摘要:

AbstractThe numbers and positions of contractile vacuole pores (CVP) have been examined in strains representing ten genetically isolated groups ofTetrahymena pyriformis. In all strains the position of the CVP's moves, relative to the individual ciliary rows, as a function of the total number of ciliary rows in the cortex (Corticotype). Similarly, the number of CVP's varies in a systematic way through the corticotypic array in each strain. The development of contractile vacuole pores is shown to be regulated by gross geometrical properties of the cortex and can be described with the aid of a simple geometrical model. At least three classes of strains can be distinguished by the patterns of correlation between CVP position and corticotype. Further discriminations are possible within each class through the relationships between CVP number and corticotype. These observations aid in understanding ciliate morphogenesis and Tetrahymena taxonomy.

ISSN:0022-104X    

DOI:10.1002/jez.1401610302

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

年代:1966

数据来源: WILEY

摘要:

AbstractAcrylamide gel electrophoresis of aqueous homogenates from whole brain of perfused chick embryos of 18 days' incubation results in three anodally migrating zones having the properties of cholinesterases (ChE's 1, 2 and 3). These sites hydrolyze acetylthiocholine, alpha‐naphthyl acetate and alpha‐naphthyl propionate. Their activity is inhibited by 10−5M eserine sulfate, by 10−4M di‐isopropylfluoro‐phosphate, and by a 10−4M solution of Burroughs‐Wellcome compound 284c51j dibromide. Homogenization with 0.1% Triton X‐100 selectively increases activity of ChE's 1 and 3, especially the former.The three ChE zones occur in all sub‐regions of brain which were examined: optic tectum, medulla, cerebellum, telencephalon, and optic nerve, although activities in the last area are very low. In homogenates of adult brain, ChE 1 (the most rapidly migrating form) is considerably less active, relative to ChE's 2 and 3, than in embryos of 18 days' incubation.Aqueous homogenates of heads of embryos at stages 17–18 (3rd day of incubation) show a weak ChE 2. Inclusion of Triton X‐100 in the homogenate results in appearance of all three ChE zones in this tissue.Electrophoresis of blood plasma from embryos of 18 days' incubation produces two zones of activity comparable in mobility and substrate affinity to ChE's 2 and 3 of brain. The relative intensities of the reactions in electrophoretic preparations of the two tissues plus the results from perfused brains indicate that residual blood is not the source for the brain enzymes.Electrophoresis of homogenates of skeletal muscle from embryos of 18 days' incubation produces three zones of ChE activity similar to those of brain. In adult muscle, the ChE's 2 and 3 are present, although less intense, and ChE 1 is not detectable. Electrophoretic preparations of limbs from embryos of stages 20–22 show the fastest migrating ChE (ChE 1) as the predominant form. All three ChE's are detectable in limbs at stages 26–27.The results are discussed in relation to literature in the fields of manometric and microscopic studies of cholinesterase

ISSN:0022-104X    

DOI:10.1002/jez.1401610303

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

年代:1966

数据来源: WILEY

摘要:

AbstractThe localization of acid phosphatase in the telotrophic ovary of the water strider,Gerris remigis, has been studied by light microscopy, utilizing a simultaneous coupling azo dye technique on frozen sections. The enzyme is demonstrable in the cytoplasm of advanced nurse cells, and to a variable degree in the trophic core. Reactivity is also distributed throughout the cytoplasm of young (germarial) oocytes. As oocytes enlarge and pass into the vitellarium, reactivity becomes confined to a peripheral band, which widens and becomes associated with a peripheral accumulation of preyolk bodies. This reactivity disappears from the ooplasm before vitellogenesis is entirely completed. Oocytes which undergo degeneration before completing maturation display large, internal, phosphatase‐reactive areas.Acid phosphatase is first demonstrable in follicle cells at the onset of vitellogenesis. Variations in its intensity and intracellular localization are in conformity with previous suggestions in the literature that follicle cells are implicated in vitellogenesis and in subsequent chorion elaboration. Following ovulation, the follicle cells become intensely reactive and as they degenerate, some of this reactive material is expelled from the ovary through the follicle cell basal surfaces. Reactive residues accumulate in the yellow body at the base of the ovary. Thus the enzyme localization is correlated with physiological autolysis in nurse cells and post‐ovulatory follicle cells and with pathological autolysis in oocytes. Its localization in normally developing oocytes and follicle cells suggests involvement in the process of vitellogenesis and chorion formation as w

ISSN:0022-104X    

DOI:10.1002/jez.1401610304

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

年代:1966

数据来源: WILEY

摘要:

AbstractActinomycin D elevates the alkaline phosphatase activity of the duodenum of the mouse. The effect is relatively slight, but positive, during the first postnatal week, but thereafter becomes marked, not only in the period before the normal maximal level of phosphatase activity is reached at 20 days, but also afterwards, as the activity declines to the adult level. The effect is not manifested in mice at the age of one month, but reappears in adults. Doses of actinomycin that enhance duodenal phosphatase activity depress the activity of the same enzyme in the kidney.Puromycin also increases duodenal phosphatase activity, the effect again being quite small in the first week. At all stages from nine days to adult, however, puromycin strongly elevates activity. Cycloheximide is also effective in raising duodenal phosphatase activity in young mice.Glucocorticoids are known to control the normal developmental increase of phosphatase, but the effect of actinomycin D can be exerted in adrenalectomized mice. The effects of both actinomycin and puromycin are additive with those of hydrocortisone acetate, and both raise phosphatase activity after 15 days, when exogenous corticoids no longer exert any influence.Puromycin stops mitosis in the duodenal epithelium in doses that elevate phosphatase. Hence, some alteration of the enzyme must occur in the striated border of cells that have emerged from the crypts and are in place on the surfaces of the villi. Since the phosphatase‐stimulating agents are all inhibitors of protein synthesis, the results are interpreted to mean that duodenal phosphatase normally tends to undergo an activity‐enhancing conversion that is restrained by a labile prot

ISSN:0022-104X    

DOI:10.1002/jez.1401610305

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

年代:1966

数据来源: WILEY

摘要:

AbstractThe left forelimbs of 100 adult newts (Triturus viridescens) were exposed to 1,560 or 2,000 r of localized x‐irradiation; right and left forelimbs were amputated through the distal humerus. Eighty of the left irradiated forelimbs were then implanted autoplastically with cartilage taken from the dorsal cartilaginous plate of the unirradiated contralateral scapula and rendered virtually free of all cell types other than chondrocytes by subjection to manual stripping of soft tissues and perichondrium (60 cases) and manual stripping combined with brief alcohol immersion (20 cases).The results showed that the unirradiated right forelimbs regenerated normally in all cases. They also showed that the irradiated left control limbs (no implants) failed to regenerate in all cases (20). In contrast, those irradiated limbs implanted with unirradiated cartilage developed blastemata which differentiated into irregular masses of cartilage. No blastema developed following dedifferentiation of irradiated stump tissues. The blastema developed concomitantly with the breakdown of the implanted cartilage. Since these two events were separated by a time interval of two weeks, it is concluded that the blastema was formed by a direct, massive contribution of cells from the normal autograft. Further, the histologic evidence presented indicates that the majority, if not all, of the blastema cells derived from chondrocytes of scapular origin in adult newts and implanted autoplastically into irradiated limb tissue has differentiated into chondrocyte

ISSN:0022-104X    

DOI:10.1002/jez.1401610306

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

年代:1966

数据来源: WILEY

摘要:

AbstractThe small size of the nerve fibers of the planarian nervous system render the details of its neuroanatomy invisible to optical microscopy. Electron microscopic studies on the nervous system ofDugesia dorotocephalaare described showing the neuropil of the brain, the origin of the ventral nerve cords from the brain neuropil, synaptic junctions in the neuropil, and “giant” fibers in the longitudinal conduction system. Two major kinds of synapses can be discerned as well as the pre‐ and post‐synaptic sides of each. There appear to be three major kinds of cells comprising the brain; neurons, neurosecretory cells, and neuroaccessory cells. The neurons are unmyelinated, contain neurotubules, and appear to synapse only in the centrally located n

ISSN:0022-104X    

DOI:10.1002/jez.1401610307

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

年代:1966

数据来源: WILEY

摘要:

AbstractWith the BN → Lewis rat strain combination it has been shown that the median survival time of skin homografts on three‐day‐old hosts (10.0 ± 0.5 days) does not differ significantly from that of similar grafts on adult animals. This rapid attainment of immunologic maturity has provided the basis for a sensitive test for the induction of tolerance of skin homografts. The putative tolerance‐conferring stimulus is injected intravenously at birth and the hosts are challenged with donor strain skin three days later. With this system it has been found that whereas an inoculum of 100,000 bone marrow cells elicited weak sensitization, as evidenced by a significant curtailment of graft survival, increasing the dosage to one million or more cells induced tolerance, as shown by prolongation of graft survival. The proportion of hosts displaying tolerance and its degree, increased with the cell dosage. When test‐grafting with skin was delayed until the hosts were 50–60 days old, the minimal number of cells required to confer tolerance was seven million.With the present assay it has been shown that the tolerance induced by low dosage cellular inocula wanes fairly rapidly, though the presence of a skin homograft from the third day onwards may prolong its duration.A previous finding that, with the present strain combination, bone marrow cells are significantly superior to either spleen or lymph node cells in conferring tolerance of skin homografts has been confirmed. It has been shown that adult thymocytes are only capable of inducing feeble degrees of tolerance over a wide dosage range (5 ‐ 50 × 106) and that thymocytes frominfantdonors are ineffective.Viable suspensions of epidermal cells and x‐irradiated or frozen‐thawed suspensions of bone marrow cells failed to confer tolerance, though it was induced fitfully by means of a microsomal lipoprotein extract of BN lymphoid tissue.Finally, it was shown that the survival of BN test grafts on three‐day‐old Lewis hosts was significantly prolonged if they were born of Lewis mothers specifically presensitized against BN antigens. This constitutes evidence of a passive transfer of the isoantibodies responsible for the phenomenon of im

ISSN:0022-104X    

DOI:10.1002/jez.1401610308

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

年代:1966

数据来源: WILEY

摘要:

AbstractThe pattern of transmission of Sex Ratio spirochetes to the progeny ofDrosophila robustafemales that had been injected with spirochete‐laden hemolymph was studied. Males appeared with about the same low frequencies in all the broods, but spirochetes were transmitted in high frequencies only to the early brood progeny, the transmission to later progeny being greatly reduced. This pattern is in striking contrast to that observed inD. melanogasterandD. pseudoobscurafemales in which males appear in nearly equal numbers along with females in the early broods, when the frequency of spirochete transmission is low, but disappear completely from the later broods, when all the females possess a dense population of spirochetes in their hemolymph.The transmission pattern inD. robustasupports the idea of a separation between the spirochete itself and the factor responsible for male lethalit

ISSN:0022-104X    

DOI:10.1002/jez.1401610309

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

年代:1966

数据来源: WILEY

ISSN:0022-104X    

DOI:10.1002/jez.1401610301

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

年代:1966

数据来源: WILEY