Changes of gonadal morphology and mRNA expression patterns of vitellogenin were investigated in Siberian sturgeon Acipenser baerii (Chondrostei) during its early gonadal maturation period. Early differentiations and morphological transitions of both ovaries and testes appeared to occur actively until the age of 3 years, however from then on, the maturation patterns to full maturity were largely gender-dependent, in which males showed a faster progression of maturation than did females while females experienced a steady-state progress with a lagged interval before entering the final maturation. Expression of vitellogenin mRNAs are closely correlated with transitional patterns of gonadal appearances. In both females and males, hepatic mRNA levels of vitellogenin exponentially increased in the earliest interval (up to 1-year-old). However, in subsequent periods, vitellogenin expression in females continued to increase with age, whereas in males, the expression stabilized at a younger age. Nevertheless, at the age older than or equal to 7-year-old, fully matured individuals showed a quite low level of vitellogenin expression in both females and males. Collectively, results from this study could be useful as a fundamental guideline to address the gonad maturation of this sturgeon species, which is helpful for making practical decisions about farming practices and management for caviar production on local sturgeon farms.

Honeybee (Apis mellifera) egg-yolk protein vitellogenin (Vg) plays roles in immunity, antioxidation, and life span beyond reproduction, but it also acts as an allergen Api m 12 in venom. Here we established antimicrobial and antioxidant roles of honeybee Vg in the body and venom. Using the cDNA encoding Vg identified from Asiatic honeybee (A. cerana) workers, recombinant A. cerana Vg (AcVg) protein of approximately 180 kDa was produced in baculovirus-infected insect cells. In A. cerana worker bees, AcVg was expressed in the fat body and venom gland and was present in the secreted venom. AcVg induced structural damage in microbial cell walls via binding to microbial surfaces and exhibited antimicrobial activity against bacteria and fungi. AcVg protected mammalian and insect cells against oxidative damage through direct shielding of cell membranes. Interestingly, AcVg exhibited DNA protection activity against reactive oxygen species (ROS). Furthermore, the transcript level of AcVg was upregulated in the fat body, but not in the venom gland, of worker bees with antimicrobial peptides and antioxidant enzymes in response to microbial infection and oxidative stress. Our data indicate that AcVg is involved in innate immunity upon infection and in a defense system against ROS, supporting a crucial role of honeybee Vg as an antimicrobial and antioxidant agent in the body and venom.

Bee venom contains a variety of toxic components, including vitellogenin, which display various biological, toxicological,and pharmacological activities. However, the biological actions of vitellogenin, a venom protein in bee venom, remainlargely unknown. Here, we demonstrate that Asiatic honeybee (Apis cerana) venom vitellogenin (AcV-Vg) exhibits anti-oxidantand anti-microbial activities. AcV-Vg is expressed in the venom gland and is then secreted into venom. The recombinantAcV-Vg protein was produced in baculovirus-infected insect cells. We found that AcV-Vg reduced cytotoxicity and oxidativedamage against oxidative stress. Furthermore, AcV-Vg bound to microbial surfaces and induced structural damage in themicrobial cell walls, which, in turn, exhibited anti-microbial activity against bacteria and fungi. Together, our data demonstratedthat the bee venom protein AcV-Vg has multifunctional roles as an anti-oxidant and anti-microbial agent.

The Osmia cornifrons plays an important role in pollinating fruit trees, such as apple trees. To better understand diapause and oviposition in O. cornifrons, we investigated the correlation between the ovarian development and secretion level of OcVg protein in hemolymph. During ovarian development in wintering the number of oocytes progressively increased in comparison with the length of the ovaries and the oocytes. After emergence, the oocyte and ovary sizes developed until 6 days after emergence and declined after 6 days, but the number of oocytes decreased gradually. The secretion level of OcVg protein in hemolymph revealed that during wintering, the secretion level increased from 1 month to 2 months and then stagnated after 2 months. After diapause, the secretion level increased gradually until day 6 of the newly emerged adult from cocoon stage, and thereafter gradually declined, remaining detectable until day 30 of the adult stage. The correction analysis between ovarian development and OcVg secretion level in hemolymph found that in wintering, the number of oocytes was positively correlated to OcVg secretion level. After diapause, the ovary and first oocyte lengths and the number of oocytes showed significant changes in OcVg secretion level and positively correlated with OcVg secretion level, respectively. These results suggest that there is a significant interaction between ovarian development and the secretion level of OcVg protein and the pattern of ovarian development and secretion of OcVg protein are stage-specific in the O. cornifrons female.

Osmia cornifrons plays a major role in the pollination of orchards, but basic information on vitellogenin and the oocyte development is limited. To better understand vitellogenin in hymenopteran insects, we cloned a cDNA encoding vitellogenin from the hornfaced bee O. cornifrons. O. cornifrons vitellogenin cDNA contains 5477 bp with an open reading frame of 1,783 amino acid residues, and has a predicted molecular mass of approximately 200.21 kDa and a pI of 6.55. O. cornifrons vitellogenin possesses four consensus (RXXR/S) cleavage sites and has conserved DGXR and GL/ICG motifs in the C-terminus. The deduced amino acid sequence of the O. cornifrons vitellogenin cDNA showed a 66% identity with Megachile rotundata, 53% to Apis mellifera, 51% to Bombus ignitus, and 42%-30% with other hymenopteran insect vitellogenins. Phylogenetic analysis showed that O. cornifrons vitellogenin clustered with vitellogenins from Megachildae, Apidae, Vespidae, and Formicidae species but not with those from Pteromalidae, Aphelinidae or Ichneumonidae species.

Vitellogenins (Vgs) are precursors of the major egg storage protein, vitellin (Vn), in many oviparous animals. Insects Vgs are large molecules (200-kD) synthesized in the fat body in a process that involves substantial structural modifications (e.g., glycosylation, lipidation, phosphorylation, and proteolytic cleavage, etc.) of the nascent protein prior to its secretion and transport to the ovaries. However, the extent to which Vgs are processed in the fat body varies greatly among different insect groups. We were cloned Vgs partial genes PaVgs and BgVgs from Periplaneta americana and Blattella germanica. Real-time quantitative PCR shows that PaVgs and BgVgs were differential-regulated with aging. In insects, glutathione S-transferases (GSTs) are enzymes involved in detoxification of insecticides. We were cloned GST partial genes PaGST and BgGST from Periplaneta americana and Blattella germanica. Real-time quantitative PCR shows that PaGST and BgGST were up-regulated with aging, and the mRNA level of PaGST and BgGST was higher in 4℃ and 37℃ than room temperature. The expression level of PaGST and BgGST exposure to temperature stress suggests that PaGST and BgGST are up-regulated after exposure low and hige temperature treatments.

vitellogenin cDNA was cloned from the bumblebee Bombus ignitus. The cDNA encoding B. ignitus vitellogenin (BiVg) is 5473 bases long with an open reading frame of 1773 amino acid residues. BiVg possesses two consensus (RXXR/S) cleavage sites and has the conserved DGXR and GL/ICG motif near its C-terminus. The deduced amino acid sequence of BiVg cDNA showed significant similarity with hymenopteran Vgs (51% identity to Apis mellifera Vg, and 33-36% to other insect Vgs). The BiVg cDNA was expressed as a 200-kDa polypeptide in baculovirus-infected insect Sf9 cells. Northern and Western blot analyses showed the expression of BiVg in fat bodies of pupae and adults. In queens, the expression of BiVg was first detected in late pupal stage fat bodies, and secreted BiVg was also observed in late pupal stage hemolymph.

Female ticks require a blood meal for vitellogenesis to occur. Vitellogenin (Vg), a precursor of yolk protein, is essential for egg development and Vg synthesis appears to be regulated by ecdysteroids in ticks. To better understand the regulation of Vg synthesis in ticks, the Vg gene was identified from Orinthodoros moubata. OmVg is composed of 5,502 bp encoding a 1,834 aa protein with Vg specific characteristics. OmVg gene showed the highest homology with the hard tick Dermacentor variabilis and was included in the same clade of a phylogenetic tree as the hard tick and crustacean Vg genes. OmVg gene expression was observed in females but not in nymphal stages and during molting. Both mated and virgin females showed OmVg expression approximately 3 days after engorgement. However, as time passed, mated females showed significant increases in OmVg expression whereas virgin females didn’t. OmVg expression is thought to be regulated by ecdysteroids functioning through a complex with an ecdysteroid receptor (EcR) and retinoid X receptor (RXR). EcR and RXR expression increased in both mated and virgin females soon after engorgement. However, ecdysteroid titer only increased in mated females indicating a high titer of ecdysteroids in mated females up-regulates OmVg expression. The OmVg gene was expressed in the fat body and midgut of O. moubata. Further studies are underway to determine other factors that may explain differences between mated and virgin O. moubata females. Understanding the regulation of reproduction in ticks may lead to the development of better mechanisms for controlling ticks and preventing the spread of tick vectored diseases.

시설재배 작물의 주요 화분매개곤충인 땅뒤영벌의 난황단백질(Vitellogenin; Vg) 유전자를 클로닝하고 휴면 및 사회성에 따른 발현 양상을 조사하였다. 클로닝한 Vg 유전자의 일부분은 꿀벌 및 기생벌의 Vg와 높은 유사성을 나타냈다. Northern blot을 통해서 Vg 유전자의 발현 패턴을 조사해 본 결과 우화한 여왕벌은 교미를 했으나 휴면 전 단계에는 난소가 발달하지 않았고 Vg 발현이 아주 저조했다. 그러나 3개월 동안 저온에서 휴면기간을 지내고 난 뒤에 상온에서 산란유도를 했을 시에는 Vg 유전자의 발현이 증가하였다. 여왕벌의 휴면 전 단계(우화후 6일간)와 여왕벌의 지배를 받지 않은 같은 나이의 일벌을 대상으로 Vg 유전자의 발현패턴을 비교한 결과, 우화한 이 후 여왕벌은 Vg 발현이 저조한 반면 일벌은 증가하였다. 또한 여왕벌의 몸무게에 따라서 Vg의 발현이 차이가 있었다. 즉, the heavy group(>0.9g)은 Vg 발현이 저조한 반면 휴면에 들어가지 않는 the light group(<0.7g)은 증가하였다. 땅뒤영벌의 유약호르몬인 JH-III를 먹이에 혼합하여 휴면 전 단계인 여왕벌을 습식시킨 결과 0.1μM 농도에서 Vg 유전자의 발현이 촉진되었다. 하지만 다른 농도에서는 그 영향이 나타나지 않았다. 본 연구를 통하여 Vg 유전자의 발현패턴은 여왕벌의 휴면생리와 관련하여 차이가 있었을 뿐만 아니라 사회성에 의한 영향도 관찰할 수 있었다. 또한 유약호르몬의 습식에 의한 Vg의 발현이 유도되는 것으로 보아 호르몬처리에 의한 여왕벌의 휴면타파를 예상할 수 있으며 휴면기작 연구를 위한 분자 마커로서 활용할 수 있을 것으로 기대된다.

To develop a biomarker for the monitoring of the contamination of estrogenic endocrine disrupters in the aquatic environment, reverse transcription -polymerase chain reaction (RT-PCR) analysis of vitellogenin (Vg) mRNA expression was optimized in Bombina

In an effort to develop the tools for monitoring the contamination of xenoestrogen in the aquatic environment of Korea, reverse transcription-polymerase chain reaction (RT-PCR) analysis of vitellogenin (VTG) mRNA expression were optimized in Synechogobius

난황형성(vitellogenesis)은 난생동물의 번식에서 매우 중요한 과정으로 간에서 난황전구물질(vitellogenin,Vg)의 생성과 단백질 수준에서 Vg의 변형과 난자내 축적 및 난황물질(vitellin)로의 전환을 포함한다. 난황은 경골어류의 배아의 영양물질 및 삼투압 조절을 통한 부유특성의 조절에 관여한다. 척추동물의 Vg유전자는 lipoprotein계열의 유전자로 복수의 Vg유전자가 존재하며 서로 다른 크기의 Vg단백질을 암호화한다. 에스트