Mating-Induced Trade-Offs upon Egg Production versus Fertilization and Offspring’s Survival in a Sawfly with Facultative Parthenogenesis

Investigation of mating-induced trade-offs between reproduction and survival is conducive to provide evolutionary insights into reproductive strategies and aging. Here, we used RNAseq and bioinformatics to reveal mating-induced changes of genes and pathways related to reproduction and survival in female Cephalcia chuxiongica, a pine defoliator with facultative parthenogenesis and long larval dormancy. Results showed that mating induced substantial downregulation on genes and pathways associated to immunity, stress response, and longevity. However, mating induced divergent reproductive response, with downregulation on genes and pathways related to egg production while upregulation on genes and pathways related to egg fertilization. Considering the nature of limited resources in adults, low fecundity, and egg protection behavior in C. chuxiongica, we suggest that mating triggers trade-offs between reproduction and survival in this insect and females of this species may have evolved specific strategies to adapt to the environmental and hosts’ conditions, e.g., restrict whole fecundity to ensure higher fertilization and offspring’s survival. Moreover, mating induced significant responses on genes and pathways that play important roles in vertebrate reproduction while their function in insects are unclear, such as the progesterone-mediated oocyte maturation pathway; the significant regulation after mating suggests that their function may be evolutionarily conserved in animal kingdom.

Mucosal Nanoemulsion Allergy Vaccine Suppresses Alarmin Expression and Induces Bystander Suppression of Reactivity to Multiple Food Allergens

We have demonstrated that intranasal immunotherapy with allergens formulated in a nanoemulsion (NE) mucosal adjuvant suppresses Th2/IgE-mediated allergic responses and protects from allergen challenge in murine food allergy models. Protection conferred by this therapy is associated with strong suppression of allergen specific Th2 cellular immunity and increased Th1 cytokines. Here we extend these studies to examine the effect of NE-allergen immunization in mice sensitized to multiple foods. Mice were sensitized to both egg and peanut and then received NE vaccine formulated with either one or both of these allergens. The animals were then subjected to oral challenges with either egg or peanut to assess reactivity. Immunization with NE formulations containing both egg and peanut markedly reduced reactivity after oral allergen challenge with either allergen. Interestingly, mice that received the vaccine containing only peanut also had reduced reactivity to challenge with egg. Protection from oral allergen challenge was achieved despite the persistence of allergen-specific IgE and was associated with strong suppression of both Th2-polarized immune responses, alarmins and type 2 innate lymphoid cells (ILC2). NE-induced bystander suppression of reactivity required IFN-γ and the presence of an allergen in the NE vaccine. These results demonstrate that anaphylactic reactions to food allergens can be suppressed using allergen-specific immunotherapy without having to eliminate allergen-specific IgE and suggests that modulation of Th2 immunity towards one allergen may induce bystander effects that suppress reactivity to other allergens through the induction of IFN-γ and suppression of alarmins in the intestine. In addition, these data suggest that a NE vaccine for a single food allergen may lead to a global suppression of allergic responses to multiple foods.

A highly stable, non-digestible lectin from Pomacea diffusa unveils clade-related protection systems in apple snail eggs

ABSTRACTThe acquisition of egg protection is vital for species survival. Poisonous eggs from Pomacea apple snails have defensive macromolecules for protection. Here we isolated and characterized a novel lectin called PdPV1 that is massively accumulated in the eggs of Pomacea diffusa and seems part of its protective cocktail. The native protein, an oligomer of ca 256 kDa, has high structural stability, withstanding 15 min boiling and denaturing by SDS. It resists in vitro proteinase digestion and displays structural stability between pH 2.0 and pH 12.0, and up to 85°C. These properties, as well as its subunit sequences, glycosylation pattern, presence of carotenoids, size and global shape resemble those of its orthologs from other Pomacea. Furthermore, like members of the canaliculata clade, PdPV1 is recovered unchanged in feces of mice ingesting it, supporting an anti-nutritive defensive function. PdPV1 also displays a strong hemagglutinating activity, specifically recognizing selected ganglioside motifs with high affinity. This activity is only shared with PsSC, a perivitelline from the same clade (bridgesii clade). As a whole, these results indicate that species in the genus Pomacea have diversified their egg defenses: those from the bridgesii clade are protected mostly by non-digestible lectins that lower the nutritional value of eggs, in contrast with protection by neurotoxins of other Pomacea clades, indicating that apple snail egg defensive strategies are clade specific. The harsh gastrointestinal environment of predators would have favored their appearance, extending by convergent evolution the presence of plant-like highly stable lectins, a strategy not reported in other animals.

A highly stable, nondigestible lectin from Pomacea diffusa unveils clade-related protection systems in apple snail eggs

The acquisition of egg protection is vital for species survival. Poisonous eggs from Pomacea apple snails have defensive macromolecules for protection. Here we isolated and characterized a novel lectin called PdPV1 that is massively accumulated in the eggs of Pomacea diffusa and seems part of its protective cocktail. The native protein, an oligomer of ca. 256 kDa, has high structural stability, withstanding 15 min boiling and denaturing by sodium dodecyl sulphate. It resists in vitro proteinase digestion and displays structural stability between pH 2.0–12.0 and up to 85 °C. These properties, as well as its subunit sequences, glycosylation pattern, presence of carotenoids, size, and global shape resemble those of its orthologs from other Pomacea. Further, like members of the canaliculata clade, PdPV1 is recovered unchanged in faeces of mice ingesting it, supporting an antinutritive defensive function. PdPV1 also displays a strong hemagglutinating activity specifically recognizing selected ganglioside motifs with high affinity. This activity is only shared with PsSC, a perivitelline from the same clade (bridgesii clade). As a whole, these results indicate that species in the genus Pomacea have diversified their eggs defences: Those from the bridgesii clade are protected mostly by non-digestible lectins that lower the nutritional value of eggs, in contrast with protection by neurotoxins of other Pomacea clades, indicating apple snail egg defensive strategies are clade-specific. The harsh gastrointestinal environment of predators would have favoured their appearance, extending by convergent evolution the presence of plant-like highly stable lectins, a strategy not reported in other animals.Summary statementAnalysis of key snail egg proteins shows evolutionary defensive trends associated with the phylogenetic position, extending by convergent evolution the presence of plant-like defensive strategies not reported in other animals

Conservation of the Southern River Terrapin Batagur affinis (Reptilia: Testudines: Geoemydidae) in Malaysia: a case study involving local community participation

It is evident that the participation of the local community plays a crucial role in the success of a conservation project. Despite initiating and leading the oldest Batagur affinis conservation project in Malaysia since 1967, which involved egg protection, head starting and reintroduction programs, the Department of Wildlife and National Parks did not involve the participation of the local community. This study provides the first account of the involvement of local villagers in B. affinis research and conservation project in the Kemaman River, Terengganu, Malaysia. As a result of involving this group of local villagers, the Village Development and Security Committee was recruited to be involved in the conservation project. From 2012 to 2016, we hand captured and processed 102 post-nesting females. The Schnabel mark-recapture method estimated at least 186 wild female B. affinis in the river. We collected 2,542 B. affinis eggs from 205 nests for incubation, and produced 1,723 hatchlings (mean hatching success 67.8%). Survivorship of head started B. affinis hatchlings in captivity ranged from 96.7−100 % among cohorts. Head started hatchlings recorded a 467% increase in body mass and 90% increase in straight carapace length. We reintroduced 1,690 B. affinis juveniles into the river. We also initiated a symbolic adoption program to raise funds and ensure the sustainability of the conservation project. This study proves that local communities are capable of managing their own resources, given sufficient training in conservation techniques.

implications of different brood pouch structures in syngnathid reproduction

the evolutionary radiation of the family syngnathidae was accompanied by a diversification of structures involved in male parental care whose anatomical variations may signal differences in reproductive strategies, with increasing egg protection possibly affecting female investment in offspring or larvae quality at the end of the embryonic development phase. an analysis of egg numbers showed significant differences between syngnathids with and without marsupium, suggesting that the brood pouch, besides increasing protection to the male and its eggs, also introduced the ability to carry an additional number of offspring per pregnancy, from one or more females. curiously, even though larvae sizes do not significantly differ between the considered brooding structures (controlling for male length), seahorse larvae were smaller than expected, given the large volume of the pear-shaped eggs. these observations suggest that the sealed seahorse pouch, although allowing the transport of a great number of offspring and capable of multiple consecutive pregnancies, may impose serious functional constraints, namely those related with oxygenation of the developing larvae, thus explaining the increased egg surface together with the presence of specific salinity control mechanisms inside the marsupium.