Limited degradation of vitellin and egg-specific protein in Bombyx eggs during embryogenesis

5′ coding region of the follicular epithelium yolk polypeptide 2 cDNA in the moth,Plodia interpunctella, contains an extended coding region

“…4). In addition to the cleavage of the hydrophobic leader, ESP is also cleaved at two additional sites, between amino acids 132 and 133 and amino acids 228 and 229, by a trypsin-like protease during embryogenesis (Indrasith et al, 1987(Indrasith et al, , 1988bInagaki and Yamashita, 1989). Cleavage by the ESP-specific protease results in the production of a 55 and 36 kDa hydrolytic fragment (Indrasith et al, 1988b).…”

“…Typically, the FEYPs contribute approximately 25-40% of the proteinacious material in the oocytes and are the first to be degraded among the yolk proteins during embryogenesis. The digestion of ESP in B. mori has been shown to be carried out by a highly specific trypsin-like protease that appears early during embryogenesis (Indrasith et al, 1987(Indrasith et al, , 1988b. Proteolytic cleavage of the YP2 subunit of FEYP from P. interpunctella has also been observed (Bean et al, 1988).…”

Biomolecular changes and somatic mutations induced by UV laser irradiation at embryonic stage ofBombyx mori

“…This asynchronous degradation of proteins could be due to modification in the expression of proteases, induced by UV laser light, during embryonic development compared to the control group (Table I). However, the activity of the proteases depends on increased transcriptional activity of the genes, not on the activation of pre-existing enzyme(s) or on the disappearance of protease inhibition (Indrasith et al 1987(Indrasith et al , 1988.…”

Yolk granules are differentially acidified during embryo development in the stick insect Carausius morosus

“…To accomplish this goal, oocytes are endowed with the capability of sequestering a yolk precursor or vitellogenin (Vg) from the maternal blood stream through a process of receptor-mediated endocytosis (Raikhel 1984;Telfer and Pan 1988;Raikhel and Dhadialla 1992;Schneider 1996). The sequestered Vg is deposited in yolk granules as vitellin (Vt) (Giorgi et al 1993a;Snigirevskaya et al 1997aSnigirevskaya et al , 1997b, and eventually degraded by a process of limited proteolysis to yield a number of lower molecular weight polypeptides with the onset of development (Indrasith et al 1987;Masetti and Giorgi 1989;Nordin et al 1990). As this process occurs, yolk granules are structurally modified and progressively reduced in size.…”