摘要:

AbstractCiliated epithelia, especially the ciliary bands used in swimming and filter feeding, of representatives of the following phyla have been investigated: Porifera, Cnidaria, Annelida, Mollusca, Sipuncula, Nemertini, Platyhelminthes, Entoprocta, Ectoprocta, Rotifera, Pterobranchia, Phoronida, Brachiopoda, Echinodermata and Enteropneusta. The trochaea theory predicts that Porifera and Cnidaria have only monociliate cells and lack ciliary bands used in filter‐feeding, that the gastroneuralian larvae have downstream‐collecting ciliary bands with prototroch and metatroch of compound cilia on multiciliate cells, and that notoneuralian larvae have an upstream‐collecting neotroch on monociliate cells. The observations generally fit these predictions and the exceptions are discussed. In all the ciliated epithelia, except that of the sponge larva, each ciliated cell has an accessory centriole perpendicular to the basal body of the cilium and situated on its downstream

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1987.tb00892.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractConcentrations of estrogens in the plasma ofMyxine glutinosawere measured in an attempt to determine whether different stages of reproduction are connected with certain levels of steroid concentration. After extraction with diethylether and column chromatography on Sephadex LH‐20, the plasma was radioimmunoassayed for estrogens. Samples were subdivided into 9 groups according to the gonadal conditions of the animals. There appears to be a positive correlation in females between plasma estrogen concentration and egg size (taken as an indication of reproductive stage). After ovulation the level of plasma estrogens fell appreciably. Estrogen levels of most of the samples from male animals were also determine

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1987.tb00893.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractIn tardigrades of the genusMacrobiotushistochemically localized alkaline phosphatase (ALP) and aminopeptidase (AMP) are taken as markers of absorptive/secretory cells. The enzyme reaction intensity is also related to different metabolic activities of the body tissues and compared with other histochemical and histological features of the cells. ALP and AMP distribution pattern is investigated in the Malpighian tubules, the gut, ovary, testicle and the storage and epidermal cells during female and male gonad development. The results strongly support the hypothesis that the Malpighian tubules are osmoregulatory‐excretory organs and may also perform secretory functions. They show morpho‐functional variations which are related to sexual maturity and differ in the female and the male: possible physiological roles are discussed. In the female all the tissues here examined undergo changes in size, enzyme activities and other features that show a relationship with phases of both oogenesis and molt: a physiological explanation is suggested that takes into account previously obtained evidence of neuroendocrine regulation. In the male the stages of testicle maturity and molt seem to be independent of each other and the changes of the body tissues found in the female are less or not evid

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1987.tb00894.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY