Vitellogenin receptor selectively endocytoses female-specific and highly-expressed hemolymph proteins in the silkworm,Bombyx mori

Abstract

VgR, a member of the LDLR family, functions to transport vitellogenin into the ovaries to protome ovarian growth and embryonic development. In insects, the only widely accepted ligand of VgR is Vg. Recently, BmVgR has been shown to interact with BmSP1 in vitro. Therefore, in this study, we evaluated whether BmVgR could transport BmSP1 into certain cells. Although BmVgR could combine with BmVg and BmSP1, BmVgR did not affect the amount of BmSP1 taken up by Sf9 cells. Parallel immunofluorescence showed that most BmVg and BmVgR were localized in the inner oocyte membrane, showing tissue localization similar to that of BmVg labeled with pHrodo Red absorbed by the ovaries on day 2 of pupation. Although BmSP1 showed localization similar to BmVgR during the same phase, little BmSP1 was present in the ovary. Additionally, BmSP1 did not exist in ovaries when the ovaries contained BmVgR on day 5 of pupation, suggesting that BmSP1 in the ovaries was not endocytosed by BmVgR. In summary, BmVgR could facilitate uptake of BmVg by developing oocytes, but did not modulate in the transport of BmSP1.

CRISPR/Cas9-Mediated Vitellogenin Receptor Knockout Leads to Functional Deficiency in the Reproductive Development of Plutella xylostella

“…Both qPCR and Western blot analyses indicated that PxVgR specifically expressed in the ovaries of P. xylostella, which were similar to those in other insects, including B. mori (Han et al, 2017), Nilaparvata lugens (Lu et al, 2015), and S. litura (Shu et al, 2011). Tissue-specific expression profiles of VgRs further confirm their pivotal roles in reproductive regulation Takeda, 2005, 2007;Shu et al, 2011;Lin et al, 2013;Lu et al, 2015).…”

“…An increasing number of studies has explored the VgR functions in insects using RNA interference technology (RNAi). For example, VgR knockdown through RNAi can significantly suppress egg production and ovary development (Lu et al, 2015;Moriyama et al, 2016;Zhang et al, 2016;Han et al, 2017). However, an effective RNAi is difficult to obtain in some insects, especially in Lepidoptera (Terenius et al, 2011).…”

Expressional analysis of the silkworm storage protein 1 and identification of its interacting proteins

“…Insect storage proteins are selectively reabsorbed by the fat body, where they form dense protein particles in cells during pupation. They provide protein and amino acids for adult organ development and new tissue formation during pupa-to-adult metamorphosis (Han et al, 2017). Silkworm haemolymph contains unique proteins that exhibit anti-apoptotic activity against mammalian cells.…”

“…Storage proteins play important physiological and biochemical roles in insects. For example, they can be used as amino acid storage and supply amino acids essential for insect metamorphosis and diapause and play a significant role in regulating adult metamorphosis and egg formation in females (Han et al, 2017). Storage proteins also act as carriers that participate in the formation of the insect epidermis and the development of insect immunity (Zhang et al, 2014).…”

A Comparative Protein Profile of Virgin and Mated Male of Leucinodes Orbonalis Accessory Gland

“…Hexamerins may simply be considered as 'storage proteins' (Fujii et al, 1989;Tojo and Yoshiga, 1994;Wang et al, 1993) or maybe repressed by juvenile hormone, and thus have been named 'juvenile-hormone suppressible proteins' (Jones et al, 1990(Jones et al, ,1988(Jones et al, ,1993. They provide energy in the form of amino acids essential for insect metamorphosis, diapause, egg development (Han et al, 2017), etc. Hexamerins may transport the hormones (Braun and Wyatte, 1996) and also possess certain immune activities, such as the inhibition of apoptosis (Lee et al, 2015;Rhee et al, 2007), antioxidant activity (Lee et al, 2017) and antifungal activity (Li et al, 2019;Ujita et al, 2005).…”