bluuebunny/crossref_metadata_2025_split huggingface dataset:
The microscopic structure of the shell and ligament of cardium (cerastoderma) corbis martyn
Authors: Mitchell Harold D. 
Published: February 2005

AbstractThe shell of Cardium corbis is composed of three layers, an outer periostracum of conchyolin and two layers of aragonite. The outer aragonitic layer presents a laminated appearance, but in reality is made up of fibers which extend across several of the curved lamellar lines. Each fiber is enclosed in an organic sheath which can be dissolved in potassium hydroxide. The inner aragonitic layer is composed of vertical prisms which are made up of two sets of fibers inclined to each other at an angle of 55 to 60°. The outer layer of aragonite is secreted by glands on the mantle edge outside the pallial line; the inner layer is secreted by glands on the mantle area within the pallial line. The dentition is formed of the same material as the inner aragonitic layer.The ligament is composed of two layers, the outer being less impregnated with calcium carbonate than the inner. Both layers are continuous with the organic matrix of the shell.
The myology of salamanders with particular reference to Dicamptodon ensatus (Eschscholtz). I. Muscles of the head
Authors: Eaton Theodore H. 
Published: February 2005

AbstractThis paper is the first of a series of four describing the anatomy and development of the muscles of Dicamptodon ensatus (Ambystomidae) and comparing them in detail with those of other genera and families of Urodela. In the present paper the muscles of the eye, jaw and hyobranchial apparatus are included, with the exception of the few longitudinal throat muscles derived from trunk myotomes; the second paper will include those of the trunk and tail and their derivatives; the third, those of the limbs and the fourth, a discussion of developmental principles in myology and the bearing of muscles upon classification and phylogeny in the salamanders. The correlation of data on various larval, perennibranchiate and adult forms reduces many muscle names to synonymy, and simplifies the understanding of certain difficult parts of the anatomy. Less attention is given to innervation than to developmental changes and the derivation of the muscles. Dicamptodon, in the larval stage, typifies other larval and most perennibranchiate forms, at metamorphosis it shows the most generalized methods of muscular and skeletal transformation, and when adult the animal serves as a landmark for recognizing the directions of evolution among other Urodela.
Germ cell origin and spermatogenesis in the Siamese fighting fish, Betta splendens
Authors: Bennington N. L. 
Published: February 2005

AbstractResidual germ cells larger than primary spermatogonia but similar in other respects are found throughout the testis in the walls of the lobules and in the cysts of developing germ cells. There is no evidence for germ cell migration through the testis. Spermatogonia arise in situ from residual cells.Forty‐two chromosomes are found in the spermatogonial cells. Two of these chromosomes are much larger than the others and possibly represent sex chromosomes. The haploid chromosome number as seen in primary spermatocyte cells is twenty‐one. A large ovoid chromosome, considered to be a sex chromosome, lags during the formation of the primary spermatocyte spindle. It divides after the division of the other chromosomes into equal chromosomes which pass to opposite poles of the spindle.The evidence for sex chromosomes as presented here is meagre but is consistent with the evidence from chromosome studies in other teleosts. It has been proposed that sex chromosomes are in a nascent condition and hence are differentiated but little from autosomes and also that the members of the sex chromosome pair are morphologically alike.
Phylogeny of the distal musculature of the pectoral appendage
Authors: Howell A. Brazier 
Published: February 2005

AbstractThe musculature of forearm and manus basically is divisible into dorsal matrix and ventral matrix of elbow, and dorsal matrix and ventral matrix of the podium. The former contributes to the present musculature of brachium and antibrachium, and the latter to the musculature of antibrachium and podium. The forearm muscles of the former category are divisible into humero‐radial (carpi radialis), humero‐podial (digitorum communis et sublimis), and humero‐ulnar (carpi ulnaris) components. The deep muscles of the forearm (mm. abductor pollicis longus, extensor pollicis longus, extensor indicis proprius; flexores digitorum profundus et pollicis longus) have been derived from podial matrices that have migrated proximally along the ulna. The short flexors of the hand have been derived from a superficial and a deep basic series: From the former have come mm. palmaris brevis, abductor pollicis brevis, superficial head of the flexor pollicis brevis, abductor et flexor digiti 5, and lumbricales. From the deep series have been derived mm. contrahentes (including adductor pollicis), interossei, opponens pollicis, deep head of flexor pollicis brevis, and opponens digiti 5.
Panniculus carnosus and formation of the pouch in Didelphids
Authors: Enders Robert Kendall 
Published: February 2005

AbstractPanniculus carnosus is well developed in the five Didelphids studied. It is described in three parts: pars dorsalis, pars thoracoabdominalis and pars pudenda, in Marmosa, Didelphis, Metachirops, Metachirus and Chironectes, and in Orolestes, a caenolestid marsupial. Pars dorsalis is well developed in all five genera, but not so well developed as in Orolestes; pars thoracoabdominalis is present in all five Didelphids, but not in Orolestes; and the degree of development of pars pudenda is correlated with the development of the pouch, being absent in Orolestes, weak in Marmosa and strong in both males and females of the other genera. In Chironectes, in which genus the male develops a pouch, pars pudenda is strikingly developed. The ‘sphincter marsupii’ of other writers is considered to be a portion of pars pudenda.In early development an epidermal ridge arises surrounding part of the mammary area. In Marmosa these ridges move laterally and posteriorly before the expanding mammary area. In Didelphis, Metachirops, Metachirus and Chironectes the ridges form the lips of the pouch. The pouch is formed when the ridges remain stationary and the expanding mammary area throws the skin into a double‐walled fold.
Morphology of Campeloma rufum, a parthenogenetic snail
Authors: Mattox N. T. 
Published: February 2005

AbstractCollections of Campeloma rufum were made at all seasons of the year from the Salt Fork River at Homer Park, Illinois, for gross anatomical and histological studies. No males nor male reproductive cells were found, all individuals showing definite female structures. The gonad, found on the columellar surface of the digestive gland, shows ovarian cells. A U‐shaped tube from the albumen gland to the uterus receives the oviduct near its proximal end. This duct leads into a glandular pocket, the shell gland, which in turn empties into the sac‐like uterus. The uterus terminates near the edge of the mantle in a muscular vaginal tube. The previously undescribed kidney, a glandular, pyramidal organ, lies posterior and to the left of the upper end of the mantle cavity. The kidney possesses two orifices opening into the pericardium and ureter respectively. The ureter opens between the vagina and the anus. Intra‐uterine young were observed during all seasons of the year varying progressively from small veliger to fully formed young. A later paper on oogenesis, will attempt to substantiate parthenogentic reproduction for C. rufum.
The embryology of the guinea pig. II. The polydactylous monster. A new teras produced by the genes PxPx
Authors: Scott J. P. 
Published: February 2005

AbstractA detailed study of Wright's polydactylous monster (produced by a semi‐dominant lethal gene) indicates that it belongs to a general type found also in rare human cases. The diagnostic characteristics are: clubbed feet and approximately double the usual number of digits, embryonic posture, microphthalmia and enlargement of the diencephalon, and missing tibia and telescoped sternum; all organ systems in the body except the genital and circulatory are grossly abnormal. The defects appear to be produced by an arrest of morphogenesis and an alteration of relative growth rates. It is indicated that a controlling center of digit formation exists on the lateral (postaxial) side of the foot, that skeletal and dermal structures are controlled by it, but that muscles are differentiated according to the area of the limb in which they lie. The gene itself is not atavistic, although its effects in the heterozygote have that appearance.
Adaptations for viviparity in embryos and ovary of Anableps Anableps
Authors: Turner C. L. 
Published: February 2005

AbstractIn the Anablepidae, a family of viviparous Cyprinodont fishes, the mature eggs are fertilized in the ovarian follicles. The embryos are retained in the modified ovarian follicles until birth and are born when about 44 mm. in length. The embryos develop expanded yolk sacs which reach a maximal diameter of about 10. mm. The vitelline veins on the surface of the yolk sac develop rows of bead‐like swellings, yolk sac bulbs, which serve to facilitate absorption of materials from the fluid of the follicle cavity. There is an extensive system of follicular villi upon the internal lining of the follicular capsule, the apparent function of which is to increase the vascular surface of the internal lining of the follicular capsule and to facilitate the interchange of materials between the blood of parent and fluid of the follicular cavity. The follicular villi and the yolk sac bulbs develop at the same time. These two adaptations for viviparity are apparently unique in this family of fishes.
The microscopical anatomy of metamorphosis in a haploid salamander, triton taeniatus laur
Authors: Fankhauser Gerhard 
Published: February 2005

AbstractThe microscopical examination of the first haploid salamander to live through metamorphosis shows that the transformation to a terrestrial vertebrate was normal and practically completed at the time of its death. All the organs and structures that develop shortly before and during metamorphosis and are typical for the adult salamander, e.g., the integument, the pharyngeal derivatives, and various glands of special function, are present.The nuclei in all organs and tissues of the haploid animal are smaller than normal. This is indirect evidence of the uniformly haploid condition of the animal. The majority of the organs are smaller than in the control but contain a larger number of cells. In some glands, the reduced cell size has been completely compensated by the increase in cell number.
The feeding mechanism of the oyster. I. On the pallium and the branchial chambers of Ostrea virginica, O. Edulis and O. Angulata, with comparisons with other species of the genus
Authors: Nelson Thurlow C (Hristian) 
Published: February 2005

AbstractSeparation of the mantle from the visceral mass on the right side in deeply cupped species of oyster provides a shorter channel for egress of water from the right demibranchs. Correlated with this change is reduction in size of the right epibranchial chamber beneath the adductor together with backward displacement of the adductor itself. This water passage, designated the promyal chamber, develops during the first week after attachment of the oyster larva. The greatest displacement of the adductor and the largest promyal chamber occur in O. frons. The mantle border shows three reduplications of which the innermost, the pallial curtain, controls the amount and the place of entrance and egress of water. The importance of pallial curtains and promyal chamber to survival in turbid waters is discussed; oysters with the promyal chamber have invaded the river mouths, the flat oysters without this chamber have remained in the clear waters of high salinity near the sea. The bearing of these factors on the disappearance of fossil oysters is considered. It is proposed to relate to the genus Ostrea all flat, larviparous oysters which lack the promyal chamber and to raise the subgenus Gryphaea to generic rank to include all deeply cupped oviparous oysters with the promyal chamber. Anatomical and histological features of the pallium and branchial chambers are considered in detail.
On the solvability of a nonlinear boundary value problem arising in the theory of growing cell populations
Authors: Latrach K. , Taoudi M. A. , Zeghal A. 
Published: February 2005

AbstractIn this paper we establish some results regarding the existence of solution on L1 spaces to a nonlinear boundary value problem originally proposed by Lebowitz and Rubinow (J. Math. Biol. 1974; 1:17–36) to model an age‐structured proliferating cell population. Our approach, based on topological methods, uses essentially the specific properties of weakly compact sets on L1 spaces. Our results provide positive answers to the questions posed in Jeribi (Nonlinear Anal. Real World Appl. 2002; 3:85–105). Copyright © 2005 John Wiley & Sons, Ltd.
Effects of various enzymes on the ability of hamster egg plasma membranes to fuse with spermatozoa
Authors: Hirao Y. , Yanagimachi R. 
Published: February 2005

AbstractTo investigate which component of the plasma membrane of the hamster egg plays the central role in the sperm–egg fusion, the egg membrane was treated with a variety of proteolytic, carbohydrate‐hydrolyzing, lipid‐hydrolyzing, and other enzymes. The only enzyme that markedly effected the ability of the egg membrane to fuse with spermatozoa was phospholipase C. The lipid moieties of the egg plasma membrane (and possibly of the sperm membrane) must be of primary importance in sperm–egg fusion at fertilization.
Observations on the fine structure of vole spermatozoa with particular reference to cytoskeletal elements in the mature sperm head
Authors: Koehler James K. 
Published: February 2005

AbstractEpididymal spermatozoa from two species of vole demonstrate cytoskeletal structures closely associated with the plasma membrane. Microtubule‐like elements (2O–24 nm in diameter) form a parallel sheath radiating from the posterior ring to the inferior acrosomal margin just beneath the plasma membrane. Fine filaments (5–8 nm in diameter) are associated with the cell surface, especially in the region of the concave curvature of the acrosomal hook. Both of these elements may aid in stabilizing these respective areas and it is suggested that microtubule‐like and filamentous structures may serve important cytoskeletal roles in the mature sperm head.
Release of acrosomal enzymes following in vitro capacitation of ejaculated rabbit spermatozoa
Authors: Akruk S. R. , Farooqui A. A. , Williams William L. , Srivastava P. N. 
Published: February 2005

AbstractSignificant release of the acrosomal enzymes arylsulfatase, β‐N‐acetylhexosaminidase and hyaluronidase was observed following the treatment of ejaculated rabbit spermatozoa for 12 hours in 20% rabbit serum for inducing in vitro capacitation, and these sperm were capable of in vivo fertilization; however, the treatment of sperm for 15 minutes in high ionic strength (380 mOsm/kg) or low ionic strength medium (305 mOsm/kg) for in vitro capacitation did not result in any significant release of the above enzymes nor were the sperm capable of in vivo fertilization. Serum‐treated spermatozoa remained significantly motile following the 12 hour treatment, 51% underwent the acrosome reaction and were capable of fertilizing 66% of the ova in vivo. Identical serum treatment of lysosomes from rabbit liver resulted in a comparable release of the lysosomal enzymes. Serum treatment for in vitro capacitation resulted in vesiculation of the anterior margin of half the spermatozoa, but left their inner acrosomal membranes and equatorial segments intact. A biochemical relationship between the release of acrosomal enzymes and capacitation is suggested.
Cell surface changes in the proteins of rabbit spermatozoa during epididymal passage
Authors: Nicolson Garth L. , Brodginski Adele B. , Beattie Gillian , Yanagimachi Ryuzo 
Published: February 2005

AbstractDifferences in the exposure of spermatozoa surface components during epididymal passage have been examined using lactoperoxidase‐catalyzed 125I‐iodination or labeling with 125I‐diazodiiodosulfanilic acid. Labeled surface proteins obtained from caput and cauda epididymides were solubilized in detergent, separated by sodium dodecylsulfate polyacrylamide slab gel electrophoresis, and identified by radiography. Densitometer scans of autoradiograms revealed increased amounts or exposures of surface proteins of ∼35,000, ∼39,000, ∼50,000, and ∼78,000 molecular weight on the cauda epididymal spermatozoa.
Evidence that selenium in rat sperm is associated with a cysteine‐rich structural protein of the mitochondrial capsules
Authors: Calvin Harold I. , Cooper George W. , Wallace Edith 
Published: February 2005

AbstractThe keratinous capsules surrounding rat sperm mitochondria were isolated 24 days after intratesticular injections of [75Se] selenite or [35S] cysteine. Dodecyl sulfate‐polyacrylamide gel electrophoresis of purified, doubly labeled mitochondrial capsules revealed only a single 75Se‐labeled component, whose molecular weight was 17,000, in agreement with previously reported observations obtained with cruder sperm fractions. Most of the 35S label and the major zone of stained protein on the gels coincided with the position of 75Se, suggesting that selenium is associated with a cysteine‐rich structural protein. The level of selenium in rat sperm, 195 ± 3.2 ng/108 sperm (approximately 30 ppm), determined by hydride generation and atomic absorption spectrophotometry, is consistent with a structural function for this trace element in the sperm.
Effects on spermiogenesis in the mouse of a male sterile neurological mutation, Purkinje cell degeneration
Authors: Handel Mary Ann , Dawson Melissa 
Published: February 2005

AbstractPurkinje cell degeneration (pcd) is a neurological mutation in the mouse that causes male sterility, but not female sterility. In order to assess the effects of this mutation on spermiogenesis, the structure of the testis and of epididymal spermatozoa was examined by transmission and scanning electron microscopy. In the mutant males, the sperm count was reduced, sperm were nonmotile, and 93% of the sperm were characterized by structural abnormalities of the head, the tail, or both. In the testes of mutant mice, Sertoli cell structure was normal, as were also the early stages of spermiogenesis. However, the elongating and maturing spermatids were characterized by abnormally shaped heads and tails with extraneous and ectopic outer dense fibers. These defects were common in the testes of the mutant mice and rare in the testes of the littermate control mice. It was concluded that the structural abnormalities of the pcd sperm occurred during spermiogenesis and were not due to degeneration of the sperm in the epididymis. These structural abnormalities are similar to those found in all other reported male sterile mutants of the mouse; therefore, although they are caused by the expression of the pcd gene, they are not unique to the expression of this gene.
Inhibition of the metabolism of ram spermatozoa by derivatives of α‐chlorohydrin
Authors: Brown‐Woodman P. D. C. , White I. G. , Ridley D. D. 
Published: February 2005

AbstractThe effects of the male antifertility agent, α‐chlorohydrin, six of its derivatives, and glycidol were studied on the metabolism of washed ram spermatozoa in vitro with fructose as substrate. The α‐chlorohydrin derivatives were the amino, the phosphorylated, and four glycol‐bridge (ketal) compounds. All compounds except glycidol, in a concentration between 0.1 and 100 mM, reduced the aerobic glycolsis and/or oxidation of fructose. However, there was not a high correlation between the ability of these compounds to inhibit the metabolism of ram spermatozoa in vitro and their antifertility activity when administered to male rats. Other factors are clearly involved in their antifertility activity, eg, the concentration of the compounds in the epididymis and their conversion of either more or less spermicidal compounds in the body.
Effects of various lipids on the acrosome reaction and fertilizing capacity of guinea pig spermatozoa with special reference to the possible involvement of lysophospholipids in the acrosome reaction
Authors: Fleming Alan D. , Yanagimachi Ryuzo 
Published: February 2005

AbstractThe effects of lipids on the survival, acrosome reaction, and fertilizing capacity of guinea pig spermatozoa were studied by incubating the spermatozoa in media containing various concentrations of the lipids. Lipids tested were: phosphatidyl‐choline (PC), ‐ethanolamine (PE), ‐inositol (PI), ‐serine (PS), sphingomyelin (S), cholesterol (C), lysophosphatidyl‐choline (LC), ‐ethanolamine (LE), ‐inositol (LI), ‐serine (LS), and glyceryl monooleate (M).When spermatozoa were incubated in a regular medium (containing 2 mM Ca2+) with M, the majority underwent the acrosome reaction within 1 hour. None of the other lipids were as effective as M, and some were totally ineffective under the same conditions. However, when spermatozoa were preincubated in Ca2+‐free medium containing LC, LE, or LI, they gained the ability to undergo the acrosome reaction. One hour of preincubation in Ca2+‐free medium with LC, LE, or LI was enough to render the vast majority of spermatozoa capable of undergoing the acrosome reaction in response to Ca2+. The optimum concentrations for LC, LE, and LI were approximately 85 μg/ml, 210 μg/ml, and 140 μg/ml, respectively. Spermatozoa that had undergone the acrosome reaction by pretreatment with LC, LE, or LI remained actively motile and were capable of fertilizing eggs. LS was totally ineffective in rendering the spermatozoa capable of undergoing the acrosome reaction, and in fact it inhibited the acrosome reaction by itself and also inhibited the LC‐, LE‐, or LI‐mediated acrosome reaction. LS did not prevent acrosome‐reacted spermatozoa from penetrating the zona pellucida, but did prevent sperm‐egg fusion.Based on these findings, it is suggested that lysophospholipids are intricately involved in the sperm acrosome reaction and perhaps in sperm‐egg fusion.
Fine structural abnormalities in the developing mouse embryo
Authors: Chakraborty Jyotsna 
Published: February 2005

AbstractInitial changes in the fine morphology of apparently normal mouse zygotes and embryos were studied in serial sections of mouse oviducts that had been fixed in situ. These changes included extra sperm in the perivitelline space, nuclear budding, the presence of large nucleoli, perinuclear vesicles, the concentration of cytoplasmic organelles, and the extrusion of cytoplasmic ground substance. Initial changes in the nucleus and cytoplasm were undetectable when the zygotes and embryos were examined with the light microscope. It was concluded that serious abnormalities in zygotes and embryos, which may not be identified at the light microscope level, may be detected if they are examined in the electron microscope. Therefore, zygotes and embryos should be critically evaluated before being rated as normal.