Showing papers in "International journal of invertebrate reproduction in 1980"
TL;DR: The content in non-liver-fed animals, specially females, was significantly higher than if given liver, and the level in liver-fed whole animals increased during oogenesis from the onset of follicular growth until the 4B—4C stage, and decreased thereafter.
Abstract: Ecdysteroid levels were determined by radioimmunoassay, using an antiserum with higher affinity for ecdysterone than for ecdysone. In both sexes, the ecdysteroid level remains low until day 3 after eclosion. When fed liver on day 3, the ecdysteroid titre declines within 4 h in both sexes, stays low in males, but increases again after 12 h in females. The content in non-liver-fed animals, specially females, was significantly higher than if given liver. The level in liver-fed whole animals increased during oogenesis from the onset of follicular growth until the 4B—4C stage, and decreased thereafter. During embryogenesis, a new high level was found in females, due to the developing embryos which contained a high titre. In isolated ovaries, the ecdysteroid content increased during follicular growth, with a steep increase during the last phase (4C—M and from M to uterine eggs). The ecdysteroid content in hemolymph of 7-day-old females, fed liver or not, was around 10 ng/ml, but in hemolymph of males of the sam...
46 citations
TL;DR: The spawning seasons in Holothuria (Halodeima) floridana, H. mexicana, and their hybrids are concurrent and thus do not aid in prevention of hybridization.
Abstract: 1. Gametogenesis in Holothuria (Halodeima) floridana, H. (H.) mexicana and their hybrids occurs during spring and summer in southern Florida. 2. Spawning occurs in late summer and is followed by resorption of relict gametes. 3. The spawning seasons of these species are concurrent and thus do not aid in prevention of hybridization.
43 citations
TL;DR: Using immunofluorescence, vitellogenin has been identified in the fat body of ovariectomized females of Porcellio dilatatus and storage, but not synthesis, has been proven in a particular kind of hepatopancreatic cell which might play a part in the resorption of viteLLogenin excess.
Abstract: Using immunofluorescence, vitellogenin has been identified in the fat body of ovariectomized females of Porcellio dilatatus. Using immunoradiography of incubated fat body in leucine-14C-labeled medium, this organ has been demonstrated to be the synthesis site. Storage, but not synthesis, has also been proven in a particular kind of hepatopancreatic cell which might play a part in the resorption of vitellogenin excess.
41 citations
TL;DR: The effect of ecdysterone on specific phases of the cell cycle of Locusta migratoria migratorioides spermatogonia was assayed in vitro, and an increase in labeling index was noted, indicating a decrease in duration of the G1 phase.
Abstract: The effect of ecdysterone on specific phases of the cell cycle of Locusta migratoria migratorioides spermatogonia was assayed in vitro. An increase in labeling index was noted, indicating a decrease in duration of the G1 phase. On addition of the hormone to adapted organs in vitro, spermatogonial mitotic index increases rapidly, then declines to a basal level within a time period which approximates that of the G2 phase. Such a response indicates a removal of a G2/M inhibition by the hormone.
36 citations
TL;DR: The ovary appears to have to pass through a period of oogonial proliferation under the influence of the moult-precipitating hormones during the moulting season, and subsequently through aperiod of oocyte differentiation during the prebreeding season, for normal vitellogenesis during the breeding season.
Abstract: In Calicut populations of P. hydrodromous, the ovary is not refractory during September—November of the prebreeding season; it is inhibited from developing apparently by a gonad-inhibiting hormone(s) contained in the eyestalks. The prevalent tendency in Paratelphusa during the prebreeding season is to reproduce, and not to moult. The precocious ovarian growth induced by eyestalk removal during this season is biochemically impoverished, possibly due to uneven oocyte development, which in turn may be caused by the unpreparedness of a section of the population of oocytes for vitellogenesis. The ovary appears to have to pass through a period of oogonial proliferation under the influence of the moult-precipitating hormones during the moulting season, and subsequently through a period of oocyte differentiation during the prebreeding season, for normal vitellogenesis during the breeding season.
34 citations
TL;DR: Ovarian development, including vitellin deposition, was initiated in more than 80% of the decapitated A. atropalpus females after they received an injection of an aqueous saline cell-free extract prepared from heads of non-blood-fed anautogenous A. aegypti adult females.
Abstract: Aedes atropalpus is an autogenous mosquito, i.e. adult females will undergo complete oocyte maturation without the benefit of a bloodmeal. Ovarian development is completely inhibited if these animals are decapitated within 6 h of adult emergence, suggesting that a factor from the head is required for vitellogenesis to proceed. Ovarian development, including vitellin deposition, was initiated in more than 80% of the decapitated A. atropalpus females after they received an injection of an aqueous saline cell-free extract prepared from heads of non-blood-fed anautogenous A. aegypti adult females. The active factor(s) in this extract appears to be a relatively stable macromolecule(s) of between 3500 and 12,000 daltons.
30 citations
TL;DR: Synthesis of soluble proteins by the ovary was studied in blood-fed Aedes aegypti and Culex nigripalpus, and in unfed, autogenous Aedes atropalpUS, and both types were found to be phosphoproteins.
Abstract: Synthesis of soluble proteins by the ovary was studied in blood-fed Aedes aegypti and Culex nigripalpus, and in unfed, autogenous Aedes atropalpus. Synthesis of the ovary-specific proteins was compared, in vitro and in vivo, with synthesis of vitellogenin by the fat body. Both types were found to be phosphoproteins. Synthesis of ovary-specific proteins reached a peak, dependent on species, 12–24 h after maximal synthesis of vitellogenin. A. atropalpus synthesized both types of proteins without a blood meal.
29 citations
TL;DR: The sperm of the tropical land hermit crab, C. clypeatus, has an elongate acrosome anterior to a lamellar region of cytoplasm and numerous projections of nuclear materials are seen.
Abstract: The sperm of the tropical land hermit crab, C. clypeatus, has an elongate acrosome anterior to a lamellar region of cytoplasm. Mitochondria near the lamellar region are associated with microtubules. These microtubules project into the 3 cytoplasmic arms. The nucleus occupies the posterior-most position in the sperm. The chromatin is not condensed and numerous projections of nuclear materials are seen. It is not known how the various organelles of the sperm function during fertilization.
29 citations
TL;DR: The differentiation from early spermatid to spermatozoon is described with special emphasis on the formation of the helix of chromatin and mitochondrial junctions and the role of microtubules in morphogenesis is discussed.
Abstract: The differentiation from early spermatid to spermatozoon is described with special emphasis on the formation of the helix of chromatin and mitochondrial junctions. The role of microtubules in morphogenesis is discussed. New observations on the role of the recently described spermatheca are presented; phagocytosis and digestion of spermatozoa are proven, and the various origins of the sperm found in the spermatheca are specified.
28 citations
TL;DR: The nature of a number of fundamental processes occurring during reproduction in sponges still remains in doubt and it is considered mandatory that new techniques be developed in order to further elucidate these.
Abstract: The nature of a number of fundamental processes occurring during reproduction in sponges still remains in doubt. Among the more significant of these are: the true status of sponges described as dioecious, namely whether some are actually successive hermaphrodites; the origin of oogonia, which have recently been claimed to be derived from choanocytes; the origin and mechanism of formation of large spermatogenic masses; the specific pathway leading to fertilization taken by sperm cells within the sponge tissue of viviparous species; the role played during larval metamorphosis by somatic cells which are incorporated into embryos; the cell lineage of choanocytes which form flagellated chambers during larval metamorphosis; the specific relationship of somatic growth and dormancy to gametogenesis; the role of budding and fragmentation in population maintenance; the role, if any, of gemmules in dispersion. It is considered mandatory that new techniques be developed in order to further elucidate these and other r...
27 citations
TL;DR: In the Oniscoid Armadillidium vulgare, inside the thelygenic line of the Niort population, intersexed females, whatever their sizes, and most of the young neo-females from 5 to 6 mm long, are masculinized, which implies that special forms of bacteroids continue to exist and t...
Abstract: In the Oniscoid Armadillidium vulgare, inside the thelygenic line of the Niort population, intersexed females, whatever their sizes, and most of the young neo-females from 5 to 6 mm long (males feminized by a polytropic intracytoplasmic bacteroid kept for 13— 47 days at 35°C, and then replaced at 20°C, are masculinized. The masculinization of their external sexual characters is more or less complete, and the ovary is changed into a functional testicle with one or several utricles, each of them having an androgenic neogland. This masculinization, which restores a phenotype corresponding with the genotype, goes with the disappearance of the typical forms of the bacteroid, such as they are observed in neo-females and the intersexed individuals kept at 20° C. Yet, this male physiology is only temporary: a female physiology is restored after the animals have been kept at 20° C for 2–4 mth, but the acquired male differentiation is maintained. This implies that special forms of bacteroids continue to exist and t...
TL;DR: Evidence for the existence of a gonadotrophic hormone and the possible existence of an ovulation-inhibiting hormone is presented together with further data on the timing of spawning hormone product release.
Abstract: Evidence for the existence of a gonadotrophic hormone and the possible existence of an ovulation-inhibiting hormone is presented together with further data on the timing of spawning hormone product...
TL;DR: The reproductive bionomics of two Canadian sublittoral amphipods, Casco bigelowi and Leptocheirus pinguis, are compared in a Bay of Fundy estuary to determine a combination of wave-caused sediment washout and predation within the estuary.
Abstract: The reproductive bionomics of two Canadian sublittoral amphipods, Casco bigelowi and Leptocheirus pinguis, are compared in a Bay of Fundy estuary. Casco is semelparous and Leptocheirus iteroparous, although both have a biannual life history. The relatively high reproductive potential of each species, Casco with a reproductive potential of 12.5 and Leptocheirus with 25.5 young per year, is dictated by a combination of wave-caused sediment washout and predation within the estuary.
TL;DR: Ectobius pallidus has a semivoltine life cycle, overwintering as an egg and intermediate nymphal instar, and a number of developmental pathways are defined, involving both quiescence and diapause.
Abstract: Ectobius pallidus has a semivoltine life cycle, overwintering as an egg and intermediate nymphal instar A range of instars may overwinter, although the exact composition of an overwintering population varies annually A number of developmental pathways are defined, involving both quiescence and diapause The proportion of an instar following each pathway also varies annually In ‘advanced’ years more 3rd and 4th instars enter diapause The ecological significance of the different developmental strategies is discussed
TL;DR: A histological study of the gonads and androgenic glands of Carcinus parasitized with Sacculina carcini showed no correlation between the degree of infestation by the roots of the parasite and the progressive inhibition of the course of male and female gametogeneses.
Abstract: A histological study of the gonads and androgenic glands of Carcinus parasitized with Sacculina carcini showed no correlation between the degree of infestation of the gonads by the roots of the parasite and the progressive inhibition of the course of male and female gametogeneses. Also, no correlation could be observed between the degree of degeneration of the androgenic glands and that of the testes. Modifications in parasitized crab testes essentially involve a degeneration of the mesoderm tissue of the germinative zone; primary gonia become pycnotic after an abnormal development; germ cells already engaged in spermatogenesis become blocked in prophase of meiosis; and ultimately, the testis becomes empty. Progressive degeneration of the androgenic glands, after an initial hypertrophy that starts as early as the internal Sacculina stage, seems related to the disorganization of the neurosecretory centers of the host. Arrest of spermatogenesis at a more or less advanced stage is probably the result of an i...
TL;DR: Measurements of the length of the developing gut indicate that the bending of the gut is facilitated by a doubling of theLength of the digestive tract between two fixed points, the mouth and the anus, indicating that shaping of the larval gut is due to regions of allometric cell proliferation.
Abstract: The 3 elements of the digestive tract of the pluteus larva (esophagus, stomach and intestine) acquire their characteristic shapes between 60 and 72 h after fertilization (15°C). The number of cells in the developing gut increases sigmoidally from about 100 at the completion of gastrulation to about 425 in the feeding pluteus. Embryos in which cytokinesis was inhibited with colchicine were able to form typically shaped guts comprising about 150 cells. Autoradiographs of embryos that had been cultured in sea water containing [3H]thymidine during shaping of the gut indicated no regions of enhanced thymidine incorporation. The hypothesis that shaping of the larval gut is due to regions of allometric cell proliferation was rejected. Measurements of the length of the developing gut indicate that the bending of the gut is facilitated by a doubling of the length of the digestive tract between two fixed points, the mouth and the anus.
TL;DR: The temporal sequence observed in the deposition of various deutoplasmic bodies, the occurrence of carotenoids linked to yolk, and the chemical nature of the follicle cells suggest an autoheterosynthesis of yolk in this species.
Abstract: Histochemical studies on maturing ovaries of C. clibanarius reveal that the yolk is deposited in 3 different forms: yolk spheres containing lipoproteins, smaller globules of a glycolipoproteinaceous nature, and granules containing only neutral and phospholipids. The temporal sequence observed in the deposition of various deutoplasmic bodies, the occurrence of carotenoids linked to yolk, and the chemical nature of the follicle cells suggest an autoheterosynthesis of yolk in this species.
TL;DR: The oviduct of the pink bollworm is innervated by an intrinsic neural network arising from 4 nerves from the terminal ganglion, suggesting that the visceral muscles of the reproductive tract possess super-contracting properties.
Abstract: The oviduct of the pink bollworm is innervated by an intrinsic neural network arising from 4 nerves from the terminal ganglion. The nerve tracts in this network often contained elliptical swellings, each with a central nucleus. A distinct surface topography was evident in the muscular sheath of the common and lateral oviduct. A very thin muscular envelope consisting of an inner band of circular fibers and an outer layer of longitudinal fibers was also found in the ovarioles. Although conventional A and I bands were recognized, the z-disk was composed of an irregular and loose meshwork, suggesting that the visceral muscles of the reproductive tract possess super-contracting properties. Even when the oviduct and the ovarioles were isolated from the central nervous system, an endogenous rhythmic activity was evident. Two types of spontaneous excitatory postsynaptic potentials were detected in the oviduct. The type most frequently observed had a complex of multiple spikes with a duration of 18–32 msec. The ot...
TL;DR: In S. holoschista, the vas deferens is differentiated into 3 regions based on the functional morphology of the epithelial lining, and the principal function of this secretion appears to be the digestion of the sperm cord in the oviduct.
Abstract: In S. holoschista, the vas deferens is differentiated into 3 regions based on the functional morphology of the epithelial lining. The proximal part with a highly secretory epithelial layer may be responsible for the secretion which is rich in protein, and moderately so in carbohydrate and lipid substances. The mid-region serves for storage of the spermatozoa. The distal part has specialized epithelial cells of a secretory nature. In addition, there are 4 typhlosole-like ridges fringed with cilia which probably aid in the conduction of the sperm cord during copulation. Secretions of the accessory reproductive glands contain a large number of discrete granules rich in mucoprotein. The principal function of this secretion appears to be the digestion of the sperm cord in the oviduct.
TL;DR: Stereological analysis of the volume and contents of the major helix within the mitochondrial derivative of mature spermatozoa of Arion hortensis and Lymnea peregra demonstrates a non-linear disposition of the glycogen deposits.
Abstract: Stereological analysis of the volume and contents of the major helix within the mitochondrial derivative of mature spermatozoa of Arion hortensis and Lymnea peregra demonstrates a non-linear disposition of the glycogen deposits. The distal part of the sperm tail contains significantly more glycogen than those regions nearer the sperm head.
TL;DR: The ultrastructural study demonstrates two formations in this spermiocyst: the ‘head’, surrounded by a lamellar envelope, consists mainly of a nucleus with ring-shaped chromatin, and a large area with a periodic structure corresponding to the modified ‘middle piece’ or ‘mitochondrial body’ of other authors.
Abstract: The fertilization of a calcareous sponge is studied by means of the electron microscope, in Grantia compressa F.. The mature oocyte lies beneath the choanoderm; the carrier cell is applied to its surface, and the spermiocyst enters its cytoplasm. The ultrastructural study demonstrates two formations in this spermiocyst: (i) the ‘head’, surrounded by a lamellar envelope, consists mainly of a nucleus with ring-shaped chromatin; (ii) a large area with a periodic structure corresponding to the modified ‘middle piece’ or ‘mitochondrial body’ of other authors.
TL;DR: Comparative studies on the structure of genitalia in Pseudoxychila tarsalis Bates and the copulating behavior in 5 species of Cicindela respectively complement similar findings by Freitag and Palmer to strengthen the hypothesis that in tiger beetles the flagellum fits into the spermatheca duct during copulation.
Abstract: Comparative studies on the structure of genitalia in Pseudoxychila tarsalis Bates and the copulating behavior in 5 species of Cicindela respectively complement similar findings by Freitag [1] on Cicindela spp. and Palmer [4] on P. tarsalis. These strengthen the hypothesis that in tiger beetles the flagellum fits into the spermatheca duct during copulation; that the main function of the flagellum, which is closed at the apex and not connected to the ejaculatory duct, is to open and prepare the lumen of the spermatheca duct for sperm movement from the bursa copulatrix to the spermatheca; and that copulation proceeds in 3 phases: phase 1 in which the lumen of the spermatheca duct is cleared by the flagellum, phase 2 in which the flagellum is withdrawn from the spermatheca duct, and phase 3 in which semen is transferred from the gonopore of the ejaculatory duct to the bursa copulatrix, usually with a spermatophore.
TL;DR: Gonocyst growth in the drone of S. postica is characterized by a series of 5 synchronous mitoses in which cytokinesis is incomplete, and the original cells remain interconnected until spermatozoa formation.
Abstract: Gonocyst growth in the drone of S. postica is characterized by a series of 5 synchronous mitoses in which cytokinesis is incomplete, and the original cells remain interconnected until spermatozoa formation. During meiosis the division of spermatocytes I was terminated with an anomalous metaphase plate formation at the end of prophase (I). A concentric endoplasmic reticulum encircled the metaphase chromosomes; though microtubules were present, spindles were not formed. This abortive division also affected the particular behavior of the centrioles. Although the centrioles proliferated during prophase I, they did not give rise to a spindle, but became associated with the formation of centriolar blebs at cell surface, and seemed eventually to be eliminated. In S. postica, the chromosome number is maintained due to the abortiveness of the first meiotic division; therefore, chromosome distribution is normal during the subsequent division. The second meiotic division resulted in the formation of two spermatids, ...
TL;DR: The presence of enzymes with somewhat different properties in different tissues suggests that trehalose utilization and trehalase activity may be regulated by way of a tissue-specific mechanism.
Abstract: Trehalase activities were found in several tissues of the adult American cockroach, Periplaneta americana. Among these, male accessory glands, fat body, thoracic muscle, hepatic cecum, blood and mid-gut contained high trehalase activity; activity in the male accessory gland was especially high. The enzymic properties of soluble trehalases were investigated and the enzymes from the male accessory gland were highly purified. The properties of these enzymes were electrophoretically and kinetically distinct from each other. The presence of enzymes with somewhat different properties in different tissues suggests that trehalose utilization and trehalase activity may be regulated by way of a tissue-specific mechanism. The detailed properties of these enzymes are presented with a discussion of their regulation.
TL;DR: Immunological study of Perinereis cultrifera reveals the existence of an identical antigen in the coelomic fluid of females (oocyte diameter > 140 (μm), in oocytes, and in coelomocytes), which is not found in the body fluid of males or young females.
Abstract: Immunological study of Perinereis cultrifera reveals the existence of an identical antigen in the coelomic fluid of females (oocyte diameter > 140 (μm), in oocytes, and in coelomocytes. This factor is not found in the body fluid of males or young females. The elution patterns obtained after Sephadex chromatography shows a similar glycoprotein fraction (fraction I) in the coelomic fluid, in coelomocytes, and in soluble oocyte extracts. This fraction includes the main part of the antigenic components of the coelomic fluid. Gas chromatography reveals that identical monosaccharides are present, albeit in varying proportions, in samples of fraction I obtained from the different sources. The metabolic interrelationships of coelomocytes, coelomic fluid and oocytes is discussed. Glycoprotein synthesized by coelomocytes may be discharged into the coelomic fluid and contribute to the development of the cortical alveoli of the oocytes. No evidence of an involvement of this material in yolk synthesis has been obtained.
TL;DR: In the developing pluteus larva of S. purpuratus, the initial morphogenetic event in the formation of a functional gut is the appearance of two constrictions in the archenteron, which become the cardiac and pyloric sphincters.
Abstract: In the developing pluteus larva of S. purpuratus, the initial morphogenetic event in the formation of a functional gut is the appearance of two constrictions in the archenteron. These two constrictions become the cardiac and pyloric sphincters. During the 2 h in which the constrictions form, the sphincter cells change from cuboidal to wedge-shaped, and the apical ends of the sphincter cells develop an electron-dense region in which microfilaments can be resolved. Constriction of the archenteron was reversibly inhibited by cytochalasin B, although cytochalasin B had no effect once the constrictions had fully formed. Neither the electron-dense region nor the microfilaments were observed after cytochalasin B treatment. It is suggested that sphincter formation is initially accomplished by a microfilament-mediated contraction of the apical ends of the sphincter cells, which changes their shape and constricts the archenteron.
TL;DR: The sperm of A. perniciosus provide strong evidence that the microtubules arranged asymmetrically represent the elements directly involved in sperm motility.
Abstract: The mature sperm of A. perniciosus are organized into bundles, about 350 μm long by 9–10 μm wide. Each bundle contains 32 sperm enclosed by a common sheath. The sperm contains an elongated ‘central core’, representing nuclear material, surrounded by a spiral microtubular sheath and cytoplasm. The electron-dense nuclear material is localized in the more pointed half of the sperm. The spiral microtubular sheath is composed of 30— 100 microtubules (depending on the cross-sectional level), situated parallel to the longitudinal axis of the sperm. On the basis of this ultrastructural organization, the motility of the sperm and sperm bundle as a whole is discussed. The sperm of A. perniciosus provide strong evidence that the microtubules arranged asymmetrically represent the elements directly involved in sperm motility.
TL;DR: Unmated E. cautella of both sexes were caged together and the ensuing behaviours of females were recorded, with particular attention to orientations to other insects.
Abstract: Unmated E. cautella of both sexes were caged together and the ensuing behaviours of females were recorded, with particular attention to orientations to other insects. Calling females engaged in ‘turning-to-face’ and ‘walking up to’ orientations directed almost exclusively at wing-beating males (flying, or sexually excited and ambulatory). Non-calling, locomoting females engaged in ‘flying at’, ‘landing near’ and ‘walking into’ orientations directed predominantly at wing-beating or resting males, and occasionally at mating pairs or at calling females. The activities of the orienting female led to changes in the behaviour of some target insects, and 4% of all females mated directly after approaching males. Results are discussed in relation to sexual receptivity, locomotory excitation, and the pheromonal control of this species.
TL;DR: The tracing of the origin of this neurohormone has been done by culturing in vitro ovaries and testes with different ganglia of the nerve cord, finding that in the presence of cerebral ganglia (CG), the percentage of testes transformed into ovotestes was low, while the percentage in the associations with sub-esophageal ganglia was high.
Abstract: Previous culture experiments revealed that, in reproductively active E. foetida, the central nervous sytem (CNS) produces a neurohormone necessary for the secretion of an androgen by testes. The tracing of the origin of this neurohormone has now been done by culturing in vitro ovaries and testes with different ganglia of the nerve cord. In the presence of cerebral ganglia (CG), the percentage of testes transformed into ovotestes was low (3%), while reaching respectively 32% and 17% in the associations with sub-esophageal ganglia (SEG) or ganglia of the male or female genital segments (GS ♂ or ♀). Only the neurohormone produced by CG was able to stimulate secretion of the testicular androgen, the existence of which was proved by previous experiments. The secretion of this androgen was enough to transform 28% of the ovaries into ovotestes. On the other hand, no masculinization of the ovaries was observed in the presence of various ganglia of the ventral nerve cord (SEG, GS ♂ or ♀). It appears, therefore, th...
TL;DR: Early morphogenesis of the archenteron and invagination of the ectoderm during mouth formation appear to be intrinsic properties of these structures.
Abstract: The process of mouth and coelom formation in exogastrulae of the starfish, Pisaster ochraceus, induced by LiCl, has been studied with the light microscope, scanning and transmission electron microscopes. Bending and segmentation of the exogastrulated archenteron with the formation of either single or double coelomic pouches follows the same schedule as the control. In addition, a region of the exogastrular ectoderm, which corresponds to the area of the mouth in controls, undergoes invagination. Early morphogenesis of the archenteron and invagination of the ectoderm during mouth formation appear to be intrinsic properties of these structures. At the time of mouth formation in the controls, a discrete region adjacent to the distal end of the exogastrulated archenteron becomes sticky. Examination of this region shows that the surfaces of the archenteron cells are relatively smooth and that processes of the mesenchyme cells extend between them. The evidence suggests that the mesenchyme cells are responsible f...