摘要:

AbstractTreatment of immature and mature epididymal spermatozoa with SDS and DTT reveals differences in the structural character of their respective tail organelles as a function of their maturity, which are not apparent in untreated spermatozoa. The response of mature sperm tails of rat, rabbit and other mammals to these reagents indicates that the segmented connecting pieces, the coarse outer fibers, the outer membrane of the mitochondrion and the fibrous sheath of the principal piece, as well as the relationships between these organelles, are stabilized highly by intermolecular SS crosslinks. The disruption of these structures by SDS alone in caput epididymal spermatozoa, however, implies their stabilization by disulfide bonds during sperm passage through the epididymis. Hence the pattern of flagellar beat seen typically in mature epididymal or ejaculated spermatozoa is probably determined by post‐spermiation changes in the structural as well as in the metabolic properties of the tail organelles.In similar studies of a wide variety of sub‐mammalian species, the sperm tails fell into two broad classes. The “simple” tail, a plasma membrane enclosing only mitochondria and microtubule doublets (teleosts, frog, chicken and pigeon), disappeared immediately in SDS, though a partial SS dependent stability was inducible in the microtubules of teleost sperm tails. In the second class, the coarse fibers, arrayed as a nine‐membered ring (octopus, snake, lizard, turtle and sparrow) or otherwise (skate, newt), and the fibrous sheath (snake, lizard) also are stabilized by SS bonds, as is the undulating membrane of the urodele sperm tail.Since the sperm mitochondria in all sub‐mammalian species were totally disrupted by SDS alone, an extreme SS dependent stability of the outer mitochondrial membrane may well be a feat

ISSN:0022-104X    

DOI:10.1002/jez.1401870202

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

年代:1974

数据来源: WILEY

摘要:

AbstractEleven weeks of treatment with growth hormone (20 μg 3 times/wk) and prolactin (20 μg 3 times/wk) increased the size of immaturePseudomys scripta elegansbeyond controls. Food consumption was controlled so that all effects of the hormones were direct ones on growth and not due to hyperphagia. Hypophysectomy decreased growth, food consumption and liver protein inChelydra serpentina. Growth hormone replacement (20 μg/2 days) in hypophysectomized animals increased growth, food consumption, liver protein, liver water and decreased liver lipid and liver glycogen compared to hypophysectomized animals. In intactChelydra serpentina, growth hormone (5 and 50 μg/2 days) also increased appetite, growth, liver protein, liver water and decreased liver lipid and glycogen. Blood sugar was not altered by growth hormone treatm

ISSN:0022-104X    

DOI:10.1002/jez.1401870203

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

年代:1974

数据来源: WILEY

摘要:

AbstractAdultAedes aegyptifemales contain very low levels of dopa decarboxylase activity. However, after a blood meal the activity of this enzyme rises dramatically.1Most of the dopa decarboxylase activity is lost after females are allowed to oviposit.2The bulk of the dopa decarboxylase activity observable was accounted for by direct assay of mature ovaries.3Blood feeding did not stimulate any increase of dopa decarboxylase levels in ovariectomized females.4It was concluded that after a blood meal the enzyme eventually becomes incorporated into the mature oocyte to be used for subsequent sclerotization when it is oviposited. Furthermore the presence of an intact resting ovary is necessary in order for the observed blood feeding stimulation of enzymatic activity to occur. This suggests that the follicular epithelium of the ovary may be the site of synthesis or activation of dopa decarboxylase.

ISSN:0022-104X    

DOI:10.1002/jez.1401870204

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

年代:1974

数据来源: WILEY

摘要:

AbstractThe regeneration blastema when autoplastically transplanted to the enucleated orbit of a larval axolotl will differentiate only those structures which lie distal to the level of its origin. Minced limb muscle treated in the same manner will reorganize into muscle, however imperfect, but form no regenerate. When a distal limb blastema is superimposed on minced limb muscle in the orbital site, it produces structures proximal as well as distal to the original level of amputation. Epimorphic regeneration therefore appears to be dominant over tissue regeneration of minced muscle and hypermorphogenesis may be elicited from a distal blastema by augmenting the mesenchymal mass with minced limb muscle.

ISSN:0022-104X    

DOI:10.1002/jez.1401870205

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

年代:1974

数据来源: WILEY

摘要:

AbstractPituitary extracts from 560 matureRana hexadactylaof both sexes from winter and summer seasons were collected locally and were injected into frogs from summer and winter months. The adenohypophysial gonadotrophes were studied from normal animals and from the animals injected with pituitary extracts. The pituitary cell types changed in experimental frogs in comparison to the corresponding cells of normal animals. An attempt has been made to correlate the changes of gonadotrophes with changes in spermatogenetic proliferation as reported earlier (Kasinathan and Basu, '72).

ISSN:0022-104X    

DOI:10.1002/jez.1401870206

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

年代:1974

数据来源: WILEY

摘要:

AbstractVitelline membranes were removed from two‐cellRana pipiensembryos by papain‐cysteine. Uptake of several different metabolites was enhanced, some more than others, but they all slowly reached about the same plateau, 11.2–13% (average) volumetric equilibration of the embryos with the radioactive medium. Active transport was ruled out as the uptake mechanism.Similarly, direct measurement of the volume of the aqueous phase, or “non‐yolk” cytoplasm, of egg homogenates gave an average value of 12.3% of the total egg volume. We conclude that this represents the available embryonic diffusion space and that the metabolites saturated it by passive diffusion. The importance of the concept of non‐yolk cytoplasm, or egg functional volume, as a developmentally significant parameter

ISSN:0022-104X    

DOI:10.1002/jez.1401870207

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

年代:1974

数据来源: WILEY

摘要:

AbstractA study was made of the response of adult newt ventricle to injury. The major events in the repair process after wounding involve blood clot formation, coagulation necrosis, macrophagic activity, regenerative activity of heart muscle, and connective tissue formation. Light microscopic autoradiography indicated that there was a definite area of labeled cells in trabeculae adjacent to the wound, beginning at about ten days after injury. Electron microscopic autoradiography confirmed that myocytes containing myofibrillae underwent DNA synthesis. It was concluded that adult newt myocardium is capable of reacting to injury by the proliferation of myocytes at the wound area as indicated by both DNA synthesis and mitosis.

ISSN:0022-104X    

DOI:10.1002/jez.1401870208

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

年代:1974

数据来源: WILEY

摘要:

AbstractRecent experiments involving the reaggregation of dissociated cells and fusion of intact tissue fragments have indicated that whereas heart cells and tissue fragments from young chick embryos (1.5–2 days) displayed a tendency to assume external positions in combination with neural tube, those from older embryos (4–5 days) tended to segregate to the inside of neural tube. In the present experiments, we have used the same techniques in conjunction with autoradiography to determine the relative positions of two‐day and five‐day heart ventricle cells in fusion masses and in reaggregates. Sections of 30 fusion masses revealed that the two‐day heart fragment enveloped the five‐day heart fragment in every case. Sections of 29 reaggregates showed that the two‐day and five‐day heart cells were still randomly mixed at the end of the two and one‐half day culture period. The consistent spreading of intact two‐day heart ventricle fragments over five‐day heart ventricle fragments confirms the indication of the previous experiments that heart cells change their morphogenetic properties between two days and five days of incubation. The failure of five‐day and two‐day heart cells to sort out from one another could be due to a decreased cohesiveness of five‐day heart cells caused by the try

ISSN:0022-104X    

DOI:10.1002/jez.1401870209

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

年代:1974

数据来源: WILEY

摘要:

AbstractNinety primaparae female mink were bred on two consecutive days between March 11–15. Six days after first mating mink were subjected to one of the nine treatments, control (n = 21); sham superior cervical ganglionectomy (Sham SCGX) (n = 5); bilateral orbital enucleation (n = 10); bilateral orbital enucleation and constant light (n = 16); constant light (n = 19); an accelerated photoperiod of 15L, 9D + 5 min of light per day (cumulative) (n = 10); an accelerated photoperiod and SCGX (n = 6); SCGX and environmental light (n = 5); bilateral orbital enucleation and SCGX (n = 5). The interval between first mating and calculated date of nidation [copulation to implantation (CI) interval] was compared among groups. CI interval was significantly abbreviated in accelerated photoperiod treated animals, and significantly lengthened by constant light; blindness regardless of light regime; and SCGX with accelerated photoperiod. Nonsignificant variation in the CI interval was observed in the blinded or environmental light treated SCGX animals that underwent implantation. Reproductive failure, defined as either absence of embryos in necropsied animals or failure to whelp by females alive on June 1, occurred less frequently in accelerated photoperiod animals and with considerably greater frequency in blind, SCGX, or constant light treated intact animals. Observations in blinded animals suggest that this treatment and presumably SCGX and constant light extend the period of embryonic diapause to the point of blastocyst degeneration resulting in reproductive failure. The occurrence of nidation in some blinded, and constant light animals indicates that this event can occur independent of either retinal receptor or photoperiod. The effects of SCGX suggest that the pineal body is either not involved in nidation or has a facilitatory rather than inhibitory rol

ISSN:0022-104X    

DOI:10.1002/jez.1401870210

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

年代:1974

数据来源: WILEY

摘要:

AbstractThirteen sugars were fed in 0.125, 0.5, and 2 M solutions in water and in 0.5 M sucrose: L‐arabinose, D‐xylose, D‐fructose, D‐glucose, D‐galactose, D‐mannose, lactose, maltose, melibiose, sucrose, trehalose, melezitose, and raffinose. Survival, water consumption, and sugar consumption were measured. No sugar equaled sucrose in acceptance or sustenance. Reduced survival seemed to be associated with aldoses that contain axial hydroxyl groups at C2or C4in a C1 pyran ring (mannose, galactose, or arabinose) even if they were in a sucrose solution that ensures feeding. Acceptance was correlated with survival, but whether low acceptance is a consequence or a cause of mortality was not established. When 0.5 M sucrose was supplied separately, bees showed a strong preference for the sucrose solution and were not harmed by small quantities of the o

ISSN:0022-104X    

DOI:10.1002/jez.1401870211

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

年代:1974

数据来源: WILEY