Notes on floral traits and gender expression of Dryas octopetala under a simulated environmental change

This study presents empirical data for variations of floral traits and gender expression in Arctic Dryas octopetala L. under a simulated environmental amelioration using an open-top chamber (OTC). The short-term experiment (from 8 August 1997 to 2 August 1998) demonstrated in Ny-Alesund, Svalbard that dry weights of gynoecium, peduncle, and hermaphrodite flowers were significantly heavier, whereas petal and androecium weight were significantly lighter in OTC-manipulated shoots than in controls. As a result, "femaleness" (dry-weight allocation to the female organs) showed a significantly higher value in OTC-manipulated shoots as compared to the controls. Moreover, femaleness was significantly positively correlated with flower weight both in OTC-manipulated and control shoots. Thus, it was experimentally demonstrated that the gender as a reproductive effort of D. octopetala flowers changed from male- to female-biased expression under a less stressful condition

日本とくに北海道の乳牛舎の比較研究

In Japan as in Belgium the cow house should be constructed as a single-floor-building. As well from the point of view of labour requirement ;and animal health as construction costs the loose house with_ cubicles and concrete slatted floors between the cubicle rows, must be preferred above the stanchion barn, when the size of the herd is 25 or more cows. In Hokkaido the loose house and the stanchion barn should be insulated, the latter more than the former ; in Honshu only the stanchion barn and the roof of the loose house must de insulated (K≦1) . Natural ventilation can give complete satisfaction, when it is well regulated. When constructing a stanchion barn, one should build the strawless type in order to reduce labour requirement. Full attention should be given to all construction details in order to avoid injuries with the cows and save labour

Origin and Genetic Evolution of the Vertebrate Skeleton

The current understanding of the origin and evolution of the genetic cassette for the vertebrate skeletal system is reviewed. Molecular phylogenetic analyses of fibrillar collagen genes, which encode the main component of both cartilage and mineralized bone, suggest that genome duplications in vertebrate ancestors were essential for producing distinct collagen fibers for cartilage and mineralized bone. Several data Indicate co-expression of the ancestral copy of fibrillar collagen with the SoxE and Runx transcription factors. Therefore, the genetic cassette may have already existed in protochordate ancestors, and may operate in the development of the pharyngeal gill skeleton. Accompanied by genome duplications in vertebrate ancestors, this genetic cassette may have also been duplicated and co-opted for cartilage and bone. Subsequently, the genetic cassette for cartilage recruited novel genetic material via domain shuffling. Aggrecan, acquired by means of domain shuffling, performs an essential role in cartilage as a shock absorber. In contrast, the cassette for bone recruited new genetic material produced by tandem duplication of the SPARC/osteonectin genes. Some of the duplicated copies of SPARC/osteonectin became secretory Cabinding phosphoproteins (SCPPs) performing a central role in mineralization by regulating the calcium phosphate concentration. Comparative genome analysis revealed similar molecular evolutionary histories for the genetic cassettes for cartilage and bone, namely duplication of the ancestral genetic cassette and recruitment of novel genetic material

Ets identified as a trans-regulatory factor of amphioxus Hox2 by transgenic analysis using ascidian embryos

AbstractAlthough the functions of Hox genes in anterior–posterior patterning and their clustered organization are well conserved among metazoans, some Hox genes have lost their original function, as exemplified by zen, ftz and bicoid in Drosophila. The Hox2 gene of amphioxus has also lost its original function and instead is expressed specifically in the preoral pit. As new cis-elements governing its expression in the preoral pit must have been essential for retention of AmphiHox2, we analyzed the transcriptional regulation of AmphiHox2. Although it is possible to make transgenic amphioxus, several technical limitations restrict their practical use; thus, we analyzed the cis-regulatory region surrounding AmphiHox2 in transgenic ascidians (Ciona intestinalis). We found that Ets binding sites of AmphiHox2 functioned in the ascidian embryo. As the amphioxus Ets1/2 homologue is expressed in the preoral pit, we concluded that AmphiHox2 is activated by Ets1/2 in the preoral pit. These analyses demonstrate the utility of Ciona embryos as a transgenic system for analyses of cis-elements from animals whose embryos are relatively inaccessible, such as amphioxus and hemichordates