Analysis of the reproductive potential of diploid males in the wasp Diadromus pulchellus (Hymenoptera: Ichneumonidae)

AbstractIn the ichneumonid wasp Diadromus pulchellus (Wesmael), diploid males may regularly be produced in laboratory populations by inbreeding. They are viable, produce diploid sperm and are equally capable of multiple inseminations as are haploid males. Their spermatozoa are also able to penetrate the oocyte. Progeny sired by diploid males are essentially haploid sons with only a few daughters. The sons are normal haploid individuals, produced in a frequency significantly higher than in crosses between females and haploid males. The daughters are normal diploid females probably resulting from the fertilization of an oocyte by an exceptional haploid sperm rarely produced by diploid males. Triploid individuals were not observed and their absence was correlated with the high mortality observed during the first developmental stages. The death of these individuals is discussed in the light of the phenomenon of superparasitism to explain the increase in the frequency of sons produced in crosses with diploid males. Despite their viability, their ability to produce sperm and their normal potential insemination, diploid males of Diadromus pulchellus are therefore almost sterile.

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Diploid males, diploid sperm production, and triploid females in the ant Tapinoma erraticum

The Science of Nature ◽

10.1007/s00114-009-0590-1 ◽

2009 ◽

Vol 96 (12) ◽

pp. 1393-1400 ◽

Cited By ~ 16

Author(s):

Laurent Cournault ◽

Serge Aron

Keyword(s):

Sperm Production ◽

Diploid Males ◽

Tapinoma Erraticum ◽

Diploid Sperm

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Eimeria mitis: a comparison of the endogenous developmental stages of a line selected for early maturation and the parent strain

Parasitology ◽

10.1017/s0031182000054329 ◽

1984 ◽

Vol 88 (1) ◽

pp. 37-44 ◽

Cited By ~ 10

Author(s):

V. McDonald ◽

M. W. Shirley

Keyword(s):

Life Cycle ◽

Epithelial Cells ◽

Parent Strain ◽

First Generation ◽

Developmental Stages ◽

Reproductive Potential ◽

Life Cycles ◽

Endogenous Development ◽

Early Maturation ◽

Precocious Line

SUMMARYThe endogenous development of the Houghton (H) strain of Eimeria mitis (= mivati) was compared with the life-cycle of a precocious (HP) line derived from the H strain. In both parasites 4 generations of schizonts which developed in epithelial cells were observed: the 1st and 2nd were found in the crypts and the 3rd and 4th in the villi. Gametocytes and zygotes occupied epithelial cells at the tips of the villi. The onset of gametogony normally coincided with the maturation of 4th-generation schizonts. The infection was confined initially to an area of the gut extending from the jejunum to the ileo-caecal junction but 3rd-generation merozoites and subsequent stages were also found in the caeca and rectum. The life-cycle of the precocious line was shorter than that of the parent strain. Gametocytes appeared to develop from 3rd-generation as well as from 4th-generation merozoites. Also, sporozoites of the precocious line transformed to trophozoites before those of the parent strain. First-generation schizonts of the HP line tended to be smaller and to contain fewer merozoites than those of the H strain. The differences between the life-cycles of the two parasites account for the lower reproductive potential of the precocious line.

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Gonadal Development of Females of the White Shrimp Penaeus schmitti (Burkenroad, 1936) Caught in Southeastern Brazil

Journal of Marine Science and Engineering ◽

10.3390/jmse9060653 ◽

2021 ◽

Vol 9 (6) ◽

pp. 653

Author(s):

Roberta Cardozo P. Garcia ◽

Cecília Fernanda F. Craveiro ◽

Caroline V. Bernabé ◽

Maria Aparecida Silva ◽

Paulo Henrique R. Aride ◽

...

Keyword(s):

Native Species ◽

Histological Analysis ◽

Visual Analysis ◽

Developmental Stages ◽

Reproductive Potential ◽

Gonadal Development ◽

White Shrimp ◽

Southeastern Brazil ◽

Initial Development ◽

In Captivity

This study describes the reproductive cell development and ovarian developmental stages, and identifies the nongerminal components of white shrimp (Penaeus schmitti) caught off the southern coast of Espírito Santo, Brazil. P. schmitti specimens were collected monthly from March 2019 to February 2020, by artisanal fishing. All shrimps were analyzed macroscopically (n = 181) and females were randomly selected monthly (n = 154) for ovarian histological analysis. The ovaries were extracted for visual analysis and then submitted to histological analysis. Macroscopic analysis determined five stages of gonadal development from the color and turgidity of the fresh ovary. Histological observations allowed us to observe five stages of gonadal development: immature, initial development, advanced development, mature and spawning. This information are fundamental for understanding the reproductive aspects of P. schmitti, as well as other penaeid shrimps, in order to promote preservation of natural stocks and provide information to assist in the development of the reproductive potential of native species in captivity.

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Reproductive potential and developmental stages of Bandicota indica from four villages in four Townships in Magway Region, Myanmar

International International Journal of Avian & Wildlife Biology ◽

10.15406/ijawb.2018.04.00143 ◽

2019 ◽

Vol 4 (1) ◽

Author(s):

Aye Yu San ◽

Mie Mie Sein ◽

Yu Xu

Keyword(s):

Developmental Stages ◽

Reproductive Potential

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Field evidence of intra- and interspecific predation in rock-pool corixids (Heteroptera, Corixidae)

Entomologica Fennica ◽

10.33338/ef.83566 ◽

1992 ◽

Vol 3 (1) ◽

pp. 15-19 ◽

Cited By ~ 3

Author(s):

Irmeli Pajunen ◽

V. Ilmari Pajunen

Keyword(s):

High Mortality ◽

Developmental Stages ◽

Field Conditions ◽

Considerable Proportion ◽

Rock Pool ◽

Field Evidence ◽

Large Numbers ◽

Interspecific Predation

Small corixid larvae were introduced into a rock-pool containing large numbers of later developmental stages. High mortality of small larvae was observed. A considerable proportion of larval carcases recovered each had triangular holes on its upper surface. Similar holes are characteristic of carcases recovered in laboratory cannibalism experiments. The dimensions of the punctures in field and laboratory samples match closely. Predatory interactions between large and small rock-pool corixid larvae are thus common in field conditions.

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Impacts of Parasitism on the Survivorship and Reproduction of the Madeira Mealybug (Hemiptera: Pseudococcidae)

Journal of Entomological Science ◽

10.18474/0749-8004-43.2.169 ◽

2008 ◽

Vol 43 (2) ◽

pp. 169-176 ◽

Cited By ~ 3

Author(s):

Juang-Horng Chong ◽

Ronald D. Oetting

Keyword(s):

Survival Rate ◽

Developmental Stages ◽

Reproductive Potential ◽

Reproductive Period ◽

Reproductive Status ◽

Host Feeding ◽

Parasitism Rate ◽

Phenacoccus Madeirensis

This study was conducted to assess the impacts of parasitism by Anagyrus sp. nov. nr. sinope Noyes and Menezes on the reproductive potential and the survivorship of the Madeira mealybug, Phenacoccus madeirensis Green. The reproductive responses of P. madeirensis to parasitism were dependent upon the reproductive status of the adult mealybugs. The reproductive period and fecundity of parasitized preovipositing adult mealybugs were significantly lower (4 d and 290 eggs, respectively) than those of the unparasitized individuals (8 d and 380 eggs, respectively). However, the reproductive longevity and fecundity were not different between the parasitized and unparasitized ovipositing mealybugs. Destructive feeding by parasitoid larvae reduced the total longevity of all adult mealybugs by 1–4 d. The parasitoid only host fed on 2.4% of the 1st-instar mealybugs and none in other developmental stages. In the 4 developmental stages examined (1st, 2nd and 3rd nymphal instars, and prereproductive adult), only the survival rate of 1st-instar nymphs was significantly reduced by ovipositor insertion (97% of the unparasitized versus 88% of the parasitized). After accounting for the mortality due to host feeding and ovipositor insertion, the parasitism rate of P. madeirensis by Anagyrus sp. nov. nr. sinope was estimated at 30%.

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Reproductive potential and developmental stages of Bandicota indica from four villages in four Townships in Magway Region, Myanmar

International International Journal of Avian & Wildlife Biology ◽

10.15406/ijawb.2019.04.00143 ◽

2019 ◽

Vol 4 (1) ◽

Author(s):

Aye Yu San ◽

Mie Mie Sein ◽

Yu Xu

Keyword(s):

Developmental Stages ◽

Reproductive Potential

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Effects of Functional Depletion of Doublesex on Male Development in the Sawfly, Athalia rosae

Insects ◽

10.3390/insects12100849 ◽

2021 ◽

Vol 12 (10) ◽

pp. 849

Author(s):

Shotaro Mine ◽

Megumi Sumitani ◽

Fugaku Aoki ◽

Masatsugu Hatakeyama ◽

Masataka G. Suzuki

Keyword(s):

Developmental Stages ◽

External Genitalia ◽

Sex Reversal ◽

Diploid Males ◽

Male And Female ◽

Athalia Rosae ◽

Male Development ◽

Female Sex ◽

Rnai Treatment ◽

Male To Female

The doublesex (dsx) gene, which encodes a transcription factor, regulates sexual differentiation in insects. Sex-specific splicing of dsx occurs to yield male- and female-specific isoforms, which promote male and female development, respectively. Thus, functional disruption of dsx leads to an intersexual phenotype in both sexes. We previously identified a dsx ortholog in the sawfly, Athalia rosae. Similar to dsx in other insects, dsx in the sawfly yields different isoforms in males and females as a result of alternative splicing. The sawfly exploits a haplodiploid mode of reproduction, in which fertilized eggs develop into diploid females, whereas unfertilized eggs parthenogenetically develop into haploid males. In the present study, we knocked down the A. rosae ortholog of dsx (Ardsx) during several developmental stages with repeated double-stranded RNA (dsRNA) injections. Knockdown of Ardsx via parental RNA interference (RNAi), which enables knockdown of genes in offspring embryos, led to a lack of internal and external genitalia in haploid male progeny. Additional injection of dsRNA targeting Ardsx in these animals caused almost complete male-to-female sex reversal, but the resulting eggs were infertile. Notably, the same knockdown approach using diploid males obtained by sib-crossing caused complete male-to-female sex reversal; they were morphologically and behaviorally females. The same RNAi treatment did not affect female differentiation. These results indicate that dsx in the sawfly is essential for male development and its depletion caused complete male-to-female sex reversal. This is the first demonstration of functional depletion of dsx not causing intersexuality but inducing total sex reversal in males instead.

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The genome trilogy of Anopheles stephensi, an urban malaria vector, reveals structure of a locus associated with adaptation to environmental heterogeneity

10.1101/2021.08.25.457468 ◽

2021 ◽

Author(s):

Aditi Thakare ◽

Chaitali Ghosh ◽

Tejashwini Alalamath ◽

Naveen Kumar ◽

Himani Narang ◽

...

Keyword(s):

Malaria Vector ◽

Anopheles Stephensi ◽

Environmental Heterogeneity ◽

Developmental Stages ◽

Direct Consequence ◽

Malaria Vectors ◽

Laboratory Populations ◽

Exonic Snps ◽

Water Tanks ◽

Survival Of The Fittest

Background: Anopheles stephensi is the most menacing malaria vector to watch for in newly urbanizing parts of the world. The fitness is reported to be a direct consequence of the vector adapting to laying eggs in over-head water tanks with street-side water puddles polluted by oil and sewage. Large frequent inversions of malaria vectors are implicated in adaptation. Results: We report the assembly of a strain of An. stephensi of the type-form, collected from a construction site from Chennai (IndCh) in 2016. The genome completes the trilogy with respect to a 16 Mbp inversion (2Rb) in An. stephensi associated with adaptation to environmental heterogeneity. Comparative genome analysis revealed breakpoint structure and allowed extraction of 22,650 segregating SNPs for typing this inversion. Using whole genome sequencing of 82 individual mosquitoes, we conclude that one third of both wild and laboratory populations maintain heterozygous genotype of 2Rb. The large number of SNPs are tailored to assign inversion genotype directly from 1740 exonic SNPs 80% of which are expressed in various developmental stages. Conclusions: The genome trilogy approach accelerates study of fine structure and typing of important inversions in malaria vectors putting the genome resources for the much understudied An. stephensi, on par with the extensively studied malaria vector, Anopheles gambiae. We argue that the IndCh genome is relevant for field translation work compared to those reported earlier by showing that individuals from diverse populations cluster with IndCh pointing to significant commerce between cities, perhaps, allowing for survival of the fittest strain.

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