Female Hemolymph Research Articles

Sex-linked differences in phenol oxidase in the fairy shrimp Streptocephalus dichotomus Baird and their possible role (Crustacea: Anostraca)

Phenol oxidase activity in the hemolymph of male Streptocephalus dichotomus is only 1/3rd of that of females. About 70% of this activity resides in cell lysate and 30% in plasma. Electrophoretic analysis revealed that male plasma has a single fraction of tyrosine hydroxylase, evidenced by positivity towards tyrosine methylester-PMS-NBT. Female hemolymph has as many as three isozymes showing diphenoloxidase activity. The significance of these results is discussed with reference to sex-linked enzyme activity and its possible role in longevity.

Isolation and Characterization of the Female-Specific Protein (Vitellogenin) in Mature Female Hemolymph of the Freshwater Prawn,Macrobrachium rosenbergii:Comparison with Ovarian Vitellin

Purification and characterization of the female-specific protein (vitellogenin) from the hemolymph of mature female prawn,Macrobrachium rosenbergii,were the objectives of this study. The comparison of biochemical characteristics between vitellogenin and ovarian vitellin was also conducted. Hemolymph vitellogenin was purified with DEAE, hydroxylapatite, and another DEAE chromatographic column. The specific protein (vitellogenin) was shown in the fractions of chromatographic columns on the basis of ELISA, Western blotting, and immunoprecipitation. A purified vitellogenin was obtained with an apparent molecular weight of 700 kDa as determined by PAGE. The purified vitellogenin was considered as a lipoglycoprotein on the basis of staining data. Three subunits (170, 100, and 89 kDa) in purified vitellogenin and two subunits (100 and 89 kDa) in vitellin were detected with SDS–PAGE. Nondisulfide bonds were found in the binding of polypeptide subunits. Only the 89-kDa subunit was a glycopolypeptide in both vitellogenin and vitellin. The amino acid composition of vitellogenin differed from that of vitellin in a few amino acids. Eight amino acid sequences from the N-terminal end of 89- and 100-kDa subunits were determined and they were identical between vitellogenin and vitellin. Seven amino acid sequence from the N-terminal end of the 170-kDa subunit were also identical to the 100-kDa subunit. Purified vitellogenin was more susceptible to precipitation in a solution with low ionic strength than vitellin. This study suggests a close relationship between vitellogenin and vitellin inM. rosenbergiiin their biochemical characteristics.

Amino Acids and Lipids of the Plasma HDL from the White Shrimp Penaeus vannamei Boone

Studies about lipids are taking importance in shrimp, due to their physiological role in nutrition, development and reproduction. These molecules are mobilized through hemolymph by lipoproteins. A 98 kDa high density lipoprotein (HDL) has been detected in shrimp plasma and it is non–sex-associated, since it is present in both, male and female juvenile shrimp. The HDL was purified by density gradient ultracentrifugation from the hemolymph of juvenile white shrimp Penaeus vannamei males and females, separately; and the protein and lipid moieties studied. The amino acid composition and the N-terminal sequence for 15 residues of the 98 kDa apolipoprotein were determined. In addition, the plasma lipid components from male and female were detected by TLC, identifying phospholipids, sterols, and acylglycerols. The lipid concentration of plasma and purified HDL were determined by enzymatic assays, quantifying phosphatidyl choline, acylglycerols, free fatty acids and sterols. Similar concentrations of the lipid classes were found in male and female HDL confirming its sex independence. Purified HDL contains approximately 50% lipids, where the major components are phospholipids followed by acylglycerols, sterols, and free fatty acids. Considering that the HDL plasma concentration is approximately 2% of total protein, HDL could be the major lipid-transporting molecule in shrimp.

Isolation and characterization of the high-density lipoproteins from the hemolymph and ovary of the penaeid shrimp Penaeus semisulcatus (de Haan): apoproteins and lipids.

The high-density lipoproteins (HDLs) found in the male and female hemolymph of Penaeus semisulcatus de Haan were isolated by NaBr (1.22 g/ml) followed by sucrose gradient (5-25%) ultracentrifugation. The male HDL contained one protein, lipoprotein 1 (LP1), composed of one 110-kDa peptide subunit. The female HDL contained two proteins: 1) the LP1 that was immunoidentical to the male LP1 and was similarly composed of one 110-kDa peptide subunit and 2) vitellogenin (Vg), reacting positively with the rabbit antiserum generated against vitellin (Vt) that was isolated from vitellogenic ovaries. Both Vg and Vt consisted mainly of three polypeptide subunits (200, 120, and 80 kDa) as revealed by denatured PAGE and Western blot. The LP1 from males or females did not react with the Vt rabbit antiserum. Similarly, Vg and Vt did not react with the rabbit antiserum prepared against LP1. Phospholipids (PL) constituted 71-76% of the total lipids in the hemolymph and HDLs of both male and female hemolymph. Cholesterol (Ch) amounted to 17-20%, and small amounts (5%) of diacylglycerols (DAG) were also carried by these HDLs. Both the PL and DAG contained highly unsaturated fatty acids (20:5 omega 3 and 22:6 omega 3) that are transported from the food or hepatopancreas to the tissues, including the vitellogenic ovaries in females. In the present study we show for the first time the separate lipid composition of female LP1 and Vg and compare them with the lipids attached to the Vt. Vg had a lower lipid content than LP1 (540 and 1089 mg/g protein, respectively). Differences were also found in the relative abundance of PL, Ch, and DAG classes in the LP1 in comparison with Vg. Furthermore, small amounts (approximately 3.8%) of triacylglycerols (TAG) were found only in the hemolymph of vitellogenic females, and they were associated with the Vg. Although Vg and Vt were composed of similar polypeptides, their lipid composition was different Vt, in contrast to Vg, carried considerable amounts of TAG (approximately 22%) and only trace amounts of DAG. The significance of the TAG in the hemolymph of vitellogenic females is not known, and the functional relationship between Vg and Vt requires future extensive studies. Lipids were not detected in hemocyanin that was purified from clotted hemolymph.

Purification and partial properties of vitellins from the tick Haemaphysalis longicornis (Acari: Ixodidae)

Abstract Fresh eggs were collected daily from ovipositing female Haemaphysalis longicornis, homogenized and then centrifuged. The supernatant was applied to a gel filtration column of Sepharose CL-4B and then to an ion exchange column of DEAE-cellulose (52); two vitellins (VnA and VnB) were purified. Native PAGE showed that VnA and VnB had equal molecular weights (about 220 kda). The female haemolymph at vitellogenesis period also showed Vn bands. Four similiar polypeptides (molecular weight about 67, 64, 52, 48 kda) for both VnA and VnB were demonstrated by SDS-PAGE.

Haemolymph from female beetles infected with Hymenolepis diminuta metacestodes retards the development of ovarian follicles in recipient Tenebrio molitor (Coleoptera).

Infection with developing metacestodes of the rat tapeworm, Hymenolepis diminuta, is known to retard the accumulation of the yolk protein, vitellin, in the terminal ovarian follicles of the intermediate host, Tenebrio molitor. It is probable that this is the result of competitive inhibition of juvenile hormone binding at a microsomal binding site in the beetle follicular epithelium. Experiments were designed to test the hypothesis that inhibitor molecules were circulating in the haemolymph of infected beetles. Whole haemolymph, collected from male or female beetles at various stages post-infection, was injected into non-infected female recipients 2 days post-emergence. Ovaries were removed 3 days later and the vitellin content of the same sized follicles measured using an ELISA. The vitellin content of follicles from recipients of haemolymph from females infected with metacestodes at stage 1 and stage 3-4 was significantly reduced (24 and 27.9%) compared to sham-infected females. However, haemolymph from females infected with mature metacestodes did not affect the vitellin content. Results were thus comparable to those obtained by monitoring ovarian vitellin levels in female T. molitor with bona fide infections. Haemolymph from infected males did not affect ovarian vitellin content. These results indicate that molecules that can modulate vitellogenesis may be present in the haemolymph of females infected with developing metacestodes but that these factors disappear later in infection.

Native vitellins are modified during ovarian development in the stick insect Carausius morosus (Br.).

Vitellins from ovarian follicles and newly laid eggs of the stick insect Carausius morosus were examined by ion exchange chromatography on a HPLC Mono Q column. Under these conditions, vitellins from newly laid eggs resolved as two distinct peaks, referred to as VtA and VtB, that eluted at 8.5 and 12.0 min, respectively. On native gels, both VtA and VtB separated into two different variant forms (VtA' and VtA", VtB' and VtB"). By two-dimensional gel electrophoresis, VtA' and VtA" were shown to contain polypeptides A1, A2 and A3. On the other hand, VtB' and VtB" appeared to comprise polypeptides B1 and B2 and B1, A1, A2, B2 and A3*, respectively. A similar Vt polypeptide composition was also observed by size-exclusion chromatography of vitellins from newly laid eggs. Vitellins from early vitellogenic ovarian follicles resolved into a single chromatographic peak at 7.5 min that coeluted with a major peak from the hemolymph of egg-laying females. Ovarian follicles progressively more advanced in development exhibited a more complex chromatographic profile, consisting of three separate peaks. By two-dimensional gel immunoelectrophoresis, vitellins from ovarian follicles appeared to consist of two closely related, immunologically cross-reacting antigens that gradually shifted apart as ovarian development proceeded to completion. By size-exclusion chromatography, each Vt from ovarian follicles was shown to consist of a unique set of polypeptides different from those listed above. Single ovarian follicles were fractionated into yolk granules and yolk fluid ooplasm and tested by immunoblotting against Mab 12. Under these conditions, VtA variant forms in yolk granules and yolk fluid ooplasm reacted differently. Sections from ovarian follicles in different developmental stages were exposed to Mab 12 and stained with a peroxidase-conjugated, goat anti-mouse antibody. Regardless of the developmental stage attained, staining for peroxidase was restricted to free yolk granules, suggesting that native vitellins in stick insects are structurally modified upon fusion into the yolk fluid ooplasm.

Vitellogenin and egg production in the moth,Heliothis virescens

The characteristics of vitellogenin (Vg) and the relationship between Vg production and egg production in the tobacco budworm, Heliothis virescens, were studied. The relationship between Vg production and juvenile hormone (JH) and the impact of mating on Vg and egg production were also investigated. Vg appears in the hemolymph of H. virescens about 6 h after moth eclosion. Vg may be separated into two apoproteins (ApoVg-I and ApoVg-II) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weights were calculated to be 156,065 ± 800 for ApoVg-I and 39,887 ± 323 for ApoVg-II. SDS-PAGE analysis revealed that the female hemolymph Vg polypeptides appear to be identical to those from eggs but are absent in male hemolymph. Vg concentration was significantly higher in mated females than in virgin females of the same age at 48 h after emergence. Rates of egg production increased as Vg production increased; rates of egg production in mated females were significantly higher than those of virgin females at 48, 72, 96, and 120 h postemergence. Vg production is dependent on JH, because hemolymph from decapitated females lacked Vg while that of decapitated females treated with synthetic JH had Vg at levels comparable to similarly aged, normal H. virescens females. Hemolymph JH titers in mated females were significantly higher compared with those in virgin females at all sampling periods. The high JH level in mated females may explain the high Vg and egg production in mated H. virescens. Arch. Insect Biochem. Physiol. 34:287–300, 1997. © 1997 Wiley-Liss, Inc.

Mutational analysis of N-linked glycosylation of esterase 6 in Drosophila melanogaster.

The primary sequence of the esterase 6 (EST6) enzyme of Drosophila melanogaster contains four potential N-linked glycosylation sites, at residues 21, 399, 435, and 485. Here we determine the extent to which EST6 is glycosylated and how the glycosylation affects the biochemistry and physiology of the enzyme. We have abolished each of the four potential glycosylation sites by replacing the required Asn residues with Gln by in vitro mutagenesis. Five mutant genes were made, four containing mutations of each site individually and the fifth site containing all four mutations. Germline transformation was used to introduce the mutant genes into a strain of D. melanogaster null for EST6. Electrophoretic and Western blot comparisons of the mutant strains and wild-type controls showed that each of the four potential N-linked glycosylation sites in the wild-type protein is glycosylated. However, the fourth site is not utilized on all EST6 molecules, resulting in two molecular forms of the enzyme. Digestion with specific endoglycosidases showed that the glycan attached at the second site is of the high-mannose type, while the other three sites carry more complex oligosaccharides. The thermostability of the enzyme is not affected by abolition of the first, third, or fourth glycosylation sites but is reduced by abolition of the second site. Anomalously, abolition of all four sites together does not reduce thermostability. Quantitative comparisons of EST6 activities showed that abolition of glycosylation does not affect the secretion of the enzyme into the male sperm ejaculatory duct, its transfer to the female vagina during mating, or its subsequent translocation into her hemolymph. However, the activity of the mutant enzymes does not persist in the female's hemolymph for as long as wild-type esterase 6. The latter effect may compromise the role of the transferred enzyme in stimulating egg-laying and delaying receptivity to remating.

Vitellogenins and vitellins in the bean bug,Riptortus clavatus (hemiptera: alydidae): Purification, immunological identification, and induction by juvenile hormone

Vitellogenins (Vgs) and vitellins (Vns) were purified from reproductive female adult hemolymph (HL) and newly laid eggs of the bean bug, Riptortus clavatus. They were separated into two (Vg-1 and 2) and three (Vn-1′, Vn-1, and Vn-2) sub-components, respectively, by ion exchange chromatography. Fused rocket immunoelectrophoresis using anti-(Vn-1) serum showed that they are distinguished clearly into two immunologically distinct groups, i.e., Vg-1/Vn-1/Vn-1′ and Vg-2/Vn-2. SDS-PAGE analysis showed Vn-1 (Vn-1′) and Vn-2 have the same and/or smaller subunit component polypeptides as Vg-1 and Vg-2, respectively. Vn-1′ has some lower molecular weight peptides than Vn-1. Quantitative rocket immunoelectrophoretic analysis showed that Vg-1 and Vn-1 (plus V-1′) were detected first on day 3 in the HL and day 4 in the ovary, respectively, after adult emergence, and increased by day 10 in non-diapause female adults. Vg-1 synthesis is induced in diapause female adults in 1 day after the treatment with juvenile hormone (JH) and JH analog (JHA) or in a few days after transfer from short day to long day conditions. © 1996 Wiley-Liss, Inc.

A new type of highly polymerized yolk protein from the cochineal insect Dactylopius confusus.

A female specific protein was isolated from eggs and female hemolymph of cochineal insects, using density gradient ultracentrifugation, ammonium sulfate precipitation, and size exclusion column chromatography. The protein was found to consist of four different subunits with apparent molecular weights (Mr) 45,000, 49,000, 53,000, and 56,000, respectively. All four subunits were found to be glycosylated; no association of lipids was detected. Size exclusion column chromatography and non-denaturing polyacrylamide gel electrophoresis demonstrated that the native yolk protein exists as large polymers. Electron microscopy showed that these molecules are long, helical ribbons of variable size which are found in both hemolymph and eggs. Using cryo-electron microscopy, it was shown that the ribbons were 14.6 +/- 1.5 nm wide; the helix they form has a repeat distance of 104.9 +/- 11.3 nm and a diameter of 42.1 +/- 5 nm. A clear substructure of the ribbons was recognized. The newly identified protein is the major yolk protein of Dactylopius confusus and no other proteins resembling the more familiar vitellins of other insect species were detected. Moreover, the D. confusus yolk protein appears to be unique both in its subunit structure and in its polymerizing qualities. Thus, the cochineal yolk protein (CYP) is suggested to represent a new type of insect yolk protein.

Isolation and characterization of the female-specific protein (vitellogenin) in mature female hemolymph of the prawn Penaeus chinensis

Purifying and characterizing the female-specific protein (vitellogenin) from the hemolymph of mature female prawns, Penaeus chinensis, were the objectives of this study. Hemolymph was stained with Sudan Black B and fractionated by an ultracentrifuge. A specific protein (vitellogenin) appeared in the third fraction of the female hemolymph, based on polyacrylamide gel electrophoresis (PAGE), Western blotting and immunoprecipitation. A purified vitellogenin was obtained from PAGE and electroelution. Two polypeptide subunits (191 and 85 kDa) were detected in SDS-PAGE. The purified vitellogenin was considered as a lipoglycophosphoprotein on the basis of staining data. Amino acid composition was also determined in the purified vitellogenin after acid hydrolysis. A very low level of cysteine was detected. Non-disulfide bonds were found in the binding of polypeptide subunits.

Vitellogenesis in the terrestrial isopod,Oniscus asellus(L.): Characterization of vitellins and vitellogenins and changes in their synthesis throughout the intermoult cycle

Summary Egg vitellin of the terrestrial isopod Oniscus asselus is a 290 kD, female-specific lipoglyco-protein (V1) comprising two subunits, A (98 kD) and B (82 kD). An additional related protein (V2, 180 kD) was found in developing oocytes but not in mature eggs. Vitellogenin (VG) is electrophoretically and immunologically indistinguishable to V1 and was detected in oocytes, fat body and haemolymph of vitellogenic females. In vitro incorporation studies revealed that VG is synthesized by both fat body and ovaries, but by no other tissues of either females or males. Oniscus VG, therefore, has both intra- and extra-ovarian origins. Following long-term incorporation, the VG synthesized by either fat body or ovaries comprises only subunits A and B of V1. However, following short-term incorporation, larger polypeptides are present in these tissues, which are also recognized by an antiserum raised against V1. It is speculated that VG in Oniscus is synthesized as a large polypeptide which is subsequently processed to smaller fragments. Synthesis of VG by explants of fat body was studied throughout the intermoult cycle. A single large peak of VG synthesis was seen in the second half of premoult; during this time, VG comprises 40% of the total protein synthesized by fat body and oocytes increase in volume 100-fold. The chronology of VG synthesis and oocyte growth are related to known times of release of hormones in Oniscus. It is suggested that vitellogenesis is regulated by both ecdysteroids and neuropeptide(s) from the sinus gland.

In vitro growth of corpora allata from Diploptera punctata.

An in vitro organ culture system was established to support growth of corpora allata from the cockroach Diploptera punctata. During a 1-wk incubation in L-15B medium supplemented with 10% fetal bovine serum (FBS) and 10% cockroach hemolymph, adult male corpora allata exhibited a cycle of de novo DNA synthesis followed by cell division. The number of S-phase cells and metaphase cells per corpus allatum were counted from whole-mount monolayers after labeling in vitro with 5'-bromo-2'-deoxyuridine and exposure to colchicine, respectively. While both FBS and cockroach hemolymph were essential for proliferation of allatal cells, the growth-promoting effect of insect hemolymph was not species-specific and adult female hemolymph was more potent than hemolymph from adult males. Furthermore, DNA synthesis of corpus allatum cells was stimulated in vitro by 20-hydroxyecdysone. This sensitive assay system will be of immense utility in the search for allatal growth factors.

A non-sex-specific hemolymph lipoprotein from the white shrimp Penaeus vannamei boone. Isolation and partial characterization

A procedure was designed to isolate a lipoprotein (Lp) from the hemolymph of juveniles of the white shrimp, Penaeus vannamei Boone, using two high-speed ultracentrifugation steps. The lipoprotein fraction presented a buoyant density of 1.1-1.17g/ml with a peak at 1.14 g/ml. The isolated Lp corresponds to 0.93 and 0.73% of the total female and male hemolymph protein content, respectively. The Lp from males and females consisted of an apoprotein with an apparent molecular weight of 98 kDa as was shown by electrophoresis under denaturing and reducing conditions and it is a glycoprotein that contains mannose. In the hemolymph of both males and females one main native form of the Lp was found. The isoelectric point of the Lp was 5.81, but minor forms of different isoelectric points were also found.

Development of a highly sensitive ELISA for the determination of PBAN and its application to the analysis of hemolymph in Spodoptera littoralis

AbstractA highly sensitive enzyme linked immunosorbent assay (ELISA) for the determination of the pheromone biosynthesis activating neuropeptide (PBAN) has been developed. Six antisera have been obtained that recognize the carboxyl terminal side of this peptide. Two immunogens have been rationally designed and synthesized in order to direct antibody specificity, using as haptens PBAN or PBAN(20‐33) with a Cys residue attached to their amino‐terminal side. The Cys thiol group has been used to covalently bind the peptide to keyhole limpet hemocyanin (KLH) by using N‐succinimidyl‐4‐(maleidimidomethyl) cyclohexane carboxylate (SMCC) as a convenient heterobifunctional cross‐linker. Several usable competitive immunoassays have been obtained by synthesizing eight different coating antigens and screening the sera against all of them. The best assay was obtained with antibody 4 using Cys‐Hez‐PBAN(20‐33) coupled to bovine serum albumin (BSA) through the Lys groups by using the homobifunctional cross‐linker dimethylpimelidate dihydrochloride (DMP) as the coating antigen. The optimized assay allows to detect PBAN at concentrations as low as 1 fmol/well (l50 = 2.5 fmol/well). An extraction procedure for the hemolymph has been developed that allows to perform PBAN measurements in this tissue even after a tenfold dilution. In these conditions matrix effect is negligible. Preliminary results on the presence of PBAN like immunoreactivity (PBAN‐IR) in the hemolymph of Spodoptera littoralis females are reported.© 1995 Wiley‐Liss, Inc.

Dynamics of ejaculate nutrient transfer in Locusta migratoria

Crosses were made to investigate whether males of Locusta migratoria perform cryptic reproductive investment by means of the transference of proteinaceous nutrients to females and eggs and, if so, the dynamics with which these substances are incorporated into the receptor individuals. The results show that males transferred very significant amounts of a mixture of 16 amino acids, radioactively labelled with 14C, through the ejaculate and that females transferred these to the eggs they subsequently laid. Whereas radioactive label in male and female haemolymph was only dependent on time from male injection (negatively and positively correlated, respectively), ejaculate nutrient transfer to the eggs was positively correlated with the time from first mating. The amount of radioactive amino acids transferred to females in the ejaculate with the first mating increases with the number of days since the male was injected with the radioactive solution, which suggests that it is dependent on the time available for their incorporation into the ejaculate. The amount of ejaculate nutrients transferred to the eggs was dependent only on the number of copulations of the female with the injected male before laying. Male nutrients appear to be incorporated into eggs proportionately to their concentration in the female, suggesting a generalized investment. These results are discussed in relation to the expectations of parental investment theory on mating behaviour and confidence of paternity.

Changes in hemolymph proteins and their synthetic activities during development and engorgement, and after juvenile hormone treatment in the kissing bug, Rhodnius prolixus

The hemolymph from the kissing bug, Rhodnius prolixus, contains two major proteins, i.e. storage protein (SP) and lipophorin (LP) in all stages of both sexes, and egg yolk main protein precursor vitellogenin (Vg) in the adult females. We studied changes in the profiles of SP, LP and Vg in the hemolymph and their synthetic activities during nymphal and adult development. Bugs were labeled in vivo with [ 35S]methionine, hemolymph was separated by native or SDS-PAGE, and visualized with Coomassie blue and fluorography. SP and LP are detected in the hemolymph of both sexes throughout life. Vg appears only in the hemolymph of females both immediately after adult emergence and after engorgement in starved adults. SP is observed both in the fat body and the ovary throughout the nymph and adult stages. Vg (or Vn) is detected in the adult fat body and ovary. SP synthesis is detected in every stage of development and reproduction. The synthetic activity of SP increases after engorgement and decreases during starvation in both nymphs and adults. In autogenous and blood-fed reproductive female adults SP synthesis is reduced except during a short time after emergence and after engorgement. The level of LP synthesis is lower than that of SP and Vg, but detected during the entire life span. In adult females, Vg synthesis is superior to SP synthesis both after emergence and after engorgement. Synthesis of both SP and Vg are detected in the fat body and the ovary. Both SP and LP synthesis are induced in decapitated adult females and males after JH treatment, whereas no protein synthesis is detected in acetone treated animals. Vg synthesis increases greatly after 4 days of JH treatment in adult females and is maintained at a high level for at least 1 week.

Purification and characterization of the female-specific protein (vitellogenin) in mature female hemolymph of the prawn,Penaeus monodon

Summary Purifying and characterizing the female-specific protein (vitellogenin) from the hemolymph of mature female prawn, Penaeus monodon, were the objectives of this study. Hemolymph was stained with Sudan Black B and fractionated by an ultracentrifuge. A specific protein (vitellogenin) appeared in the fourth fraction of the female hemolymph based on the Western blotting and polyacrylamide gel electrophoresis (PAGE). The fourth fraction of the female hemolymph was further purified by PAGE and electro-elution. A purified vitellogenin was obtained according to the PAGE. Two polypeptide subunits (170 kD and 82 kD) were detected in the SDS-PAGE. The purified vitellogenin could be stained with Sudan Black B and periodic acid-Schiffs reagents and further considered as a lip-glyco-phosphoprotein. Amino acid composition was also characterized in the purified vitellogenin of P. monodon after acid hydrolysis. High levels of glutamic acid, aspartic acid and glycine were detected. Cysteine was undetected. Non-disul...

In vitro stimulation by progesterone of the main nidamental glands biosyntheses in the mollusc cephalopod Sepia officinalis L.

The nature of the ovarian factor(s) stimulating biosyntheses in the main nidamental glands of Sepia officinalis L. was investigated using radioinimunoassay (RIA) and in vitro bioassay. RIA revealed the occurrence of progesterone in the follicles and hemolymph of maturing and mature females. We observed a dose-dependent stimulation by progesterone of the incorporation of [ 14C] labelled d-glucose in polysaccharides of nidamental cells in suspension. These results show that the ovary is one of the organs involved in the regulation of the activity of the main nidamental glands.