Change in the Mode of Gene Expression of the Hypopharyngeal Gland Cells with an Age‐dependent Role Change of the Worker Honeybee Apis mellifera L.

Abstract

Major proteins synthesized in the hypopharyngeal gland of the worker honeybee change from bee-milk proteins to alpha-glucosidase in accordance with the age-dependent role change of the worker bee. Previously, we showed that the gene for alpha-glucosidase is expressed specifically in the forager-bee gland [Ohashi, K., Sawata, M., Takeuchi, H., Natori, S. & Kubo, T. (1996) Biochem. Biophys. Res. Commun. 221, 380-385]. Here, we describe the isolation and analysis of cDNAs for two bee-milk 56-kDa and 64-kDa proteins. The 56-kDa protein was a glycoprotein which shared 63.2% and 56.9% amino acid sequence identities with proteins encoded by cDNA for royal-jelly-related protein 57-1 (pRJP57-1) and pRJP57-2. The 64-kDa protein cDNA was identical to pRJP57-1. Thus, these bee-milk proteins seem to form a structurally related protein family. The gene for the 64-kDa protein/RJP57-1 was expressed specifically in the nurse-bee gland, whereas that for the 56-kDa protein was expressed in both the nurse-bee and forager-bee glands. mRNAs for the 56-kDa and 64-kDa proteins were detected by in situ hybridization in a whole acinus of the nurse-bee gland, whereas mRNAs for the 56-kDa protein and alpha-glucosidase were detected in that of the forager-bee gland. Therefore, the individual secretory cells of the acinus of the hypopharyngeal gland were shown to express these genes differently with the age-dependent role change of the worker bee.

Some properties of the main protein of honeybee (Apis mellifera) royal jelly

“…We have detected by imunoblotting using polyclonal antibodies against recombined MRJP1 ) that MRJP1 was the most abundant protein in the water soluble fractions of the pollen pellet and honeybee's pollen bread (S l imúth et al, unpublished data). In addition to nutrition function, MRJP1 could also play a particular role in a honeybee colony in processing honeybee products because mRNA for MRJP1 was detected in hypopharyngeal glands of foragers (Kaludiny et al, 1994a;Ohashi et al, 1997). The structural properties, mainly flexible self-assembly of MRJP1 presented in Figure 2C,D,E, as well as biochemical stability of RJ-gel in water (Fig.…”

“…It is assumed that MRJP1 belongs to the albumin-like proteins and, therefore it is named as apalbumine. From the amino acid sequence of MRJP1 (Ohashi et al, 1997;Schmitzova et al, 1998) it was possible to predict (Rost and Sander, 1993) its preliminary secondary structure. According to this prediction MRJP1 contained 20% α-helix segments and 17.6% β-conformation of the total amino acids residues, that is, a relatively less ordered secondary structure than ovalbumin containing 30.6% α-helix and 31.4% β-sheets segments (Stein et al, 1991;Tatsumi and Hirose, 1997).…”

The influence of sublethal doses of imidacloprid on protein content and proteolytic activity in honey bees (Apis mellifera L.)

“…The causes of this phenomenon presumably lie in a decrease in the size of HPG lobules (Hatjina et al, 2013). This leads to a disturbed protein synthesis in the glands, and in particular to a decrease in the production of royal jelly by nurse bees (Ohashi, Natori, & Kubo, 1997). Soybean trypsin inhibitor (SBTI) can also have a negative effect on the development of HPGs.…”

Order, Disorder, Death: Lessons from a Superorganism

“…Specifically, vitellogenin gene activity suppresses the endogenous juvenile hormone level during the nurse bee stage, whereas reduced signaling from the vitellogenin gene releases juvenile hormone activity during the forager differentiation (Guidugli et al, 2005). This endocrine signal feeds back to the regulatory system to further inhibit the synthesis of vitellogenin protein (Pinto et al, 2000), shift the gene expression pattern of the hypopharyngeal glands (Ohashi et al, 1997), and suppress immunity Rutz et al, 1974;Wille and Rutz, 1975).…”