豚の嗅球における完全長cDNA libraryの作製および,発現遺伝子と転写開始位置の解析 Analysis of a Full-Length cDNA Library Constructed from Swine Olfactory Bulb for Elucidation of Expressed Genes and Their Transcription Initiation Sites

動物の嗅覚システムは摂食行動,生殖活動には不可欠である。本研究では,豚嗅球の完全長cDNAライブラリーを作製し,発現遺伝子の解析を行った。得られたライブラリーのインサートサイズは平均1.7kb,完全長率は約80%であった。ライブラリーからクローンをランダムに1,000個選択し,5'末端よりその塩基配列を解析した。5'末端配列のクラスタリングおよびホモロジー検索を,データベースGenBank/EMBL/DDBJに対して行い,遺伝子機能に基づいて分類を試みた。結果,723個のクラスターについて解析結果が得られた。このうち655個は既知の遺伝子配列と相同性が認められた。残りの68個の塩基配列は相同性を持つ遺伝子がデータベース上に存在しなかったことから,新規の遺伝子を含む可能性が示唆された。また,発現頻度の高かった遺伝子7種,SLC25A,CK8,TU884,TUBB,YWHAH,TUBB2,CNPについて,転写開始領域を決定した。

The olfactory system is indispensable to the survival of animals in finding foods and for the reproductive process. Odorant signals are conveyed through olfactory sensory neurons to the olfactory bulb, which modifies the signals and relays them to the neocortex. In the present study, a "full-length" cDNA library was constructed from the main and accessory olfactory bulbs of 5-week-old male pigs, in order to elucidate the expressed genes. The average insert size of the library was estimated to be 1.7 kb based on 54 randomly-selected clones. One thousand randomly selected clones were subjected to sequencing, and the resulting 883 sequences were then clustered into 753 sequences based on similarity. Since 723 of the 753 sequences had sufficient sequence information for homology analysis, the 723 sequences were subjected to BLAST analysis against GenBank/EMBL/DDBJ; 655 out of the 723 sequences showed similarities with known genes, and the remaining 68 were indicated to be novel sequences. The full-length rate of the library was estimated to be ca. 80%, using 70 sequences corresponding to human full-length cDNAs. The full-length cDNA sequences of a single gene appearing more than 6 times in the analysis were aligned to determine major transcription initiation sites for SLC25A, CKB, TUBB4, TUBB, YWHAH, TUBB2, and CNP genes.