台灣地區馬類肉瘤之研究－組織病理變化、病毒之核酸檢測、與牛乳突病毒E2基因序列之關聯

Abstract

為了解在北台灣地區馬類肉瘤的感染情況，在2007年1月至2008年12月期間，我們總共採樣了十四個皮膚腫瘤樣本，其中有七個經組織病理學診斷為馬類肉瘤，顯微鏡檢查下，此七個類肉瘤樣本皆可見或多或少的角質層增生、上皮增生和真皮層纖維母細胞增生。而這七個馬類肉瘤樣本經巢式聚合酶鏈鎖反應檢測牛乳突病毒，設計包含E2基因部分序列作為引子，結果有四個偵測到陽性，產物大小為462個鹼基對。將這些具有陽性反應的DNA產物進行定序，之後作核苷酸和胺基酸多重序列比對，並且使用鄰近連接法和最大概似法等兩種分析法，將所有定序結果和牛乳突病毒第一型和第二型作親源樹分析比對。結果顯示，這四個牛乳突病毒陽性產物之中－有兩個陽性產物序列近似於牛乳突病毒第一型；有一個近似於牛乳突病毒第二型；剩餘一個陽性產物，採集自一匹臺灣自產的迷你馬，其產物序列和牛乳突病毒第一型、第二型以及其他三個序列明顯地較為不同，產生11個點突變，但是都屬於沒有造成胺基酸變異的緘默突變，可能是地理變異所造成的影響，需要後續更進一步的研究進行追蹤評估。

In order to realize infectious conditions of equine sarcoid in Northern Taiwan, we collected 14 equine cutaneous lump samples during 2007-2008, and there were 7 equine sarcoids which were diagnosed by histopathological examination among these. Microscopically, there were mild to severe hyperkeratosis, epithelial hyperplasia, and dermal fibroblastic hyperplasia within 7 equine sarcoids. There were 4 BPV-positive of 7 equine sarcoids, whose size were 462bp, were examined by PCR, and partial sequences of E2 gene was used as primers. All DNA sequencings were performed, and then nucleotides and amino acids multiple sequence alignments were proceeded. And two analytic methods which were included Neighbor-joining method and maximum likelihood method were used to compare with all DNA sequences and BPV-1&2. The results showed that 2 BPV-positive products were similar to BPV-1, and 1 BPV-positive product was similar to BPV-2, and last one BPV-positive product which was collected from a Taiwan pony, was apparently not so similar to BPV-1, BPV-2 and the others. There were 11 point mutations within DNA sequences of the last one, but they are all silent mutations whose nucleotide variation didn’t cause variation of amino acid. The results may be affected by geographic variation, and they need more researches to trace and evaluate further in future.