bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrokinetic characterization of two ascites tumours: TA3 and M.Mel. 1
Authors: Roeder Claudia , Cook G. M. W. , Haemmerli Gisela , Sträuli P. 
Published: April 2021

ABSTRACT
The electrokinetic surfaces of cells of the TA3 ascites tumour of the mouse and the M.Mel. 1 ascites tumour of the golden hamster have been studied for the past 3 years. It became evident that with regard to their electrophoretic mobility (E.P.M.), TA3 cells were stable and melanoma cells were not. Therefore, results discussed in this paper only refer to the melanoma ‘subline’ used for the present investigation. A comparison of the electrokinetic properties of the 2 tumours gives the following information: 1. TA3 and M.Mel. 1 cells have similar E.P.M.s: —103 and — 1·05/ffli s−1 V−1 cm, respectively. 2. Treatment with 15 % formaldehyde raises the E.P.M. of TA3 cells by 18% and of M.Mel. 1 cells by 11%. 3. Incubation with neuraminidase lowers the E.P.M. of TA3 cells by 46 % and of M.Mel. 1 cells by 24%. 4. Consecutive treatment with formaldehyde/neuraminidase and with neuraminidase/formaldehyde produces identical pH-mobility profiles for TA3 and M.Mel. 1 cells. Further, the electrokinetic data suggest that in addition to anionogenic groups, cationogenic groups are present on the surfaces of both TA3 and M.Mel. 1 cells.
Mitotic indices and E.P.M.s of standard washed and neuraminidase-treated M.Mel. 1 cells, examined on consecutive days after implantation, indicate a continuous loss of sialic acid from the electrokinetic surface during the progress of a transplantation passage.
These results are discussed with regard to the significance attributed to ionogenic groups at the surface of normal and neoplastic cells by other authors.
Differences in ploidy and degree of intercellular contact in differentiating and non-differentiating sycamore calluses
Authors: Wright K. , Northcote D. H. 
Published: April 2021

ABSTRACT
Comparisons have been made between a sycamore callus (S4) isolated in 1970 and one first isolated in 1958 (S2). Incubation of S4 on media containing different concentrations of auxin and kinetin showed that the ratio of the hormones was the factor which controlled the growth pattern within the tissue. High ratios of auxin: cytokinin favoured a white friable tissue, whereas a compact callus with a much harder texture was formed at low ratios. Roots were differentiated at intermediate values.
Callus (S2) has not been induced to undergo cellular differentiation. No soluble factors which were capable of stimulating differentiation in S2 were produced during the differentiation of S4, and S2 did not affect the ability of S4 to form roots.
Divisions seen in suspension cultures of S4 callus were mainly diploid; the cells of S2 were predominantly tetrapioid. When S2 suspensions were grown in the cytokinin-free medium used for S4 a considerable number of diploid cells were seen. A number of S2 clones have been isolated and all these developed chloroplasts on exposure to continuous light and, when grown on the medium used to induce differentiation in S4, five of them showed a growth pattern in which the cells were more closely packed than is usually the case in S2 callus.
A greater degree of cell contact has also been induced by including polyethylene glycol in the medium and so restricting the availability of water to the callus. Under these conditions the cells must have a greater capacity for interaction with one another. The effect of tissue texture on the extent of cell contact and adhesion between the cells is discussed in relation to the composition of the plant cell wall and ideas on the totipotency of plant tissue cultures.
An electron-microscope study of the extranucleolar bodies during growth of the oocyte in the prepubertal mouse
Authors: Chouinard L. A. 
Published: April 2021

ABSTRACT
The dictyate nucleus of the growing mouse oocyte exhibits, besides the nucleolus, 3 ultrastructurally distinct types of smaller formed entities referred to as extranucleolar bodies. The extranucleolar bodies of the first type (fibrillogranular bodies) consist of intermingled masses made up of closely arranged convoluted fibrils, 6-10 nm in width, interspersed with electrondense granules approximately 15 nm in diameter. The extranucleolar bodies of the second type (fibrillar bodies) are composed of an entanglement of loosely arranged convoluted fibrils 4-10 nm in diameter; such bodies are also characterized by the presence within their mass of irregularly shaped widely scattered islands of varying sizes made up of densely packed fibrillar material exhibiting a somewhat greater electron opacity. The extranucleolar bodies of the third type (coiled bodies) appear to consist of an aggregate of highly contorted threads, the thickness of which varies from 20 to 35 nm; the threads themselves are composed of bundles of fibrils 5 nm thick which are irregularly twisted along their axis.
An attempt is made to interpret these morphological findings in the light of current knowledge concerning the architectural and functional organization of the oocyte nucleus in general during the protracted dictyate stage of meiotic prophase. Our observations would be consistent with the view that the various types of extranucleolar bodies are morphological expression - like the puffs of the polytene and the loops or spheroids of the lampbrush chromosomes - of differential gene activity on the part of the localized regions of the chromosomes during oocyte growth.
Comparative isolation of cilia and flagella from the lamellibranch mollusc, Aequipecten Irradians
Authors: Linck R. W. 
Published: April 2021

ABSTRACT
Gill cilia and sperm flagella from the lamellibranch mollusc Aequipecten irradians were compared with respect to their ultrastructures and adenosinetriphosphatase activities. Cilia were isolated from excised gills using 3 different solutions: twice-concentrated seawater, 10% ethanol–10 mM CaCl2 and 60% glycerol. In each case deciliation occurs by the severance of the cilium at the junction of the transition zone and the basal body, and in each case the ciliary ultrastructure is maintained. Sperm flagella were purified by mechanical decapitation. Cilia and sperm flagella have similar fine structures, except that the matrix of the cilia contains substantially more electron-dense material than that of flagella. The ATPase activity of purified cilia is approximately 0·09 μmol P1min/mg protein; that of flagella is 0·13. Ciliary and flagellar axonemes were prepared by repeated extraction of the membranes with 1 % Triton X-100. Ciliary axonemes maintain their 9 + 2 cylindrical orientation, whereas flagellar axonemes often appear as opened or fragmented arrays of the 9 + 2 structure, due to the partial breakdown of the flagellar nexin fibres. A-subfibre arms which were obvious in whole organelles are rarely seen in axoneme preparations. Again the ciliary matrix is considerably more amorphous than in flagellar axonemes. The ATPase activities of ciliary and flagellar axonemes are 0·13 and 0·12 μmol P1/min/mg protein respectively; however, activities of ciliary axonemes may vary by a factor of 2, depending on the method of isolation. The difficulty in observing A-subfibre arms in cross-sections of ciliary and flagellar axonemes is discussed in terms of random, non- reinforcing arrangements of the dynein arms.
Identification of a heat-inducible novel nuclear body containing the long noncoding RNA MALAT1
Authors: Onoguchi-Mizutani Rena , Kirikae Yoshitaka , Ogura Yoko , Gutschner Tony , Diederichs Sven , Akimitsu Nobuyoshi 
Published: April 2021

ABSTRACT
The heat-shock response is critical for the survival of all organisms. Metastasis-associated long adenocarcinoma transcript 1 (MALAT1) is a long noncoding RNA localized in nuclear speckles, but its physiological role remains elusive. Here, we show that heat shock induces translocation of MALAT1 to a distinct nuclear body named the heat shock-inducible noncoding RNA-containing nuclear (HiNoCo) body in mammalian cells. MALAT1-knockout A549 cells showed reduced proliferation after heat shock. The HiNoCo body, which is formed adjacent to nuclear speckles, is distinct from any other known nuclear bodies, including the nuclear stress body, Cajal body, germs, paraspeckles, nucleoli and promyelocytic leukemia body. The formation of HiNoCo body is reversible and independent of heat shock factor 1, the master transcription regulator of the heat-shock response. Our results suggest the HiNoCo body participates in heat shock factor 1-independent heat-shock responses in mammalian cells.
Emerging evidence for kindlin oligomerization and its role in regulating kindlin function
Authors: Bu Wenting , Levitskaya Zarina , Tan Suet-Mien , Gao Yong-Gui 
Published: April 2021

ABSTRACT
Integrin-mediated cell–extracellular matrix (ECM) interactions play crucial roles in a broad range of physiological and pathological processes. Kindlins are important positive regulators of integrin activation. The FERM-domain-containing kindlin family comprises three members, kindlin-1, kindlin-2 and kindlin-3 (also known as FERMT1, FERMT2 and FERMT3), which share high sequence similarity (identity &gt;50%), as well as domain organization, but exhibit diverse tissue-specific expression patterns and cellular functions. Given the significance of kindlins, analysis of their atomic structures has been an attractive field for decades. Recently, the structures of kindlin and its β-integrin-bound form have been obtained, which greatly advance our understanding of the molecular functions that involve kindlins. In particular, emerging evidence indicates that oligomerization of kindlins might affect their integrin binding and focal adhesion localization, positively or negatively. In this Review, we presented an update on the recent progress of obtaining kindlin structures, and discuss the implication for integrin activation based on kindlin oligomerization, as well as the possible regulation of this process.
Enrichment of Zα domains at cytoplasmic stress granules is due to their innate ability to bind to nucleic acids
Authors: Gabriel Luisa , Srinivasan Bharath , Kuś Krzysztof , Mata João F. , João Amorim Maria , Jansen Lars E. T. , Athanasiadis Alekos 
Published: April 2021

ABSTRACT
Zα domains recognize the left-handed helical Z conformation of double-stranded nucleic acids. They are found in proteins involved in the nucleic acid sensory pathway of the vertebrate innate immune system and host evasion by viral pathogens. Previously, it has been demonstrated that ADAR1 (encoded by ADAR in humans) and DAI (also known as ZBP1) localize to cytoplasmic stress granules (SGs), and this localization is mediated by their Zα domains. To investigate the mechanism, we determined the interactions and localization pattern for the N-terminal region of human DAI (ZαβDAI), which harbours two Zα domains, and for a ZαβDAI mutant deficient in nucleic acid binding. Electrophoretic mobility shift assays demonstrated the ability of ZαβDAI to bind to hyperedited nucleic acids, which are enriched in SGs. Furthermore, using immunofluorescence and immunoprecipitation coupled with mass spectrometry, we identified several interacting partners of the ZαβDAI–RNA complex in vivo under conditions of arsenite-induced stress. These interactions are lost upon loss of nucleic acid-binding ability or upon RNase treatment. Thus, we posit that the mechanism for the translocation of Zα domain-containing proteins to SGs is mainly mediated by the nucleic acid-binding ability of their Zα domains.
This article has an associated First Person interview with Bharath Srinivasan, joint first author of the paper.
Some Effects of Unilateral Ovariotomy in Rabbits
Authors: Asdell S. A. 
Published: April 2021

ABSTRACTA number of rabbits were partly ovariotomotised, the quantity of ovarian material removed being from one-half to five-sixths of the total present. These operations were performed before puberty.On breeding, the size of litter was found to be little smaller than that of control rabbits living under the same conditions.The number of eggs shed by the operated rabbits is but little different from that shed by the controls, suggesting that the basis of fecundity is to be found in somatic conditions rather than in the quantity of oöcytic material present.The incidence of fœtal atrophy is greater in operated rabbits than in controls. Reasons are advanced in support of the view that the cause of this increased atrophy is different from that prevailing in normal rabbits. Normally, uterine accommodation is not a limiting factor in fertility, or in the size of young born.Hypertrophy of the remaining ovarian tissue occurs to a varying degree, and is proportionately the greater as more ovarian material is removed. This is probably due to the tendency to produce a definite number of ripe follicles at any one time. No hypertrophy of interstitial material could be detected.Ova are unable to travel from one uterine horn to the other across the vagina, though migration across the body cavity does occur.Unilateral ovariotomy does not affect the sex ratio of offspring in rabbits.
Studies on Internal Secretion III.—The Action of Pituitary Extract and Adrenaline on Contractile Tissues of Certain Invertebrata
Authors: Hogben Lancelot T. , Hobson A. D. 
Published: April 2021

ABSTRACTThe action of adrenaline and pituitary extract has been studied on the isolated heart of the crab Maia, the perfused heart of the bivalve Pecten, the isolated crop of the Gasteropod mollusc Aplysia, and the isolated pharynx of the annelid Aphrodite. Methods for the study of the physiology of rhythmical contraction in these invertebrate preparations are described. Pituitary extract in quantities comparable with those which excite the mammalian uterus was not found to have any action on invertebrate muscle. Adrenaline (and epinine) in all cases produced a very pronounced increase in tone accompanied (in Maia, Aphrodite, and Pecten) with acceleration of the normal rhythm. The specificity of the oxytocic action of pituitary extract and the parallelism between the action of adrenaline and of sympathetic excitation in vertebrates are discussed.
On Phosphorus Metabolism in Embryonic Life
Authors: Baldwin Ernest , Needham Dorothy Moyle 
Published: April 2021

ABSTRACT
Estimations have been made of the content of creatine phosphate and inorganic phosphorus in the chick embryo from the 70th to the 360th hour of incubation. The inorganic phosphorus in per cent, of the body weight rises gradually until the 240th hour, at which time there is a sudden and enormous increase, due to ossification of bone. Creatine phosphate was found to be present at the earliest stage investigated. In per cent, of the body weight it rises up to the 4th day and then slowly falls off. At the 4th day there is also a maximum in the phosphagen considered as per cent, of the inorganic plus labile phosphorus. The significance of these results, especially in connection with the existing data on the appearance of muscular movements, is discussed in the text.
The Manner of Sperm Entry in Various Marine Ova
Authors: Chambers Robert 
Published: April 2021

ABSTRACT
This paper is a record of observations on insemination in five species of marine forms, Arbacia punctulata (sea urchin), Woods Hole, Mass., Paracentrotus (Strongy-locentrotus) lividus (sea urchin), Villefranche-sur-Mer, Echinachnius panna (sand-do liar), Mt Desert Island and Woods Hole, Cerebratutus lacteus (nemertine), Mt Desert Island and Woods Hole, and Nereis Embata (annelid), Woods Hole. The observations on all except the European species were made at different times during several summers.
The Mechanism of Projection of the Chameleon’s Tongue
Authors: Zoond A. 
Published: April 2021

ABSTRACT
The projection of the chameleon’s tongue constitutes a unique problem in muscular organisation. It has frequently been recorded that a chameleon can project its tongue to a distance as great, or slightly greater than the length of the animal’s body from nose to anus, and that projection takes place with instantaneous rapidity. Various theories have been advanced to explain this remarkable mechanism, yet still it remains imperfectly understood. The variety of the explanations offered is clearly due to the fact that investigation of this problem has been entirely anatomical, and that no attempt has hitherto been made to apply the test of experiment to it Such an experimental investigation forms the subject of this paper. The experiments here described deal with the tongue, the hyoid apparatus and the accessory muscles, and permit of the formulation of a complete account of this highly complicated and highly perfected response.
Metabolic Changes Associated with Endocrine Activity and the Reproductive Cycle in Xenopus Laevis
Authors: Shapiro H. A. , Zwarenstein H. 
Published: April 2021

ABSTRACT
A new micro-method for the estimation of serum calcium requiring only 0.4 c.c. serum is described. Castration causes a persistent fall (17–34 per cent.) in the calcium content of the serum in females of Xenoput laevis as soon as a months after operation. In males there is no effect 312 months after castration but a foil (16 per cent.) 6 months after. Removal of the anterior lobe (i.e. pars anterior and pars tuberalis) of the pituitary leads to a significantly lower calcium level than removal of the entire gland. Injection of antuitrin into completely hypophysectomised animals causes a rise, injection of pituitrin a foil in serum calcium. Injection of antuitrin into normal animals leads to maximal contraction of melanophores on a black background and injection of pituitrin into normal or completely hypophysectomised toads causes maximal expansion on a white background. When the pars tuberalis regenerates the serum calcium returns to normal concomitantly with the reappearance of the white background response, but without regeneration of the ovaries. The influence of the pituitary on ovarian activity and its effect on serum calcium are. concomitant but independent activities. It is suggested that the pars tuberalis and the posterior lobe have antagonistic effects on both colour change and serum calcium, and that the pars anterior and the posterior lobe exert antagonistic influences on ovarian activity. It is further suggested that the pituitary directly controls ovarian activity, but that both the pituitary and the gonads control calcium metabolism through some other endocrine gland.
Growth Stimulation of Blow-Fly Larvae Fed on Fatigued Frog Muscle
Authors: Fox H. Munro , Smith G. Pugh 
Published: April 2021

ABSTRACT
Blow-fly larvae were fed on (1) resting, and (2) fatigued frog muscle. The larvae fed on fatigued muscle attained a body weight 9 per cent greater than those fed on resting muscle, and the rate of their heart beat was increased by 14 per cent The length of larval life and the oxygen consumption was the same in the two sets of larvae.
The Survival of the Spermatozoon in the Domesticated Fowl
Authors: Walton Arthur , Whetham E. O. 
Published: April 2021

ABSTRACT
In the large majority of animals which have internal fertilisation the effective length of life of the spermatozoon within the body of the female is extremely short. In no mammal is it known to extend from one oestrous period to another. A certain number of more exact determinations have been made. In rabbits, for example, fertilising capacity is retained for about 30 hours (Hammond and Asdell, 1926), and in sheep fertility diminishes presumably from death of the spermatozoa about 27 hours after mating (McKenzie and Phillips, 1930). Data on the survival of motility, which it is to be supposed coincides approximately with fertilising capacity, has been collected by Hammond and Marshall (1925, chap. 6) and Yochem (1930), and the latter found 41 and 17 hours’ survival in the uterus of the guinea pig and rat respectively. However, there are also many known instances of long survival, especially in the invertebrates. In the queen bee, for example, sperm may be stored 7 years and still retain its fertilising power (Bishop, 1920; Courrier, 1921), and in other Hymenoptera spermatozoa may be stored during hibernation or throughout the whole period of egg-laying. Many invertebrates have spermathecae in which spermatozoa are stored presumably for considerable periods. Among the vertebrates prolonged survival is much less common. Some teleosts which have internal fertilisation store spermatozoa for long periods (van Oôrdt, 1928). In some bats, which have their mating season in the autumn and in which the follicles do not ripen till the following spring, the spermatozoa remain alive within the female during the winter (Courrier, 1924; Redenz, 1929). In the male mammal spermatozoa may also be stored for a considerable time in the epididymus (Benoit, 1925, 1926 ; Hammond and Asdell, 1926; Redenz, 1924, 1925, 1926; Young, 1929, 1929 a, 1931). In all these cases of long survival the spermatozoa are stored under what are probably very favourable conditions, of which perhaps the most important is the dense concentration of the sperm-suspension. This is universally characteristic. It has long been known that spermatozoa survive better in concentrated suspension (Gemmill, 1900; Cohn, 1918). Gray (1928, 1928 a, 1931) provides the most likely explanation, having shown for the sea-urchin that dilution activates the sperma-tozoon and that the rate of senescence is an inverse function of the activity.
On the Control of the Level of Activity of the Animal Body
Authors: Carter G. S. 
Published: April 2021

ABSTRACT
Hibernation and the other seasonal variations of activity in the vertebrate have been the subject of a very large amount of investigation and of an even larger literature. This has been recently summarised by Pocock (1926) from the standpoint of general biology, and by Gorer (1931) from that of comparative physiology. Here, it is only necessary to discuss previous work on those aspects of the subject with which this paper is immediately concerned.
Ion Concentration and Activity in the Haemolymph of Aedes Aegypti Larvae
Authors: Edwards H. A. 
Published: April 2021

ABSTRACT
The ionic composition of the haemolymph was measured in fourth instar larvae of Aedes aegypti (reared in 0–30% sea water, the animals’ natural salinity range). Inorganic ions and free amino acids form a substantial part of the haemolymph osmotic concentration. With increasing external osmotic pressure, there is an increase in the concentration of the amino acids, not the major inorganic cations.
Measurements with ion-selective electrodes indicate that the activities of sodium, potassium and chloride can vary independently of their total concentration. The osmotic contribution of these inorganic ions is therefore not necessarily determined by their total concentration.
Peripheral Influences On the Movement of the Legs in A Walking Insect Carausius Morosus
Authors: Cruse H. , Epstein S. 
Published: April 2021

ABSTRACT
Anterior extreme position (AEP) and posterior extreme position (PEP) of the legs of stick insects were measured during walking on a treadwheel or on a slippery glass plate. In several experiments, either protraction or retraction of a middle or hind leg was interrupted. The AEP of other legs was independent of a protraction interruption but PEP was displaced backward in the leg anterior to the interrupted leg. When a leg was standing on a fixed platform (interruption of retraction) no changes were found in AEP and PEP for the other legs but if the platform was slowly moved, PEP of leg on the platform was moved forward. These results disagree with several published hypotheses. The results suggest the hypothesis of a position-dependent threshold value for protraction which is modulated by co-ordinating influences from other legs.