昆蟲Hz-1病毒屬於無脊椎動物病毒(invertebrate viruses)的一種.
能夠感染數種鱗翅目昆蟲細胞, 其具有一雙股環狀 228 Kb 的DNA基因體.
由於它能在數種昆蟲細胞株中進行急性和持續性感染, 因此成為研究持續
性感染機制的模式病毒. 此病毒在急性感染時表現了100多個 RNA; 但在
持續感染時只表現一個RNA. 因此欲研究病毒進入急性或持續性感染的機
制, 有必要了解早期基因的表現和調控情形.Hz-1病毒 其大部分極早期基
因皆位在Hind III A, D, I 三個片段上.因此本實驗針對I 片段hhi1基因
進行序列分析. 結果得到長度為7704bp 的序列, 經由 Frames 和
CodonPreference 程式分析, 找到 2 個Open Reading Frams (ORF), 其
大小分別為1851 bp及 3426 bp, 中間有一 gap region 為 431 bp. 而
3'-RACE 的結果, 找到 hhi1 基因 3'端的端點, 其端點大約位在第 7478
個 bp 附近. 由 TestCode 程式分析及 RT-PCR 之結果, 顯示此 2 個
ORF 中間之 gap region 並未因 splice 分離, 而實際上連成一長度為
5670 bp 的大片段. 利用活體外轉錄及轉譯試驗的結果發現 hhi1 基因可
能製作一個 226 KD 的蛋白質, 顯示此蛋白質可能由 5670 bp 的大 ORF
製作而成.

Hz-1 virus is an insect virus. It can induce both productive
and persistent viral infections in the Lepidopteran culture
cells. In order to understand the molecular switches of
productive and persistent viral infections, gene expression and
regulation specifically associated to these two phases should
be compared. During persistent viral infection, there is only
one gene, the persistence-associated gene 1(pag1), is expressed.
Since pag1 is also expressed as an immediate early (IE) gene
during productive viral infection, it is necessary to compare
pag1 and other productive specific IE genes to illucidate the
controlling mechanisms as why all the other productive-specific
IE genes are turned off during persistent viral infection but
not the pag1 gene. Most of the immediate early genes of Hz-1
virus were found to locate in Hind III A, D, and I fragments
previously. In this study, a sequence of 7704 base pair region
has been determined in Hind III-I fragment. Computer analysis
revealed the presence of two Open Reading Frames(ORF) of 1851 bp
and 3426 bp onthis region. Between two ORFs, a 431 bp gap region
was found. The 3'-RACE study showed the 3' end of hhi1 gene is
located at nucleotide 7478.TestCode analysis of hhi1 gene and
the result of RT-PCR showed that the gap region between these
two ORFs is not removed by splicing. Forthermore, in vitro
translation assay also revealed that a 226 KD protein could be
generated by hhi1 gene suggesting that it is resulted by a
single ORF of 5670 base long.
Hz-1 virus is an insect virus. It can induce both productive