Analysis Of Differentially Expressed Genes Between The Wild Type And The L-e~m Mutant Ovaries

Lethal egg of “ming”(l-e~m) is an egg mutant in silkworm, Bombyx mori. The eggs laidby the l-e~mmutant lose water, ultimately causing death within short time. Previous studieshave shown that the deletion of BmEP80is responsible for the l-e~mmutation. BmEP80is avitelline me~mbrane protein as a kind of structural protein in the ovary of Silkworm, Bombyxmori. Differentially expressed genes were researched in ovaries of l-e~mmutant using Digitalgene expression (DGE), which gives the basic information for further research on theoogenesis in Silkworm, Bombyx mori.1. Differentially expressed genes between the wild type and the l-e~mmutant ovariesDGE was performed to investigate the difference of gene expression in ovariesbetween wild type and l-e~mmutant on the sixth day of the pupal stage to obtain a globalview of gene expression profiles using the ovaries of l-e~mmutants and wild types. Theresults showed a total of3,463,495and3,607,936clean tags in the wild type and the l-e~mmutant libraries, respectively. Compared with those of wild type,239differentiallyexpressed genes were detected in the l-e~mmutant, wherein181genes are up-regulated and58genes are down-regulated in the mutant strain. The Kyoto Encyclopedia of Genes andGenomes (KEGG) pathway analysis results showed that no pathway was significantlyenriched and three pathways are tightly related to protein synthesis among the five leadingpathways. Moreover, the expression profiles of eight important differentially expressedgenes, including19.5kDa heat shock protein gene (Hsp19.5) and BmVMP30, were made. Inthe present study, Hsp19.5was highly expressed and maintained at a certain level ofexpression in the wild type, but not in the l-e~mmutant.2. Expression of Hsp19.5and BmEP80induced by insect hormoneHormonal regulation plays an important role in the development of ovaries in silkworm.In order to explore the interaction between insect hormone and Hsp19.5or BmEP80,Molting hormone (MH), Juvenile hormone (JH) and Diapause hormone (DH) were fed intothe wild type and the l-e~mmutant, respectively. Meanwhile, the expression profiles ofHsp19.5and BmEP80were built. Results showed that the expression of BmEP80wasup-regulated in MH-and DH-induced ovaries. The expression of Hsp19.5was up-regulatedin MH-induced wild type and down-regulated in JH-induced wild type, while it was notclear in DH-induced wild type. But it was no induction in MH-, JH-or DH-induced l-e~m mutant.The current study of the differentially expressed genes between the wild type and thel-e~mmutant provide theoretical basis for elucidating the molecular mechanism of theoogenesis.