摘要:

Structural and experimental data are given to compare Isopod anternnary organs with Decapod mandibulary organs (DMO). The physiological role of both organs is discussed and their involvement in vitellogenesis control is suggested.

ISSN:0792-4259    

DOI:10.1080/07924259.1989.9672064

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Two stable strains of bilaterally allophenic nemertines were obtained 15 years ago by vegetative multiplication of two bipartite chimeras constructed from symmetrical worm halves of opposite sexes.

ISSN:0792-4259    

DOI:10.1080/07924259.1989.9672065

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Materials immunologically related to luteinising hormone (LH), follicle stimulating hormone (FSH) and the gonadotropin releasing hormone (GnRH) were localised in cerebral tissue ofLocusta migratoriaandSarcophaga bullataby means of the peroxidase-antiperoxidase method. Several polyclonal and a monoclonal antisera were used. From the third larval instar a positive reaction was observed in cells located in several parts of the brain. Each antiserum reacted with a constant number of well defined cells and nerve fibers. No differences between sexes were observed.

ISSN:0792-4259    

DOI:10.1080/07924259.1989.9672066

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The regulation of ovulation and parturition, in the viviparous tsetse flies, constitutes a very precisely adjusted mechanism, Indeed the process of vitellogenesis takes places, in one oocyte only, during the incubation period when the larva is nourishedin uteroon milk produced by the mother. Neuropeptides, biogenic amines, neurotransmitters as well as ecdysone, and 20-hydroxyecdysone and also nervous outputs regulate ovulation and parturition. A model is proposed for the mechanisms controlling these processes.

ISSN:0792-4259    

DOI:10.1080/07924259.1989.9672067

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In unfed virgin or mated females ofRhodnius prolixus, a proportion of females makes some eggs. Vitellogenesis in this prefeed period resembles closely that in fed females: it involves the activation of follicle cells, the development of spaces between the follicle cells, and a dependency on the corpus allatum and juvenile hormone. It is concluded that juvenile hormone is normally secreted in the period between emergence and the first adult blood meal. Eggs are produced only if sufficient blood remains in the crop from the previous larval meal. The data concerning crops size are consistent with the hypothesis that the activity of the corpus allatum is governed by the degree of distension of the crop or abdomen.

ISSN:0792-4259    

DOI:10.1080/07924259.1989.9672068

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The two characterized crustacean pigment-dispersing hormones (α-PDH; β-PDH) are octadecapeptides which differ in primary structure at six positions. Assays for melanophore pigment-dispersing activity showed β-PDH to be 21-fold more potent than α-PDH. In an effort to explain the difference in potencies between the two PDHs, we synthesized and purified six analogs of α-PDH (Leu4−, Leu11−, Lys13−, Asn16−, Asp17−, and Glu3, Leu4−α-PDH) in which the amino acid residues of α-PDH were substituted with those of β-PDH. Four analogs (Leu11−, Lys13−, Asn16−, and Asp17−α-PDH) possessed melanophore-dispersing activity equivalent to α-PDH. Leu4−α-PDH and Glu3, Leu4−α-PDH were 2.4− and 4-fold more potent than α-PDH, respectively. Glu3-α-PDH was 3.3-fold more potent than α-PDH (Jorenby et al., 1987). These results suggest that the 21-fold increase in activity of β-PDH over α-PDH is due to an interactive effect of two or more substitutions rather than from the product of the effects brought about by individual substitutions.

ISSN:0792-4259    

DOI:10.1080/07924259.1989.9672069

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Long-term maintenance of lobster,Homarus americanusand crayfish,Pacifasticus leniusculusprimary cell cultures of testicular and hematopoietic tissues, for 11 and 3 months, respectively, succeeded in a modified Medium 199 supplemented with 10% fetal bovine serum (pH 7.5, 200°C). In addition, NaC1 was used to adjust the lobster culture medium to 1000 mOsm and the crayfish medium to 400 mOsm. Proline concentration was also elevated. Testes were dissociated with 200 U/ml type II collagenase 2–3 days prior to culture.

ISSN:0792-4259    

DOI:10.1080/07924259.1989.9672070

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

After solubilization of membranes from vitellogenic oocytes of the crayfishOrconectes limosus, a component with an apparent molecular weight between 28 and 30 kDa that specifically binds vitellogenin, could be identified by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and by electroblotting. Because this component was pronase sensitive, we assume that we are dealing with a protein. A polyclonal rabbit antiserum was produced against this component and its tissue specificity was verified.

ISSN:0792-4259    

DOI:10.1080/07924259.1989.9672071

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0792-4259    

DOI:10.1080/07924259.1989.9672072

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Red pigment-concentrating hormone stimulates the mandibular organ ofProcambarus clarkiito synthesize methyl famesoate. The mandibular organs of male crayfish were more active than those of females. Hormonal stimulation can be mimicked by calcium ionophore A23187 and the activity of the gland can be reduced by replacing calcium in the media with lanthanum. Mandibular organ synthetic activity is inhibited by pigment-dispersing hormone.

ISSN:0792-4259    

DOI:10.1080/07924259.1989.9672073

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor