Contractability of a Chorionic Opercular Corolla on Eggs of the Assassin bug Sinea rileyi Montandon (Heteroptera: Reduviidae)

Summary

A chorionic opercular rim corolla contracts in response to submersion of eggs in water and dilates again when eggs dry. This “behavior” ceases in hatched and dead unhatched eggs. We suggest that contraction serves a group respiratory function. Egg clutches are sibships of high relatedness in close spatial proximity with shared susceptibilities. These factors suggest the possibility of various cooperative interactions especially in insects with elaborate chorionic structures.     

α-(15-Hydroxyhexadecyl)itaconic acid from Usnea aliphatica

The structure of a new aliphatic acid from Usnea aliphatica was established by spectroscopic and chemical methods as α- (15-hydroxyhexadecyl)itaconic acid.     

Aedes aegypti dyspepsia encodes a novel member of the SLC16 family of transporters and is critical for reproductive fitness

As a key vector for major arthropod-borne viruses (arboviruses) such as dengue, Zika and chikungunya, control of Aedes aegypti represents a major challenge in public health. Bloodmeal acquisition is necessary for the reproduction of vector mosquitoes and pathogen transmission. Blood contains potentially toxic amounts of iron while it provides nutrients for mosquito offspring; disruption of iron homeostasis in the mosquito may therefore lead to novel control strategies. We previously described a potential iron exporter in Ae. aegypti after a targeted functional screen of ZIP (zinc-regulated transporter/Iron-regulated transporter-like) and ZnT (zinc transporter) family genes. In this study, we performed an RNAseq-based screen in an Ae. aegypti cell line cultured under iron-deficient and iron-excess conditions. A subset of differentially expressed genes were analyzed via a cytosolic iron-sensitive dual-luciferase reporter assay with several gene candidates potentially involved in iron transport. In vivo gene silencing resulted in significant reduction of fecundity (egg number) and fertility (hatch rate) for one gene, termed dyspepsia. Silencing of dyspepsia reduced the induction of ferritin expression in the midgut and also resulted in delayed/impaired excretion and digestion. Further characterization of this gene, including a more direct confirmation of its substrate (iron or otherwise), could inform vector control strategies as well as to contribute to the field of metal biology.     

Species specificity of hybridoma antibodies to surface antigens of guinea pig sperm

The species specificity of hybridoma antibodies to sperm surface antigens was studied. A collection of over 50 hybridoma antibodies that bind to the guinea pig sperm surface was tested for binding to mouse, rat, hamster, and human sperm by indirect immunofluorescence. None of the antibodies bind to mouse sperm. rat sperm, or human sperm. All but three of the antibodies also fail to bind to hamster sperm. AH-30, AH-31, and AH-1032, the three antibodies that crossreact with hamster sperm, show a different topographical localization on hamster sperm from that seen on guinea pig sperm. The three antibodies do not precipitate a ¹²⁵I surface-labeled antigen from hamster sperm extracts. However, from guinea pig sperm extracts, all three antibodies precipitate ¹²⁵I surface-labeled polypeptides with molecular weights (M_r) of 62,000, 52,000, and 38,000. This result suggests that the crossreacting antibodies may be recognizing different antigens on hamster and guinea pig sperm.