The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Atsushi Watanabe - One of the best experts on this subject based on the ideXlab platform.
-
determination of male Strobilus developmental stages by cytological and gene expression analyses in japanese cedar cryptomeria japonica
Tree Physiology, 2016Co-Authors: Miyoko Tsubomura, Manabu Kurita, Atsushi WatanabeAbstract:The molecular mechanisms that control male Strobilus development in conifers are largely unknown because the developmental stages and related genes have not yet been characterized. The determination of male Strobilus developmental stages will contribute to genetic research and reproductive biology in conifers. Our objectives in this study were to determine the developmental stages of male strobili by cytological and transcriptome analysis, and to determine the stages at which aberrant morphology is observed in a male-sterile mutant of Cryptomeria japonica D. Don to better understand the molecular mechanisms that control male Strobilus and pollen development. Male Strobilus development was observed for 8 months, from initiation to pollen dispersal. A set of 19,209 expressed sequence tags (ESTs) collected from a male reproductive library and a pollen library was used for microarray analysis. We divided male Strobilus development into 10 stages by cytological and transcriptome analysis. Eight clusters (7324 ESTs) exhibited major changes in transcriptome profiles during male strobili and pollen development in C. japonica. Two clusters showed a gradual increase and decline in transcript abundance, respectively, while the other six clusters exhibited stage-specific changes. The stages at which the male sterility trait of Sosyun was expressed were identified using information on male Strobilus and pollen developmental stages and gene expression profiles. Aberrant morphology was observed cytologically at Stage 6 (microspore stage), and differences in expression patterns compared with wild type were observed at Stage 4 (tetrad stage).
-
the promoter of an a9 homolog from the conifer cryptomeria japonica imparts male Strobilus dominant expression in transgenic trees
Plant Cell Reports, 2013Co-Authors: Manabu Kurita, Teiji Kondo, Atsushi Watanabe, Kenichi Konagaya, Katsuaki Ishii, Toru TaniguchiAbstract:Key message GUS analysis inCryptomeria japonicarevealed that theCjMALE1promoter is activated in the male Strobilus ofC. japonica.
-
spatiotemporal gene expression profiles associated with male Strobilus development in cryptomeria japonica by suppression subtractive hybridization
Breeding Science, 2011Co-Authors: Manabu Kurita, Toru Taniguchi, Ryogo Nakada, Teiji Kondo, Atsushi WatanabeAbstract:To identify the genes associated with the formation and development of the male Strobilus of Cryptomeria japonica D. Don (Sugi), male Strobilus-specific suppression subtractive hybridization (SSH) libraries were constructed from three different stages of male Strobilus development. From these SSH libraries, 1,012 unigene sets including 314 contigs were assembled from 2,448 sequences. The profiles of the genes isolated from the SSH libraries differed strongly according to developmental stage: 49%, 13% and 29% of genes were unique to the early stage (stage E), tetrad stage (stage T), and mature stage (stage M) SSH libraries, respectively. To evaluate the reliability of the SSH libraries, we focused on the eight genes strongly concentrated in the three SSH libraries and performed RT-PCR analysis. All genes tested were expressed more strongly in the male Strobilus than in the shoot. Our findings suggest that the gene profiles associated with male Strobilus development differ in both number and kind of dominantly expressed genes.
Taber D. Allison - One of the best experts on this subject based on the ideXlab platform.
-
Variation in sexual reproduction in Taxus cuspidata Sieb. & Zucc
Plant Species Biology, 2008Co-Authors: Taber D. Allison, Tatemi Shimizu, Masashi Ohara, Norikazu YamanakaAbstract:Male and female Strobilus production and seed production were measured in multiple years in three natural populations of Taxus cuspidata in Japan. Our goal was to record variation in these parameters among individuals, among populations, and from year to year in this species, which is defined as dioecious. We also wished to determine whether cosexual individuals occurred in the sampled T. cuspidata populations. Male and female Strobilus production varied significantly among male and female individuals, respectively, and individuals had significant annual variation in male and female Strobilus production. Significant variation in male and female Strobilus production was also recorded in comparisons among T. cuspidata populations. In some populations, males were significantly larger than females, but this result was not consistently observed. No cosexual individuals were recorded in any of the populations studied. Correlations among reproductive variables and measured vegetative characters were generally non-significant at all sites and in most years, with a few exceptions. When compared with other Taxus species, Strobilus ratios in T. cuspidata were less male biased (2.3 male strobili per female Strobilus in T. cuspidata versus 8.7 and 7.0 male strobili per female Strobilus in Taxus brevifolia and Taxus canadensis, respectively). Seed production efficiency was comparable to T. brevifolia, but less than half of that recorded for T. canadensis, the only species of the genus that has individuals that are typically cosexual.
-
Further studies on sex expression in Taxus canadensis Marshall1
Journal of The Torrey Botanical Society, 2008Co-Authors: Taber D. AllisonAbstract:Abstract Sex expression was examined in two island populations of the monoecious Taxus canadensis at the Apostle Island National Lakeshore, USA. Long-term observations of tagged plants supported earlier published conclusions based on comparisons among populations of the effect of size and age on sex expression, measured as standardized phenotypic gender. As populations of plants increased in size and age, Strobilus ratios became more male-biased and gender concordance increased. Male-biased plants remained male-biased and female-biased plants remained female-biased; gender switching was not a feature of either of these populations. The two Taxus canadensis populations were mapped to examine spatial dispersion of plants and plant attributes, such as size, Strobilus production, and gender. Frequency distribution of gender in both populations was significantly bimodal supporting earlier studies; this conclusion held even when small (typically male) plants with unstable gender were excluded from the analysis....
-
The influence of deer browsing on the reproductive biology of Canada yew (Taxus canadensis marsh.). III: Sex expression
Oecologia, 1992Co-Authors: Taber D. AllisonAbstract:Browsed Canada yew (Taxus canadensis) populations have a higher proportion of males and a lower proportion of monoecious plants than unbrowsed yew populations. The proportion of monoecious plants increases with time following protection from browsing suggesting that deer browsing causes male-biased sex expression in Canada yew. In contrast, results from comparing browsed and unbrowsed populations, exclosure studies, and browse simulation experiments indicate that Strobilus ratios and phenotypic gender of browsed yews may be female-biased. In part, these results correspond to the influence of size on sex expression in Canada yew; small yews tend to be male, but if monoecious, have female-biased Strobilus ratios. Large yews are monoecious, but have male-biased Strobilus ratios. There is, however, no consistent relationship between size and gender in Canada yew, suggesting that in some circumstances, yews shift allocation to female function in response to browsing.
-
VARIATION IN SEX EXPRESSION IN CANADA YEW (TAXUS CANADENSIS)
American Journal of Botany, 1991Co-Authors: Taber D. AllisonAbstract:Sex expression was measured in several Canada yew (Taxus canadensis Marsh.) populations of the Apostle Islands of Wisconsin and southeastern Minnesota to determine the extent of variation within and among populations. Sex expression was recorded qualitatively (monoecious, male, or female) and quantitatively (by male to female Strobilus ratios or standardized phenotypic gender). No discernible trends in differences in sex expression among populations or habitats were recorded. Trends in sex expression of individuals within populations were complex. Small yews tended to be male or, if monoecious, had female-biased Strobilus ratios. Large yews were monoecious but had male-biased Strobilus ratios. Phenotypic gender, recorded as relative maleness, however, was negatively, but weakly, correlated with plant size. Gender distribution in four of five populations was bimodal, suggesting that cosexual populations consist of male and female morphs. Strobilus ratios of individuals in Apostle Island populations showed significant annual variation, but gender for these same plants was significantly correlated from year to year. Annual adjustments in gender were most pronounced in small yews. The results indicate that relative investment in male and female reproductive structures by Canada yew individuals is responsive to environmental variation, but sex expression also has a proximate genetic component. Several studies have shown that plants of cosexual species (containing individuals producing both pollen and ovules) vary widely in their relative male and female reproductive effort. Lloyd (1980) developed the concept of standardized phenotypic gender to provide a quantitative measure of this variation. According to this measure, a plant's gender ranges from 0.0 (female) to 1.0 (male) and is the contribution of male function (pollen) and female function (ovules and seeds) to a plant's fitness relative to other members of the population. The variation in gender among individuals within a population, or gender distribution, suggests mechanisms by which sex expression in a plant population is determined. For example, in many plant species gender distribution is unimodal or monomorphic; functional gender may vary widely and continuously among individuals (Primack and Lloyd, 1980;
-
The influence of deer browsing on the reproductive biology of Canada yew (Taxus canadensis marsh.). I, Direct effect on pollen, ovule, and seed production
Oecologia, 1990Co-Authors: Taber D. AllisonAbstract:Canada yew (Taxus canadensis) populations currently browsed by white-tailed deer (Odocoileus virginianus) or browsed by deer in the past had significantly lower production of male strobili, female strobili, and seeds than unbrowsed yew populations. Exclosure studies showed that protected yews produced significantly more male and female strobili than unprotected yews, but only after several years of protection. Seed production did not respond as readily to protection from deer perhaps because of reduced pollination levels in browsed yew populations. Previously unbrowsed yews were clipped at different levels of removal of available browse (control (no removal), 25%, 50%, 75%, and 100% removal) to simulate deer browsing. Reduction in male Strobilus production was linearly related to clipping intensity in three years of observation. Female Strobilus production was significantly reduced only at the 100% level of removal. Intermediate levels of clipping may have even stimulated production of female strobili. Analysis of covariance, with previous year's branch production as the covariate, showed no significant effect of clipping on male Strobilus production except in the 100% removal group. Female Strobilus production showed no such covariance with branch production. Effects of clipping on seed production could not be reliably assessed in 1984 and 1985 due to low seed production. Seed production in 1986 was significantly reduced only in the 100% removal group. Field observations of deer browsing of Canada yew indicate that 100% levels of removal are typical of natural levels of browsing.
Zhao Peng - One of the best experts on this subject based on the ideXlab platform.
-
analysis on the variation of female male flowers and Strobilus production of clonal seed orchard of pinus tabulaeformis carr
Journal of Anhui Agricultural Sciences, 2007Co-Authors: Zhao PengAbstract:The Strobilus production of female flowers,male flowers and 2-year-old cone of 222 plants from 37 clones of Pinus tabulaeformis Carr. in Luonan Gucheng seed orchard was investigated and the genetic variation law was analyzed based on above the data.The result indicated that the difference was remarkable within the clones on Strobilus production of female and male flowers,2-year-old cone,tress height and tress crown size.The some difference existed within the plans among the clones on Strobilus production of female and male flowers and cone production.The more the Strobilus production of female flowers was,the smaller their difference was.The difference in the north and south branch on one clone on Strobilus production of female flowers and the 2-year-old cone was extremely significant,but that on Strobilus production of male flowers was not remarkable.The "phenomenon of toward female or male toward" also occurred in the some plants of clones.According to 5 quantity characters of the Strobilus production of female flowers,2-year-old cone production,tree high,tree diameter at chest height,crown size,6 good clones of No.285,No.273,No.291,No.10,No.266,No.289 were selected by integrated scoring method of breeding value based on ranking(CICR).
Manabu Kurita - One of the best experts on this subject based on the ideXlab platform.
-
determination of male Strobilus developmental stages by cytological and gene expression analyses in japanese cedar cryptomeria japonica
Tree Physiology, 2016Co-Authors: Miyoko Tsubomura, Manabu Kurita, Atsushi WatanabeAbstract:The molecular mechanisms that control male Strobilus development in conifers are largely unknown because the developmental stages and related genes have not yet been characterized. The determination of male Strobilus developmental stages will contribute to genetic research and reproductive biology in conifers. Our objectives in this study were to determine the developmental stages of male strobili by cytological and transcriptome analysis, and to determine the stages at which aberrant morphology is observed in a male-sterile mutant of Cryptomeria japonica D. Don to better understand the molecular mechanisms that control male Strobilus and pollen development. Male Strobilus development was observed for 8 months, from initiation to pollen dispersal. A set of 19,209 expressed sequence tags (ESTs) collected from a male reproductive library and a pollen library was used for microarray analysis. We divided male Strobilus development into 10 stages by cytological and transcriptome analysis. Eight clusters (7324 ESTs) exhibited major changes in transcriptome profiles during male strobili and pollen development in C. japonica. Two clusters showed a gradual increase and decline in transcript abundance, respectively, while the other six clusters exhibited stage-specific changes. The stages at which the male sterility trait of Sosyun was expressed were identified using information on male Strobilus and pollen developmental stages and gene expression profiles. Aberrant morphology was observed cytologically at Stage 6 (microspore stage), and differences in expression patterns compared with wild type were observed at Stage 4 (tetrad stage).
-
the promoter of an a9 homolog from the conifer cryptomeria japonica imparts male Strobilus dominant expression in transgenic trees
Plant Cell Reports, 2013Co-Authors: Manabu Kurita, Teiji Kondo, Atsushi Watanabe, Kenichi Konagaya, Katsuaki Ishii, Toru TaniguchiAbstract:Key message GUS analysis inCryptomeria japonicarevealed that theCjMALE1promoter is activated in the male Strobilus ofC. japonica.
-
spatiotemporal gene expression profiles associated with male Strobilus development in cryptomeria japonica by suppression subtractive hybridization
Breeding Science, 2011Co-Authors: Manabu Kurita, Toru Taniguchi, Ryogo Nakada, Teiji Kondo, Atsushi WatanabeAbstract:To identify the genes associated with the formation and development of the male Strobilus of Cryptomeria japonica D. Don (Sugi), male Strobilus-specific suppression subtractive hybridization (SSH) libraries were constructed from three different stages of male Strobilus development. From these SSH libraries, 1,012 unigene sets including 314 contigs were assembled from 2,448 sequences. The profiles of the genes isolated from the SSH libraries differed strongly according to developmental stage: 49%, 13% and 29% of genes were unique to the early stage (stage E), tetrad stage (stage T), and mature stage (stage M) SSH libraries, respectively. To evaluate the reliability of the SSH libraries, we focused on the eight genes strongly concentrated in the three SSH libraries and performed RT-PCR analysis. All genes tested were expressed more strongly in the male Strobilus than in the shoot. Our findings suggest that the gene profiles associated with male Strobilus development differ in both number and kind of dominantly expressed genes.
Toru Taniguchi - One of the best experts on this subject based on the ideXlab platform.
-
the promoter of an a9 homolog from the conifer cryptomeria japonica imparts male Strobilus dominant expression in transgenic trees
Plant Cell Reports, 2013Co-Authors: Manabu Kurita, Teiji Kondo, Atsushi Watanabe, Kenichi Konagaya, Katsuaki Ishii, Toru TaniguchiAbstract:Key message GUS analysis inCryptomeria japonicarevealed that theCjMALE1promoter is activated in the male Strobilus ofC. japonica.
-
spatiotemporal gene expression profiles associated with male Strobilus development in cryptomeria japonica by suppression subtractive hybridization
Breeding Science, 2011Co-Authors: Manabu Kurita, Toru Taniguchi, Ryogo Nakada, Teiji Kondo, Atsushi WatanabeAbstract:To identify the genes associated with the formation and development of the male Strobilus of Cryptomeria japonica D. Don (Sugi), male Strobilus-specific suppression subtractive hybridization (SSH) libraries were constructed from three different stages of male Strobilus development. From these SSH libraries, 1,012 unigene sets including 314 contigs were assembled from 2,448 sequences. The profiles of the genes isolated from the SSH libraries differed strongly according to developmental stage: 49%, 13% and 29% of genes were unique to the early stage (stage E), tetrad stage (stage T), and mature stage (stage M) SSH libraries, respectively. To evaluate the reliability of the SSH libraries, we focused on the eight genes strongly concentrated in the three SSH libraries and performed RT-PCR analysis. All genes tested were expressed more strongly in the male Strobilus than in the shoot. Our findings suggest that the gene profiles associated with male Strobilus development differ in both number and kind of dominantly expressed genes.
