New Horizons in Insect Science Towards Sustainable Pest Management

Diapause-Related Gene Expression in Eggs of Multivoltine Bombyx mori L. Silkworm Races 193

the upregulation of pseudouridine synthase gene
confirms the possible role of pseudouridine syn-
thase in cell growth and proliferation.
Remodelling and spacing factor 1 (Rsf-1) is a
member of the chromatin-remodelling complex
family of proteins that regulate gene expression
and cell growth. Rsf-1 is a nuclear protein that
acts as a histone chaperone and binds to another
member of the chromatin-remodelling complex,
hSNF2H. Together, this protein duplex regu-
lates RNA transcription and DNA replication by
spacing nucleosome arrays and mobilizing nu-
cleosomes when chromatin remodelling occurs
(Loyola et al. 2003 ).
RNA-binding proteins (RBPs) play key roles
in post-transcriptional control of RNAs, which,
along with transcriptional regulation, is a major
way to regulate patterns of gene expression dur-
ing development. Post-transcriptional control can

occur at many different steps in RNA metabo-

lism, including splicing, polyadenylation, mRNA

stability, mRNA localization, and translation

(Curtis et al. 1995 ; Wickens et al. 2000 ; de Moor

and Richter 2001; Johnstone and Lasko 2001 ).

Translationally controlled tumor protein

(Tctp) is known to be synthesized preferentially

in cells during the early growth phase of tumors,

but is also expressed in normal cells. RT-PCR

analyses indicated that the BmTCTP mRNA was

transcribed in all larval organs examined and was

present constantly during the cell cycle of BmN4

cells (Lee et al. 2004 ). In this study, the qPCR

analysis confirmed the upregulation of Tctp in

non-diapause eggs suggesting a similar role of

Tctp during embryonic development in B. mori.

Eukaryotic elongation factor promotes the

delivery of aminoacyl-tRNA to the acceptor site

of the ribosome during protein synthesis and has

Table 4 Functional classification of genes isolated through suppressive subtractive hybridization
Diapause Non-diapause
Regulatory 40S ribosomal protein S19 1. Pseudouridine synthase

2. Remodelling and splicing factor 1


3. 40S ribosomal protein S14


4. 40S ribosomal protein S5


5. RNA binding


6. Translationally controlled tumor protein
   homolog


7. Eukaryotic translation elongation factor


8. Nucleosome assembly protein


9. Nascent protein


10. B. mori profilin protein


11. B. mori acyl-coenzyme A dehydrogenase
    Food utilization Taste receptor type 2 member 117
    Stress response Heat shock cognate 71 kDa protein Ubiquitin family protein
    Similar to ubiquitin c-terminal hydrolase x4 Polyubiquitin 4 UBQ4
    Metabolic genes Chitin metabolic process Propanediol utilization protein
    Chitinase domain-containing protein 1 Chitinase A precursor
    Cytoskeletal Nil Nil
    Ribosomal B. mori ribosomal protein L41 Ribosomal protein L23Ae
    60S ribosomal protein L8
    60S ribosomal protein L18
    60S ribosomal protein L27a
    Ribosomal protein L14
    60S ribosomal protein L13
    Transposable Elements Negative regulation of transcription Nil