摘要:

This is the first report of haploid and diploid cell culture from the haplo-diploid parasitoid wasp,Mormoniella vitripennis.Cells were cultured from haploid and diploid wasps by collecting populations of eggs from virgin females (unfertilized, haploid, parthenogenetic eggs) and mated females (mostly fertilized, diploid eggs). Eggs were surface sterilized in 70% ethanol, followed by 50% Chlorox, and rinsed in phosphate buffered saline; larvae were allowed to hatch in culture. Larval cells were dissociated and cultured at 28°C in the presence of Grace's medium supplemented with fetal bovine serum. Most cells in the HMV (predominantly haploid) and DMV (predominantly diploid) cell cultures grew in suspension in the first week, formed monolayers of fibroblasts and epithelial cells by the second week in culture, and continued to grow in monolayers and vesicle-like structures for up to three months. Chromosome analysis of HMV. cells demonstrated over 70% haploid cells, with five chromosomes (N=5). The remainder were aneuploid. No diploid cells (2N= 10) were found in the HMV cell culture. Chromosome analysis of DMV cultures revealed 62% diploid, with ten chromosomes; 13% were haploid, with five chromosomes; the remainder were aneuploid. These data confirm that haploid and diploid cells can be cultured from a haplo-diploid insect species. The HMV cells which are predominantly haploid, and DMV cells which are predominantly diploid may be valuable models for the study of cellular and gene activity in haploid and diploid genetic milieux.

ISSN:0792-4259    

DOI:10.1080/07924259.1993.9672336

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Bruchidius atrolineatus(Pic) (Coleoptera: Bruchidae) is a beetle developing in the seeds of cowpea (Vigna unguiculataWalp) in the Niamey region of Niger (13°N). Adults of this tropical bruchid undergo a reproductive diapause during the dry season when the pods of their host-plant are unavailable. The reproductive organs of the diapausing beetles were non-functional and two specific diapause proteins appear in the haemolymph at the beginning of the imaginal life of both sexes. These diapause proteins disappear when diapause terminated and vitellogenesis began. B.atrolineatusis a short-day species and photoperiods of 13:13 h or 12:12 h LD are required to terminate diapause. Relative humidity has an important role in diapause termination. The beetles remained in reproductive diapause regardless of the photoperiod when the relative humidity was lower than 40% (8–9 g of water per kg air). For males, changes in photoperiod and relative humidity were enough to terminate the diapause. For females, the presence of pods or inflorescences of cowpea was required. Certain specific allelochemical compounds of the host-plant organs are enough to terminate female diapause by a neurosensory pathway or by atrophic action. The regulation of diapause in B.atrolineatusby various climatic and host-plant factors is important in this species, which has a large distribution area in tropical Africa.

ISSN:0792-4259    

DOI:10.1080/07924259.1993.9672337

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Spawning behavior and male-female superposition ofNeosmilaster georgianus, a common brooding asteroid, were observed both in the field and the laboratory at Palmer Station, Antarctica, during the austral spring of 1991. Pseudocopulation is preceded by exploration, contact, and mounting of a female by individual or multiple males. Male pre-mating activity in the field was initiated by the spawning of a nearby conspecific female. However, in laboratory experiments a similar pattern of activity was triggered by the presence of spawning conspecific males or male sea urchins, indicating the presumed inductive signal lacks specificity. Pseudocopulation in this species may ensure maximal fertilization and enhance reproductive success. This is the first reported instance of aggregative spawning in an Antarctic echinoderm. Moreover, pseudocopulation is a rare phenomenon among echinoderms worldwide andN. georgianusis only the third asteroid described to utilize this fertilization strategy.

ISSN:0792-4259    

DOI:10.1080/07924259.1993.9672338

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

5-hydroxytryptamine (5-HT) at a final concentration of 5 μm triggered dissolution of germinal vesicle (GVBD) inSpisulaoocytes suspended in natural sea water (NSW). The maturation inducing potency of 5-HT decreased with decreasing concentration and was ineffective at/or below 500 nm. Incubation ofSpisulaoocytes with low concentration of 5-HT (10 nm) increased fertilizability of oocytes by fresh motileSpisulasperm. The present findings suggest that the action of 5-HT is to sensitizeSpisulaoocytes to interact with sperm, to promote maturation and to facilitate fertilization.

ISSN:0792-4259    

DOI:10.1080/07924259.1993.9672339

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Ovarian and haemolymph ecdysteroid levels in adult femalePenaeus monodonat various stages of vitellogenesis have been studied. The concentration of free ecdysteroids, predominantly 20-hydroxyecdysone, was maximal in animals with immature (stage 0) ovary, decreased gradually during early vitellogenesis (stage 0 to stage I) and fell sharply during later vitellogenesis (stage I to stage IV). 20-hydroxyecdysone 22-phosphate was identified in stage 0 ovary and in stage 0 and I–II haemolymph, and 20-hydroxyecdysonoic acid was observed in stage 0 ovary and haemolymph. Low levels of 20-hydroxyecdysone 22-fatty acyl esters were detected in stage 0 ovary but did not occur in the haemolymph. A major component of the stage IV haemolymph ecdysteroids was 20-hydroxyecdysone 22-acetate. The significance of the results is discussed.

ISSN:0792-4259    

DOI:10.1080/07924259.1993.9672340

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Coelomic fluid proteins, which are expected to include vitellogenin and putative yolk proteins isolated from the oocytes, were found to be transported selectively into the oocytes of specific stages ranging from 70–140 μm in diameter; whereas bovine serum albumin, a nonspecific protein, was not incorporated into the oocytes of any size class. Furthermore, removal of the oocyte membrane proteins with trypsin effectively retarded the transport of the coelomic fluid proteins and yolk proteins. Carbohydrate residues of the membrane proteins appear to play a significant role in transferring vitellogenin into oocytes since the transport of the coelomic fluid proteins and yolk proteins was completely blocked by saturating with Concanavalin A or by digesting with endoglycosidase F. The observations strongly suggest that the selective transport of the coelomic fluid proteins into the oocytes of specific stages is mediated by the membrane proteins, which appear to be receptors.

ISSN:0792-4259    

DOI:10.1080/07924259.1993.9672341

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Analysis of the gonadal index and seasonal cytological changes of the gonads of the Japanese limpet,Cellana nigrolineata(Reeves), covering two breeding seasons (July 1989 to November 1990) showed a marked reproductive cycle. A new method, equivalent circular diameter (d-circle), was employed in measuring the polygonal-shaped oocytes. Measurements were made of oocyte size and their frequency distribution, as well as the percent area occupied by the various stages of gametogenesis per gonadal acinus. The time of gonadal growth, maturation, spawning, post-spawning and resting was related to the annual sea temperature cycle. The gonads contained immature gametes in winter which later increased in size and occupied a greater area of the gonad. During the warm season (from July to September) gonads were full of mature oocytes and sperm, indicating that the breeding season occurs during this period.

ISSN:0792-4259    

DOI:10.1080/07924259.1993.9672342

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Using transmission electron microscopy, bundles of tubular elements were detected within the extracellular space of the testis sheath and the testicular lumen of a Lepidoptera species,Phragmatobia fuliginosa(Arctiidae). In both cases the diameter of the extracellular tubules was between 24–25 nm, and the thickness of the tubular wall was approximately 3 nm. The extracellular tubules were morphologically very similar to microtubules within the cytoplasm of neighbouring cells. The extracellular tubules occurred in bundles made up of up to 75 individual elements. Within the bundles the tubules were arranged in a hexagonal pattern with their walls in close contact. In this respect they differed from cytoplasmic and spindle microtubules which rarely showed direct contacts with one another. Since degenerating cell fragments containing morphologically intact microtubules were found within the testis sheath, the extracellular tubules presumably arise from cytoplasmic microtubules after degeneration of the cells and persist for a while. It is conceivable that the extracellular tubules stiffen the testis sheath and thus act—like their cytoplasmic similes—as skeletal elements.

ISSN:0792-4259    

DOI:10.1080/07924259.1993.9672343

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The reproduction ofTrochus niloticuswas very unusual and was not similar to any previously described prosobranch. The population as a whole was asynchronous; nevertheless, the population contained several sub-groups that had synchronized reproductive cycles. Spawning occurred primarily at the new moon lunar phase (the day of the new moon and the three following days). The reproductive cycle was approximately eight lunar months.T. niloticuswas a complete spawner with each individual having only one cohort of gametes developing at a time. Gametogenesis occurred during the first one to two lunar months after spawning, which was followed by an almost linear increase in the oocyte size during vitellogenesis. A secondary layer formed around the oocyte at the end of gonad development.

ISSN:0792-4259    

DOI:10.1080/07924259.1993.9672344

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0792-4259    

DOI:10.1080/07924259.1993.9672345

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor