Effects of starvation and sucrose feeding on corpora allata of last instar larvae of Manduca sexta: in vitro activity, size, and cell number

Abstract Larvae of the tobacco hornworm moth Manduca sexta starved for the first 3 days of the last (fifth) stadium undergo a supernumerary moult. If they are provided with sucrose during the starvation period, they develop into normal pupae although pupation is delayed. The activities of the corpora allata (CA) from normal, starved, and sucrose fed larvae were followed through the fifth stadium with a radiochemical assay for Juvenile Hormone (JH) biosynthesis. An attempt was made to correlate CA-activity with CA cell number, size, and protein content.
In CA of normally fed larvae the rate of JH synthesis declined to undetectable levels by day 4 which was also the time of exposure of the dorsal vessel. In CA of starved larvae, the rate of JH synthesis at first decreased but began to increase on day 3 and reached a peak value by day 7 , at which time head capsule slippage occurred. In CA of sucrose fed larvae, the rate of biosynthesis declined as in normal larvae but the decline was extended over a longer period. Exposure of the dorsal vessel was delayed in the same manner and occurred on days 7–9. The major JH in all cases was JH-II.
The CA comprise c. 150 cells in the early fifth stadium, and this number remained constant during the fifth stadium in all three feeding regimens. In normal larvae, CA size and protein content increased several-fold during the stadium whereas in starved and sucrose-fed larvae they increased slowly and in agreement with the altered timing of developmental events. In none of the groups was the CA activity pattern correlated with morphometric changes of the CA. The rates of JH biosynthesis were not closely correlated with published JH titre curves. The in vivo mechanisms for regulation of JH production remain to be elucidated.     

Identification and characterization of ten polymorphic microsatellite loci in the red panda Ailurus fulgens

Ten polymorphic microsatellite loci were characterized from two genomic DNA-enriched libraries of the red panda (Ailurus fulgens). The number of observed alleles among 35 samples of red pandas ranged from five to 12. Observed and expected heterozygosities were 0.286–0.971 and 0.443–0.894, and the mean polymorphic information content was 0.712. All loci followed Hardy–Weinberg expectations except Aifu-14 and Aifu-16, which may due to the presence of inbreeding or null alleles. Three pairs of loci exhibited significant linkage disequilibrium after Bonferroni correction for multiple comparisons. These microsatellites would be useful to strengthen population management, genetic diversity exploration, and demographic history speculation of this species.     

Activity-dependent changes of the hippocampal CA3–CA1 synapse during the acquisition of associative learning in conscious mice

Contemporary neuroscientists are paying increasing attention to subcellular, molecular and electrophysiological mechanisms underlying learning and memory processes. Recent efforts have addressed the development of transgenic mice affected at different stages of the learning process, or emulating pathological conditions involving cognition and motor-learning capabilities. However, a parallel effort is needed to develop stimulating and recording techniques suitable for use in behaving mice, in order to grasp activity-dependent neural changes taking place during the very moment of the process. These in vivo models should integrate the fragmentary information collected by different molecular and in vitro approaches. In this regard, long-term potentiation (LTP) has been proposed as the neural mechanism underlying synaptic plasticity. Moreover, N -methyl- d -aspartate (NMDA) receptors are accepted as the molecular substrate of LTP. It now seems necessary to study the relationship of both LTP and NMDA receptors with the plastic changes taking place, in selected neural structures, during actual learning. Here, we review data on the involvement of the hippocampal CA3–CA1 synapse in the acquisition of classically conditioned eyelid conditioned responses (CRs) in behaving mice. Available data show that LTP, evoked by high-frequency stimulation of Schaffer collaterals, disturbs both the acquisition of CRs and the physiological changes that occur at the CA3–CA1 synapse during learning. Moreover, the administration of NMDA-receptor antagonists is able not only to prevent LTP induction in vivo , but also to hinder the formation of both CRs and functional changes in strength of the CA3–CA1 synapse. Thus, there is experimental evidence relating activity-dependent synaptic changes taking place during actual learning with LTP mechanisms and with the role of NMDA receptors in both processes.     

CA9 transcriptional expression determines prognosis and tumour grade in tongue squamous cell carcinoma patients

CA9 is a member of the carbonic anhydrases’ family, that is often expressed in cancer cells under hypoxic condition. However, the role of CA9 in the molecular mechanisms of tongue squamous cell carcinoma (TSCC) pathogenesis remains unclear. CA9 expression was analysed using the TCGA database, and its influence on survival was performed using Kaplan-Meier, LASSO and COX regression analyses. The correlation between CA9 and immune infiltration was investigated by CIBERSORT and ESTIMATE. Moreover, the relationship between CA9 expression and downstream molecular regulation pathways was analysed by GSEA, GO and WGCNA. CA9 expression correlated with clinical prognosis and tumour grade in TSCC. Moreover, CA9 expression potentially contributes to the regulation of cancer cell differentiation and mediates tumour-associated genes and signalling pathways, including apoptosis, hypoxia, G2M checkpoint, PI3K/AKR/mTOR signalling and TGF-beta signalling pathways. However, the follicular helper T cells, regulatory T cells, immune and stromal scores showed no significance between high and low CA9 expression groups. These findings suggested that CA9 plays a critical role of TSCC prognosis and tumour grade. CA9 expression significantly correlated with the regulation of cell differentiation, various oncogenes and cancer-associated pathways.     

A set of microsatellite primers for the striped possum,Dactylopsila trivirgata (Petauridae: Marsupialia)

The New Guinean endemic dactylopsilines are members of the Petauridae possum family, represented in Australia only by the striped possum Dactylopsila trivirgata. The shy nature and low density of this species have hampered studies of its ecology to date, so we developed nine highly variable polymorphic microsatellite markers to enable molecular genetic analysis of population structure and mating system parameters. This will add substantially to our understanding of the behavioural ecology of this species. The low degree of cross‐amplification of the primers in other petaurid species lends weight to other evidence suggesting that this family underwent a relatively early radiation.     

血清VEGF，IGF-1和CA125水平与子宫动脉栓塞术(UAE)治疗子宫腺肌症的相关性

目的:探讨血清血管内皮生长因子(VEGF)、胰岛素样生长因子-1(IGF-1)和CA125水平和子宫动脉栓塞术(UAE)治疗子宫腺肌症的之间的相关性。方法:选择接受子宫动脉栓塞术治疗的39例子宫腺肌症患者作为患者组,取同时期参加健康体检的30名健康者作为健康对照组。用ELISA法检测子宫腺肌症患者子宫动脉栓塞术前和术后不同时点血清VEGF、IGF-1、CA125的水平,评估子宫动脉栓塞术后的患者的疗效。结果:34例痛经患者术后1个月开始改善,最终29例完全缓解,有效率85.2%。患者组治疗前血清VEGF、IGF-1、CA125水平均显著高于健康对照组(P0.05)。子宫动脉栓塞术治疗后,患者组血清IGF-1、VEGF和CA125的水平与治疗前相比均显著降低,术后6月,恢复正常水平。结论:血清IGF-1、VEGF、CA125的变化可能在子宫动脉栓塞术治疗子宫腺肌症中作为疗效和预后评估指标。     

The facets of olfactory learning

Volatile chemicals in the environment provide ethologically important information to many animals. However, how animals learn to use this information is only beginning to be understood. This review highlights recent experimental advances elucidating olfactory learning in rodents, ranging from adaptations to the environment to task-dependent refinement and multisensory associations. The broad range of phenomena, mechanisms, and brain areas involved demonstrate the complex and multifaceted nature of olfactory learning.     

Medial and Lateral Entorhinal Cortex Differentially Excite Deep versus Superficial CA1 Pyramidal Neurons

1. Download high-res image (151KB)
2. Download full-size image