Genomics Of Wild Silkmoths I:

The thesis focuses on the Genomics of Wild Silkmoths and contains two parts. One is to characterize the expressed sequence tags (EST) of Chinese Oak Silkmoth, Antheraea pernyi. In this part, EST-SSR loci are identified and two functional genes, KK-42BP and eIF-4A, are characterized, based on the information of EST. The other is to determine the mitochondrial genome of the atlas moth, Attacus atlas.The simple sequence repeat (SSR) loci were charaterized in1500ESTs of A. pernyi previously obtained in our lab. We identified a total of71locis from these unigenes, with an average of5.2kb locus. Among mono-to hexa-nucleotide repeat types, tri-nucleotide and tetra-nucleotide repeats are the dominant types. Twenty-five of29pairs of EST-SSR primers designed gave effective amplication products, and7pairs of EST-SSR primers are polymorphic. Further sequencing identified that four pairs out of these7pairs were the real SSR loci. Our work may contribute to further research on the analysis of genetic diversity and genetic structure of A. pernyi population in future.Based on the EST information obtained in our lab, we cloned the KK-42BP gene from A. pernyi that undergoes a pupal diapause in winter. Protein homologous comparison, motif scan and phylogenetic analysis suggested that KK-42BP is a new member of the minor yolk proteins. ApKK-42BP mRNA was expressed in all of the tissues tested, throughout four developmental stages, and in both female and male. The expression patterns of ApKK-42BP mRNA stated that a lack of KK-42BP is associated with pupal diapause. Our results suggested that the KK-42BP gene is likely involved in a function other than as a yolk protein.Based on the EST information, we isolated the eIF-4A gene from A. pernyi. ApeIF-4A was transcribed at four developmental stages and in all tissues tested, suggesting that it plays an important role in development of A. pernyi. Homologous alignment suggested that eIF-4As are highly conserved throughout evolution of eukaryote organisms. Phylogenetic trees based on the sequences of elF-4A demonstrated a similar topology with the classical systematics, suggesting that it has the potential value in phylogenetic inference of eukaryotes.We also determined the complete mitogenome(mitochondrial genome) of the atlas moth, Attacus atlas. The mitogenome is a circular molecule of15,282bp long. The genome comprises13protein-coding genes (PCGs), two ribosomal RNA genes (rRNAs),22transfer RNA genes (tRNAs), and the A+T-rich region. It is of note that the genome exhibits a slightly positive AT skew, which is different from the other known Saturniidae species. The phylogenetic relationships based on Maximum Likelihood method provide a well-supported outline of Saturniidae, which is in accordance with the traditional morphological classification and recent works.