Degree Of Ovarian Development Research Articles

A proteomics analysis of the ovarian development in females of Haemaphysalis longicornis.

Haemaphysalis longicornis is an ixodid tick that can spread a wide variety of pathogens, affecting humans, livestock and wildlife health. The high reproductive capability of this species is initiated by the ingestion of a large amount of blood ingested by the engorged female tick. The degree of ovarian development is proportional to the number of eggs laid. Studying the regulatory mechanism of tick ovary development is relevant for the development of novel tick control methods. In this study, we used quantitative proteomics to study the dynamic changes in protein expression and protein phosphorylation during ovarian development of engorged female H. longicornis ticks. Synergistic action of many proteins (n = 3031) is required to achieve ovarian development and oocyte formation rapidly. Through bioinformatics analysis, changes in protein expressions and phosphorylation modifications in regulating the ovarian development of female ticks are described. Many proteins play an essential role during ovarian development. Also, protein phosphorylation appeared an important reproductive strategy to enable ticks to efficiently convert large amounts of blood in the ovaries into egg-producing components and ultimately produce many eggs.

THE INFLUENCE OF METHOTREXATE ON THE CHANGE IN THE INTENSITY OF CELLULAR DEATH IN THE OVARIES OF DROSOPHILA MELANOGASTER

The purpose of this work to determine the influence of different concentration of methotrexate on apoptosis level in the ovaries of Drosophila melanogaster at normal and elevated temperature during development. In the experiment was used 300 hybrid individuals “Oregon-R x vg” with spontaneous mutation like Beadex phenotype. We investigated six group: control, a group after the methotrexate 400 mkg/ kg medium treatment, a group with 2000 dose, a group with 10000 dose, temperature 28 C treatment and a group after methotrexate 400 and temperature 28 C treatment together. During the experiment we found that apoptosis in checkpoint #1 reaches to maximum values of the group MTX 10000 and of group after the temperature 28 C treatment. There was also a dose dependence on the intensity of apoptosis from increased concentration in checkpoint #1. The experimental group MTX 400 has the maximum intensification of cellular ath in the checkpoint #2, which is not observed in the other groups. Due to the fact that the 400mkg/kg is close to 50LD, probably most of the individuals survive. The high index of the presence of apoptosis observed in control group of this hybrid strain. Correlations between the increase in MTX dosesang degree of ovarian development were not observed. However, the 2000 MTX group has a high rate of atrophy of both ovaries.

Is Heliothis viriplaca (Lepidoptera: Noctuidae) a long-distance migrant?

Heliothis viriplaca (Hüfnagel) (Lepidoptera: Noctuidae) is an important polyphagous pest of beans, cotton, maize, and alfalfa worldwide. H. viriplaca is a long-distance migrant, and if so, what pattern of seasonal migration this species exhibits in northern China remains unknown. In this study, in order to determine the seasonal migration of H. viriplaca in northern China, the combination of searchlight trapping and ovarian dissection was carried out on an isolated small island in the center of the Bohai Strait during 2003-2014. The results confirmed that H. viriplaca undertakes long-distance migration on the prevailing winds of the East Asian monsoon airflows. This species exhibited a regular pattern of seasonal migration across the sea from May to October, but there was considerable yearly and monthly variation in the trapped numbers, with the majority being trapped in summer (67.99 ± 6.54%). The mean period when migration was detectable at the island was 116.5 ± 5.6 days from 2003 to 2014, with the shortest time span of 74 days in 2013 and the longest of 144 days in 2005. Trapped females in May and June showed a relatively higher mating rates and some degree of ovarian development when compared with July, August and September, suggesting the migration of this species is not completely bound by the 'oogenesis-flight syndrome'. These findings will be helpful to improve the forecasting system and managing strategies of H. viriplaca.

Male influence on the ovarian development of the crustacean parasite Bopyrina abbreviata (Isopoda, Bopyridae)

The presence of a male in a population of terrestrial isopods can accelerate the onset of female reproduction, a feature that has been suggested also to occur in bopyrid isopods. This paper aims to estimate the influence of the male presence on the ovarian maturation of Bopyrina abbreviata. Females of B. abbreviata of different sizes were collected at Términos lagoon, Campeche, Mexico. The organisms were morphometrically classified as immature or mature, the male presence or absence at female's marsupium was recorded, and the degree of ovarian development was determined histologically. The internal organization of B. abbreviata agrees with that described for bopyrids and isopods in general. The ovarian cells originate from a dorsal lamina germinal layer that extends horizontally. The ovarian development of lone and paired immature females was classified as incipient and medium, respectively. In mature females it was classified as advanced, in the paired females and in the one lone mature female studied. The lone mature female differed from paired mature females only in the presence of reabsorption process in some oocytes located closer to the ventral wall of the ovary. Morphology variations between lone and paired females suggests that the presence of a cryptoniscus larva or a male between the female's pleopods stimulates the onset of reproduction and accelerates the ovarian development of B. abbreviata.

Seasonal Pattern of Spodoptera litura (Lepidoptera: Noctuidae) Migration Across the Bohai Strait in Northern China.

The common cutworm, Spodoptera litura (F.), is a serious crop pest with a strong migratory ability. Previous studies on the migration of S. litura were mostly carried out in its "year-round breeding region" (YBR) or "overwintering region" (OR). However, the pattern of seasonal movements in its "summer breeding region" (SBR; i.e., northern China where they cannot overwinter) remains unknown. Here, we present data from an 11-yr study of this species made by searchlight trapping on Beihuang (BH) Island in the center of the Bohai Strait, which provides direct evidence that S. litura regularly migrates across this sea. There was considerable yearly and monthly variation in the number of S. litura trapped on BH, with the vast majority trapped in the autumn. The mean time from the earliest trapping to the latest trapping within a year was 110±12 d during 2003-2013, with the shortest time span of 40 d in 2003 and the longest of 166 d in 2012. S. litura moths had downwind displacement rather than randomly by heading toward their seasonally favorable direction (i.e. toward southwest in the four autumn migration events by prevailing northeasterly winds). Some females trapped in July showed a relatively higher proportion of having mated and a degree of ovarian development, suggesting that the migration of this species is not completely bound by the "oogenesis-flight syndrome." These findings provide a good starting point of research on S. litura migration between its OR (or YBR) and SBR, which will help us develop more effective regional management strategies against this pest.

Seasonal Migration of Ctenoplusia agnata (Lepidoptera: Noctuidae) Over the Bohai Sea in Northern China

Ctenoplusia agnata (Staudinger) (Lepidoptera: Noctuidae) is an important polyphagous pest in East Asia. Previous studies showed that C. agnata moths possesses the potential to undertake long-distance migration; however, knowledge of whether or not the migration of C. agnata moths is a regular ecological behavior and what the pattern of seasonal migrations is in case of regular migration is currently lacking. In the current study, systemic monitoring of population dynamics of C. agnata was conducted by a searchlight trap on an island in the center of Bohai gulf in northern China, during 2003-2013. Our results provided strong evidence for the hypothesis that C. agnata is one of the pest species undertaking regular high altitude long-distance migration and we have depicted the seasonal migration pattern over the Bohai Sea. The first capture of C. agnata generally appeared in late April and early May, then the daily number of catches increased to high levels in late July and formed two waves of migration through August and early September, and finally, the moths disappeared in late October. The mean time from the earliest trapping to the latest trapping within a year was 141.0 +/- 3.0 days. The index of ovarian development of female C. agnata showed seasonal variability and suggested that its migratory flight may be independent of the degree of ovarian development and mating status. In addition, strong migration events took place in 2003, 2004, 2008, and 2010 (annual sum of catches > 10,000). The research result from this work is helpful for understanding the occurrence regularity of C. agnata and developing an integrated pest management strategy.

Ovarian indexes as indicators of reproductive investment and egg-laying activity in social insects: a comparison among methods

High reproductive skew among colony members is a fundamental feature of insect’s societies, where one or few individuals monopolize reproductive output. However, many social insect species retain a high reproductive plasticity, with all colony members able of developing ovaries and laying eggs. Understanding the partition of reproduction inside these plastic societies is a key step in the comprehension of social evolution. The reproductive status of social insects is usually evaluated by looking at the degree of ovarian development, and a great variety of different methods has been used even in the same species. It is not known, however, to which extent the different methods give comparable results and represent good indexes of individual egg-laying activity. We used the model paper wasp species Polistes dominula to tackle these issues, by compiling the main methods of ovarian development assessment on the same set of individuals and quantifying their egg-laying activity. Our results showed that all examined methods give similar and highly correlated results, but none of them allows reliable estimates of the egg-laying activity. Ovarian indexes (whatever method is used) are good indicators of individual reproductive potential, but can only roughly reflect actual reproductive activity. We thus propose to be very cautious in extrapolating egg-laying activity levels from ovarian index estimations.

Cuticular hydrocarbons correlate with fertility, not dominance, in a paper wasp, Polistes dominulus

Cuticular hydrocarbons (CHCs) are information-rich signals in social insects that coordinate behaviors within nests. However, in some taxa, the precise information conveyed by CHCs is poorly understood. In particular, there is a debate over whether CHCs convey information about their bearer's dominance or fertility. Distinguishing between dominance and fertility signaling is difficult because fertility and rank are frequently correlated within social insect colonies. This study disentangles those relationships by examining CHCs of Polistes dominulus paper wasps during the early nest-founding stage before dominance and fertility become correlated. First, we confirm that dominance and fertility are not associated in early spring foundresses. Then we show that CHCs are more strongly associated with fertility than dominance. There was no relationship between cuticular hydrocarbon profiles and a wasp’s ability to dominate rivals through aggression, suggesting that CHCs are unlikely to provide information about dominance. However, there was a significant correlation between ovarian development and the CHC profile, suggesting that CHCs could convey valuable information about their bearer's fertility. Furthermore, our data provide a potential mechanism for chemical signaling of fecundity, as there is a relationship between endogenous juvenile hormone titer (a gonadotropin), degree of ovarian development, and the CHC profile. Hormonal regulation of CHC profile expression offers a physiological mechanism to coordinate behavior, physical state, and signal expression.

Reproductive biology of the rock shrimp Sicyonia dorsalis (Decapoda: Penaeoidea) from the southeastern coast of Brazil

Summary Sicyonia dorsalis is not commercially exploited in Brazil, but it forms a critical link in marine food chains by converting detritus food sources into microorganism biomass that is available for higher trophic levels. We examined the reproductive biology of this species, sampled for five and a half years in a tropical locality, the southeastern coast of São Paulo (23° S), Brazil. Monthly samples were taken from January 1998 to June 2003 at depths of 5 to 45 m. Degree of ovarian development was used to examine breeding in adult females. Recruitment was estimated by changes in proportion of individuals in juvenile size classes of carapace length (CL #8.2 mm) in relationship to the total number of individuals. The largest immature female measured 9.2 mm CL, but 75% of females were smaller than 7.3 mm CL. The largest immature male measured 6.8 mm CL. The relative frequency of reproductive females was negatively correlated with the relative frequency of recruitment (p <0.001). Reproductive females were found in every season, with peaks in December-February following the recruitment peak in March-June, and a second peak of spawning in May-July and of recruitment in September-November. The continuous reproductive pattern observed for S. dorsalis, combined with the hypothesis that during spring and summer the phytoplankton production is higher, when the South Atlantic central water mass intrudes into the region during upwelling events, suggests that food availability for protozoeal and mysis larvae may be an important selective factor shaping the seasonal breeding pattern for S. dorsalis. The classical paradigm of continuous reproduction at lower latitudes, with increased seasonality of the breeding period at higher latitudes, seems to be valid for this species.

Aspectos ecológicos da população de Culex quinquefasciatus Say (Diptera, Culicidae) em abrigos situados no Parque Ecológico do Tietê, São Paulo, SP

O estudo objetivou conhecer, ao longo das estacoes do ano, aspectos ecologicos da populacao adulta de Culex quinquefasciatus em abrigos. As coletas dos adultos foram realizadas mensalmente, cobrindo-se o periodo de um ano, na vegetacao da margem de um canal de circunvalacao. Os insetos foram capturados com o auxilio de um aspirador a bateria. O material foi acondicionado e transportado ao laboratorio e, posteriormente, a especie de interesse foi identificada; machos e femeas foram quantificados e o desenvolvimento ovariano foi identificado segundo o criterio de Sella. Dados metereologicos foram coletados visando correlaciona-los com a variacao sazonal da populacao de mosquitos. Foram coletados 8.298 mosquitos da especie Culex quinquefasciatus. Desse total, 6.313 (76%) eram machos e 1.985 (24%) femeas. As femeas foram encontradas com o abdome vazio (90,1%), com sangue (7,4%) ou com ovulos maduros (2,5%). As correlacoes de numero de mosquitos coletados versus temperatura mensal media e precipitacao mensal total nao indicaram influencia forte e positiva desses fatores na frequencia de mosquitos. A maior frequencia de machos pode ser explicada pela dispersao das femeas e pela permanencia dos machos nos abrigos, representados pela vegetacao na margem do canal favorecendo o acumulo de mosquitos.

Changes in juvenile hormone biosynthetic rate and whole body content in maturing virgin queens of Solenopsis invicta

Studies were conducted on the physiological and hormonal changes following the release of alates from developmentally suppressive pheromones produced by mature queens of the fire ant Solenopsis invicta Buren. Winged virgin queens were removed from the pheromonal signal and placed in colony fragments. The time for dealation, degree of ovarian development, and biosynthesis rate and whole body content of juvenile hormone (JH) were measured. The production rate and content of JH were highly correlated. Dealation and the initiation of oviposition corresponded to peak production of JH. JH production rose sharply following separation from the natal nest, peaking after 3 days. After 8 days of isolation, JH production gradually subsided to levels similar to that found in pre-release queens, but began to increase again after 12 days. Mature queens had highly elevated levels of JH relative to recently dealate females, probably reflecting the increased reproductive capability of these older females. The results support the hypothesis that the pheromone released by functional queens inhibits reproduction in virgin alates by suppressing corpora allata activity and the production of JH.

Quantitative aspects of the regulation of ovarian development in selected anautogenous Diptera: integration of endocrinology and nutrition

AbstractAspects of the influence of nutrition on the degree of ovarian development in selected anautogenous Diptera are reviewed. The Diptera considered are several mosquito species, with emphasis on Aedes aegypti, the house fly, Musca domestica, the Australian bush fly, M. vetustissima and the blowflies, Lucilia cuprina and Phormia regina. All the selected species display discrete ovarian cycles in which all oocytes destined to reach maturity in a particular ovarian cycle develop synchronously. In these species, the proportion of females maturing oocytes and, where such data exist, the number of oocytes they mature are positively correlated with the amount of any particular nitrogen‐containing material ingested or given by enema or by infusion. In addition, the degree of ovarian development may be affected by the chemical composition of nitrogen‐containing food. Possible physiological bases for the observed relationships are discussed. Available evidence suggests that whether or not a female matures any oocytes is hormonally regulated and that the number of oocytes matured is probably regulated by the availability of nutrients. Some approaches that might further elucidate the physiological regulatory mechanisms involved in ovarian development are outlined.

Investigations of the oogenesis-flight syndrome inAnthonomus grandis (Coleoptera: Curculionidae) using tethered flight tests

This paper investigates the relationship between oogenesis and flight duration and the use of tethered flight as an indicator of tendency to migrate inAnthonomus grandis grandis Boheman (Coleoptera: Curculionidae), the boll weevil. When boll weevils were flown to exhaustion in tethered flight tests, many flew between 2 and 3 h, with several flying more than 4 h. To test the validity of the tethered flight test as an indicator of tendency to migrate, comparisons of mean flight duration were made between boll weevils trapped in pheromone traps far from any cultivated cotton and those trapped at the edge of heavily infested, flowering cotton fields. There was a significant difference in mean flight time between the two groups, supporting the assumption that long-duration tethered flight in the laboratory reflects the tendency to make long-distance flights in the field. Groups of weevils of different ages were killed after flight testing, and the degree of ovarian development and fat body status were determined and related to duration of tethered flight. Insects with undeveloped or partially developed ovaries were the most likely to make long flights. Weevils with ovaries bearing chorionated eggs made very few long flights. Flight duration was positively correlated with degree of fat body development. In contrast, there were no significant differences in the degree of ovarian development with fat body status. We conclude from these experiments thatA. grandis grandis is capable of long-distance flight, that this species displays some behavioral and physiological characteristics typical of many insect migrants including an oogenesis-flight syndrome, and that a tethered flight test is an appropriate means of measuring migratory tendency in this species.

Social Behavior of Parischnogaster nigricans serrei (Hymenoptera: Vespoidea) in Java1

Parischnogaster nigricans serrei (Du Buysson) constructs a linear series of nonoverlapping cells on roots or hanging threads. Colonies consist of males and both fertilized and unfertilized females. In the single observed nest initiation, a lone female was joined by 4 males who were faithful to the nest and solicited food aggressively from her. Mating was not observed, but aggregations of up to 22 males clustered on roots near nests. Oviposition is indirect, with the egg emitted close to the mouth, then delicately grasped with the mandibles and inserted into the cell. Oviposition is preceded and followed by the emission of a gelatinous material from the ventrally flexed abdomen tip into the mouth. Aided by her anterior legs, the wasp collects and wads this material into a ball, then places it on the cell bottom. More mature larvae presumably are fed with masticated insects. Females eat their own and other females' eggs. Cells with full-grown larvae are sealed by adult females, reopened to extract the fecal remains, and resealed. An essentially linear hierarchy exists among the females on all nests, with only rare evidence of inversion. Both degree of ovarian development and a division of labor are correlated to hierarchy position. The alpha female almost always resides on the nest, where she alternates long periods of immobility with cell inspection, patrol, and aggressive flights against conspecifics approaching the nest. Subordinate females are more often absent, and perform the bulk of the foraging activities. Subordinates contribute to most nest activities, including larval nutrition and ant guard construction, but only the alpha deposits eggs. Fertilized females have significantly larger heads and better-developed ovaries than unfertilized females.

Ovarian development, pheromone production, and mating in the eye gnat, Hippelates collusor

Mating in female eye gnats is correlated with the degree of ovarian development which is utilized as a physiological age indicator. Mating occurred in females having egg development of stages 6 to 9. Females at stage 7 mated more frequently than females at the other stages of ovarian development when the males were given a choice of different aged females. Live females with ovaries in stages 6 to 9 produced a sex attractant and females at stage 10 produced a repellent. Females with stages 2 to 4 ovaries did not attract males. Ether extracts from females with stages 6 to 9 ovaries attracted males, extracts from females with mature eggs repelled males, and extracts from females with stage 2 ovaries did not attract males. Attractancy was only detectable in laboratory olfactometer tests. Field tests on female extracts did not attract males in the field. The sex attractant produced by female eye gnats probably acts as a sex recognition scent.