摘要:

AbstractLarval development of the parasitoidCardiochiles nigricepsViereck occurs in the last instar larva of its host,Heliothis virescens(F.). This allows the parasitoid to exploit the nutritional increase in the biosynthetic activity occurring in the host in preparation for metamorphosis. To understand the biochemical basis of this host parasitoid developmental synchrony, we undertook host ligation studies and analyzed host hemolymph for proteins and glycerol esters. Parasitization affected the biochemical profile of the host. The hemolymph protein concentration of parasitized last instarH. virescenslarvae increased through time, whereas unparasitized (control) larvae were characterized by a decrease in the protein titer when they reached the prepupal stage. The effect of parasitism on glyceride titers of host hemolymph was not as pronounced as the effect on proteins. Ligation conducted on 5th instar hosts, which were parasitized as 4th instars, affected parasitoid development in a time‐dependent way. The percentage of successfully developingC. nigricepslarvae increased with the increase of the time interval between parasitization and ligation. Ligation performed before day 2 of the 5th larval instar ofH. virescenscompletely inhibited parasitoid development. Ligations that disrupted parasitoid developmentwere associated with a low host hernolymph protein concentration. Parasitoid development was successful when hernolymph protein titer was high, as occurred when ligations were performed after day 3 of the 5th host instar in both control and parasitized larvae. Ligations in both situations resulted in a slight increase in glyceride titers. The results suggest that host proteins and/or some factor(s) associated with them may play a role in parasitoid growth and development. © 1993 Wiley‐Liss,

ISSN:0739-4462    

DOI:10.1002/arch.940240202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractDiploptera punctataallatostatins are brain neuropeptides that inhibit juvenile hormone synthesis by corpora allata. They also occur in nerves of many organs other than ocrpora allata. The distribution of allatostatins in, and the effect of allatostatins on two other organs, antennal pulsatile organ and hindgut, are demonstrated here. Allatostatin I‐like immunoreactive material is present in cells of subesophageal and terminal abdominal ganglia; these ganglia are known to contain the cells that project to antennal heart nerve and proctodeal nerve, respectively. Electron micrographs of both organs show nerve terminals with allatostatic immunoreactive granules along with terminals containing nonimmunoreactive granules. Immunoreactive neurosecretory granules are about 200 nm in largest dimension. In the antennal pulsatile organ, profiles of the nerve terminals are larger in the ampullar wall than in the muscle; in hindgut the terminals with immunoreactive granules are associated with the muscle net below the circular muscle. Hindgut responded to allatostatins I and IV with a dose‐dependent decrease in amplitude and frequency of contraction that was reversible, with the threshold concentration for response between 10−8and 10−7M. In contrast, pulsatile organ muscle showed no such change with either allatostatin at 10−7–10−4M. However, both organs responded to proctolin with increased amplitude and frequency of contractions. Allatostatins I and IV inhibited the proctolin‐induced increase of hindgut contraction, whereas no such effect was seen in antennal pulsatile organ muscle. Extract of antennal pulsatile organ muscle showed proctolin‐like bioactivity that comigrated with authentic proctolin on three sequential HPLC systems. © 19

ISSN:0739-4462    

DOI:10.1002/arch.940240203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractNewly laid eggs of the stick insectCarausius morosuscontain two native vitellins (Vit A and Vit B). Under denaturing conditions, these vitellins resolved into 3 (A1, A2, and A3) and 2 (B1and B2) polypeptides. All of these polypeptides had counterparts in the female hemolymph from which they were shown to be derived by in vivo labelling. During ovarian development, the 2 vitellins changed both in charge and polypeptide composition. In EV and LV follicles, Vit A resolved into 4 distinct vitellin polypeptides (A0, A1, A2and A3). Using a panel of monoclonal antibodies, polypeptide A0proved to be immunologically related to polypeptide A2. In follicles about to begin choriongenesis, polypeptide A3was gradually replaced by a lower Mrpolypeptide. Over the same time period, polypeptide B1changed in charge, but not in Mr. To confirm the existence of a polypeptide processing inC. morosus, ovarian follicles of different developmental stages were exposed in vivo to [35S]‐methionine from 6 to 72 h. Data showed that A0and B1were the polypeptides most heavily labelled after short time exposures to the radioisotope. Polypeptides B2and A3were also labelled to some extent. With progressively longer exposures, polypeptides A1and A2also became labelled. In vivo exposure to [3H]‐GlcNAc caused all vitellin polypeptides to become heavily labelled. Autoradiographic analysis of ovarian follicles labelled this way showed that, during development, radioactivity was gradually transferred from newly formed yolk spheres in the cortical ooplasm to the central ooplasm. Data were interpreted as suggesting a causal relationship between polypeptide processing and progressive yolk sphere fusion to yield the central ooplasm. © 1993 Wiley‐Lis

ISSN:0739-4462    

DOI:10.1002/arch.940240204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940240201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY