The Research Of Vitellgoenin In Two Silk Insects Bombyx Mandarina And Actias Selene H(?)bner

This thesis contains two major parts. The first part is the research of identification of vitellogenin and analysis of its cDNA sequence, and research of composition of yolk protein in Bombyx mandarina Moore. The large subunit and small subunit of vitellogenin in Bombyx mandarina are identified through SDS-PAGE and Western blotting, which molecular weight are about 175kD and 42 kD respectively based on hight molecule weight marker. The vitellogenin in haemolymph have expression difference in different sexes and times. The tendency to change of total RNA in the female fat body of Bombyx mandarina from spinning day 0 to day 5 is consistent with that of vitellogenin in haemolymph of female silkworms. Several primers are designed according to cDNA sequence of vitellogenin in Bombyx mori and conservatism of insect vitellogenins. The cDNA sequence of vitellogenin in Bombyx mandarina is obtained through RT-PCR to the total RNA and RACE amplification to 3'-end and 5'-end, which contains 5754 bases, an open reading frame which encodes 1780 amino acids, and the putative cleavage sites RSRR for the proteases of the subtilisin family at position 364-367 where provitellogenin is cleaved into two subunits which molecular weight are 161.571kD and 40.794kD respectively based on amino acids, which are in accord with the result of SDS-PAGE if modification is considered after translation. The homology of amino acids and bases between Bombyx mori and Bombyx mandarina are 97.6% and 98.1% respectively. Phylogenetic tree of the entire amino acid sequence of Vg in eighteen insects is constructed and the result proves the conservation among evolution of insect vitellogenins, especially five silk insects and their homology of Vg amino acid is consistent with RAPD analysis. Yolk protens of Bombyx mandarina are also composed of vitellin, egg specific proteins(ESP) and 30K proteins on the base of SDS-PAGE of egg subsracts of Bombyx mori and Bombyx mandarina. Native molecular mass of Vg in the Bombyx mandarina is around 440kD through Native-PAGE of egg substracts of the two silkworms.The second part is biology characteristics of Moon silkworm Actias seleneHiib.ier and identification of its vitellogenin. Moon silkworm Actias selene Hubner is one of economic insects with spinning and cocooning, which belongs to Lepidoptera. There are little study related to moon silkworm at home and abroad. This paper states the biology characteristics of moon silkworm through rearing in room and microcharacters of its egg hole through scanning electron microscope (SEM) , and its instar has four moulting and five stadiums, divoltinism, diapause with pupa and forty days of all instars in Hefei. Two subunits of Vitellogenin in moon silkworm are identified, which molecular weight are about 175kD and 45kD respectively through SDS-PAGE and Western blotting, and also have expression difference in different sexes, tissues, times.