摘要:

AbstractSeveral species‐specific proteins have been identified by polyacrylamide gel electrophoresis (PAGE) of skeletal muscle extracts from the diploid gynogen,Poecilia formosa, its related triploid unisexuals, and their sympatric, bisexual species,P. mexicanaandP. latipinna. These water‐soluble, low molecular weight proteins (7,000‐13,000) comigrate with a fraction of purified rabbit parvalbumin on nondenaturing gels and show staining properties similar to rabbit parvalbumins. The electrophoretic patterns of these muscle proteins provide a set of distinctive phenotypic markers for each of the host species involved in naturally occurring breeding complexes withP. mexicana × P. latipinnashow no evidence of sexual dimorphisms. Furthermore, the hybrid phenotypes are those that would be predicted from appropriate combinations of parental alleles at three gene loci. The patterns found by PAGE for several generations of pedigreed stocks ofP. formosashow strictly matroclinous inheritance of a characteristic muscle protein phenotype and coupled with the electrophoretic patterns of several enzymic proteins reflect the probable hybrid origin of this diploid unisexual. Finally, paternal contributions byP. mexicanato the hybrid genome of triploid unisexuals are clearly demonstrated by comparative analyses of muscle protein phenotypes forP. formosaand its contemporary host species. Our identification of distinctive phenotypic markers in the muscle proteins of several poeciliid species involved in unisexual‐bisexual breeding complexes provides an important new tool for further studies on the adaptive significance of unisexuality, hybridization, and fixed heterozygosity in the evolutionary biology of thes

ISSN:0022-104X    

DOI:10.1002/jez.1402210302

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

年代:1982

数据来源: WILEY

摘要:

AbstractFollicles of 28 day‐old prgnant mare serum gonadotropin (PMSG)‐primed rats, were cultured for up to 24 hours in the presence or absence of ovine gonadotropins, highly purified rat gonadotropins, dibutyryl cyclic AMP (dbcAMP), methylisobutylxanthine (MIX), choleratoxin (CT), or prostaglandin E2(PGE2). The morphology of the cumulus‐oocyte complexes isolated from these follicles was subsequently examined with the light microscope. Cumulus mucification was studied under the different culture conditions using scanning electron microscopy (SEM) and the hyaluronidase sensitivity test. The features of the cumulus‐oocyte complexes in the control cultures did not change throughout the incubation period, while complexes from follicles incubated with LH, FSH, dbcAMP, MIX, CT, or PGE2changed their appearance and accumulated extracellular mucoid material. Treatment of these cumuli with hyaluronidase resulted in lysis of the extracellular mucus and dispersal of the cumulus masses. The results of this study agree with our earlier observation that the maturation of the cumulus‐oophorus, which occurs in vivo following the LH surge, can be induced in vitro by either gonadotropins or cAMP. Prostaglandin E2did not affect cumulus cells, unless incubated enclosed by their follicles. This suggests that this hormone may influence the cumulus cells indirectly, probably via other c

ISSN:0022-104X    

DOI:10.1002/jez.1402210303

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe substrate specificity of five peptidases in tissues of the leopard frog,Rana pipiens, corresponds to mammalian peptidases (Pep) A, B, C, D, and S. The inheritance of electrophoretic variants of Pep A, B, C, and D verifies the genetic basis of the variants and the control of the enzymes by separate genetic loci. Electrophoretic patterns of heterozygotes suggest that Pep A, B, and D are dimers, whereas Pep C has a monomer structure. The tissue distribution and developmental patterns suggest that frog peptidases are subject to cellular regulation. Tests of genetic linkage show independent assortment for Pep A and Pep C and for Pep C and Pep D. Pep C is closely linked to superoxide dismutase‐1 (6.87% recommbination), and Pep B is linked to mannose phosphate isomerase (30.4% recommbination

ISSN:0022-104X    

DOI:10.1002/jez.1402210304

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe large subunit of (Na++ K+)‐activated ATPase from brine shrimp,Artemia salina, migrates as two bands in sodium dodecyl sulfate‐polyacrylamide gels. The slower migrating band, as observed in neutral or alkaline gel systems, is designated α1and the faster, α2. Structural and biosynthetic studies have been performed to determine if these two bands represent independent molecular forms or precursor products. Peptide mapping of partial proteolytic digests of α1and α2showed no distinguishable difference between them, whereas this technique produced very distinct differences in the large subunit derived from three different species. The two large subunit bands also behaved identically when cross linked with cupric phenanthroline either in the presence or absence of digitonin, whereas other proteins in these preparations were unaffected. The peptide mapping and cross‐linking experiments demonstrate that α1and α2have identical or nearly identical primary and probably higher order structure. Their different mobilities may be due to post‐translational modification leading, for example, to different oligosaccharide composition. During development of the brine shrimp nauplius, α1increases in relative abundance while α2decreases. NaH14CO3incorporation and pulse‐chase experiments indicate that α1and α2, as well as the small subunit of the brine shrimp (Na++ K+)‐activated ATPase, are synthesized at the same time during development and that all changes in the rates of synthesis of these subunits occur at the same time. The apparent rates of degradation of the subunits are also similar. These results are inconsistent with a precursor‐product relati

ISSN:0022-104X    

DOI:10.1002/jez.1402210305

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

年代:1982

数据来源: WILEY

摘要:

AbstractA sensitive pH‐stat assay was used to determine the distribution in aquatic and terrestrial decapod crustaceans, correlation to osmoregulation, and selected kinetic properties of carbonic anhydrase. In all species the enzyme was concentrated in the gills, and specifically the posterior three or four gill pairs. Activity was highest in the gills of osmoregulating species, and the enzyme could be localized in the areas of the gill lamellae which contained a high density of salt absorbing cells. The enzyme from the blue crab,Callinectes sapidus, exhibits a number of characteristics remarkably similar to the Na+/K+ATPase from that species. Both enzymes show the same inter‐ and intrabrachial distribution and the same reactions to altered environmental salinity. Branchial CA from both species was inhibited by high concentrations of NaCl and increasing pH. The enzyme showed a temperature optimum of 25°C. On the basis of these initial results, it appears that crustacean gill carbonic anhydrase plays an important role in the blood osmoregulatory pro

ISSN:0022-104X    

DOI:10.1002/jez.1402210306

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

年代:1982

数据来源: WILEY

摘要:

AbstractThirty‐six measured variables were compared in crabs de‐eye‐stalked (DE) for 24 hours to 45 days and with normal animals well advanced in the premolt stage of the molting cycle. DE crabs generally differed from premolts in water and ion composition of carapace and blood, but not in organ water content, and differences were independent of time after DE. Furthermore, acute (24‐hour) DE animals displayed 30‐fold higher uptake of cholesterol‐14C in Y‐organs (four to fivefold higher in hepatopancreas and hypodermis) than premolts; uptakes dropped to premolt levels in long‐term DE animals. It is concluded that acute and long‐term de‐eyestalking induce abnormalities in several physiological parameters but also induce changes in cholesterol processing suggestive of normal early and late premolt s

ISSN:0022-104X    

DOI:10.1002/jez.1402210307

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe cranial paraxial mesoblast is patterned into segmental units termed somitomeres. Recently we demonstrated the morphological relationship between the migratory pathways of cranial neural crest cells and the patterned primary mesenchyme of chick embryos (Anderson and Meier, '81). Since extracellular matrix, particularly hyaluronate, is also distributed in cranial crest pathways, embryos were given sub‐blastodisc injections of hyaluronidase just prior to neural tube fusion and neural crest migration to remove matrix. Histological sections of enzyme‐treated embryos showed that Alcian blue staining of hyaluronate was significantly reduced. Surface ectoderm appeared collapsed on the subjacent mesoderm as well. Examination of embryos with the scanning electron microscope (SEM) revealed that paraxial mesoderm remained segmentally patterned even though it appeared more condensed because of a reduction in intercellular space between mesenchymal cells. In enzyme‐treated embryos, the rostral crest cells spread over the dorsal surfaces of the first four somitomeres, as they would do normally. This distribution of neural crest cells occurs even when enzyme treatment interferes with neural tube fusion at that level. We conclude that 1) neural tube fusion is not a prerequisite for the timely release of cranial crest in the chick embryo and 2) that much of the organized hyaluronate‐rich matrix that lies in the path of cranial crest is not essential for crest emigration or patterned distr

ISSN:0022-104X    

DOI:10.1002/jez.1402210308

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

年代:1982

数据来源: WILEY

摘要:

AbstractLeft hind limbs, including the pelvis, of adult newts (Notophthalmus viridescens) were locally irradiated with a dose of x‐rays that inhibited regeneration (2,000 R). This x‐ray dose and other doses (700‐2,000 R) capable of inhibiting limb regeneration also cause limb regression prior to amputation. Before limb regression occurred, there was a latent period of 3 to 6 weeks. Limb regression was characterized by necrotic wasting and resorption of distal elements. The degree of loss was variable and dependent upon dosage. After this further degenerative changes were not noted. Proliferation of epidermal cells was examined 4 days after irradiation prior to limb regression or after x‐ray‐induced degeneration of the limbs had ended. Proliferative activity in x‐ray limbs was also compared at various stages of contralateral control limb regeneration. Limbs examined after x‐ray‐induced limb regression had ended showed levels of [3H]‐thymidine incorporation into DNA comparable to normal epidermis. In contrast, limbs examined 4 days after irradiation had lower levels of DNA synthesis (P≪ 0.01). Amputation of limbs in both groups caused an increase in DNA synthesis (P≪ 0.01). Histological examination showed that cellular proliferation was associated primarily with the epidermis. These results indicate that epidermal cell proliferation was not resistant to x‐rays. However, levels of normal cell division were observed after amputation or after cessation of x‐ra

ISSN:0022-104X    

DOI:10.1002/jez.1402210309

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

年代:1982

数据来源: WILEY

摘要:

AbstractBased on the criteria of relative size and cell surface polarization, subpopulations of outer (larger, polar) and inner (smaller, apolar) blastomeres have been isolated from mouse 16‐cell morulae and reaggregated in groups of 16 cells, and the developmental potential of the aggregates has been assessed both in vitro and in vivo. Aggregates of outer, inner, or mixed groups of cells all formed blastocysts which outgrew and contained both characteristic trophectoderm and alkaline phosphatase positive inner cell masses in vitro. However, significant differences were observed in the timing of blastocyst formation, depending on cell type. Aggregates of outer cells recompacted more slowly, commenced fluid accumulation earlier, and contained more cells at the blastocyst stage than did inner cell aggregates. Aggregates containing both outer and inner cells were intermediate. Postimplantation development of blastocysts derived from aggregates of outer or inner cells, after transfer to pseudopregnant recipients, was normal and comparable to zona‐intact control embryos. This relationship between the expression of different morphological and behavioural properties by the precursor cells of the trophectoderm and inner cell mass and the existence of totipotent cells in both outer and inner subpopulations is discus

ISSN:0022-104X    

DOI:10.1002/jez.1402210310

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe secretion produced at the most cephalic portion of the oviduct of the toad (pars recta inBufo arenarum) is involved in fertilization. Although the present study indicates that a prerequisite for the fertilization of coelomic eggs is either their passage through the pars recta (PR) or their treatment with PR secretion fluid prior to insemination, the exact role of this secretion in the fertilization process is still not clearly understood. A protein acting upon the vitelline envelope (VE) ofBufo arenarumcoelomic eggs has been purified from secretion fluid (pars recta protein, PRP). Some properties of both this protein and the secretion fluid are examined in an effort to understand their mechanism of action. It was shown that PRP partially dissolves the VE of coelomic oocytes in a way that resembles the action of proteolytic enzymes. PRP has also proved to be active on synthetic substrates of proteolytic enzymes such as p‐Tosyl‐L‐arginine methyl ester‐HCl (TAME), α‐N‐benzoyl‐L‐arginine ethyl ester‐HCl (BAEE), and α‐N‐benzoyl‐DL‐arginine‐p‐nitroanilide HCl (BAPNA). PR enzyme is activated by calcium ions, shows a broad peak of maximum activity at pH 7.8, is stable at alkaline pH, and is inhibited by soybean trypsin inhibitor (SBTI) and N‐α‐p‐tosyl‐L‐lysine chloromethyl ketone HCl (TLCK) but not by lima bean trypsin inhibitor (LBTI) or L‐1‐tosyl

ISSN:0022-104X    

DOI:10.1002/jez.1402210311

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

年代:1982

数据来源: WILEY