Bioinformatics Studying Of The Selenoprotein In Durum Wheat (Triticum Durum Desf.)

Selenium is a microelement which is essential to mammalian and hunman being. It participates process of the metabolism of thyroid gland,antioxidant system and ensuring organism exert normal immune function. Selenoproteins were found in eukaryotes and archaea. However, no selenoprotein was found in plants except the Chlamydomonas. There is no clear answer whether the selenoproteins exist in plants until now. So it is important to search and research the clues of the possible selenoproteins in plants with bioinformatics means.The first part of this paper synthetically sumed up the research means and outcomes in the area of selenoproteins research, the reason for the stagnant situation of research of selenoproteins in plants was analysed also. At the basis of previous analysis, we choosed the Durum Wheat as the research target and carefully designed the research methods. The bioinformatics research of the target was carried out subsequently.Due to the selenoproteins having the SECIS, we searched and filtered the expressed nucleic acid sequences of Durum Wheat from Genbank to find out the objects with SECIS and 47 object sequences was found aggregately. The AY146587.1 sequence ( with complementary sequence of AY146587.1 sequence)was determined the research object finally for its sufficient data.An expressed area in object sequence was found which had highly similar structure with the selenoproteins of Chlamydomonas after the object sequence and six selenoproteins of Chlamydomonas were synthetically comparative analysed with tools such as Vector NT. Subsequently, the possibility, that whether the object sequence coding the selenoprotein, has been analysed. Aiming at the query that there was no TGA in the above-mentioned sequence, more full-scale searching work was made and another expressed sequence which has TGA and the similar structural character with the selenoproteins of Chlamydomonas was found. The two expressed sequences located in the same gene area presumed by GENSCAN and were contiguous to each other.Whlie the two object expressed sequences were translated, much researching and analysing work was carried out. Some clues were found and which revealed the object expressed sequences had the similar function characters with the selenoproteins. Due to all-inclusive result, we presumed the area where the object sequences located had high possibility to coding the selenoproteins which had relationg to enerye regulation in durum wheat embryo growth period.In course of our work, we found it was hard to apply the existing tools and methods which were builted on the basis of known knowledge to the research work to the possible selenoproteins in plants. It was so different from the area of a creatural selenoproteins. One reasonable predication was put forward that there were selenoproteins in plants which had similar functions to the creatural selenoproteins but different coding principle whereas. We even predicated that there may be unknown amino acid existed.All the content in the first part of this paper had described the important result of our research work in selenoprotein of plants. At the same time, innovative thinking and method was put forward to promote the studying of selenoprotein in plants.On the other hand, an optimal pooling system called Accurate and Fast Target Screening has been developed for high-throughput identifying the rare marker-free transformants in plant genetic engineering and which may be important for high-throughput identifying test of the selenoproteins in plants for the future. This system could identify targets between ten- and hundred-fold more efficiently than analysis of individual samples. By considering the efficiency for different values of the proportion and corresponding optimal group size for varying total numbers of samples, we are able to estimate an upper limit for the number of tests that are required. The application of this system to determine the transgene in an artificially constructed population of transgenic and non-transgenic wheat lines successfully identified the 10 positive samples located randomly within 1000 samples using only 92 PCR reactions. The same approach was also applied to determine transgene expression by SDS-PAGE of seed proteins. This system should be applied to high-throughput screening for rare marker-free transformants in plant genetic engineering.