very low in 'JM 5'. The two JM rootstocks produced very low amount of burrknots compared to 'M.9EMLA' and 'M.26EMLA'. The cumulative yield efficiency of 'Fuji' was lower on 'JM 2', but was higher on 'JM 5' than that of 'M.9EMLA'. Fruit weight, red color development, soluble solids content, titratable acidity, and flesh firmness of 'Fuji' were measured. Large differences were not found in these traits except for lower fruit weight in 'JM 2' In 'JM 5', soluble solids content and flesh firmness were higher than those of 'M.9EMLA' and 'M.26EMLA' . Our results suggest that these two new rootstock varieties are worthy replacements for Marubakaido [Malus prunifolia (Willd.) Borkh.] or 'M.27' in Japan.departmental bulletin pape
New Dwarfing Apple Rootstocks 'JM 1', 'JM 7' and 'JM 8'
No full textAn apple rootstock improvement program at the Morioka Branch, Horticulture Research Station, now reorganized as the Apple Research Center, NIFTS, was started in 1972. Main objectives of the program were: to develop excellent rootstocks that are able to control tree size favorably; to resist diseases and pests such as crown rot (Phytophthora cactorum. P cambivora), wooly apple aphid (Eriosoma lanigerum); to tolerate water-logged soils; and to propagate easily by hardwood cuttings. A controlled cross of Malus prunifolia 'Seishi' x 'M.9' was made during 1972 -1975. Over the next 11 years initial screening of the seedlings continued at Morioka and three clones together with other seven clones were selected in 1984 with the desirable characteristics for putative vigor estimated by bark/wood ratio of root and propagative ability. Beginning in 1985, these rootstock selections were subjected to field trials executed by 12 experiment stations located in apple growing districts in Japan. Based on orchard performance and observation of disease and pest resistance, 'JM 1','JM 7'and 'JM 8' were released in 1996, and registered as No.7443,7444,7445 respectively, under the Plant Variety Protection and Seed Act of Japan to keep plant breeder's right on September 21,1999. Three JM rootstocks were resistant to crown rot disease and wooly apple aphid. 'JM 7' and 'JM 8' were also resistant against CLSV, but 'JM 1' was susceptible. 'JM 1'and'JM 7' were less susceptible to fire blight than' M.26' Over 90% of cuttings in 'JM 7', over 80% in 'JM 1', over 70% in 'JM 8' rooted by using hardwood cuttings in the nursery, while 0 - 8% in 'M.9EMLA' and 'M.26EMLA'. Average shoot diameters were 6.6 to 7.0 mm and length of shoots were 77 to 101 cm. Rooting abilities of these JM rootstocks are much better than 'M.9EMLA' and 'M.26EMLA.' Observations of 'Fuji' trees over 15 seasons in the orchard at Morioka proved that 'JM 1', 'JM 7' and 'JM 8' produced trees smaller than 'M.9EMLA'. Trees on 'JM 7'and'JM 8' tend toward typical overgrowth of the rootstocks. Three JM rootstocks produced very low number of suckers and very low amount of burrknots compared to 'M.9EMLA' and 'M.26EMLA'. Trees of 'Fuji' on JM rootstocks had similar precocity to 'M.9EMLA.' Cumulative yield efficiency of 'Fuji' was highest in 'JM 7', and it was higher in 'JM 1' and 'JM 8' than that of 'M.9EMLA' or 'M.26EMLA'. Fruit weight, red color development, soluble solids content, titratable acidity, and flesh firmness of 'Fuji' were measured. Large differences were not found in these traits except for soluble solids content and flesh firmness among the fruits. Average soluble solids and flesh firmness were higher in JM rootstocks than 'M.9EMLA' and 'M.26EMLA' every year. Our results suggest that resistance to several diseases and pests are better, and the trees are more productive on these JM rootstocks than they are on 'M.9EMLA' or 'M.26EMLA'. We regard these new rootstock varieties as worthy replacements for 'M.9' and 'M.26' in Japan.departmental bulletin pape
New Apple Cultivar 'Chinatsu'
No full textChinatsu' is a very early maturing, relatively small red apple (Malus pumila Mill.) released in 1998 by the National Institute of Fruit Tree Science (NIFTS), Ministry of Agriculture, Forestry and Fisheries. 'Chinatsu' originated from a cross of 'Akane' × 'Stark Earliest' made in 1972. The tree was first selected based on its fruit quality and growth habit in 1982, and was subjected to the regional trial, conducted at 18 research sites in 13 prefectures in Japan, as selection number Apple Morioka No.49 from 1989. It was ultimately selected and released as 'Chinatsu' in 1998, and registered as No.9402 under the Plant Variety Protection and Seed Act of Japan on October 18, 2001. At NIFTS in Morioka the 'Chinatsu' fruit ripens in mid-August, about one week before 'Kizashi'. The shape of the fruit is round with a short peduncle, and the mean fruit weight is 205 g. The skin color of the fruit at harvest time is striped deep red. Russeting in the stem cavity occasionally occurs. The flesh is crisp, juicy and subacid. Mean soluble solids content (Brix) in juice is 11.5% and titratable acidity as malic acid averages 0.61 g/100 ml at harvest. The fruit maintains firmness and crisp texture for about 50 days in refrigerated storage at 1 - 4℃. The tree is upright in shape, and medium in vigor, blooming at the same time as 'Tsugaru'. 'Chinatsu' is cross-compatible with major commercial cultivars such as 'Fuji' and 'Tsugaru'. 'Chinatsu' is resistant to Alternaria leaf spot and seems to be moderately tolerant to scab.departmental bulletin pape
