bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monoclonal antibodies to testicular autoantigens of a teleost, the Nile tilapia, Oreochromis niloticus
Authors: Mochida Kazuhiko , Adachi Shinji , Nakamura Ikumi , Yamauchi Kohei 
Published: June 2005

AbstractIn teleosts, several autoantigens, so‐called sperm‐specific antigens, are expressed on the germ cell surface during spermiogenesis and are thought to have sperm‐specific functions. To investigate the functions of the autoantigens in Nile tilapia, Oreochromis niloticus, monoclonal antibodies to these polypeptides were produced. Balb/c mice were immunized with the autoantigens purified from the detergent‐solubilized sperm protein by antisperm autoantibody affinity chromatography. Four hybridomas producing specific antibodies to the autoantigens were obtained. The monoclonal antibody, TAT (Testicular Antigen of Tilapia)‐10 recognized a 27 kDa antigen. This antigen was localized in A and early B type of spermatogonia, spermatids in late spermiogenesis, and spermatozoa. This antigen was located primarily in the mid piece of the spermatozoa. Another antibody, TAT‐20, recognized a 80 kDa polypeptide and another of about 40 kDa. TAT‐21 recognized only a 80 kDa antigen. The antigens recognized by both TAT‐20 and 21 were localized in spermatids in late spermiogenesis and in spermatozoa. TAT‐30 reacted with a 120 kDa antigen which was localized in the epithelium of seminal ducts, Sertoli cells and spermatozoa. The antigens recognized by TAT‐20, 21, and 30 were primarily on the head of spermatozoa. The possible functions of these autoantigens were discussed. © 1994 Wiley‐Liss, Inc.
Ontogeny of feeding in pigeons: A cinefluoroscopic and electromyographic analysis
Authors: van Gennip E. M. S. J. , Berkhoudt H. 
Published: June 2005

AbstractThis study presents a cinefluoroscopic and electromyographic analysis of the feeding behavior of squab during regurgitation feeding. Two phases are distinguished in this behavior: the gaping phase, in which the squab holds its beak wide open while the parent compresses its crop; and the snapping phase, in which the squab opens and closes its beak several times while the parent raises its head. Unlike adult food uptake, the transport of food in squab occurs passively, using the flow in the crop contents which is caused by the compression of the crop of the parent. This feeding behavior does not change when squab grow older, but on average the duration of the gaping phase increases and the duration of the snapping phase decreases. Even squab of 19 days old, which are capable of independent feeding, display the same type of feeding behavior when they feed from the crop of the parent. A gradual transition from ontogenetic feeding to adult feeding or drinking behaviour is not observed, neither in movement patterns. nor in EMG patterns. © 1994 Wiley‐Liss, Inc.
Sex ratios of sea turtles
Authors: Mrosovsky N. 
Published: June 2005

AbstractEstimates of sex ratios of hatchling sea turtles range from approximately 50% female (Chelonia mydas and Dermochelys coriacea in Suriname) to approximately 90% female (Caretta caretta in Florida). Seasonal sex production profiles (SSPPs) show how similar overall sex ratios can be achieved in dissimilar ways. Possible explanations of the data include sampling error, constraints on evolutionary adjustment of pivotals or behavior to local thermal conditions, and violations of assumptions required by classical Fisherian theory. © 1994 Wiley‐Liss, Inc.
Sex‐determining mechanisms in squamate reptiles
Authors: Viets Brian E. , Ewert Michael A. , Talent Larry G. , Nelson Craig E. 
Published: June 2005

AbstractTwo modes of sex determination occur in squamates: genotypic sex determination (GSD) and temperature‐dependent sex determination (TSD). Within each of these two major modes, there are many different variants, or mechanisms. Male heterogamety, female heterogamety, multiple sex chromosome systems, and homomorphic sex chromosome systems are all types of GSD found in squamates. Two patterns of TSD have been reported.Only three snakes have been investigated for their sex‐determining mechanisms, each having GSD, although incubation temperature does cause differential mortality and affects post‐hatching physiology. Less than 50 lizard species have been investigated, but there is considerable diversity in the sex‐determining mechanisms reported thus far. Apparently, TSD (and/or GSD) has evolved multiple times within a given taxon. Presently, both GSD and TSD are found in the Agamidae, Eublepharidae, and Gekkonidae, and possibly in the Iguanidae, Lacertidae, and Varanidae as well. Only GSD has been reported for the Scincidae and Teiidae.Correlations within the Eublepharidae suggest an adaptive explanation for the evolution of sexdetermining mechanisms; a shift from male‐larger dimorphism to female‐larger (or no sexual size dimorphism) is accompanied by a shift in sex‐determining mode. These shifts are in agreement with similar correlations observed in turtles. © 1994 Wiley‐Liss, Inc.
Sertoli cell differentiation and gonadogenesis in Alligator mississippiensis
Authors: Smith Craig A. , Joss Jean M. P. 
Published: June 2005

AbstractTemperature‐dependent sex determination (TSD) was first described for a crocodilian in Alligator mississippiensis, in which egg incubation at 33°C produces 100% male hatchlings and incubation at 30°C produces 100% females. Ultrastructural signs of testis differentiation in embryos incubated at 33°C are first detected during days 28–34 (developmental stages 21–22), when small numbers of enlarged “presumptive” Sertoli cells (pre‐Sertoli cells) appear in the gonadal medulla of most embryos. These pre‐Sertoli cells proliferate and differentiate into Sertoli cells during stage 23 at 33°C (days 35–41), marking seminiferous cord formation. At 30°C, some pre‐Sertoli‐like cells are also present in the medulla, but they are less numerous than at 33°C and they do not differentiate into Sertoli cells. Ovary differentiation at 30°C is characterized by proliferation of cortical germs cells from day 39 (stage 22), closely followed by proliferation of somatic (pre‐follicular) cells in the cortex and regression of the medullary cords from day 43 (stage 23). We hypothesize that TSD in the alligator might be a function of a temperature‐derived mismatch between Sertoli cell differentiation and germ cell/cortex proliferation. © 1994 Wiley‐Liss, Inc.
Epidermal cell cycle and region‐specific growth during segment development in Artemia
Authors: Freeman John A. 
Published: June 2005

AbstractDuring larval development in instar IV brine shrimp, segment 1 grew by cell replication and cell differentiation. Cell cycle analysis revealed that the cell cycle was synchronized with the molt cycle. Mitosis occurred late in the instar and S phase began at hr 6 of the following instar. Three populations of cells comprised the dorsal integument. The medial‐dorsal region did not grow. Cell enlargement occurred in the dorsal‐lateral population while cell replication took place in the lateral population. The limb bud (ventral surface) grew in width by replication in the distal population, and in height by enlargement of the general epidermal cells in the proximal population. Expansion of each region of the integument was proportional to the cell growth in that region. Moreover, both growth processes were dependent on the level of nutrients and were enhanced by diets enriched in polyunsaturated fatty acids. A nutrient‐dependent growth control point occurred in the G1 period. The commitment to replication and differentiation occurred by hr 2 of instar IV. The findings show that integumental growth is a result of regionspecific cell growth processes which are controlled by nutrients during the G1 period. © 1995 Wiley‐Liss, Inc.
Purification of the δ isoenzyme of protein kinase C from the hepatopancreas of the shrimp Penaeus monodon with phosphorylation on tyrosine residues
Authors: Huang Chein‐Fuang , Chuang Nin‐Nin 
Published: June 2005

AbstractThe δ isoenzyme of protein kinase C (PKC‐δ), purified from the plasma membrane of the hepatopancreas of the shrimp Penaeus monodon is specifically phosphorylated at tyrosine residues, as demonstrated by specific dephosphorylation by phosphotyrosyl protein phosphatase from the hepatopancreas of the shrimp Penaeus monodon. The specific activity of purified PKC‐δ was 200 units/mg of protein. The subunits of Mr 66,000, 62,000, and 58,000 of PKC‐δ were not autophosphorylated after the addition of phosphatidylserine and diolein. However, the purified PKC‐δ was active and catalyzed the phosphorylation of myelin basic protein. The kinase activity of the purified PKC‐δ could be decreased after treatment with phosphotyrosyl protein phosphatase. © 1995 Wiley‐Liss, Inc.
Effects of body size and thermal acclimation on parvalbumin concentration in white muscle of striped bass
Authors: Rodnick Kenneth J. , Sidell Bruce D. 
Published: June 2005

AbstractParvalbumin from anaerobic white skeletal muscle of striped bass (Morone saxatilis) was characterized and the hypothesis tested that parvalbumin concentration varies with body size and thermal acclimation. Two parvalbumin isotypes (molecular weights 8.7 and 10.3 kDa, with pIs of 4.63 and 4.90, respectively) were identified from whole‐muscle extracts by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE), immunoblotting with a monoclonal antibody specific for parvalbumin, and two‐dimensional PAGE of heat‐treated supernatants. Total concentrations of parvalbumin were exceptionally high, ranging from 5.2 to 12.3 mg·g−1 wet wt. or 0.55 to 1.29 millimoles per kg wet wt. of tissue. There was a significant inverse relationship between body size and total parvalbumin titer in white muscle (r = −0.89, P < .001), with small fish (<500 g body weight) having twofold more parvalbumin than large fish (>2 kg). However, only concentration of the 8.7 kDa isotype varied between animals of different size. Given that parvalbumin can bind two calcium ions with high affinity, the higher titer of parvalbumin in muscles of small fish may be partially responsible for a higher tail‐beat frequency and faster rate of muscle relaxation than in larger animals. Lower titers of parvalbumin also may prolong the active state of muscle contraction in large striped bass and promote higher muscle force production than in small animals. In contrast to the effects of body size on parvalbumin content, thermal acclimation at cold termperature (5°C) for 8–10 weeks did not change the concentration of parvalbumin in white muscle. © 1995 Wiley‐Liss, Inc.
Flagelliform or coronata glands of Nephila clavipes
Authors: Rodríguez Rosa , Candelas Graciela C. 
Published: June 2005

AbstractThe flagelliform or coronata glands of the orb‐web spider, Nephila clavipes, have been studied and compared to other silk‐producing glands from the organism. The glands, which produce silk for the double filament of the core thread in the sticky spiral, exhibit three distinct morphological areas: tail, sac, and duct. Electrophoretic separation of the solubilized contents of the glands yields an uppermost diffuse band of high molecular size, preceded by a stepladder of well‐defined peptides, which have been shown to be products of discontinuous translation in three other sets of glands. The luminal contents do not migrate as a discrete and well‐defined band as those of the other glands, but rather as a diffuse area, typical of glycosylated proteins. Fibroin synthesis is stimulated by the mechanical depletion of the organism's stored silks, as in other Nephila glands, judged by the increased intensity of the bands and also by the structural alterations seen in cross sections of the glands' tails. © 1995 Wiley‐Liss, Inc.