scholarly journals Crowded locusts produce hatchlings vulnerable to fungal attack

2009 ◽  
Vol 5 (6) ◽  
pp. 845-848 ◽  
Author(s):  
Gabriel A. Miller ◽  
Judith K. Pell ◽  
Stephen J. Simpson
Keyword(s):  
Disease Resistance ◽  
Metarhizium Anisopliae ◽  
Fungal Pathogen ◽  
Schistocerca Gregaria ◽  
Positive Density ◽  
Transgenerational Effects ◽  
Parental Experience ◽  
Rearing Density ◽  
Parental Rearing ◽  
The Impact

Transgenerational effects of parental experience on offspring immunity are well documented in the vertebrate literature (where antibodies play an obligatory role), but have only recently been described in invertebrates. We have assessed the impact of parental rearing density upon offspring disease resistance by challenging day-old locust hatchlings ( Schistocerca gregaria ) from either crowd- or solitary-reared parents with the fungal pathogen Metarhizium anisopliae var. acridum . When immersed in standardized conidia suspensions, hatchlings from gregarious parents suffered greater pathogen-induced mortality than hatchlings from solitary-reared parents. This observation contradicts the basic theory of positive density-dependent prophylaxis and demonstrates that crowding has a transgenerational influence upon locust disease resistance.

scholarly journals Transgenerational effects modulate density-dependent prophylactic resistance to viral infection in a lepidopteran pest

2015 ◽  
Vol 11 (3) ◽  
pp. 20150012 ◽  
Author(s):  
Kenneth Wilson ◽  
Robert I. Graham
Keyword(s):  
Disease Resistance ◽  
Survival Rates ◽  
Post Challenge ◽  
Transgenerational Effects ◽  
Density Dependent ◽  
Offspring Fitness ◽  
Rearing Density ◽  
Lepidopteran Pest ◽  
The Impact ◽  
Resistance To Viral Infection

There is an increasing appreciation of the importance of transgenerational effects on offspring fitness, including in relation to immune function and disease resistance. Here, we assess the impact of parental rearing density on offspring resistance to viral challenge in an insect species expressing density-dependent prophylaxis (DDP); i.e. the adaptive increase in resistance or tolerance to pathogen infection in response to crowding. We quantified survival rates in larvae of the cotton leafworm ( Spodoptera littoralis ) from either gregarious- or solitary-reared parents following challenge with the baculovirus S. littoralis nucleopolyhedrovirus. Larvae from both the parental and offspring generations exhibited DDP, with gregarious-reared larvae having higher survival rates post-challenge than solitary-reared larvae. Within each of these categories, however, survival following infection was lower in those larvae from gregarious-reared parents than those from solitary-reared, consistent with a transgenerational cost of DDP immune upregulation. This observation demonstrates that crowding influences lepidopteran disease resistance over multiple generations, with potential implications for the dynamics of host–pathogen interactions.

scholarly journals Improvement of water quality for mass anopheline rearing: evaluation of the impact of ammonia-capturing zeolite on larval development and adult phenotypic quality

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Nwamaka Oluchukwu Akpodiete ◽  
Frédéric Tripet
Keyword(s):  
Water Quality ◽  
Larval Development ◽  
Larval Density ◽  
Malaria Vector Control ◽  
Larval Rearing ◽  
Emergence Success ◽  
Phenotypic Quality ◽  
Rearing Density ◽  
Daily Water ◽  
The Impact

Abstract Background Malaria vector control approaches that rely on mosquito releases such as the sterile insect technique (SIT) and suppression or replacement strategies relying on genetically modified mosquitoes (GMM) depend on effective mass production of Anopheles mosquitoes. Anophelines typically require relatively clean larval rearing water, and water management techniques that minimise toxic ammonia are key to achieving optimal rearing conditions in small and large rearing facilities. Zeolites are extensively used in closed-system fish aquaculture to improve water quality and reduce water consumption, thanks to their selective adsorption of ammonia and toxic heavy metals. The many advantages of zeolites include low cost, abundance in many parts of the world and environmental friendliness. However, so far, their potential benefit for mosquito rearing has not been evaluated. Methods This study evaluated the independent effects of zeolite and daily water changes (to simulate a continuous flow system) on the rearing of An. coluzzii under two feed regimes (powder and slurry feed) and larval densities (200 and 400 larvae per tray). The duration of larval development, adult emergence success and phenotypic quality (body size) were recorded to assess the impact of water treatments on mosquito numbers, phenotypic quality and identification of optimal feeding regimes and larval density for the use of zeolite. Results Overall, mosquito emergence, duration of development and adult phenotypic quality were significantly better in treatments with daily water changes. In treatments without daily water changes, zeolite significantly improved water quality at the lower larval rearing density, resulting in higher mosquito emergence and shorter development time. At the lower larval rearing density, the adult phenotypic quality did not significantly differ between zeolite treatment without water changes and those with daily changes. Conclusions These results suggest that treating rearing water with zeolite can improve mosquito production in smaller facilities. Zeolite could also offer cost-effective and environmentally friendly solutions for water recycling management systems in larger production facilities. Further studies are needed to optimise and assess the costs and benefits of such applications to Anopheles gambiae (s.l.) mosquito-rearing programmes. Graphic abstract

Papuana huebneri (taro beetle).

2021 ◽  
Author(s):  
Angela Whittaker
Keyword(s):  
Papua New Guinea ◽  
Metarhizium Anisopliae ◽  
Fungal Pathogen ◽  
Management Strategy ◽  
Solomon Islands ◽  
Cultural Control ◽  
Control Measures ◽  
Pacific Region ◽  
Cultural Traditions ◽  
Loss Of Genetic Diversity

Abstract Papuana huebneri is one of at least 19 species of known taro beetles native to the Indo-Pacific region; it is native to Papua New Guinea, the Molucca Islands in Indonesia, the Solomon Islands and Vanuatu, and has been introduced to Kiribati. Taro (Colocasia esculenta) is an important crop in these countries; high infestations of P. huebneri can completely destroy taro corms, and low infestations can reduce their marketability. The beetle also attacks swamp taro or babai (Cyrtosperma chamissonis [Cyrtosperma merkusii]), which is grown for consumption on ceremonial occasions. Infestations of taro beetles, including P. huebneri, have led to the abandonment of taro and swamp taro pits in the Solomon Islands and Kiribati, resulting in the loss of genetic diversity of these crops and undermining cultural traditions. P. huebneri also attacks a variety of other plants, although usually less seriously. Management today relies on an integrated pest management strategy, combining cultural control measures with the use of insecticides and the fungal pathogen Metarhizium anisopliae.

The Impact of Domestication on Red Deer Immunity and Disease Resistance

1992 ◽  
pp. 120-125 ◽  
Author(s):  
J. Frank ◽  
T. Griffin ◽  
Anthony J. Thomson ◽  
John P. Cross ◽  
Glenn S. Buchan ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Red Deer ◽  
The Impact

scholarly journals Epigenetic dynamics of centromeres and neocentromeres in Cryptococcus deuterogattii

PLoS Genetics ◽  
2021 ◽  
Vol 17 (8) ◽  
pp. e1009743
Author(s):  
Klaas Schotanus ◽  
Vikas Yadav ◽  
Joseph Heitman
Keyword(s):  
Dna Methylation ◽  
Transposable Element ◽  
Fungal Pathogen ◽  
Fusion Partner ◽  
Epigenetic Memory ◽  
Chromosome Fusion ◽  
Human Fungal Pathogen ◽  
Chromosome Fusions ◽  
The Impact ◽  
Active Centromere

Deletion of native centromeres in the human fungal pathogen Cryptococcus deuterogattii leads to neocentromere formation. Native centromeres span truncated transposable elements, while neocentromeres do not and instead span actively expressed genes. To explore the epigenetic organization of neocentromeres, we analyzed the distribution of the heterochromatic histone modification H3K9me2, 5mC DNA methylation and the euchromatin mark H3K4me2. Native centromeres are enriched for both H3K9me2 and 5mC DNA methylation marks and are devoid of H3K4me2, while neocentromeres do not exhibit any of these features. Neocentromeres in cen10Δ mutants are unstable and chromosome-chromosome fusions occur. After chromosome fusion, the neocentromere is inactivated and the native centromere of the chromosome fusion partner remains as the sole, active centromere. In the present study, the active centromere of a fused chromosome was deleted to investigate if epigenetic memory promoted the re-activation of the inactive neocentromere. Our results show that the inactive neocentromere is not re-activated and instead a novel neocentromere forms directly adjacent to the deleted centromere of the fused chromosome. To study the impact of transcription on centromere stability, the actively expressed URA5 gene was introduced into the CENP-A bound regions of a native centromere. The introduction of the URA5 gene led to a loss of CENP-A from the native centromere, and a neocentromere formed adjacent to the native centromere location. Remarkably, the inactive, native centromere remained enriched for heterochromatin, yet the integrated gene was expressed and devoid of H3K9me2. A cumulative analysis of multiple CENP-A distribution profiles revealed centromere drift in C. deuterogattii, a previously unreported phenomenon in fungi. The CENP-A-binding shifted within the ORF-free regions and showed a possible association with a truncated transposable element. Taken together, our findings reveal that neocentromeres in C. deuterogattii are highly unstable and are not marked with an epigenetic memory, distinguishing them from native centromeres.

scholarly journals Genetic management strategies for controlling infectious diseases in livestock populations

2002 ◽  
Vol 2002 ◽  
pp. 55-55 ◽  
Author(s):  
S. C. Bishop ◽  
K. Mackenzie
Keyword(s):  
Disease Resistance ◽  
Resistance Genes ◽  
Disease Transmission ◽  
Management Strategies ◽  
Disease Resistance Genes ◽  
Breeding Strategies ◽  
Genetic Management ◽  
Control Disease ◽  
The Impact ◽  
Prp Gene

Disease resistance is often cited as the major challenge facing animal geneticists, with much effort directed towards finding disease-resistance genes. The PrP gene controlling resistance of sheep to scrapie is such an example. To design effective breeding strategies utilising such genes, it is critical to understand the impact that these genes have upon disease transmission. For example, it has been shown that it is not necessary to make all animals genetically resistant in order to protect the population as a whole from epidemics (MacKenzie and Bishop, 1999). Additionally, concern is often voiced over the possibility of the pathogen co-evolving with the host, reducing the utility of the genes. By combining animal breeding and epidemiology theory, this study derives strategies for using disease resistance genes to control disease transmission, and considers the co-evolution risks with such strategies.

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