Photoperiodic gene expression of insulin receptor is associated with diapause regulation in silkworm

Bivoltine silkworms (Bombyx mori) are destined to respectively produce diapause or non-diapause eggs when they are reared under short or long days during the larval stage. The insulin signaling pathway is thought to play an essential role in regulating diapause in various insect species, but its involvement in silkworm diapause programming has not been investigated in detail. Therefore, we examined day-night expression of the insulin receptor (InR) gene in the silkworm larval brain under different photoperiods or in night interruption experiments in which larvae were exposed to light for 2 h during the nighttime of short days. Expression of the InR gene was photoperiod-dependent and InR mRNA levels decreased with increasing daylength. As the daylength increased, expression during the nighttime decreased to lower stable levels earlier than that during the daytime. During night interruptions that induced non-diapause, the nighttime expression of InR decreased to low levels like those during long days, although daytime expression was only moderately decreased. Nighttime InR expression was downregulated in silkworms reared under non-diapause-inducing conditions (long days and night interruptions). In contrast, abundant InR was expressed during the day and night in short days that induced diapause. Our findings suggested that InR expression in the larval brain is associated with programming the diapause status in the next generation of silkworms. Downregulated InR might suppress the insulin signaling pathway and cause non-diapause induction in the next generation. DOI: http://dx.doi.org/10.5281/zenodo.1041315

Silkworm larvae (Bombyx mori) can learn cues associated with finding food

The present study investigated the ability of silkworm Bombyx mori (Lepidoptera: Bombycidae) larvae to learn. Silkworm larvae were trained to consume food that was placed on red paper; consequently they became attracted to red, rather than blue paper even in the absence of food. In contrast, untrained controls had no preference for either red or blue paper. These results suggested that silkworm larvae learned to associate red paper with food, and that they can discriminate colors. DOI: http://dx.doi.org/10.5281/zenodo.560946

Two visual pigments in a single photoreceptor cell: Identification and histological localization of three mRNAs encoding visual pigment opsins in the retina of the butterfly Papilio xuthus

This paper describes the localization of newly identified visual pigment opsins in the tiered retina of the Japanese yellow swallowtail Papilio xuthus. We first cloned three cDNAs encoding visual pigment opsins, PxRh1, PxRh2 and PxRh3, and then carried out histological in situ hybridization to localize their mRNAs in the retina. By combining the present data with our previous electrophysiological results, we concluded that both PxRh1 and PxRh2 correspond to visual pigments expressed in photoreceptor cells sensitive in the green wavelength region (green receptors), whereas PxRh3 corresponds to a pigment in red receptors. The in situ hybridization studies showed that some photoreceptor cells express two opsin mRNAs. In the ventral half of the eye, all green receptors in the distal tier were labelled by both PxRh1 and PxRh2 probes. The labelling by the PxRh2 and PxRh3 probes was detected throughout the eye in the proximal tier; in 18 % of ommatidia, the probes labelled the same photoreceptor cell. These results suggest that the possible co-localization of two different visual pigments will broaden the sensitivity spectrum of the photoreceptor cells

Simultaneous Resection for Synchronous Double Primary Cancers of the Pancreas and the Liver

Simultaneous resection of synchronous hepatocellular carcinoma (HCC) and pancreatic ductal adenocarcinoma (PDAC) is extremely rare. Case 1 is a 64-year-old woman, who had undergone anterior resection for rectal cancer 3 years earlier was pointed out to have a cystic tumor in the pancreatic tail and a solitary tumor in the liver. CT revealed a hypovascular tumor in the pancreatic tail and a liver tumor with early enhancement. With a diagnosis of simultaneous HCC and PDAC, she underwent laparotomy, in which intraoperative frozen section examination of the liver was compatible with HCC. Therefore, she underwent hepatic resection as well as distal pancreatectomy and splenectomy. The patient received adjuvant chemotherapy with S-1 and remains well with no evidence of tumor recurrence as of 28 months after resection. Case 2 is a 73-year-old man with sustained viral response to antiviral treatment for hepatitis C virus, who was pointed out to have a tumor in the pancreatic head and a solitary tumor in the liver. Gadoxetic acid-enhanced MRI exhibited enhancement compatible with HCC. With a diagnosis of concomitant HCC and PDAC, surgery was performed. Intraoperative frozen section examination was compatible with HCC, for which a pancreaticoduodenectomy was performed. The patient received adjuvant chemotherapy with S-1 and remains well with no evidence of tumor recurrence as of 16 months after resection. In conclusion, we describe 2 cases of hepato-pancreatectomy for synchronous double primary cancers of the pancreas and the liver, where exclusion of the liver tumor as a metastatic lesion from the pancreatic cancer is important

Spontaneous Pathological Complete Regression of Hepatocellular Carcinoma

Several possible mechanisms for spontaneous regression of hepatocellular carcinoma (HCC) have been reported. Spontaneous complete regression of HCC is extremely rare. We herein report a case of spontaneous pathological complete regression of HCC following decrement of elevated serum alpha-fetoprotein (AFP). The serum AFP of a 74-year-old man who underwent hepatic resection for HCC twice increased up to 7,529 ng/mL and then spontaneously decreased to 404 ng/mL in 2 months. Computed tomography, magnetic resonance imaging, and angiography revealed a liver tumor in segment 7 without early enhancement. With a diagnosis of recurrent HCC, partial hepatic resection was performed. The resected specimens revealed no HCC macroscopically, and pathological examination revealed only a small area with cell dysplasia. The patient remains well with normal serum AFP and protein induced by vitamin K absence or antagonist-II (PIVKA-II) levels for 29 months after the third hepatic resection without recurrence of HCC. We describe a case of spontaneous pathological complete regression of HCC following decrement of elevated serum AFP. Further studies are needed to identify the mechanism(s) of spontaneous regression of HCC

Vacuum Structure of Twisted Scalar Field Theories on M^{D-1} \otimes S^1

We study scalar field theories on M^{D-1} \otimes S^1, which allow to impose twisted boundary conditions for the S^1 direction, in detail and report several interesting properties overlooked so far. One of characteristic features is the appearance of critical radii of the circle S^1. A phase transition can occur at the classical level or can be caused by quantum effects. Radiative corrections can restore broken symmetries or can break symmetries for small radius. A surprising feature is that the translational invariance for the S^1 direction can spontaneously be broken. A particular class of coordinate-dependent vacuum configurations is clarified and the O(N) \phi^4 model on M^{D-1}\otimes S^1 is extensively studied, as an illustrative example.Comment: 27 pages, 4 figures, LaTex2

Light-Induced Phase-Shifting of the Peripheral Circadian Oscillator in the Hearts of Food-Deprived Mice

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