J Comp Physiol A Neuroethol Sens Neural Behav Physiol
January 2025
Terrestrial molluscs living in temperate and polar environments must contend with cold winter temperatures. However, the physiological mechanisms underlying the survival of terrestrial molluscs in cold environments and the strategies employed by them are poorly understood. Here we investigated the cold tolerance of Ambigolimax valentianus, an invasive, terrestrial slug that has established populations in Japan, Canada, and Europe.
View Article and Find Full Text PDFWe established a knockout strain of a clock gene, (), by using TALEN in a bivoltine strain (Kosetsu) of (Insecta, Lepidoptera), and examined the effect of knockout on the circadian rhythm and photoperiodism. The generated knockout allele was considered to be null, because a new stop codon was present in the insertion allele. The wild type (Kosetsu) showed clear circadian rhythms in eclosion and hatching, whereas the knockout strain showed arrhythmic eclosion and hatching under constant darkness.
View Article and Find Full Text PDFComp Biochem Physiol Part D Genomics Proteomics
December 2020
Many insect species use photoperiod as a cue for induction of seasonal responses, including seasonal polyphenism. Although most aphid species viviparously produce parthenogenetic and sexual morphs under long and short days, respectively, a seasonal timer suppresses the sexual morph production over several successive generations during a few months following hatching of a sexually produced diapause egg. To reveal the relative influences of photoperiod and the seasonal timer on the reproductive polyphenism at the gene expression level, we performed RNA sequencing-based transcriptome analyses in the pea aphid, Acyrthosiphon pisum (Hemiptera: Aphididae).
View Article and Find Full Text PDFIn Lepidoptera, the roles of period ( per) and the negative feedback involving this gene in circadian rhythm are controversial. In the present study, we established a per knockout strain using TALEN in Bombyx mori, and compared eclosion and hatching rhythms between the per-knockout and wild-type strains to examine whether per is actually involved in these rhythms. The generated per knockout allele was considered null, because it encoded an extensively truncated form of PERIOD (198 aa due to a 64-bp deletion in exon 7, in contrast to 1113 aa in the wild-type protein).
View Article and Find Full Text PDFConjugates of semiconductor quantum dots (QDs) and antibodies have emerged as a promising bioprobes due to their great combination of QD's efficient fluorescence and the high specificity of antigen-antibody reactions. For further developments in this field, it is essential to understand the molecular conformation of the QD-antibody conjugates at the single-molecule scale. Here, we report on the direct imaging of QD-antibody conjugates at the single-molecule scale by using high-speed atomic force microscopy (HS-AFM).
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