scholarly journals Rapid stress hardening in the Antarctic midge improves male fertility by increasing courtship success and preventing decline of accessory gland proteins following cold exposure

2021 ◽  
Author(s):  
Oluwaseun M. Ajayi ◽  
J. D. Gantz ◽  
Geoffrey Finch ◽  
Richard E. Lee Jr. ◽  
David L. Denlinger ◽  
...  
Keyword(s):  
Cold Exposure ◽  
Accessory Gland ◽  
Egg Viability ◽  
Accessory Gland Proteins ◽  
Rapid Hardening ◽  
Direct Exposure ◽  
Belgica Antarctica ◽  
Courtship Success ◽  
Male Activity ◽  
The Antarctic

Rapid hardening is a process that quickly improves an animal's performance following exposure to a potentially damaging stress. In this study of the Antarctic midge, Belgica antarctica (Diptera, Chironomidae), we examine how rapid hardening in response to dehydration (RDH) or cold (RCH) improves male pre- and post-copulatory function when the insects are subsequently subjected to a damaging cold exposure. Neither RDH nor RCH improved survival in response to lethal cold stress, but male activity and mating success following sublethal cold exposure was enhanced. Egg viability decreased following direct exposure of the mating males to sublethal cold but improved following RCH and RDH. Sublethal cold exposure reduced expression of four accessory gland proteins, while expression remained high in males exposed to RCH. Though rapid hardening may be cryptic in males, this study shows that it can be revealed by pre- and post-copulatory interactions with females.

scholarly journals Rapid stress hardening in the Antarctic midge improves male fertility by increasing courtship success and preventing the decline of accessory gland proteins following cold exposure

2021 ◽  
Author(s):  
Oluwaseun M. Ajayi ◽  
J.D. Gantz ◽  
Geoffrey Finch ◽  
Richard E. Lee ◽  
David L. Denlinger ◽  
...  
Keyword(s):  
Cold Exposure ◽  
Accessory Gland ◽  
Egg Viability ◽  
Accessory Gland Proteins ◽  
Rapid Hardening ◽  
Direct Exposure ◽  
Belgica Antarctica ◽  
Courtship Success ◽  
Male Activity ◽  
The Antarctic

Rapid hardening is a process that quickly improves animal performance following exposure to a potentially damaging stress. Features of reproduction can be improved by rapid hardening, but little is known about how rapid hardening may contribute to physiological responses in the cold environment of Antarctica. In this study of the Antarctic midge, Belgica antarctica (Diptera, Chironomidae), we examine how rapid hardening in response to dehydration (RDH) or cold (RCH) improves male pre- and post-copulatory function related to fertility when the insects are subsequently subjected to a damaging cold exposure. Neither RDH nor RCH improved survival in response to lethal cold stress, but male activity following sublethal cold exposure was enhanced. Both RCH and RDH improved mating success of males compared to those subjected directly to a sublethal bout of cold. Egg viability decreased following direct exposure to sublethal cold, but improved following RCH and RDH. Sublethal cold exposure reduced expression of four accessory gland proteins, while expression remained high in males exposed to RCH. Though rapid hardening may be cryptic in males, this study shows that it can be revealed by pre- and post-copulatory interactions with females.

scholarly journals Multi-level analysis of reproduction in the Antarctic midge, Belgica antarctica, identifies female and male accessory gland products that are altered by larval stress and impact progeny viability

2019 ◽  
Author(s):  
Geoffrey Finch ◽  
Sonya Nandyal ◽  
Carlie Perrieta ◽  
Benjamin Davies ◽  
Andrew J. Rosendale ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Storage Proteins ◽  
Adult Life ◽  
Accessory Gland ◽  
Specific Gene ◽  
Functional Studies ◽  
Accessory Glands ◽  
Belgica Antarctica ◽  
The Antarctic ◽  
The Impact

AbstractThe Antarctic midge, Belgica antarctica, is a wingless, non-biting midge endemic to Antarctica. Larval development requires at least two years, but adult life lasts only two weeks. The nonfeeding adults mate in swarms and females die shortly after oviposition. Eggs are suspended in a gel of unknown composition that is expressed from the female accessory gland. This project characterizes molecular mechanisms underlying reproduction in this midge by examining differential gene expression in whole males, females, and larvae, as well as in male and female accessory glands. Functional studies were used to assess the role of the gel encasing the eggs, as well as the impact of stress on reproductive biology. RNA-seq analyses revealed sex- and development-specific gene sets along with those associated with the accessory glands. Proteomic analyses were used to define the composition of the egg-containing gel, which is generated during multiple developmental stages and derived from both the accessory gland and other female organs. Functional studies indicate the gel provides a larval food source and thermal and dehydration buffer, all of which are critical for viability. Larval dehydration stress directly reduces production of storage proteins and key accessory gland components, a feature that impacts adult reproductive success. Modeling reveals that bouts of dehydration may significantly impact population growth. This work lays a foundation for further examination of reproduction in midges and provides new information related to general reproduction in dipterans. A key aspect is that reproduction and stress dynamics, currently understudied in polar organisms, are likely to prove critical for determining how climate change will alter survivability.

Offsetting Effects of Wolbachia Infection and Heat Shock on Sperm Production inDrosophila simulans: Analyses of Fecundity, Fertility and Accessory Gland Proteins

Genetics ◽  
2000 ◽  
Vol 155 (1) ◽  
pp. 167-178 ◽  
Author(s):  
Rhonda R Snook ◽  
Sophia Y Cleland ◽  
Mariana F Wolfner ◽  
Timothy L Karr
Keyword(s):  
Heat Shock ◽  
Natural Populations ◽  
Adult Life ◽  
Reproductive Factors ◽  
Male Gamete ◽  
Wolbachia Infection ◽  
Accessory Gland ◽  
Sperm Production ◽  
Accessory Gland Proteins ◽  
Mating Conditions

AbstractInfection in Drosophila simulans with the endocellular symbiont Wolbachia pipientis results in egg lethality caused by failure to properly initiate diploid development (cytoplasmic incompatibility, CI). The relationship between Wolbachia infection and reproductive factors influencing male fitness has not been well examined. Here we compare infected and uninfected strains of D. simulans for (1) sperm production, (2) male fertility, and (3) the transfer and processing of two accessory gland proteins, Acp26Aa or Acp36De. Infected males produced significantly fewer sperm cysts than uninfected males over the first 10 days of adult life, and infected males, under varied mating conditions, had lower fertility compared to uninfected males. This fertility effect was due to neither differences between infected and uninfected males in the transfer and subsequent processing of accessory gland proteins by females nor to the presence of Wolbachia in mature sperm. We found that heat shock, which is known to decrease CI expression, increases sperm production to a greater extent in infected compared to uninfected males, suggesting a possible link between sperm production and heat shock. Given these results, the roles Wolbachia and heat shock play in mediating male gamete production may be important parameters for understanding the dynamics of infection in natural populations.

Life history traits of adults and embryos of the Antarctic midge Belgica antarctica

Polar Biology ◽  
2014 ◽  
Vol 37 (8) ◽  
pp. 1213-1217 ◽  
Author(s):  
Eri Harada ◽  
Richard E. Lee ◽  
David L. Denlinger ◽  
Shin G. Goto
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Belgica Antarctica ◽  
The Antarctic

scholarly journals Temporal Distribution of Arsenic and Metals in Soil From King George Island, Antarctica

2022 ◽  
Vol 8 ◽  
Author(s):  
Tailisi H. Trevizani ◽  
Rosalinda C. Montone ◽  
Rubens C. L. Figueira
Keyword(s):  
Human Activities ◽  
Temporal Distribution ◽  
Polar Regions ◽  
Control Points ◽  
King George Island ◽  
Admiralty Bay ◽  
Direct Exposure ◽  
Antarctic Continent ◽  
The Antarctic ◽  
Continue Monitoring

The polar regions are vulnerable to impacts caused by local and global pollution. The Antarctic continent has been considered an environment that has remained little affected by human activities. Direct exposure to contaminants may occur in areas continuously occupied by research stations for several decades. Admiralty Bay on the southeast coast of King George Island, has potential for being affected by human activities due research stations operating in the area, including the Brazilian Commandant Ferraz Antarctic Station (CFAS). The levels of metals and arsenic were determined in soils collected near CFAS (points 5, 6, 7, and 9), Base G and at two points distant from the CFAS: Refuge II and Hennequin. Samples were collected after the fire in CFAS occurred in February 2012, up to December 2018 to assess the environmental impacts in the area. Al and As were related with Base G. Refuge II and Hennequin can be considered as control points for this region. As a consequence of the accident, the increased levels for Cd, Cu, Pb, and Zn, especially at point 9 (inside the CFAS) and in the soil surrounding the CFAS in 2013. The results from 2016 to 2018 demonstrated a reduction in levels of all studied metals near CFAS, which may be related to the leaching of metals into Admiralty Bay; it is thus, being important the continue monitoring soil, sediments, and Antarctic biota.

scholarly journals Comparative genomics identifies male accessory gland proteins in five Glossina species

2017 ◽  
Vol 2 ◽  
pp. 73 ◽  
Author(s):  
Muna F. Abry ◽  
Kelvin M. Kimenyi ◽  
Daniel K Masiga ◽  
Benard W. Kulohoma
Keyword(s):  
Comparative Genomics ◽  
Reproductive Cycle ◽  
Sequence Data ◽  
Control Strategies ◽  
Accessory Gland ◽  
Tsetse Fly ◽  
Whole Genome Sequence ◽  
Reproductive Proteins ◽  
Accessory Gland Proteins ◽  
Accessory Glands

Accessory gland proteins (ACPs) are important reproductive proteins produced by the male accessory glands (MAGs) of most insect species. These proteins are essential for male insect fertility, and are transferred alongside semen to females during copulation. ACPs are poorly characterized in Glossina species (tsetse fly), the principal vector of the parasite that causes life-threatening Human African Trypanosomiasis and Animal trypanosomiasis in endemic regions in Africa. The tsetse fly has a peculiar reproductive cycle because of the absence of oviposition. Females mate once and store sperm in a spermathecal, and produce a single fully developed larva at a time that pupates within minutes of exiting their uterus. This slow reproductive cycle, compared to other insects, significantly restricts reproduction to only 3 to 6 larvae per female lifespan. This unique reproductive cycle is an attractive vector control strategy entry point. We exploit comparative genomics approaches to explore the diversity of ACPs in the recently available whole genome sequence data from five tsetse fly species ( Glossina morsitans, G. austeni, G. brevipalpis, G. pallidipes and G. fuscipes). We used previously described ACPs in Drosophila melanogaster and Anopheles gambiae as reference sequences. We identified 36, 27, 31, 29 and 33 diverse ACP orthologous genes in G. austeni, G. brevipalpis, G. fuscipes, G. pallidipes and G. morsitans genomes respectively, which we classified into 21 functional classes. Our findings provide genetic evidence of MAG proteins in five recently sequenced Glossina genomes. It highlights new avenues for molecular studies that evaluate potential field control strategies of these important vectors of human and animal disease.

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